5 alpha-dihydrotestosterone formation is necessary for embryogenesis of the rat prostate

To determine the role of 5 alpha-dihydrotestosterone (DHT; 17 beta-hydroxy-5 alpha-androstan-3-one) in formation of the embryonic prostate, we quantitated prostatic development in urogenital tracts of control male newborn and offspring of rats treated with a specific 5 alpha-reductase inhibitor (L652,931; Merck, Sharp, and Dohme) during prostate morphogenesis. Treatment with the 5 alpha-reductase inhibitor (50 mg/kg.day) from days 14-22 of gestation impaired development of the prostate and virilization of the external genitalia in male offspring compared to those in control animals. However, virilization of the internal genitalia (seminal vesicles, epididymis) was unaffected. Simultaneous administration of DHT (50 mg/kg.day) with the 5 alpha-reductase inhibitor restored prostate development and anogenital distances of males to normal and virilized the external genitalia of females. We conclude that DHT is the active androgen responsible for prostatic development in the rat.

Change of mosaic pattern by androgens during prostatic bud formation in XTfm/X+ heterozygous female mice

The testicular feminization (Tfm) gene, which is characterized by a deficiency in androgen receptors, is located on the X-chromosome. Using steroid autoradiography, the mosaicism of the Tfm gene has been demonstrated in the androgen target tissues of XTfm/X+ heterozygous female mouse fetuses and the effects of androgens on the mosaic pattern analysed. In the mesenchyme of urogenital sinuses of wild-type female fetuses (X+/X+), more than 95% of the cells were androgen-receptor positive (labelled with [3H]testosterone) while in that of heterozygous fetuses (XTfm/X+), only half of the cells were receptor positive (Tfm gene inactive), and receptor-positive cells and -negative cells formed small irregular patches. When the heterozygous sinuses were cultured in vitro in the presence of androgens, the sinuses underwent male sexual development and formed epithelial buds (prostate gland rudiments) projecting into the surrounding mesenchyme. Autoradiographic analysis revealed that the mosaicism of the mesenchyme disappeared around the developing epithelial buds: almost all the mesenchymal cells in close vicinity to the buds were receptor positive while in the outer layers receptor-positive and -negative cells coexisted. The proportion of receptor-positive cells was greatly increased in the mesenchyme beneath the non-budding area of the sinus epithelium. This androgen-induced increase was observed before the onset of bud formation. The results obtained in the thymidine incorporation experiments suggest that the increase of receptor-positive cells beneath the sinus epithelium might be explained by the migratory behaviour of the androgen-incorporating cells rather than by their selective proliferation.

Hormonal replacement therapy: benefits, risks, doses

This chapter presents information on the indications for the use of post menopausal hormone therapy. Side effects and risks of this form of therapy are also summarized. Recommendations are made concerning the clinical management of patients receiving hormone treatment.

[General pharmacological studies on isepamicin sulfate (HAPA-B)]

General pharmacological properties of isepamicin sulfate (HAPA-B), a new aminoglycoside antibiotic, were studied in animals and the results obtained were summarized below. Intramuscular injections of HAPA-B at doses of 500 mg/kg inhibited the writing response induced by acetic acid, and at doses of 1,000 mg/kg, caused muscle relaxation, respiratory depression, suppression of spontaneous motor activity and prolongation of thiopental anesthesia. Anticonvulsive action and the effect on the rectal temperature were not observed. Intravenous Intravenous HAPA-B showed no significant effect on the general behavior and the function of the central nervous system at doses of 100 mg/kg. Intravenous injections of HAPA-B to anesthetized dogs resulted increases in the femoral arterial blood flow at doses of 12.5 mg/kg, decrease in the blood pressure and increase in the respiratory rate at doses of 25 mg/kg, and increase in the carotid arterial blood flow at doses of 50 mg/kg. Apparent changes were not recognized in the heart rate and electrocardiograms. In conscious rabbits, intravenous HAPA-B produced increases in the heart rate without significant changes of the blood pressure and electrocardiograms at doses of 100 mg/kg. Spontaneous beatings of isolated atria were depressed by HAPA-B in concentrations of 3 X 10(-4) to 10(-3) g/ml. The HAPA-B inhibited the gastric secretion at intramuscular doses of 500 mg/kg or intravenous doses of 100 mg/kg, and depressed charcoal transport through small intestine and the spontaneous movement of isolated ileum at intramuscular doses of 1,000 mg/kg and at concentrations of 3 X 10(-4) to 10(-3) g/ml, respectively. No irritative effect was found on the gastric mucous membrane. Intravenous HAPA-B inhibited the response of nictitating membrane to pre and post ganglionic stimulations of cervical sympathetic nerve at doses of 100 mg/kg. In in vitro test, HAPA-B inhibited nonspecifically the constrictive responses of trachea, aorta, stomach, ileum and vas deferens to various agonists in concentrations of 3 X 10(-4) to 10(-3) g/ml. Spontaneous movements of uteri of estrous or pregnant animals were depressed by HAPA-B at intravenous doses of 50 to 100 mg/kg and in in vitro at concentrations of 10(-4) to 3 X 10(-4) g/ml. Antidiuretic effect was also observed at intramuscular doses of 250 mg/kg. HAPA-B increased the length of the whole blood clotting time and raised the plasma glucose level at intramuscular doses of 1,000 mg/kg and inhibited the platelet aggregation induced by ADP in vitro at concentrations of 10(-3) g/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Expression of nuclear estrogen-binding sites within developing human fetal vagina and urogenital sinus

An autoradiographic study of nuclear estrogen binding was performed in developing human urogenital sinuses and vaginas derived from first and second trimester specimens. Nuclear estrogen binding was detected in all specimens greater than or equal to 10 weeks of gestation within mesenchymal cells. Nuclear labelling within epithelium was observed only in those specimens whose development and differentiation was advanced. Thus, mesenchyme appears to be the initial estrogen target tissue within the developing human vagina and may play a fundamental role in estrogen-induced teratogenesis of the human genital tract.

Effect of estrogen and progesterone treatment on calcium uptake by the myometrium and smooth muscle of the lower urinary tract

In order to elucidate the mechanisms by which estrogen treatment increases uterine contractility, the effect of estrogen on Ca uptake was measured in the isolated rabbit uterus as well as in the urethra and urinary bladder. Estrogen treatment more than doubled the amount of cellular Ca uptake in the uterus during both rest and potassium-induced depolarization. Combined estrogen and progesterone treatment had a similar effect to estrogen alone. In both urinary bladder and the urethra, treatment with estrogen alone, or estrogen combined with progesterone had no effect on Ca uptake. Cellular Ca uptake was higher in uteri of rabbits subjected to progesterone withdrawal than in those that were under progesterone dominance. It is concluded that estrogen-induced increase in Ca entry into the uterine smooth muscle cells is a likely mechanism underlying increased uterine contractility. Since this effect of estrogen was not antagonized by progesterone, it may not strictly rely on the genomic action of estrogen. The increase in cellular calcium following progesterone withdrawal could be one of the mechanisms for the evolution of myometrial activity at parturition.

Steroid-induced urogenital tract changes and urine retention in laboratory rodents

Since previous literature suggested that estrogen-treated male mice are models for human benign prostatic hypertrophy, a series of studies was designed to examine urine retention and urogenital tract changes in rodents given chronic estradiol-17 beta (E) and dihydrotestosterone (DHT) treatments. In Study 1, intact and castrate male mice received E, DHT or E plus DHT for four weeks via subcutaneous Silastic capsules. Bladder urine volume increased in the groups given E and this effect was not altered by castration, DHT or removal of E capsules two weeks before necropsy. Estrogen treatment also increased mortality. In Study 2, intact male, intact female, adrenalectomized (Adx) male and sham Adx male mice received 16 weeks of steroid treatments. Bladder urine volume increased in all E treated groups regardless of sex or Adx. Hydronephrosis, hydroureter and increased mortality were found in the E treated mice of both sexes. Estrogen induced epithelial changes and edema of the prostate, vas deferens and the utriculus prostaticus. In further studies male rats, hamsters and guinea pigs were given several different dosages of E but no evidence of urine retention or increased mortality was found. Taken together these studies suggest that E-induced urine retention is unique to mice. Although urine retention and hydronephrosis found in the mice were similar to those in humans with BPH, the lesion that results in the urine obstruction is not similar.

Leukotrienes C4, D4 and E4 cause widespread and extensive plasma extravasation in the guinea pig

Intravenous injection of leukotriene C4 (1 nmol X kg-1) caused substantial plasma exudation in anesthetized guinea pigs, as evidenced by marked hemoconcentration 15% in 5 min) and significant extravasation of Evans blue. Fluorometric quantitation of Evans blue content in 38 selected tissues documented that leukotriene C4 caused significant plasma extravasation throughout the body, except for the brain, stomach, duodenum, colon and gonads. In particular, the respiratory and the uro-genital tracts, but also the conjunctiva, the esophagus, the bile ducts and the umbilical ligaments, were very sensitive to the edema-promoting effect of leukotriene C4. Intravenous injection of leukotriene D4 (1 nmol- X kg-1) or E4 (5 nmol X kg-1) evoked plasma extravasation with a distribution and magnitude that was similar to that induced by leukotriene C4. It is concluded that the three major constituents of slow reacting substance of anaphylaxis (SRS-A), leukotrienes C4, D4 and E4, cause a generalized and extensive plasma exudation that is consistent with the proposal that these leukotrienes are important mediators of inflammation.

Transdermal hyoscine (Scopolamine). A preliminary review of its pharmacodynamic properties and therapeutic efficacy

Hyoscine (scopolamine) is a competitive inhibitor of the muscarinic receptors of acetylcholine and it has been shown to be one of the most effective agents for preventing motion sickness. However, a relatively high incidence of side effects and a short duration of action has restricted the usefulness of this agent when administered orally or parenterally, and to counter this a novel transdermal preparation of hyoscine has been developed. Pharmacokinetic studies indicate that this new method for administering hyoscine controls the absorption process and the rate of drug entry into the systemic circulation over an extended period (72 hours), providing a means of delivery which is similar to a slow intravenous infusion. However, recent evidence suggests that the response to transdermal hyoscine treatment is variable and this may reflect pharmacokinetic differences between individuals. Controlled therapeutic trials have indicated that a single transdermal hyoscine patch is significantly superior to placebo and oral meclozine (meclizine) in preventing motion sickness. Trials comparing transdermal hyoscine with oral dimenhydrinate have failed to establish any significant differences in efficacy between the 2 drugs in small numbers of subjects, although there was always a more favourable trend towards the transdermal system. In patients with acute vertigo, transdermal hyoscine and oral meclozine were equally efficacious and both were significantly better than placebo in reducing the number of attacks of vertigo. Although transdermal hyoscine has been associated with a lower incidence of side effects than orally or parenterally administered hyoscine hydrobromide, adverse systemic effects have still been frequently reported. Most commonly cited have been dry mouth, drowsiness and impairment of ocular accommodation, including blurred vision and mydriasis (some ocular effects reported may be due to finger-to-eye contamination). Adverse central nervous system (CNS) effects, difficulty in urinating, rashes and erythema have been reported only occasionally. Thus, preliminary evidence suggests transdermal hyoscine may offer an effective and conveniently administered alternative for the prevention of motion-induced nausea and vomiting in certain situations. However, the duration of its clinical effectiveness, and its relative efficacy and tolerability compared with other agents needs to be confirmed in a few additional well-designed studies.

Effects of sterilized micropulverized barium sulfate suspension and meglumine iothalamate solution on the genitourinary tract of healthy male dogs after retrograde urethrocystography

A sufficient quantity of 30% w/v sterile barium sulfate suspension was infused into the caudal portions of urinary tracts of 12 young adult healthy male Beagles to induce vesicoureteral reflux. A control group of dogs was infused with a 7.5% solution of meglumine iothalamate. The dogs were radiographed at 1, 6, 13, and 29 days later. Three dogs from each group were euthanatized and necropsied (1 each) after radiography at each of these times. In some dogs, radiopacity in the prostate, urinary bladder, and renal pelvic diverticula due to barium persisted throughout the 30-day observation period. Opacity at or beyond 24 hours was not found in dogs infused with iothalamate. Light microscopy revealed barium either free or within macrophages in the submucosa of the bladder, in glandular and stromal areas of the prostate, and in the kidney. Renal barium was limited to pelvic diverticula (3 dogs), in a medullary tubule (1 dog), and in cortical tubules (2 dogs). Significant lesions attributable to barium were not seen in kidneys of dogs in the barium group. Iothalamate induced focal to multifocal inflammatory responses in some prostates; barium was phagocytosed by macrophages. Focal transient inflammatory and ulcerative lesions induced by bladder distention were observed in the bladder and urethral mucosa in both groups.

Radiologic diagnosis of diethylstilbestrol induced teratogenesis in rats

Radiographs were used for the assessment of diethylstilbestrol-induced teratogenesis of the urogenital system of rats. Lesions such as female hypospadias were demonstrable with a 4:1 magnification of radiographs that were not observed using subgross dissection and histologic step sections.

The comparative effects of 1,2-dibromo-3-chloropropane (DBCP) and its metabolites, 3-chloro-1,2-propaneoxide (epichlorohydrin), 3-chloro-1,2-propanediol (alphachlorohydrin), and oxalic acid, on the urogenital system of male rats

Reported similarities in the acute toxic effects of 1,2-dibromo-3-chloropropane (DBCP), 3-chloro-1,2-propaneoxide (epichlorohydrin, ECH), 3-chloro-1,2-propanediol (alphachlorohydrin, ACH), and oxalic acid (OA) have been suggested as presumptive evidence that the metabolism of DBCP to OA, via ECH and ACH, is the cause of the resulting injuries to the kidney and, perhaps, to the epididymis and testis. To test this hypothesis, the comparative toxicities of these four chemicals were studied in male rats after single subcutaneous (sc) injections of maximally tolerated (nonlethal) doses. Kidney, testicular, and liver functions were monitored, and the occurrences of morphological changes in these and several other organs were evaluated 24 hr, 3, 8, 25, and 75 days post-treatment. DBCP caused renal dysfunction (alterations in urine composition and reduced glomerular filtration rate) and marked necrosis of the proximal tubular epithelium in the outer medulla of the kidney. ACH and OA also elicited renal dysfunction, but ACH produced only a mild swelling of the proximal tubular epithelium in the renal cortex and OA produced a focal necrosis anatomically associated with crystal deposition. ECH caused a swelling of the proximal tubular epithelium in the renal cortex, but not frank kidney dysfunction. DBCP also caused a reversible vacuolization of the tubular epithelium in the caput epididymis, progressive testicular atrophy, and a reduction of cauda epididymal sperm concentration. ACH and ECH produced similar effects, as well as epididymal sperm granulomas, spermatocoeles, and an increase in the number of morphologically abnormal spermatozoa. OA failed to produce discernible epididymal or testicular lesions at any time during the study. The development of similar lesions in the epididymis and testis following DBCP, ECH, or ACH treatments is consistent with the theory of metabolism of these chemicals to a common causative gonadotoxic agent. Oxalic acid (OA), however, would not appear to be the common gonadal toxicant. Differences in the effects, both morphological and functional, of DBCP, ECH, ACH, and OA on the kidney, moreover, indicate that DBCP nephropathy is not mediated through metabolism to OA and suggest, as well, that it differs causally from that induced by ECH or ACH. Therefore, the metabolism of DBCP to ECH or ACH, and of ECH or ACH to OA, is insufficient to explain totally the toxic effects of these agents on the urogenital system in male rats.

Late effects of treatment of cancer in children

Advances in surgical techniques, in chemotherapy, and in radiation therapy have led to improved survival in children treated for cancer. Children cured of cancer will soon form a significant fraction of our adult population. As we follow such survivors, we have become more aware of long-term side effects of treatment. This is not a reason to withhold therapy. Instead, careful followup of oncology patients is needed to document the late effects, to identify the etiologic agents, and to alter treatment to give the least toxic therapy without sacrificing quality or duration of survival.

[General pharmacology of traxanox sodium. I. Effects on the central, somatic, and autonomic nervous systems, digestive system, urologic organs, and reproductive system]

Traxanox at the upper dose of 300 mg/kg, p.o., showed no effect on the somatic and autonomic nervous systems in the various tests. This agent caused some relaxation of the guinea pig tracheal strip in the resting tone at a concentration of 10(-6)M or more; however, its activity was less potent than that of isoproterenol and paraverine. Traxanox had no competitive antagonistic action against chemical mediators. Treatment of rats with this agent (3 mg/kg, i.v., or 10 mg/kg, s.c.) resulted in an inhibition of gastric (acid) secretion. Intravenous injections of traxanox (1-10 mg/kg) in dogs caused an immediate but transient inhibition of gastric and jejunal movement, and after a short time, slight potentiation of the latter; however, pretreatment with atropine prevented this latter potentiation. In the in vitro test, 10(-4)M traxanox caused contraction of the guinea pig ileum, a response which was inhibited by atropine. Traxanox (300 mg/kg, p.o.), however, did not show any effects on gastrointestinal propulsion in mice, nor did it have any effect on the gastrointestinal mucosa, gastric ulcers or bile secretion in rats. Traxanox (300 mg/kg, p.o.) showed a diuretic action in both normal and adrenoectomized rats. This action, however, was not observed in the rats treated with indomethacin (1 mg/kg, i.p.). This agent (10 mg/kg, i.v.) suppressed the spontaneous uterine contractions of pregnant rats in some cases. These findings suggest that traxanox at doses (1-5 mg/kg, p. o.) showing antiallergic activity has little effect on the central, somatic and autonomic nervous systems, digestive system, urinary organs and reproductive organs.

Phosphodiesterase activity of the lower urinary tract

Cyclic AMP is believed to mediate the physiologic response of beta-receptor stimulation in the lower urinary tract. A possible novel therapy for specific dysfunctions might be via pharmacologic modification of cyclic AMP through regulation of phosphodiesterase, the enzyme responsible for metabolizing cyclic AMP. The present study characterizes the phosphodiesterase activity present in various sections of the lower urinary tract and determines the effect of calmodulin and the potency of a series of phosphodiesterase inhibitors. The results can be summarized as follows: the phosphodiesterase activity of all smooth muscle sections of the lower urinary tract were similar. They showed nonlinear kinetics with Vmax between 1.0 and 2.4 nmol./mg. protein/minute and apparent Km's around 100 microM. The external sphincter (skeletal muscle) displayed linear kinetics with a Vmax of 0.2 nmol./mg. protein/minute and a Km of 9 microM. Of the drugs tested, papaverine was the most potent inhibitor and theophylline was one of the weakest inhibitors. These studies also indicate that the major form of cyclic AMP phosphodiesterase is not sensitive to calmodulin.

[General pharmacology of 6-amino-2-fluoromethyl-3-(o-tolyl)-4(3H)-quinazolinone (afloqualone), a new centrally acting muscle relaxant. II. Effects on the peripheral system (author's transl)]

The general pharmacology of afloqualone, a new centrally acting muscle relaxant, in the peripheral system, was examined in laboratory animals and findings compared with those of some other central muscle relaxants. Afloqualone dose dependently inhibited respiration, lowered arterial blood pressure, decreased heart rate, and slightly increased femoral and renal arterial blood flow in parallel with hypotension, at doses of 1 or 2 to 20 mg/kg iv. in anesthetized cats. Afloqualone also inhibited cardiac movement in situ in anesthetized rabbits and decreased internal pressure in the urinary bladder in anesthetized cats. In in vitro experiments, afloqualone inhibited spontaneous movements of isolated rabbit atrium and ileum and isolated rat uterus at considerably high concentrations of 10(-6) g/ml or more. Oral administration of afloqualone, however, had no significant influence on respiration, the cardiovascular, digestive, and autonomic nervous systems, and urogenital organs, at doses up to 50 mg/kg except for a comparatively potent inhibitory effect on carrageenin-induced paw edema in rats. Afloqualone induced neither surface nor infiltration anesthesia.

The use of birth control pills in women with medical disorders

Since little absolute data exist in the form of large prospective studies in patients with specific illnesses who are on oral contraceptives, the clinician must rely on well-founded empiric decisions in prescribing the pill for these patients. The decision should be based on a firm understanding of the pathophysiology and laboratory effects of the oral contraceptives. This must be juxtaposed with an understanding of the efficacy and effects of the estrogen and progestational components of the birth control pill and their interactions with maintenance medications. In the final analysis, though, the clinician must rely on a trial and error method in treating these patients. It must be stressed, however, that these women require careful monitoring, both clinically and biochemically. It is comforting to note that in all diseases studied to date, the use of birth control pills has not precipitated a catastrophic change.

The apparent inhibition of urothelial DNA synthesis in neonatal rats by dietary saccharin

[3H]Thymidine ([3H]TdR) incorporation into urothelial DNA of male neonatal rats was measured autoradiographically at birth and during the first 3 weeks of life. The rats were derived from control parents and those fed saccharin (1, 3, 5 and 7.5%) in the diet from before pregnancy. [3H]TdR incorporation was inhibited and there were more lightly labeled cells (compared with controls), in all the saccharin-exposed rats in a rough dose-dependent manner. The results, in comparison with controls, suggest that saccharin exposure in utero causes DNA damage in the neonatal urothelium manifesting as reduced thymidine incorporation and a greater proportion of lightly labeled cells.