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Objectives Although not pernicious, minimal distal hypospadias is frequently obvious to parents, whose concern that their child be completely normal prompts their request for repair. A simple technique for the repair of this anomaly that results in an elliptical meatus is presented. Methods A total of 28 boys ranging in age from 3 to 100 months (mean 21.8) underwent a surgical technique in which the distal urethral plate was excised, followed by advancement of the meatus into the defect thus created. Only 5 boys (17.8%) underwent hypospadias repair as an isolated procedure. Other concomitantly repaired anomalies included hooded prepuce, phimosis, redundant prepuce after neonatal circumcision, ventral penile curvature, inguinal hernia, undescended testis, penile torsion, and meatal stenosis. Results All patients had healed well at a follow-up of 3 to 4 months (mean 3.2) and uniformly had an excellent cosmetic appearance with an elliptical meatus. Conclusions We recommend a technique for the repair of minimal distal hypospadias, consisting of excision of the distal urethral plate with advancement of the dorsal lip of the meatus into the created defect, for its simplicity and resultant elliptical meatus.

The Firlit collar technique for the approximation of the divergent inner leaf of the prepuce in operations to repair hypospadias and its variants are generally easily conceptualized and executed. However, in some cases the divergence is so great at the level of the corona that a simple approximation cannot be performed. Therefore, 2 techniques are described that facilitate completion of the Firlit collar in these instances.A total of 101 boys 6 to 101 months old (mean 18.9) underwent formation of a Firlit collar between July 2003 and July 2004. Among the patients 69 had coronal or glanular hypospadias, 17 had a penile or a more proximal meatus and 15 had only a hooded prepuce. In 5 patients the divergence of the inner leaf of the prepuce precluded a simple midline approximation of the 2 halves. Two techniques of forming rotational flaps of the inner leaf were used to complete construction of the Firlit preputial collar.The techniques were used as described in 5 repairs, with excellent cosmetic results.Two rotational flap techniques for the repair of the widely divergent inner leaf of the prepuce associated with hypospadias and its variants are described and recommended for their simplicity and uniformly good results.

Purpose: Although the cremasteric muscle is a prominent structure of the inguinal canal, specific details of its anatomy are seldom discussed in either anatomical or surgical texts. Therefore, a detailed description of the anatomy of the cremasteric muscle and fascia is provided, followed by descriptions of new applications of this knowledge for operations on the inguinal canal.Materials and Methods: Observations are described based on more than 1,000 operations on the inguinal canal conducted during a 15-year period. Magnification of 3.5 × was used in all dissections.Results: Careful dissections of the cremasteric muscle and fascia allowed for development of new approaches to enhance exposure of the inguinal canal and internal ring, and to mobilize the spermatic cord and testes.Conclusions: Knowledge of the anatomy of the cremasteric muscle and fascia, and techniques for dissection are adjuncts to surgery of the inguinal canal, including inguinal hernia repair and orchiopexy.

Purpose: We describe our experience with reconstruction of the ureter in 2 patients who sustained extensive upper and mid ureteral loss as newborns.Materials and Methods: Two male patients, a 1-month-old and a neonate, sustained extensive ureteral loss due to candidal infection involving the retroperitoneum and ureter. The 1-month-old sustained a loss of the middle third of the ureter, and the neonate sustained a 3 cm. loss of the upper ureter. The first case was managed with a combination of renal mobilization and an extensive Boari flap, while the second was managed with renal mobilization and nephropexy with primary ureteropyelostomy.Results: Both patients had a successful outcome with no evidence of anastomotic stenosis or obstruction.Conclusions: Extensive upper and middle third ureteral defects may be primarily bridged successfully in pediatric patients using the standard technique of renal mobilization combined with ureteropyelostomy and a Boari flap, respectively.

Platelet-activating factor (PAF) desensitizes as well as stimulates its various target cells, We find that human polymorphonuclear neutrophils (PMN) exposed to PAF became maximally unresponsive to a second PAF challenge within 15-90 s in assays of Ca2+ mobilization and degranulation. The cells regained full PAF-sensitivity over the ensuing 20-40 min. These effects correlated with changes in PAF receptor availability. PMN treated with PAF, washed in regular buffer and assayed for PAF binding exhibited falls (maximal in 15 s), followed by rises (reaching control levels by 60 min), in the number of high-affinity PAF receptors. However, tracking studies showed that [3H]PAF accumulated on the cell surface for approximately 2 min before being internalized. Regular-buffer washes did not remove this superficial PAF, whereas a washing regimen using excess albumin to adsorb PAF removed 99% of the surface compound. PMN washed by the latter regimen after PAF exposure lost PAF receptors relatively slowly (maximal at approximately 5 min), but the ultimate extent of this loss and the rate at which receptor expression normalized were similar to those of cells washed in regular buffer. Neither cycloheximide nor actinomycin D influenced the course of the receptor changes, but two protein kinase C (PKC) blockers, staurosporine and 1-(5-isoquinolinesulphonyl)piperazine, inhibited the receptor-receptor-depleting actions of PAF. Indeed, a phorbol diester activator of PKC also caused PMN to decrease high-affinity PAF receptor numbers, and the two PKC blockers antagonized this action at concentrations that inhibited PAF-induced PAF receptor losses. We conclude that: (a) PAF induces PMN to down-regulate and then to re-express PAF receptors independently of protein synthesis; (b) these changes are likely to underlie the later stages and reversal of desensitization; (c) the onset (t < or = 2 min) of desensitization, however, precedes receptor down-regulation and must be due to receptor uncoupling from transductional elements; and (d) down-regulation of receptors for PAF appears to be mediated by PKC and/or elements inhibited by PKC blockers.

Purpose: To perform open donor nephrectomy with the least amount of body alteration and complication, a short extraperitoneal incision was developed that preserves the ipsilateral rectus abdominis muscle and abdominal branches of the intercostal nerves.Materials and Methods: Donor nephrectomy using the new incision was performed in 11 consecutive patients.Results: Morphine was required for pain relief for 1 to 3 days (mean 1.8), patients tolerated diet at 1 to 4 days (mean 2.2) and postoperative stay was 2 to 5 days (mean 3.5). Complications were minimal, consisting of postoperative fever 1 day in duration. A viable kidney was provided for transplantation in each case.Conclusions: The extraperitoneal, rectus abdominis muscle and nerve sparing incision resulted in a short course of pain medication, early diet toleration and a short hospital stay.

Purpose: Reoperation of the inguinal canal is difficult with few available lucid descriptions of the technique. We reviewed our experience with a unique surgical approach to the spermatic cord through the cremaster fascia in patients who had undergone previous operations for undescended testis or hernia and report its outcome.Materials and Methods: A total of 54 inguinal reoperations were performed in 45 boys with an undescended testis or indirect inguinal hernia using a unique surgical approach through the cremaster fascia.Results: Of the 54 inguinal canal reoperations surgery was successful in all but 1 patient who sustained a transected vas deferens (1.8% complication rate).Conclusions: The surgical approach to the inguinal canal through the cremaster fascia is an effective technique for reoperation of the inguinal canal after orchiopexy or hernial repair.

A detailed photographically illustrated anatomic technique for the sequential dissection of the pediatric hernia sac from the spermatic cord has not been described. An illustrated technique to atraumatically dissect the hernia sac in a systematic fashion is therefore presented.

N-Formyl-methionyl-leucyl-phenylalanine (fMLP) and leukotriene B4 stimulate human polymorphonuclear neutrophils (PMN) to translocate protein kinase C from the cytosol to plasmalemma as judged by their abilities to increase PMN binding of and receptor numbers for [3H]phorbol dibutyrate [( 3H]PDB) (O'Flaherty, J.T., Jacobson, D.P., Redman, J.F., and Rossi, A.G. (1990) J. Biol. Chem. 265, 9146-9152). Platelet-activating factor (PAF) had these same effects. Moreover, two potent PAF analogs (but not an inactive analog) increased [3H]PDB binding; a PAF antagonist blocked responses to PAF without altering those to fMLP; and PMN treated with PAF became desensitized to PAF while retaining sensitivity to fMLP. Indeed, PMN incubated with 1-100 nM PAF for 5-40 min had markedly enhanced [3H]PDB binding responses to fMLP. PAF thus acted through its receptors to stimulate and prime protein kinase C translocation. Its effects, however, did not necessarily proceed by a standard mechanism: Ca2(+)-depleted PMN failed to raise Fura-2-monitored cytosolic Ca2+ concentrations [( Ca2+]i), yet increased [3H]PDB binding and receptor numbers almost normally after PAF challenge. PAF also primed Ca2(+)-depleted PMN to fMLP. Nevertheless, [3H]PDB binding responses to PAF were blocked in PMN loaded with Ca2+ chelators, viz. Quin 2, Fura-2, or 5,5'-dimethyl-1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Exogenous Ca2+ reversed Quin 2 inhibition, and a weak chelator 4,4'-difluoro-BAPTA, lacked inhibitory actions. The chelators similarly influenced fMLP and leukotriene B4. Thus, PMN can by-pass [Ca2+]i to translocate protein kinase C. They may achieve this using a regulatable pool of Ca2+ that evades conventional [Ca2+]i monitors or a signal that needs cell Ca2+ to form and/or act. This signal may mediate function in Ca2(+)-depleted cells, the actions of [Ca2+]i-independent stimuli, cell priming, and protein kinase C movements that otherwise seem [Ca2+]i-induced.

[3H]Phorbol dibutyrate [( 3H]PDB) rapidly and reversibly binds to human polymorphonuclear neutrophils (PMN). Ca2+/diacylglycerol/phospholipid-dependent protein kinase C appeared to be the receptor for this binding because: a diacylglycerol, dioctanoylglycerol, competed with [3H]PDB for PMN binding sites; a blocker of protein kinase C-phospholipid interactions, sphinganine, inhibited PMN binding of [3H]PDB; and changes in cytosolic Ca2+ apparently regulated PMN binding of the label. Relevant to the last point, disrupted PMN contained 9 X 10(5) phorbol diester receptors/cell, whereas intact PMN had only 1.6 X 10(5) such receptors that were accessed by the ligand. This number fell to 1.0 X 10(5) in Ca2(+)-depleted PMN and rose to 2.5 X 10(5) in cells stimulated with the Ca2+ ionophore, ionomycin. This ionomycin effect lasted for greater than 16 min, correlated temporally with changes in cytosolic Ca2+, did not occur in Ca2(+)-depleted PMN, and was blocked by sphinganine. A second ionophore, A23187, likewise induced Ca2(+)-dependent rises in [3H]PDB binding. These results fit the standard model, wherein rises in cytosolic Ca2+ cause protein kinase C to translocate from cytosol to plasmalemma and thereby become more available to [3H]PDB. In contrast, two humoral agonists, N-formyl-Met-Leu-Phe (fMLP) and leukotriene (LT)B4, had actions that did not fit this model. They stimulated PMN to increase the availability of PDB binding sites by a sphinganine-sensitive mechanism, but their actions differed from those of ionophores. They induced biphasic (t = 15 and 60 s) increases in [3H]PDB binding while eliciting monophasic (t = 15 s), short-lived (t less than 1 min) rises in cytosolic Ca2+. In Ca2(+)-depleted PMN, moreover, fMLP and LTB4 stimulated slow (t greater than or equal to 30 s), monophasic, prominent rises in [3H]PDB binding and binding site number without appreciably altering cytosolic Ca2+. We suggest, therefore, that fMLP and LTB4 translocate protein kinase C using two sequential mechanisms. The first involves Ca2+ transients and thus produces abrupt (t = 15 s), rapidly reversing responses. The second mechanism uses an unrelated signal to effect a more slowly evolving (t = 60 s) movement of protein kinase C to plasmalemma. Hence, the standard model does not explain all instances of protein kinase C translocation, and a cytosolic Ca2(+)-independent signal contributes to the regulation of protein kinase C as well as those responses elicited by the effector enzyme.

With the exception of stress incontinence, the most common urologic problems unique to female patients are vesicovaginal fistulas and urethral diverticula. The author describes modifications of a Foley catheter both to facilitate distention of the vagina for vaginoscopy and for urethrography and use of the visual urethrotome for urethroscopy.

Simplistically, the examination of the genitalia of the female child is uncomplicated, as is vesical catheterization, and should be. However, without attention to gentleness, understanding, and a well-thoughtout uncomplicated plan of action, the examination and manipulation can be an ordeal for the child, the parent, and the examiner. Adherence to the techniques of examination and instrumentation as described should obviate trauma to the child, both psychologically and physically, and greatly improve the diagnostic value of the procedures.

There is a need for operations by which the complications of ileal conduits can be prevented or corrected. The author details techniques to ensure the formation of a short conduit, to shorten a conduit through a peristomal incision, and to correct ileocutaneous stomal stenosis.

The author details the technique of the scrotal pouch orchiopexy. As described, the operation has been used in more than 200 consecutive orchiopexies with no scrotal hematomas, testicular atrophy, or retraction of the testes.

Penile myointimoma is a rare benign myointimal proliferation occurring exclusively within the corpus spongiosum of the glans penis and is most commonly described in adult patients. To date, there is only one reported series of 10 penile myointimomas plus one case report, representing a total of 8 adults and 3 children/adolescents. We report 5 penile myointimomas occurring in 5 patients less than 18 years of age (age range 4 to 15 y). All patients presented with a mass lesion on the glans penis ranging in size from 0.4 to 1.8 cm. All 5 lesions had the classic morphologic appearance: myointimal proliferation of the preexisting vascular spaces of the corpus spongiosum, creating a multinodular/plexiform architecture. Immunohistochemically, all stained cases showed strong cytoplasmic immunoreactivity for smooth muscle actin in the lesional cells and a collarette of native smooth muscle highlighted by desmin. None of the lesions appeared completely excised, but all 5 patients were clinically free of disease at last clinical follow-up (2 to 45 mo). In summary, we report only the second series of this distinctive, relatively rare myointimal proliferation within the corpus spongiosum of the glans penis, expand the number of published cases occurring in the pediatric/adolescent population, and confirm the benign clinical course after a marginal or incomplete excision.

The term "buried penis" has been applied to a variety of penile abnormalities and includes an apparent buried penis that is obvious at birth. The purpose of this study was to examine prospectively the congenital buried penis and to evaluate an operative technique for its management.A total of 31 males 2 to 28 months old (mean age 12.3 months) with a congenital buried penis underwent surgical correction of the anomaly. Measurements were made of the penile shaft skin, inner leaf of the prepuce, glans length and stretched penile length. Observations of the subcutaneous tissue of the penis were made. The outer leaf of the prepuce was resected, following which covering of the penile shaft was accomplished with a combination of the penile shaft skin and the inner leaf of the prepuce.Stretched penile lengths ranged from 2.3 to 4.1 cm (mean 3.1). The glans length from the tip of the glans dorsally to the corona ranged from 0.9 to 1.6 cm (mean 1.2). The inner leaf of the prepuce ranged from 0.9 to 2.2 cm (mean 1.5) in length, while the dorsal penile skin lengths were 1 to 1.6 cm (mean 0.8). In all patients complete shaft coverage was accomplished using a combination of varying degrees of penile shaft skin and inner leaf of the prepuce. In no case was there a requirement for either unfurling of the inner and outer leaf of the prepuce or mobilization of scrotal flaps to accomplish shaft coverage. All patients healed well and have done well with a followup of 6 months to 1 year.Congenital buried penis is a syndrome consisting of a paucity of penile shaft skin and a short penile shaft. The anomaly may be successfully repaired by carefully preserving a length of inner leaf of the prepuce sufficient to cover, in some instances, the length of the penile shaft. Anchoring of the penile skin to the shaft is not recommended.

Purpose: We performed a prospective study to assess the relationship between epididymal anomalies and patency of the processus vaginalis in boys presenting with hernia, hydrocele or cryptorchidism.Materials and Methods: The degree of patency of the processus vaginalis (closed, partially closed or open) and morphology of the ipsilateral epididymis were recorded in 159 consecutive inguinal explorations.Results: A closed, partially closed and open processus vaginalis was associated with an abnormal epididymis in 14, 36 and 69 percent of cases, respectively. Epididymal anomalies were more frequent in association with undescended (72 percent) than descended (34 percent) testes.Conclusions: These data confirm the observation of a higher incidence of epididymal anomalies associated with patency of the processus vaginalis irrespective of testicular position, and they support the theory that androgenic stimulation may be required for closure of the processus vaginalis as well as epididymal development.

Purpose: We reviewed the results of a large series of hypospadias repairs (311) using the modified Barcat balanic groove technique.Materials and Methods: All patients who underwent modified Barcat repair with closure of the divergent corpus spongiosum were included in our study and were seen or contacted for postoperative followup.Results: Of 295 patients available for followup 94 percent had excellent cosmetic results. The fistula rate after primary repair was 5 percent for a glanular or coronal meatus and 18 percent for a penile meatus, and meatal stenosis was rare. After secondary repair complications were common in patients with a penile meatus.Conclusions: The Barcat technique allows anatomically superior glans reconstruction in distal hypospadias repair. Fistula rates can be reduced by tissue coverage of the neourethra.

Wetting disorders in children can be frustrating for the patient, his parents and the physician caring for him. Although in most children the urinary incontinence will resolve with maturation, it is the persistent wetter that is brought in for management. There are two main categories of wetting disorders: those associated with neurological dysfunction of the lower urinary tract (neurogenic bladder) and those with normal neurological function (voiding dysfunction). This communication will be limited to the features, evaluation and management of voiding dysfunction.

7-year-old boy was referred for management of a congenital posterior urethral polyp after undergoing an evaluation for acute urinary retention. The child had no antecedent history of hematuria, urinary tract infection, or voiding dysfunction. An ultrasound examination of the kidneys and bladder showed them to be normal. Contrast cystography showed two diverticula with an otherwise smooth bladder wall. The patient was unable to void, and therefore, the urethra was not visualized by cystourethrography. Endoscopy of the urethra demonstrated a large posterior urethral polyp arising by a broad base from the verumontanum with the preponderance of the polyp occluding the vesical neck (Fig. 1). The bladder was smooth walled with the exception of two wide-mouthed diverticula. The ostium of the left diverticulum was on the posterior lateral wall, just cranial to the left ureteral orifice. The right-sided diverticulum was of the Hutch variety. The polyp was managed by a transurethral incision of its base with a narrowtipped electrode, using the cutting mode and cutting across the base of its stalk. The polyp was retrieved from the bladder with a stone basket. The child voided spontaneously and returned home immediately after surgery. A subsequent voiding cystourethrogram showed a normal urethra with the diverticula smaller and emptying with voiding. Posterior urethral polyps are rare, with sporadic reports of small series of cases. 1‐3 Histologically, the polyps are composed of smooth muscle covered by transitional epithelium, as in our patient. 2 Symptoms include hematuria, intermittent obstruction, obstructive voiding complaints, or urinary retention. 2,3 The evaluation consists of renal and bladder ultrasonography, contrast voiding cystourethrography, and endoscopy of the urethra

Urinary tract infections can result in significant morbidity and represent one of the most common urological conditions that the pediatrician and family practitioner encounter in the pediatric patient population. The prevalence of UTI in girls may be as high as 8.1%. UTIs also represent the most commonly identified serious bacterial infection in infants presenting with a febrile illness. Of febrile infants aged 2-3 months, 3-10% have a documented UTI. While the majority of the UTIs are not associated with any significant underlying conditions, the mere presence of a UTI is worrisome to most parents. An appropriate evaluation will determine which of these patients need referral. A brief summary is therefore presented to assist the primary care physician in the evaluation and management of childhood UTIs.

Bilateral single ureteral ectopia is exceedingly rare, with fewer than 80 cases reported. Fewer than 20 cases have been reported in males. We describe a recent patient with bilateral single ureteral ectopia with bilateral megaureter and ureteral orifices opening into the prostatic urethra.

Objectives. To report a recent consecutive series of children undergoing open renal and upper ureteral surgery that was analyzed for outcomes, particularly morbidity and length of stay. Methods. A total of 64 children underwent open renal or upper ureteral surgery using an upper abdominal retroperitoneal approach. Results. The mean operation time was 206 minutes, with a mean estimated blood loss of 20 mL. The mean analgesic dosage during the in-house postoperative period was 2.9 doses. The mean length of stay was 21.3 hours. A single complication occurred. One patient had a postoperative temperature of 38.6°C, which was attributed to a pulmonary causation. Conclusions. For now, open surgery remains the standard approach for pediatric renal and upper ureteral anomalies and diseases with an expected postoperative result and course similar to that of laparoscopically performed procedures.

The presentation of a boy with an acutely painful scrotum is often associated with a history of trauma. Two recent patients with a history of scrotal trauma and an enlarged hemiscrotum were found on surgical exploration to have unusual causes for the scrotal enlargement. In the first case, there was bleeding from omentum in an incarcerated inguinal hernia, and in the second, there was bleeding into a scrotal cystic lymphangioma. Fewer than 40 cases of scrotal lymphangioma have been reported.

Reports of single chromosome aberrations in Wilms' tumors are rare, with most tumors being characterized by multiple complex karyotype aberrations. An 11-month-old female patient with Wilms' tumor and a derivative chromosome 7 resulting from t(7;7)(p13;q21) as the sole cytogenetic aberration is described.

Meconium peritonitis may result in a number of genital manifestations, including inguinal and scrotal or labial hydrocele containing meconium or calcifications and hard tumor-like scrotal masses.1–3 We describe a patient with an unusual sequela of meconium peritonitis involving massive extension of a processes vaginalis to the contralateral anterior abdominal wall. To our knowledge this condition has not been reported previously.

A dressing technique for hypospadias repair is presented in detail which permitsimmediate release of the patient from the hospital and increased mobility for him at home.

Congenital scrotal anomalies are unusual, with ectopic and accessory scrota being the most rare. Scrotal ectopia, which has been described as resulting from an abnormal migration of the ipsilateral labioscrotal fold, is usually obvious and easily diagnosed in infancy.1 An 18-year-old male remained without diagnosis until exercise induced orchalgia led to the identification of an ectopic scrotum, which was a factor in the origin of the discomfort. The diagnosis and management of this case are described.

Cystic dysplasia of the testis is a rare congenital anomaly, only 29 cases having been previously reported. We report a case of cystic dysplasia of the testis and absent ipsilateral kidney, but an ipsilateral ectatic terminal ureter, suggesting involution of a dysplastic kidney as a reason for the apparent renal agenesis.

A severe form of hemorrhagic cystitis occurs when high doses of cyclophosphamide are administered before bone marrow transplantation. Severe vesical bleeding in male children is difficult to manage because the small urethra precludes the use of large catheters for bladder irrigation and clot removal. We report on the use of cutaneous vesicostomy with the instillation of 4% formalin to control bleeding in 3 boys.

Occasionally catheterization of a male infant or young boy may be exceedingly difficult following previously failed attempts. A useful technique for catheterization is described that involves stainless steel suture as a guide.

Three instances of perineal testes are described including the fourth reported case of bilateral perineal testes. In each instance the course of the cremasteric muscle was traced distally and was found to terminate in the perineum. It is suggested that if the cremasteric muscle forms in the periphery of the gubernaculum, then the cremasteric muscle should be indicative of the course and the termination of the gubernaculum.

Urethral fistulas are an inherent risk of hypospadias repair. Present-day repairs of hypospadias in which redundant skin is held to a minimum limit the applicability of skin flap advancement technique for closure. To avoid altering the cosmesis of the prior hypospadias repair, 51 urethrocutaneous fistulas were closed using a three-layer simple closure technique without urinary diversion. An 80 percent success rate was achieved following the initial closure. A second simple closure of those which failed also succeeded in 80 percent of the cases.

Vasal atresia is thought to be a contraindication to the successful performance of the Fowler-Stephens orchiopexy. A patient with the prune belly syndrome and a high intra-abdominal testis with segmental vasal atresia was managed by incision and ligation of the internal spermatic vessels followed by orchiopexy without testicular atrophy.

Vascular lesions of the scrotum other than varicocele are rare and include hemangioma, and lymphatic and arteriovenous anomalies. The continued use of outdated nomenclature has hampered meaningful comparisons among reported cases. We report on 2 boys with discrete venous abnormalities of the scrotum. To our knowledge these distinctive focal lesions have not previously been described in the scrotum.

Previous studies have concluded that cytosolic Ca2+ [(Ca2+]i) transients are essential for neutrophils (PMN) to degranulate and make superoxide anion when challenged with the receptor agonists N-formyl-methionyl-leucyl-phenylalanine, platelet-activating factor and leukotriene B4. This view is based on the profound unresponsiveness of PMN that have their [Ca2+]i fixed at resting levels by removing storage Ca2+ and loading the cells with greater than or equal to 20 microM of a Ca2+ chelator, quin2 AM. We too observed this unresponsive state in PMN loaded with 10-32 microM-quin2 AM, fura-2 AM or 1,2-bis-(2-aminophenoxy) ethane-NNN'N'-tetra-acetic acid (BAPTA). When loaded with less than or equal to 1 microM fura-2 AM, however, Ca(2+)-depleted PMN failed to alter [Ca2+]i appreciably, yet still had substantial degranulation and superoxide-anion-generating responses to the receptor agonists. Function thus did not require [Ca2+]i transients. Moreover, Ca(2+)-depleted PMN had 20-35% decreases in receptor numbers for each of the three agonists, and chelator loading of these cells decreased receptor availability by 30-50%. All receptor losses were reversed by incubating PMN with Ca2+ at 37 degrees C, but not at 4 degrees C, and agonist binding at 4 degrees C was not influenced by the presence or absence of extracellular Ca2+. Ca2+ thus caused PMN to up-regulate their agonist receptors at 37 degrees C, and the effect persisted at 4 degrees C regardless of ambient Ca2+. We conclude that Ca2+ acts in at least three ways to regulate responses to receptor agonists. First, some pool of (probably cellular) Ca2+ maintains receptor expression. Second, [Ca2+]i transients potentiate, but are not required for, function. The [Ca2+]i pool may or may not be the same as that influencing receptors. Finally, another pool(s) of Ca2+ signals or permits responses. This last pool, rather than [Ca2+]i transients, appears essential for the bioactions of standard Ca(2+)-mobilizing stimuli.