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The nutritional deficiencies of popular seed-based diets for captive psittacine birds have been linked to physical and psychological disease conditions in these species. However, bird owners often reject transitioning their pets to nutritionally complete pelleted diets because of concerns over the difficulty of diet conversion. To assess dietary conversion of psittacine birds from seed-based to pelleted diets, avian veterinarians presented 3 diet conversion methods to owners with birds of varying ages and species. The owners implemented their chosen conversion method at home and then received a survey when they successfully completed diet conversion or abandoned their attempt. "Birdies Choice" was a reward-based method in which birds were offered 3 different pelleted diets on a tabletop. If there was a positive interaction and the bird ate one or more of the diets, the bird was rewarded. The preferred pellet was then gradually transitioned into their food dishes. In the "Slow and Steady" method, pellets were alternated with familiar food at varying intervals to increase the birds' exposure to the pellets. The "Tough Love" method maximized exposure to new pellets by introducing a small portion of familiar food for a limited time, along with multiple dishes of new pellets. Survey results showed 96% of birds converted regardless of method, with 57.5% converting within the first 7 days. When conversion times were evaluated by life stage (juvenile, adult, and geriatric), sex, or bird family (Psittacidae, Cacatuidae, and Psittaculidae), differences noted between groups were not significant. The only variable significantly affecting time to conversion was method used, with Tough Love converting birds faster than the other methods. Ultimately, all 3 methods of dietary conversion were successful with the majority of birds during the first month of implementation. These results provide evidence-based information to owners and veterinarians to facilitate pellet conversion attempts for psittacine birds.

Objective: The purpose of this randomized trial was to investigate the efficacy of 2 behavioral treatments focusing on different change mechanisms in ameliorating a borderline personality disorder constellation of behaviors and substance use in adolescents referred by juvenile diversion programs., Methods: Forty adolescents 14-17 years of age and meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for borderline personality disorder and substance use disorders were randomized to integrative borderline personality disorder-oriented adolescent family therapy (I-BAFT) or individual drug counseling. This design allowed a comparison of 2 manualized interventions, 1 family based and 1 individually oriented. Profiles of clinical change were used to detect impact and estimate treatment effect sizes., Results: Primary analyses showed that both interventions had a clinically significant impact on borderline personality disorder behaviors 12 months after baseline but with no differential treatment effects. The impact on substance use was more complex. Subgroup analyses revealed that adolescents with depression had significantly more severe profiles of borderline personality disorder and substance use. These youths were the only group to show reductions in substance use, but they only did so if they received the I-BAFT intervention. Study data also documented the high dosage of intensive residential treatment needed by this population., Conclusions and Implications for Practice: Results highlight the intensive treatment needs of juvenile justice-involved youths with co-occurring substance use and borderline personality disorder including depression, the hybrid outpatient and residential treatment often required by this population, and the promise of a family-oriented approach, particularly for youths with severe symptoms and co-occurring depression. (PsycINFO Database Record, ((c) 2015 APA, all rights reserved).)

The purpose of this study is to describe the relationships among acculturation, risk behaviors, and reported physical dating violence among Cuban-American ninth grade adolescents. Participants (N=82) completed a questionnaire that assessed their level of acculturation to the U.S. (Americanism), their maintenance of the Hispanic culture (Hispanicism), binge drinking, drug use, sexual intercourse, condom use and physical dating violence victimization. Multiple logistic regression was conducted. Hispanicism was associated with a decrease in odds of reporting physical dating violence victimization. Drug use and not using a condom were associated with an increase in odds of reporting physical dating violence victimization., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: The current study aimed to identify risk factors for treatment noncompliance in a sample of veterans receiving buprenorphine/naloxone for an opioid use disorder., Methods: Records from all patients who are currently or had previously been maintained on buprenorphine in the buprenorphine maintenance treatment program at the Atlanta VA Medical Center during the years 2006 to 2013 were evaluated. Of the 209 patients treated in the clinic between 2006 and 2013, 140 were excluded from the study because they did not have a call-back done at the time of data collection. Thus, 69 patient charts were selected for review., Results: The multiple linear regression analysis of the predictable variables for noncompliance with the buprenorphine pill count showed that positive urine drug screen (UDS) for marijuana, benzodiazepines, and being a smoker (F = 3.08; P = 0.03) are significantly associated with noncompliance with buprenorphine pill count.Also, the multiple linear regression analysis of the predictable variables for noncompliance with the buprenorphine pill count showed that the psychiatric comorbidity independently (F = 4.88; P = 0.03) is significantly associated with noncompliance with buprenorphine pill count., Conclusions: Patients found to be noncompliant were more likely to suffer from comorbid psychiatric illness. Patients who tested positive for benzodiazepines or cannabis were more likely to be noncompliant with treatment. Although the rate of noncompliance (inaccurate pill count) was high, patients were still found to be taking their prescribed buprenorphine as evidenced by positive UDS for buprenorphine/norbuprenorphine. In addition, our sample had a high rate of negative UDS screens for opioids and cocaine.

We and others recently demonstrated that the readily programmable CRISPR/Cas9 system can be used to edit the Drosophila genome. However, most applications to date have relied on aberrant DNA repair to stochastically generate frameshifting indels and adoption has been limited by a lack of tools for efficient identification of targeted events. Here we report optimized tools and techniques for expanded application of the CRISPR/Cas9 system in Drosophila through homology-directed repair (HDR) with double-stranded DNA (dsDNA) donor templates that facilitate complex genome engineering through the precise incorporation of large DNA sequences, including screenable markers. Using these donors, we demonstrate the replacement of a gene with exogenous sequences and the generation of a conditional allele. To optimize efficiency and specificity, we generated transgenic flies that express Cas9 in the germline and directly compared HDR and off-target cleavage rates of different approaches for delivering CRISPR components. We also investigated HDR efficiency in a mutant background previously demonstrated to bias DNA repair toward HDR. Finally, we developed a web-based tool that identifies CRISPR target sites and evaluates their potential for off-target cleavage using empirically rooted rules. Overall, we have found that injection of a dsDNA donor and guide RNA-encoding plasmids into vasa-Cas9 flies yields the highest efficiency HDR and that target sites can be selected to avoid off-target mutations. Efficient and specific CRISPR/Cas9-mediated HDR opens the door to a broad array of complex genome modifications and greatly expands the utility of CRISPR technology for Drosophila research.

The purpose of this study was to explore perceptions of dating relationships and teen dating violence prevention within a predominantly Cuban American community in Miami-Dade County. Eight focus groups (n = 74 participants) with adolescents of Hispanic origin (n = 29), their parents (n = 29), and school personnel (n = 16) were conducted and analyzed using content analysis. Four themes characterized the nature and context of dating relationships among adolescents of Hispanic origin: YOLO -You Only Live Once, cultural unity but social division, dating is not going out, and the social environment challenges healthy relationships. The information generated from this study can be used to develop culturally tailored teen dating violence prevention programs targeting youth of Hispanic origin., (© 2014 Wiley Periodicals, Inc.)

Research suggest that Hispanics in the U.S. are disproportionately affected by the consequences of intimate partner violence. Nevertheless, few intimate partner violence prevention interventions have been developed to address the unique needs and preferences of this population. The Partnership for Domestic Violence Prevention is a community-based participatory research project that assessed the needs and preferences for prevention programs for Hispanics in Miami-Dade County. Nine focus groups with domestic violence service providers, victims and general community members were conducted (N = 76). Four major themes emerged from the focus groups. These included immigrants and teens as the highest priority groups to target in prevention efforts, culture as a double-edged sword, the system that helps and hurts the victim, and the need for wide-scale prevention programs that would reach Hispanics systematically. The results from this study have important implications for the development of intimate violence prevention interventions targeting Hispanics in the U.S.

We have adapted a bacterial CRISPR RNA/Cas9 system to precisely engineer the Drosophila genome and report that Cas9-mediated genomic modifications are efficiently transmitted through the germline. This RNA-guided Cas9 system can be rapidly programmed to generate targeted alleles for probing gene function in Drosophila.

The present study of women with substance use disorders used grounded theory to examine women's experiences in both the Women's Recovery Group (WRG) and a mixed-gender Group Drug Counseling (GDC). Semi-structured interviews were completed in 2005 by 28 women in a U.S. metropolitan area. Compared to GDC, women in WRG more frequently endorsed feeling safe, embracing all aspects of one's self, having their needs met, feeling intimacy, empathy, and honesty. In addition, group cohesion and support allowed women to focus on gender-relevant topics supporting their recovery. These advantages of single-gender group therapy can increase treatment satisfaction and improve treatment outcomes.

This paper analyzed the existing literature on risk and protective factors for intimate partner violence among Hispanics using the four-level social-ecological model of prevention. Three popular search engines, PsycINFO, PubMed, and Google Scholar, were reviewed for original research articles published since the year 2000 that specifically examined factors associated with intimate partner violence (IPV) among Hispanics. Factors related to perpetration and victimization for both males and females were reviewed. Conflicting findings related to IPV risk and protective factors were noted; however, there were some key factors consistently shown to be related to violence in intimate relationships that can be targeted through prevention efforts. Future implications for ecologically-informed research, practice, and policy are discussed.

Enhanced affiliation among members is thought to provide increased support for women in single-gender compared with mixed-gender group therapy for substance use disorders (SUDs) and to provide a potential mechanism of action for its efficacy. In a Stage I trial of single-gender versus mixed-gender group therapy for SUDs we examined affiliative statements made by members in two group treatments, single-gender Women's Recovery Group (WRG) and mixed-gender Group Drug Counseling (GDC). Twenty-eight WRG and 17 GDC group therapy tapes were coded and compared for five types of affiliative statements. Three types of affiliative statements (agreement, supportive, and completing a thought) were highly correlated and were more frequent in WRG than GDC (D=0.882, p=0.27). In GDC, women were more likely to provide an affiliative statement to a male group member than any other combination of directionality (p<0.01). Compared with mixed-gender, single-gender group therapy for SUDs may enhance support through greater frequency of affiliative statements.

Neuronal communication depends on the precisely orchestrated release of neurotransmitter at specialized sites called active zones (AZs). A small number of scaffolding and cytoskeletal proteins comprising the cytomatrix of the active zone (CAZ) are thought to organize the architecture and functional properties of AZs. The majority of CAZ proteins are evolutionarily conserved, underscoring the fundamental similarities in neurotransmission at all synapses. However, core CAZ proteins Piccolo and Bassoon have long been believed exclusive to vertebrates, raising intriguing questions about the conservation of the molecular mechanisms that regulate presynaptic properties. Here, we present the identification of a piccolo-rim-related gene in invertebrates, together with molecular phylogenetic analyses that indicate the encoded proteins may represent Piccolo orthologs. In accordance, we find that the Drosophila homolog, Fife, is neuronal and localizes to presynaptic AZs. To investigate the in vivo function of Fife, we generated a deletion of the fife locus. We find that evoked neurotransmitter release is substantially decreased in fife mutants and loss of fife results in motor deficits. Through morphological analysis of fife synapses, we identify underlying AZ abnormalities including pervasive presynaptic membrane detachments and reduced synaptic vesicle clustering. Our data demonstrate the conservation of a Piccolo-related protein in invertebrates and identify critical roles for Fife in regulating AZ structure and function. These findings suggest the CAZ is more conserved than previously thought, and open the door to a more complete understanding of how CAZ proteins regulate presynaptic structure and function through genetic studies in simpler model systems.

Hispanics are disproportionately affected by the occurrence and consequences of domestic violence when compared to their non-Hispanic counterparts. The Partnership for Domestic Violence used a community-based participatory research approach to assess the needs and preferences for preventing domestic violence (DV) among Hispanics in Miami-Dade County. Researchers conducted a community forum in which data collected from focus groups were presented to approximately 100 community members to gather their feedback regarding the development of DV prevention programs tailored for Hispanics. Participants were in high agreement that a program targeting youth is the highest priority and that specific cultural variables should be incorporated to make the program most effective. Recommendations for DV prevention targeting Hispanics and the use of community forums as a method of research are provided.

OBJECTIVE: This study examined baseline self-efficacy as a moderator of outcomes comparing women receiving either the Women's Recovery Group (WRG), a new manualized group treatment for substance use disorders combining single-gender group composition and women-focused content, or Group Drug Counseling (GDC), an empirically supported mixed-gender group treatment. METHODS: To understand the relationship of baseline scores of abstinence self-efficacy measured by the Drug-Taking Confidence Questionnaire (DTCQ) to outcome, we included the interaction of group by phase by continuous DTCQ scores in the outcome analyses. Women were split into groups of high versus low abstinence self-efficacy based on the clinical cutoff score of 80 on DTCQ. RESULTS: We found a significant 3-way interaction effect of treatment condition, time, and baseline DTCQ scores on drinking days and days of any substance use per month. Women in WRG had greater reduction in substance use from baseline to post-treatment than women in GDC, and women in WRG with low self-efficacy had the best outcomes overall. CONCLUSION: The findings suggest that women with low self-efficacy may have enhanced treatment outcomes in a single-gender substance use treatment group.

Basic differences in male versus female reproductive physiology lead to differentials in their respective susceptibilities to chemical insult as evidenced by a variety of observations. As individuals undergo maturation from prenatal sex differentiation through pubertal development, these susceptibilities become evident in each gender. Gender bias occurs in human populations for birth defects and for the acceleration of the onset of puberty. Data on gender bias in fetal origins of adult disease are more complex. Useful for understanding reproductive and developmental effects in animals are a range of standard methodological procedures including the multigeneration testing protocol and the National Toxicology Program (NTP) Reproductive Assessment by Continuous Breeding (RACB). Examples of gender-based differences seen in reproductive toxicology studies on animals include teratogenic effects, reproductive effects in adult males and females, and effects on pubertal development. It is clear that gender biases exist in the reproductive and developmental toxicity, and the biological bases for these differences need to be explored.

Polymorphisms in genes can lead to differences in the level of susceptibility of individuals to potentially adverse effects of environmental influences, such as chemical exposure, on prenatal development or male or female reproductive function. We have reviewed the literature in this area, with the caveat that papers involving straight gene knock-outs in experimental animals, without a clear human relevance, were largely excluded. This review represents current knowledge in this rapidly moving field, presenting both human epidemiological and animal data, where available. Among the polymorphic genes and environmental interactions discussed with respect to prenatal development are those for P-glycoprotein (multidrug resistance protein) and the avermectins; methylenetetrahydrofolate reductase (MTHFR), an enzyme in folate metabolism, and dietary folic acid; transforming growth factor alpha (TGFalpha) and cigarette smoke; and alcohol dehydrogenase (ADH) and cytochrome P-450 (CYP) 2E1 in association with alcohol consumption. Effects on male reproduction attributable to gene-environment interaction involve infertility seen as a result of either organophosphorous (OP) pesticide interaction with the polymorphic paraoxonase (PON1) gene or antiandrogenic agent interaction with the androgen receptor (AR). MTHFR, folate metabolism, and dietary folic acid are also considered in conjunction with preeclampsia and early pregnancy loss, and the effect of the interaction of glutathione S-transferase (GST) with exposure to benzene or cigarette smoke on pregnancy maintenance is explored. As a conclusion, we offer a discussion of lessons learned and suggested research needs.

Prior to any investigation of toxicant effects on sexual development it is necessary to have a complete understanding of the relevant physiology of reproductive development. Beginning at conception, development of males and females diverge to form the respective reproductive systems. From the prenatal period to the interval following puberty, radical changes take place in the hypothalamo-pituitary-gonadal axis of males and females. The complexity of each of these systems and their development is mirrored in the many possibilities for the means by which chemicals may produce adverse effects. For example, a chemical that affects hormone synthesis may, if administered at the proper time, affect hypothalamic development. As a consequence, pubertal development may not occur normally. In this chapter, we have outlined the basics of reproductive development and provided examples of adverse effects by endocrine disrupting chemicals (EDCs) on such development.

A potential connection exists between exposure to organochlorine chemicals and the increasing prevalence of endometriosis. Evidence shows that dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) can increase the incidence and severity of the disease in monkeys and can promote the growth or survival of endometrial tissue implanted into rodents in a surgically induced model of endometriosis. The mechanism of the connection between organochlorine chemicals and endometriosis is not clear. Effects on growth factors, cytokines, and hormones (components of the immune and endocrine systems) are potential means of mediating the possible promotion of endometriosis by dioxins. Studies on epidemiology and on structure-activity relationships of organochlorine chemicals and endometriosis have been additional approaches to this problem. In this regard, toxic equivalence (TEQ) appears to be an important determinant of the effects of organochlorine chemicals on endometriosis. In this article, we review the literature related to endometriosis and dioxins and attempt to integrate the various sources of information that bolster the hypothesis connecting dioxins and endometriosis.

Atrazine (ATR) is an herbicide that has been shown to have adverse reproductive effects including alterations in levels of pituitary hormones such as prolactin (prl) and luteinizing hormone (LH) in female LE rats when administered at doses of 200 mg/kg/day for 1 and 3 days. Because the action of prl in promotion of progesterone secretion is essential for the initiation of pregnancy in rats, this study was designed to examine the effect of exposure to ATR during early pregnancy on implantation and short-term pregnancy maintenance. Rats were divided into two groups representing periods of dosing with ATR prior to the diurnal or nocturnal surges of prl. Within each group, four groups consisting of four strains of rats [Holtzman (HLZ); Sprague Dawley (SD); Long Evans (LE); Fischer 344 (F344)] were each further subdivided into four ATR dosages. Rats were dosed by gavage with 0, 50, 100, or 200 mg/kg/day ATR on days 1-8 of pregnancy (day 0 = sperm +). All animals were necropsied on day 8 or 9 of pregnancy. The 200 mg/kg dose of ATR reduced body weight gain in all but one group. Two groups of animals dosed at 100 and 200 mg/kg/day in the nocturnal dosing period showed an increase in percent preimplantation loss, and both of these were F344 rats. HLZ rats were the only strain to show a significant level of postimplantation loss and a decrease in serum progesterone at 200 mg/kg/day both following diurnal and nocturnal dosing. Doses of 100 mg/kg/day also produced postimplantation loss following diurnal and nocturnal dosing, but progesterone levels were decreased only after nocturnal dosing. Alterations in serum LH were seen in several groups. Serum estradiol was significantly increased only in SD rats dosed at the diurnal interval with 200 mg/kg ATR. We conclude that F344 rats are most susceptible to preimplantation effects of ATR and that HLZ rats appear most sensitive to the postimplantation effects of the chemical. LE and SD rats were least sensitive to effects of ATR during very early pregnancy.

Endocrine disrupting chemicals have recently drawn increased interest. The delayed implanting rat model is a method that can identify and quantify the estrogenic activity of a chemical. In rats hypophysectomized after breeding, the administration of progesterone delays embryo implantation, and exposure to one dose of an estrogenic substance initiates implantation. Although methoxychlor was ineffective at dosages below 400 mg/kg when given by injection, the administration of the chemical by gavage resulted in an increase in the percent of fertilized rats exhibiting implantation sites. These results were statistically significant at dosages of 50, 100, 200, and 300 mg methoxychlor/kg. When bisphenol A was administered, by subcutaneous injection, dosages of 50, 100, and 200 mg/kg induced implantation. Only the 400 mg/kg dose of 4-tert-octylphenol was effective. Doses of beta-sitosterol up to 30 mg/kg failed to initiate implantation. These data confirm previous evidence of the availability of this model for evaluating estrogenic activity and provide estimates of the estrogenic potencies of several environmentally important chemicals.

Several lines of research led to our hypothesis that perinatal exposure to TCDD may alter the sensitivity of adult rodents to the promotional effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on endometriosis. Pregnant rats and mice were treated on gestation day (GD) 8 with either 1 (rats) or 3 (mice) microg TCDD/kg or vehicle. Female offspring were reared to adulthood, and endometriosis was induced surgically. All animals received 0, 3, or 10 microg TCDD/kg 3 weeks prior to surgery, at the time of surgery, and 3, 6, and 9 weeks after surgery. Necropsies were performed 12 weeks after surgery. Measurements at necropsy included the diameter of endometriotic lesions and body, uterine, ovarian and liver weights. While no effect of treatment on lesion diameter was found in rats, analyses revealed that perinatal plus adult exposure to TCDD can increase the size of endometriotic lesions surgically induced in mice. These and additional data on body and organ weights are consistent with previous work. These data confirm the sensitivity of mice to the promotion of endometriotic lesion growth by TCDD and indicate a perinatal effect of TCDD on this parameter when perinatal exposure on GD8 is supplemented with adult exposure to TCDD of female mice.

Dibromoacetic acid (DBA), a byproduct of water disinfection, has been shown to have adverse reproductive effects in male rodents. In light of the lack of data on potential effects on female reproduction, studies were initiated to evaluate the potential effect of the chemical on early pregnancy. Groups of mature Holtzman rats were used, and cycles were monitored in all animals by vaginal smears. The administration of DBA at 0, 62.5, 125, or 250 mg/kg/d to rats during the first 8 d of pregnancy had no effect on the number of implantation sites found on Day 9 nor any other progestational parameter, except for serum estradiol, which was elevated. When groups of pregnant rats treated with the same range of dosages of DBA during Days 1 through 8 of pregnancy were killed on Day 20, there was no effect of treatment on the number of pups/litter, number of resorptions, or mean pup weight. These data demonstrate that while DBA has serious adverse effects on reproduction in male rodents, the chemical does not affect early pregnancy in rats. Effects on ovarian function and latent fertility are not ruled out.

Ketoconazole (KCZ) is an imidazole antifungal agent that also affects P450 enzymes of the mammalian steroidogenic system. Several steps in the ovarian steroidogenesis pathway are known to be inhibited by KCZ, but previous work has failed to address the ramifications of such inhibition with respect to early pregnancy. In initial studies, Holtzman rats (8-10/group) were administered 10-100 mg/kg KCZ during days 1-8 of pregnancy. On day 9, evaluations revealed a reduction at both 75 and 100 mg KCZ/kg in the number of implantation sites and serum progesterone levels as well as an increase in ovarian weight. The decidual cell response (DCR) was blocked by KCZ in parallel with decreased serum progesterone and increased ovarian weight, indicating direct interference with uterine function. KCZ had no effect when given to long-term-ovariectomized rats that were hormone supplemented to permit the DCR, indicating that the ovary was at least one site of KCZ action on early pregnancy. Measurement of ovarian progesterone production in vitro from ovaries removed from rats treated in vivo with KCZ indicated a decline in progesterone production, suggesting a direct effect of KCZ on ovarian steroidogenesis. These data demonstrate that KCZ can compromise early pregnancy and appears to do so by inhibiting progesterone synthesis in the ovary.

Previous studies showed exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) enhances the development of endometriotic lesions. In this study we examined the effects of other polyhalogenated aromatic hydrocarbons on endometriotic proliferation. B6C3F1 female mice were treated via oral gavage a total of five times, with 3 weeks between each dosing, with 0, 1, 3, or 10 micrograms 2,3,7,8,-TCDD/kg body weight (bw); 3 or 30 mg 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153)/kg bw; 100, 300, or 1000 micrograms 3,3',4,4',5-pentachlorobiphenyl (PCB 126)/kg bw; 10, 30, or 100 micrograms 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF)/kg bw; or 2 or 20 mg 1,3,6,8-TCDD/kg at 10 ml/kg bw. Endometriosis was surgically induced during the week of the second dosing. Three weeks following the final dose, the mice were euthanized and endometriotic lesions, whole body, liver, ovaries, uterine horn, and thymus were weighted, and lesion diameters were measured. Lesions, uterine horns, and ovaries were fixed for histopathology and livers were processed for measurement of ethoxyresorufin O-deethylase (EROD) activity. Both 2,3,7,8-TCDD (1 and 3 micrograms/kg bw) and 4-PeCDF (100 micrograms/kg bw) significantly enhanced the growth of endometrial lesions. No statistically significant increase in endometriotic lesion size was detected in animals treated with either PCB 126 or with the highest dose of 2,3,7,8-TCDD, possibly due to the effects of histologically observed ovarian toxicity. The nondioxin-like compounds, PCB 153 and 1,3,6,8-TCDD, produced no observable effects on endometriosis. Hepatic EROD activity was significantly induced by 2,3,7,8-TCDD, 4-PeCDF, and PCB 126, but not by PCB 153 or 1,3,6,8-TCDD. The results of this study provide preliminary support for the hypothesis that halogenated aromatic hydrocarbon-promoted endometriosis may be Ah receptor mediated.

Estrogens can have a variety of physiological effects, especially on the reproductive system. Chemicals with estrogenic activity that are present in the environment may thus be considered potentially hazardous to development and/or reproduction. Methoxychlor is one such chemical, a chlorinated hydrocarbon pesticide with proestrogenic activity. Metabolism of the chemical either in vivo or using liver microsomes produces 2,2-bis(p-hydroxyphenyl)- 1,1,1-trichloroethane (HPTE), the active estrogenic form, and the delineation of this mechanism is reviewed herein. When administered in vivo, methoxychlor has adverse effects on fertility, early pregnancy, and in utero development in females as well as adverse effects on adult males such as altered social behavior following prenatal exposure to methoxychlor. Effects of methoxychlor on the female have been studied extensively, whereas reports on the chemical's effects on males are less common. From the studies reviewed here, the reproductive toxicity of methoxychlor is evident, but the significance of this toxicity with respect to human health remains to be determined.

Regional cerebral glucose metabolic rates (rCMRglc) were compared in 18 unmedicated outpatients with schizophrenia and 11 normal controls using high resolution positron emission tomography (PET) and the tracer [F-18]-2-fluoro-2D-deoxyglucose (FDG). From previous work we expected to see abnormal hippocampal rCMRglc in the patients, but no striatal abnormalities. Trial-by-trial Stroop cognitive task, which has been shown to activate the anterior cingulate, was performed within a day of the PET study. As our patients performed abnormally on the Stroop we tested for a correlation between the anterior cingulate rCMRglc and Stroop performance. We found no whole slice cortical average glucose metabolic abnormalities. As, predicted we found abnormally decreased left hippocampal rCMRglc in the patients. No striatal or cingulate rCMRglc abnormalities were noted in patients, but they demonstrated a highly positive correlation between anterior and cingulate rCMRglc and Stroop facilitation. Patients with higher Stroop interference had more prominent hippocampal metabolic decreases. These localized temporal lobe abnormalities could account for some of the patient's positive symptoms and are consistent with recent findings in the literature.

Endometriosis, a disease of women and nonhuman primates in which endometrial tissue grows outside the uterus, can be mimicked surgically in rats and mice. The disease is related to infertility in women, and surgical induction of endometriotic lesions reduces fertility in rats according to some studies. Conversely, pregnancy appears to have a beneficial effect on endometriosis in women and some rat studies. Our objective was to evaluate a new mouse model of surgically induced endometriosis with respect to the effects of pregnancy on endometriosis and the effects of endometriosis on pregnancy. Female B6C3F1 mice were divided into four groups. Those in Group A and B underwent induction surgery for endometriosis and hemi-ovariectomy, those in Group C underwent sham surgery and hemi-ovariectomy, and animals in Group D received no surgery at all. Three weeks later, Group A, C, and D were bred. Eighteen days later one half of the dams in Groups A, B, and C only were sacrificed, and evaluations included endometriotic lesion diameter, number of pups, fetal weight, and various organ weights. The remaining dams delivered, and, 18 days after parturition, dams and pups were sacrificed. Evaluations included gestation length and those listed above. Endometriotic lesion diameter was significantly reduced in pregnant animals when compared with nonpregnant controls, but the reduction was not a full regression. Lactation returned the mean lesion diameter to pre-pregnancy dimensions. When effects of endometriosis on pregnancy were evaluated, no effects on the litter size, pup weight, or gestation length were found, but trends toward increased resorptions and malformations were evident. Thus, in the mouse model of induced endometriosis, pregnancy produced a significant reduction in endometriotic lesion diameter while fertility was largely unaffected by the surgically induced endometriosis. The mouse model of endometriosis thus appears more resistant than the rat model to effects of endometriosis on fertility.

Epidermal growth factor (EGF) and its receptor (EGF-R) have been implicated as mediators for estrogen induced cellular growth. This study examines whether the action of the estrogenic pesticide methoxychlor (MXC) parallels the action of 17 beta-estradiol (E2) on uterine EGF-R. Administration of 20 micrograms E2/sexually immature female rat increased 125I-EGF binding to membranes extracted from whole uteri 175% over endogenous levels, while 500 mg MXC/kg led to a 156% increase. E2 in both 20 and 40 micrograms/rat doses and 500 mg MXC/kg led to maximal stimulation over endogenous levels, 12-h posttreatment. Rats were treated with E2, MXC, or vehicle plus 100 micrograms actinomycin-D (ACT-D) or 100 micrograms cycloheximide (CYCLO) per rat to determine if mRNA transcription and translation are involved in the increased EGF-R binding following estrogenic treatment. Only ACT-D inhibited the estrogenic stimulation of EGF-R binding, resulting in a 44% decrease when given concurrently with E2 or MXC, suggesting transcription is required. Additionally, ACT-D decreased endogenous receptor levels by 55%. No other differences were detected. When EGF-R binding data were analyzed by the method of Scatchard, both E2 and MXC, at maximal dosages, elevated uterine EGF-R binding sites by over 200% after 12 h as measured by maximal binding (Bmax) with no significant difference in dissociation constant (Kd) values. These results demonstrate that both E2 and MXC can stimulate the number of EGF-R binding sites without significantly altering the receptor binding affinity (Kd). Further, this stimulation is time dependent and is affected by dose.

In the disease of endometriosis, endometrial tissue grows outside the uterus, usually in the peritoneal cavity. Rodent models of endometriosis allow a way to reproduce the disease, evaluate effects of chemicals, and study mechanisms. Twenty-one days prior to induction surgery which produces endometriosis, female Sprague-Dawley rats and B6C3F1 mice were pretreated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at 0, 3 or 10 micrograms TCDD/kg. Animals were treated again at the time of surgery and at 3, 6, and 9 weeks following surgery. Evaluations were made at 3, 6, 9, and 12 weeks postsurgery. TCDD produced a dose-dependent increase in endometriotic site diameter when all time points were pooled within each dose in rats and a dramatic increase in site diameter in mice at 9 and 12 weeks. In rats but not mice, ovarian weight was decreased at 9 and 12 weeks, the occurrence of persistent vaginal estrus was increased at these times, and histological evaluation of the ovaries revealed ovulatory arrest at 12 weeks. In both species, thymic antrophy, indicating immune dysfunction, and hepatomegaly were observed as consequences of TCDD exposure. Body weight was reduced in rats but not in mice. Histological evaluations of endometriotic sites revealed fibrosis in control rats, necrotic and inflammatory changes in the sites from TCDD-treated rats, and predominantly fibrotic changes in sites from TCDD-treated mice. Differences observed between the rat and the mouse with respect to (a) the magnitude of the effect on endometrial site diameter (rats < mice), (b) measured effects on ovarian function (rats > mice) that may be based on the partial antiestrogenicity of TCDD, and (c) evidence that mice and rats differ in their immune response to TCDD suggest that the mechanisms mediating TCDD's action to promote endometriosis are complex and may be different in rats and mice. The mouse may be a better model for future studies necessary to elucidate these mechanisms.

Endometriosis is a disease of women where endometrial tissue is found growing at ectopic sites. While evidence suggesting a role for the ovarian hormones in endometriosis exists, no complete studies of the roles of estrogen and progesterone have heretofore been performed. Also, if estrogen has a role in the growth and/or maintenance of endometriosis, it is likely that the proestrogenic pesticide, methoxychlor (MXC), might also have such an effect. Sixty rats underwent surgery on Day 0 to induce endometriosis. On Day 21, all rats were ovariectomized. During surgery, the diameters of all endometriotic implants (which were fully developed) were measured. Starting on Day 21, groups of rats were treated daily, for 3 weeks, with (a) vehicle (b) estrone, 1 micrograms/rat, E;(c) progesterone, 2 mg/rat, P; (d) E + P, 1 micrograms + 2 mg; (e) MXC, 250 mg/kg; or (f) MXC + P, 250 mg/kg + 2 mg/rat. On Day 42, all rats were killed, and the diameters of all endometriotic sites were measured. While no differences in diameter were found across groups prior to ovariectomy, ovariectomy plus treatment altered the growth of endometriosis tissue. Progesterone and vehicle treatments produced results that were identical: regression of endometriotic sites. Both estrogen and MXC treatments maintained endometriotic site size at a level greater than that in the vehicle-treated group. The combination of progesterone with either estrone or MXC did not alter the effect of either chemical. We conclude that while estrogen promotes the growth of endometriosis, progesterone either produces regression or fails to maintain the sites. MXC, at a relatively high dose, supports the development of endometriosis. Concurrent progesterone treatment does not modulate the effects of estrone or MXC. These results suggest that exposure of women to high doses of MXC may exacerbate the development of endometriosis or contribute to its recurrence.

Endometriosis consists of the growth of endometrial tissue outside the uterus. A rat model of endometriosis is available to evaluate the potential for environmental chemicals to promote the disease but may be relatively insensitive for the evaluation of the hazard of certain compounds. Our objective, which was to develop a mouse model for endometriosis, was based on (a) the promotion of endometriosis in primates by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), (b) the apparent relationship between endometriosis and immunodeficiency, and (c) evidence that humoral immunity is suppressed in mice but not rats following TCDD exposure. In the mouse model, slices of uterus were sutured to intestinal mesenteric vessels. By 3 weeks after surgery, these sites were cyst-like structures. The growth of the sites was hormone dependent. In intact mice, sites measured 3.60 +/- 0.22 mm; vehicle and estrone (0.5 microgram/day) treatments produced site diameters of 0.95 +/- 0.128 and 5.28 +/- 0.355 mm, respectively. This new mouse model provides a sensitive and useful technique for future studies of the potential for specific xenobiotics to promote the development of endometriosis.

Methoxychlor (MXC), a proestrogenic pesticide, has adverse effects on fertility and uterine function in rodents. MXC is converted to an estrogenic substance, 2,2-bis-(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE), which binds to the estrogen receptor. We examined the similarities in mechanism between MXC (500 mg/kg) and estrogen (10 micrograms/rat) actions using the estrogen-induced protein, IP, also known as creatine kinase. Immature, female rats were treated with MXC or estradiol (E2). Concurrent treatment included actinomycin D (100 micrograms), cycloheximide (100 micrograms), or progesterone (0.5 mg). Uterine proteins were labeled in vitro with 3H for treated rats and with 14C for controls. The uteri were combined, cytosol was isolated, non-denaturing (ND) gels were run, and dpm/gel slice were plotted. In a follow-up study, labeled cytosols from MXC- and E2-treated rats were immunoprecipitated with a monoclonal antibody to creatine kinase. The immunoprecipitate was run on SDS gels. The data show that both MXC and E2 treatments result in ND gels with peaks in (a) induced protein and (b) the 3H/14C ratio, in the same position. The induction of IP by MXC is time- and dose-dependent. Concurrent treatment with MXC plus actinomycin D or cycloheximide blocked IP synthesis, a result parallel to E2 action signifying the necessity of RNA and protein synthesis for IP induction. Progesterone did not block either MXC or E2 induction of IP synthesis. Immunoprecipitation of creatine kinase revealed a single peak at a molecular weight of approximately 49,000. SDS gels of cytosol after MXC or E2 treatment also yielded protein and ratio peaks at molecular weights of approximately 49,000. This estimate is near the published estimated molecular weight of creatine kinase of 46,000. We conclude that MXC action parallels that of estradiol on the induction and regulation of the estrogen-induced protein in immature rat uterus.

Methoxychlor (MXC) has adverse effects on fertility and rat uteri via its active metabolite HPTE (2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane). Uterine peroxidase, a marker of estrogen action, was used to probe potential mechanisms of MXC's adverse effects. Specifically, our objective was to compare the regulation of the effects of estrogen and MXC on uterine peroxidase. Immature female rats were treated with MXC (250 mg/kg; gavage) 24 h prior to the measurement of uterine peroxidase activity, with or without concurrent treatment with actinomycin D, cycloheximide, progesterone, or tamoxifen. MXC alone produced an increase in peroxidase activity. The prior and/or concurrent treatment with the compounds listed blocked the MXC-induced stimulation of peroxidase. These data show similarities between the mechanisms of estrogen MXC action. Both estrogen and MXC act to stimulate uterine peroxidase activity via increased RNA and protein synthesis and this stimulation can be blocked by progesterone and tamoxifen.

The chemotherapeutic agent 5-azacytidine (5AZ) is cytotoxic via nucleic acid hypomethylation. Malformations and embryolethality result when rats or mice are exposed to 5AZ on any of Days 9 through 12 of pregnancy. To investigate the effect of 5AZ exposure during the pre- and early postimplantation period, we administered 0.15, 0.30, 0.60, or 1.2 mg/kg 5AZ/day to rats during Days 1-8 of pregnancy and evaluated outcome on Days 9 or 20. No adverse effects were detected on Day 9; the numbers and weights of implantation sites, the numbers of resorptions, maternal body weight gains, and hormone measures were not different from those of controls. However, when pregnancy outcome was evaluated on Day 20, dose-dependent decreases in offspring survival and fetal weight were observed and the incidences of two malformations, microphthalmia and exencephaly, were increased. In a follow-up study, 5AZ was administered during the preimplantation period (Days 1-3) or during the postimplantation period (Days 4-8) and pregnancy outcome was evaluated on Day 20. When rats were exposed to 5AZ during the preimplantation period, no adverse effects were seen. Postimplantation dosing produced an increase in resorptions and a decrease in fetal survival and fetal weight, with no gross external malformations evident. At the doses used in this study, 5AZ was embryotoxic, with limited embryonic vulnerability prior to Day 4 of pregnancy but serious consequences following postimplantation exposure. This embryotoxicity is not detectable by our measures on Day 9 but is evident on Day 20.

Recent attention to methanol (MeOH) as a potential alternative fuel prompted an evaluation of the chemical's effects during early pregnancy. Rats were dosed by gavage during Days 1-8 of pregnancy at 0, 1.6, 2.4, or 3.2 g MeOH/kg/day. Groups of animals were killed on Days 9, 11, or 20 of pregnancy, and maternal, embryonic, or fetal parameters were assessed, depending on the stage of pregnancy. The decidual cell response (DCR) technique was also applied to rats treated with MeOH during pseudopregnancy. Reductions in pregnant uterine and implantation site weights seen on Day 9 are the result of MeOH impedance of normal decidualization, as demonstrated by effects on the DCR. An increase in the extravasation of blood at implantation sites seen on Day 9 did not result in an increase in resorptions by Day 20. The 3.2 g/kg/day dose of MeOH produced a reduction in body weight gain by Day 9, which may be considered an indication of non-specific maternal toxicity. No effect on Day 11 or Day 20 embryo-fetal survival, or development was observed.

The pesticide methoxychlor (MXC) exhibits estrogenic activity although it is not a steroid. Therefore its mode of action may differ from that of estrogen. Here we evaluated the ability of MXC to replace estrogen in the ovariectomized, hormone-treated decidual cell response (DCR) model. Following priming with estrone, ovariectomized rats were treated with estrone plus progesterone, progesterone alone, or progesterone plus various dosage levels of MXC. Within a narrow dose range, MXC can replace estrone and, in combination with progesterone, produce a maximal DCR. In the same manner as that seen with progesterone plus estrone, progesterone plus MXC produced no effect different from progesterone alone at low to intermediate dosages and an inhibition of decidual growth at high doses. The data support the hypothesis that MXC exhibits classical mechanisms of estrogenic activity.

Antifertility properties of the pesticide methoxychlor (MXC) are well documented. Administration of MXC to rats during early pregnancy impairs implantation and reduces serum progesterone. The current study was designed to examine the effect of MXC on ovarian steroidogenesis and to define the mechanism(s) by which the pesticide exerts this effect. Rats were treated with MXC at a range of doses during days 1 to 8 of pregnancy and killed on day 9. Ovaries were incubated to assess the secretion of progesterone, estradiol, and testosterone in vitro. Steroid hormones in medium and serum were measured by radioimmunoassay. Although in vivo treatment with MXC reduced serum progesterone, no effect on the ovarian secretion of progesterone was detected in vitro. Conversely, MXC had no effect on serum estradiol levels (testosterone levels were undetectable in serum), but the incubation of ovaries in vitro revealed a reduction in the rates of ovarian estradiol and testosterone secretion.

Methyl 2-benzimidazolecarbamate (MBC) and its parent compound benomyl are used as agricultural fungicides. Both chemicals are embryotoxic if administered during organogenesis, and benomyl is teratogenic. Based on a previous study indicating a lack of maternal effects of MBC following exposure during early pregnancy, the current experiments were designed to evaluate the effect of exposure to MBC during early pregnancy on developmental parameters of offspring. Rats were administered MBC at 0, 100, 200, 400, or 600 mg/kg/day during Days 1-8 of pregnancy and killed on Day 11 or Day 20 of gestation. On Day 11, embryos were assessed for survival rate, growth parameters, and anomalies. On Day 20, standard developmental toxicity evaluations were performed. Doses of 200 to 600 mg/kg/day MBC reduced embryonic survival by Day 11; exposure to MBC at 100 to 600 mg/kg/day reduced the number of fetuses surviving on Day 20. Evidence of developmental delay was apparent on Day 11 at all doses, and fetal weight was reduced by Day 20. MBC produced a dose-dependent increase in developmental defects seen on Day 11 and in several malformations observed on Day 20. MBC exposure during the first week of pregnancy was shown to be embryotoxic, resulting in embryonic death, growth retardation, and developmental abnormalities when evaluated on Days 11 or 20 of gestation.

Validated protocols for evaluating maternally mediated mechanisms of early pregnancy failure in rodents are needed for use in the risk assessment process. To supplement previous efforts in the validation of a panel of protocols assembled for this purpose, bromoergocryptine (BEC) was used as a model compound because it is known to inhibit pituitary prolactin secretion. BEC was tested using the early pregnancy protocol (EPP), the decidual cell response technique (DCR), the pre- vs postimplantation protocol (PPP), and embryo transport rate analysis (ETRA). These protocols evaluate the effects of chemicals on multiple endpoints following exposure during (a) the first 8 days of pregnancy, (b) early pseudopregnancy accompanied by decidual induction, (c) the pre- and postimplantation intervals of early pregnancy, or (d) the period of embryo transport. In the EPP, dosing with BEC during Days 1-8 of pregnancy reduced the number of implantation sites found on Day 9 as well as serum progesterone. The DCR technique revealed a dose-dependent inhibition of decidual growth concomitant with decreased serum progesterone as a result of BEC treatment. A modified DCR technique using hormone-supplemented ovariectomized rats demonstrated that BEC did not impair decidual growth in the presence of adequate progestogenic support. Pre- vs postimplantation dosing indicated that implantation is vulnerable to BEC effects at least through Day 4. BEC had no effect on embryo transport rate. Data from these protocols identified BEC as having adverse maternal effects during early pregnancy. While the pituitary was not identified by these protocols as the site of BEC's primary action, the protocols did identify a reduction in serum progesterone and impaired uterine function as toxicological mechanisms mediating the reduced fertility seen following BEC exposure.

A battery of protocols for the assessment of maternally mediated toxicity during early pregnancy in the rat is being evaluated for its utility in detecting and defining mechanisms of early pregnancy failure. In this report, clomiphene citrate (CC), an estrogen agonist/antagonist, was used as a model compound in this evaluation process. The protocols involve dosing rats with CC during, and evaluation of multiple endpoints following, (a) the first 8 days of pregnancy; (b) early pseudopregnancy, accompanied by decidual induction; and (c) the pre- and postimplantation intervals of early pregnancy. In addition, the effect of CC on embryo transport rate was assessed. Eight days of dosing with CC during early pregnancy produced a dose-dependent reduction in the number of implantation sites seen on Day 9, concomitant with alterations in maternal hormonal parameters. No effect on the decidual cell response was found, indicating that the mechanism of fertility reduction was not mediated via compromised uterine decidualization. The preimplantation period was highly vulnerable to the toxic effects of CC while no postimplantation resorptions were seen. When embryo transport rate was measured, a statistically significant embryo transport rate acceleration was detected, but this was insufficient to account for all of the observed preimplantation loss. The data suggest an effect of CC on embryo viability, on the embryo's ability to implant, or on the reproductive tract resulting in compromised embryo survival as the potential mechanism(s) mediating CC-induced early pregnancy failure. The battery of protocols was thus successful in identifying CC as a reproductive toxicant and in elucidating the causes of the observed early pregnancy failure.

Implantation in mammals requires the successful completion of a series of integrated phenomena, including uterine preparation, synchronized embryo transport, embryonic attachment, uterine transformation, placental development, and the requisite hormonal milieu to support each step. Potential for toxic interference with early pregnancy exists at several points in this course of events via a variety of anatomical and physiological sites. An improved understanding of the mechanisms of implantation failure due to toxic insult is necessary in order to assess risks of reproductive toxicants to the human female population. As an approach to providing such information, a panel of tests has been assembled and developed to probe the mechanisms by which chemicals affect fertility in rodents. These assessments are performed only if adverse effects on litter size or pregnancy are evident from previous reproductive studies. The evaluation of methoxychlor, a weakly estrogenic pesticide, has served to partially validate this panel. The early pregnancy protocol provides dose-response information on the effects of short-term exposure of animals to compounds during early pregnancy. The pre- vs postimplantation protocol assesses the differential effects of such chemicals on the physiological events unique to the periods immediately preceding and following implantation. The decidual cell response technique can distinguish embryotoxicity from direct effects of toxicants on uterine or other physiological functions. Embryo transport rate analysis evaluates the potential for early embryonic loss via accelerated or retarded arrival of embryos into the uterus. The panel thus permits the determination of the site or sites of toxic insult and the mechanisms by which environmental toxicants may compromise fertility following short-term exposure during early pregnancy.

Methyl 2-benzimidizolecarbamate (MBC), an agricultural fungicide, and its parent compound benomyl have adverse reproductive effects on male rats and exhibit embryotoxicity, including teratogenicity, when administered to rats during mid to late pregnancy. This study was designed to assess potential maternal effects of MBC during early pregnancy, to distinguish maternal from embryotoxic effects of the chemical, and to differentiate between early pregnancy failure and late embryonic loss. MBC was administered to rats by gavage at 0, 25, 50, 100, 200, 400, and 1000 mg/kg/day during Days 1 through 8 of pregnancy (Day 0 = sperm positive). A range of maternal and embryonic parameters was assessed following euthanasia on Day 9, including the number of implantation sites, body weight gain, uterine weight, implantation site size, and serum ovarian and pituitary hormones. In a separate experiment, pseudopregnant rats were administered 0 or 400 mg/kg/day MBC during Days 1-8, received bilateral uterine decidual induction on Day 4, and were killed on Day 9 at which time the decidual cell response was evaluated as a measure of uterine competency. When dosages of up to 400 mg/kg/day of MBC were administered during early pregnancy, the chemical had no significant effect on any measured parameter but a trend toward increased resorptions was evident. The 1000 mg/kg/day dosage of MBC produced reductions in body weight gain, implantation site weight, and serum LH and an increase in serum estradiol. When administered during pseudopregnancy, 400 mg/kg/day MBC partially reduced uterine decidual growth but affected no other parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

The estrogenic pesticide methoxychlor (MXC) is known to reduce implantation, and, in our previous work, this reduction has been attributed to a direct effect on uterine function. The present study was designed to investigate the effect of MXC on embryo transport rate, another phenomenon that is vulnerable to estrogenic effects. MXC was administered by gavage, at 0, 100, 200, and 500 mg/kg/day, to groups of rats on Days 1-3 of pregnancy (Day 0 = sperm positive), and the distribution of embryos in the oviducts and uteri of animals was assessed at five time intervals prior to implantation. No effect of MXC was detected by the afternoon of Day 1. On Days 2 and 3 of pregnancy, 200 and 500 mg/kg/day MXC were found to accelerate embryo transport into the uterus; the 500 mg/kg/day dosage also reduced the total number of embryos recovered from the tract. On the third day, 100 mg/kg/day MXC also accelerated embryo transport to the uterus and 200 mg/kg/day MXC reduced total embryo recovery. Until the afternoon of Day 3, most control embryos remained in the oviduct. These data demonstrate that MXC produces a dose-dependent acceleration of embryo transport through the female reproductive tract. When compared with previous work, the current data indicate that such an acceleration is the primary cause of MXC-induced preimplantation embryonic loss when exposure occurs after fertilization.

Adenosine diphosphoribosyl transferase (ADPRT) activity was measured in endometrial nuclei isolated on estrus and day 4 from rats ovariectomized on estrus (day 0) and treated on days 0-3 with vehicle, estrone (E), progesterone (P), or E plus P, a treatment that supports a decidual response. Also, measures were made of ADPRT in endometrial nuclei isolated from rats during the estrous cycle, days 1-7 of pseudopregnancy, and days 5-7 of pseudopregnancy after decidual induction on day 4. E treatment produced an increase in ADPRT activity, DNA content, tissue mass, and total protein. P alone did not affect ADPRT activity or DNA content. Enzyme activity and DNA content measured after E plus P treatment were significantly lower than those after estrone treatment and higher than those in vehicle-treated controls. The parallel stimulation of ADPRT activity and DNA synthesis by E supports a role for ADPRT in cellular proliferation. The blockade of E-stimulated ADPRT activity by P is consistent with a previously proposed model of hormonal regulation of rat uterine pyridine nucleotide metabolism. In endometrium from cycling rats, ADPRT activity did not change between metestrus and proestrus, but declined on estrus. After a rise on day 1 of pseudopregnancy, ADPRT activity remained stable through day 5 and declined on day 6. The relatively constant enzyme activity during the cycle and early pseudopregnancy, when hormone levels undergo great changes, may reflect an additional level of control in intact animals not observed in ovariectomized hormone-treated rats. Decidual ADPRT activity declined on day 5, 1 day after uterine trauma, and increased on day 6. This pattern of enzyme activity is consistent with the initial phase of cytodifferentiation, followed by rapid proliferation during early decidualization.

During the preimplantation stages of pregnancy, rising titers of progesterone alter the metabolism of the uterine endometrium to permit implantation of the blastocyst. In this model of progestational differentiation, it is proposed that endometrial pyridine nucleotide metabolism is a key target of progestogen action. The hormone may modulate NAD metabolism to promote NADP synthesis while inhibiting NAD breakdown to ADP ribose and nicotinamide. The result of such an action would impair uterine DNA synthesis and cell division, but provide increased NADP for coenzyme-limited synthetic processes and cytodifferentiation. As a result, the endometrium differentiates and becomes sensitive to decidual-inducing stimuli (the blastocyst). The decidual stimulus reverses the process by rapidly inhibiting NADP production, and by dramatically increasing poly ADP ribosylation of nuclear protein, thus facilitating DNA synthesis and the wave of cell division associated with the initiation of decidualization. The background information and evidence in support of this model are presented.

SDS-polyacrylamide gel electrophoresis of anti-glucose-6-phosphate dehydrogenase immunoprecipitates from radiolabeled uterine tissue extracts previously revealed three proteins: A, B and C, which were tentatively identified as a 60-64 kDa precursor form, a 57 kDa predominant form, and a 40-42 kDa nascent peptide form of the enzyme, respectively. A peptide-mapping technique was used to examine structural homologies among A, B and C. Following the labeling of uterine proteins with [35S]methionine, labeled proteins A, B and C were isolated by immunoprecipitation and electrophoresis. Each protein was individually co-digested with authentic, [3H]methionine-labeled glucose-6-phosphate dehydrogenase using papain, the resulting peptides were resolved by isoelectric focusing and the peptides from the two sources on each gel were compared using double-label counting methods. Proteins A, B and C had at least eight peptides in common, both proteins A and C had two additional peptides in common that were not present in protein B, and B protein had two peptides that were either absent or present in reduced amounts in digests of proteins A and C. The extensive structural homology and immunoreactivity of these proteins indicated that proteins A, B and C were all related to glucose-6-phosphate dehydrogenase. The presence of two extra peptides in proteins A and C suggested that these peptides may be derived from a common NH2-terminal leader sequence which was present in both the precursor and nascent peptide chains. The presence of two peptides that were present in protein B and absent from proteins A and C is easiest to explain if they are derived from the two ends of the molecule, with the corresponding peptides in proteins A and C containing additional peptide sequences that are 'normally' removed by endogenous proteolytic processing enzymes. Based on the relative time-course of synthesis of the three glucose-6-phosphate dehydrogenase-related proteins in control and estrogen-treated uteri, it appears that estradiol promotes an increase in the relative rate of transfer of label from protein A into B by stimulating the rate of processing of the precursor to the predominant form of the enzyme and enhances the rate of translational conversion of protein C into higher molecular weight forms.

The pesticide methoxychlor (MXC) is a proestrogen which is metabolized to a compound that has been shown to exhibit estrogenic activity in vivo and in vitro. Following long-term exposure of female rats to MXC, fertility is reduced and fetotoxicity is evident. However, the effects of MXC on several aspects of maternal reproductive physiology, including the decidual cell response (DCR), ovarian weight, serum progesterone levels, and corpora lutea maintenance, have not been previously described. In the present study, the ability of MXC to interfere with progestational events essential for implantation and the maintenance of pregnancy in the rat was investigated. MXC was administered to pseudopregnant rats, decidualization was induced on Day 4, and the DCR and related parameters were evaluated following euthanasia on Day 9. DCR induction during estrone administration served as a positive control. MXC inhibited decidualization in a dose-dependent manner: while 100 mg/kg/day had no effect, doses of 200, 300, 400, and 500 mg/kg/day produced incremental inhibition of the response. No effects of MXC on ovarian weight, serum progesterone levels, or number of corpora lutea were observed. Estrone also inhibited the DCR in a dose-dependent manner. The data suggest that the anti-fertility effect of MXC is mediated by a suppression of decidualization and that such suppression, which is characteristic of estrogenic compounds, is a direct uterine effect. In the DCR model system, the estrogenic activity of MXC is 1/20,000 times the activity of estrone.