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Drug addiction behavior that is established and maintained by psychostimulants has been shown to be associated with the expression of brain-derived neurotrophic factor (BDNF) in the mesolimbic dopamine (DA) system. Cocaine has been used for most prior studies testing this effect of psychostimulants and therefore relatively little is known about its counterpart amphetamine (AMP). To fill this gap, the present study was designed to test whether BDNF mRNA expression levels in the DA terminal regions were changed specifically by d-AMP-induced conditioned place preference (CPP) followed by drug-primed reinstatement. The dose of d-AMP, 1mg/kg, was confirmed to significantly induce CPP. Using this dose, a group of rats was initially subjected to d-AMP CPP, which was followed by entry into an extinction protocol with an additional 3-day withdrawal before a drug-primed reinstatement test was carried out. Following extinction of d-AMP CPP, a lower dose of d-AMP, namely 0.75mg/kg, was able to significantly reinstate CPP. The BDNF mRNA levels in the selected brain areas were determined by real-time polymerase chain reaction (PCR) after the CPP and reinstatement. The BDNF mRNA level in the medial prefrontal cortex (mPFC) was significantly increased after the reinstatement, but not the CPP test. And, none of the other four assessed brain areas showed any change in BDNF mRNA level after d-AMP CPP or reinstatement. These findings support the notion that BDNF is involved in drug-seeking behavior and indicate that d-AMP reinstatement after extinction may be linked to an increase in BDNF mRNA expression in the mPFC.

By using Langendorff perfused rat heart and enzymatically isolated cardiomyocytes, we investigated the augmented injury effect of iron on the myocardium by hydrogen peroxide and the underlying mechanisms. Cell-permeable iron (Fe-HQ) decreased the contractile amplitude, velocity and end-diastolic cell length of the cardiomyocyte but increased the contents of lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary effluent and the myocardial malondialdehyde (MDA) while the left ventricular developed pressure (LVDP), +/-dp/dt(max), heart rate and coronary flow showed biphasic alterations. Hydrogen peroxide augmented the injury effect of iron accompanied by increases of coronary LDH, CK release and myocardial MDA content and decreases of LVDP, +/-dp/dt(max), and heart rate. Reduced glutathione could antagonize the injury effect of iron and hydrogen peroxide on the myocardium while dimethyl sulfoxide had no injury effect on the isolated heart. It is suggested that the functional injury of sulfhydryl group containing proteins may be involved in the augmentation of myocardial injury due to the increase of intracellular iron by hydrogen peroxide, but hydroxyl radicals may not.

The purpose of the present study was to explore the biological effects and mechanism of interleukin-2 (IL-2) on the isolated rat heart. The results showed that hrIL-2 increased the number of premature ventricular contraction, heart rate, left ventricular developed pressure, left ventricular end-diastolic pressure and coronary flow in the isolated perfused rat heart. Heat inactivated hrIL-2 had no effect on the heart. Pretreatment with ryanodine canceled the positive effects of hrIL-2 on left ventricular developed pressure, left ventricular end-diastolic pressure and coronary flow but had no effects on arrhythmogenesis and tachycardia by hrIL-2. Pretreatment with nifedipine or low extracellular calcium abolished the arrhythmogenic effect of hrIL-2 and attenuated partially the augment of heart rate, left ventricular developed pressure, left ventricular end-diastolic pressure and coronary flow. It suggests that the cardiac activity of hrIL-2 depended on the integrity of its spatial structure and transmembrane influx Ca2+ and intracellularly stored Ca2+ were involved in the cardiac activity of hrIL-2.

In the present study, the relationship between the blockade of kappa-opioid receptor and ischemic preconditioning (IP) was examined and the effect of IP and prolonged ischemia on levels of dynorphin A1-13 (Dyn A1-13) in cardiac muscle in isolated perfused rat heart was investigated. The results are as follows: (1) IP reduced the severity of ischemia/reperfusion arrhythmia (P0.05) and infarct size (P0.01), but had no significant effect on heart rate and coronary flow (P0.05); (2) MR2266, kappa opioid receptor antagonist, reduced the severity of ischemia/reperfusion arrhythmia (P0.05) and infarct size (P0.01), and also enhanced the recovery of coronary flow, but had no significant effect on heart rate (P0.05); and (3) prolonged ischemia decreased the levels of Dyn A1-13 (P0.05), which was more marked in the unpreconditioned hearts. The results suggest: (1) MR2266 can "mimic" cardioprotective effect of IP in reducing the severity of arrhythmias and limiting infarct size of cardiac muscle; (2) ischemia causes release of endogenous kappa opioids, which can be attenuated by IP; and (3) the cardioprotective effects of IP in rat heart involves endogenous kappa opioids.

To extend the investigation of tail-pinch induced behavioral changes, rats performing on a differential reinforcement of low rates of 10 sec (DRL10), a fixed-interval of 60 sec (F160), and a fixed-ratio of 20 (FR20) schedules were exposed to a paper clip applied to the tail. While a 10 min tail-pinch conducted 1 hr before operant sessions significantly altered the DRL10 behavior, this stressor had little effect on either F160 or FR20 responding. Marked DRL10 behavior performance changes following tail-pinch included increases in the number of lever presses, decreases in the number of the reinforcers, and disruption in the frequency distribution of inter-response times (IRT). These DRL10 operant deficits were diminished when the subject received a tail-pinch pretreatment followed by d-amphetamine treatment (0.2 and 2.0 mg/kg). In combination with biochemical data from others, the present results suggest that catecholamine systems are involved in modulation of DRL10 behavior following tail-pinch.

Intracellular recordings were made from bullfrog sympathetic ganglion cells to elucidate effects of 2-n-butyl-1-(4-methylpiperazinyl)-5,6-methylenedioxyindene.2 HCl (TN-871) on synaptic transmission. TN-871 at 30 nM augmented cholinergic nicotinic fast excitatory postsynaptic potentials (fast EPSPs), whereas the drug at 3 microM reversibly depressed them, without affecting acetylcholine-induced depolarizations. TN-871 did not affect active and passive electrical properties of the ganglion cells. The quantal analysis method was applied to the fast EPSPs in a 0.54 mM Ca2+/7.56 mM Mg2+ Ringer's solution. The mean quantal content was significantly increased by TN-871 at 30 nM but significantly decreased at 3 microM. TN-871 at 300 nM either increased or decreased the mean quantal content. The mean quantal size of the fast EPSPs was not changed by TN-871 at the concentrations examined. Fast EPSPs in a 0.99 mM Ca2+/4.86 mM Mg2+ Ringer's solution were not affected by nicardipine, but were inhibited in amplitude by omega-conotoxin in a concentration-dependent manner. It is likely that TN-871, in high concentrations, might block omega-conotoxin-sensitive N-type calcium channels in the presynaptic terminals. These results indicate that TN-871 modulates transmitter release from preganglionic nerve terminals without changing the postsynaptic sensitivity of the ganglion cells to ACh.

Intracellular calcium concentration ([Ca2+]i) of the rabbit eye suprachoroid was measured with microfluorophotometry using fura-2. Adenosine-5'-triphosphate (ATP) 1-100 microM, added to a perfusing solution, elicited an increase in [Ca2+]i of the suprachoroid. This action of ATP was inhibited when preparations were perfused with a nominally zero Ca2+ Krebs solution or a high magnesium Krebs solution. The [Ca2+]i-increasing action of ATP was attenuated either by lowering temperature or by a phospholipase C inhibitor, compound 48/80. These results indicate that extracellular Ca2+ is necessary to the ATP action and also suggest that the ATP action may be mediated by the intracellular signal transduction which exerts a Ca(2+)-release from intracellular Ca(2+)-store sites. The potency order of ATP-related purine nucleotides was ATPor = ATP-gamma-Sadenosine-5'-diphosphate (ADP). Adenosine-5'-monophosphate (AMP) and adenosine were not effective. It is concluded that P2-purinoceptors exist on the surface of the suprachoroid and are involved in mechanisms underlying the ATP-induced increase in [Ca2+]i of the suprachoroid.

Recent epidemiologic studies found that there is a strong association of hemostatic factors with ischemic heart disease. The Atherosclerosis Risk in Communities (ARIC) Intraindividual Variability (IIV) Study was conducted to estimate the various components of variation in hemostasis factors measured in the ARIC Study and to estimate the measures of repeatability of these factors. A total of 39 subjects (16 men, 23 women) were studied. Each had blood collected three times, with a 1- to 2-week interval between each visit. The contributions of between-person variability, within-person (biologic) variability, and processing and assay variability were estimated. Then the reliability coefficient R was estimated as the proportion of total variance accounted for by between-person variance. The reliability coefficient can be interpreted as the correlation between measures made at repeat visits. Among the various analytes, the reliability coefficients were quite high for activated partial thromboplastin time and plasma factor VIII (R = 0.92, 0.86, respectively). Low repeatability was obtained for antithrombin III activity and protein C (R = 0.42, 0.56, respectively). The lack of repeatability for these variables derives mostly from the processing (field center and laboratory) variation. Other analytes--fibrinogen, plasma factor VII, and von Willebrand factor--were intermediate in repeatability. In comparing the analyte-specific high-level to low-level groups, no substantial difference of within-person plus method coefficient of variation between the two groups was found for any analyte except for factor VIII, whereas the corresponding variance components for most analytes were higher for the higher analyte level. Reliability coefficients from this ARIC IIV study are generally higher than those found in other studies, and this is related to the relative variations in populations studied and to the time between measurements.

The findings from dissections, injection studies, and angiograms of 180 specimens of the anterior portion of left and right iliac crests taken from 90 cadavers are reported. These findings suggested that the deep circumflex iliac vessels were suitable for use as a nutritive pedicle in microvascular free transfer of iliac bone. Therefore, the technique of microvascular free transfer of iliac bone based on these vessels was developed and applied clinically in 2 cases with good results. The advantages and disadvantages of using the superficial circumflex iliac vessels or the deep circumflex iliac vessels as the vascular pedicle for iliac grafts also are discussed.

Since 1980, 110 cases of lymphedema have been treated by microlymphaticovenous anastomosis. Of these 110 patients, 91 with obstructive lymphedema of lower limbs were reviewed. The immediate and long-term results have been very satisfactory. Excellent and good results were obtained in 79.1 percent. An average reduction in circumference of the affected limb of 6.4 cm and an average reduction of excess volume of 59.2 +/- 29.5 percent (representing 703 +/- 850 ml) were obtained. Subjective symptoms and objective signs were improved. Four patients (4.4 percent) showed poor results owing to severe fibrosis of neighboring tissue; no lymphatics could be located for anastomosis. As the authors gained experience with the operation over the last 3 years, they modified the operative procedure, the anastomotic technique, and the selection of collective lymphatics. The data obtained suggest that the quality of results is proportional to the number of anastomoses. In order to obtain the best results, the criteria for selection of patients and avoidance of postoperative relapse are discussed. Finally, a test for determination of the indications for microlymphatic surgery is described.