A pseudoseasonal reproductive strategy in a tropical rodent, Peromyscus nudipes

A population of cloud forest mice (Peromyscus nudipes) at latitude 10 degrees N near Monteverde, Costa Rica, was sampled four times by live-trapping twice during the 7-8 month wet season and twice during the 4-5 month dry season in 1989 and 1990. Body weights were lower during the early part of the dry season in males and throughout the dry season in females than at other times. Testes and seminal vesicles were somewhat lighter early in the dry season, but epididymal spermatozoa were abundant in most males throughout the year. Adult females ovulated, mated and became pregnant in the wet and dry seasons, but young were produced only during the wet season. Most embryos failed to implant during the dry season, and the few that did complete implantation were reabsorbed before midpregnancy. Apparently, every year, the females in this population spend several months actively engaged in a behavioural and metabolically costly process that is doomed to be unsuccessful. This reproductive strategy is termed pseudoseasonal, because reproductive success is highly seasonal, but attempts to reproduce are nonseasonal. Implantation failures similar to those seen in the wild were induced in the laboratory using mild restriction of food or water. Field evidence points to food restriction as the more important cause of pregnancy losses in the wild. Exposure to the gradually changing daylengths typical of Costa Rica had no effect on the production of young by adults, and maintenance on light cycles of 8 h light: 16 h dark, 11 h light: 13 h dark, 13 h light: 11 h dark and 16 h light: 8 h dark had no effect on the reproductive development of young animals of either sex.

17 beta-acylurea derivatives of 4-azasteroids as inhibitors of testosterone 5 alpha-reductase

A series of 17 beta-acylurea-4-aza-5 alpha-androstan-3-one derivatives has been assayed in vitro as inhibitors of testosterone 5 alpha-reductase, using the particulate fraction of human hyperplastic prostate and rat prostate as enzyme sources. The most active derivatives were 1-[4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carbonyl]- 1,3-dicyclohexylurea (compound 1) and 1-[4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carbonyl]- 1,3-diisopropylurea (compound 3) which demonstrated IC50 values of 41 and 55 nM for the human enzyme and of 83 and 53 nM for the rat enzyme, respectively. Neither compound showed any relevant binding affinity to the rat prostate androgen receptor (IC50 of approximately 100 and 84 microM). When given orally in immature castrated rats together with subcutaneous testosterone propionate (TP) for 7 consecutive days, compound 3 (laboratory code FCE 26073), at 3 mg/kg/day, significantly decreased the ventral prostate growth promoting effect of TP by 40-50%, whereas compound 1 was ineffective up to the dose of 10 mg/kg/day.

Internal reproductive system in adult males of the genus Camponotus (Hymenoptera: Formicidae: Formicinae)

Descriptions are provided of the histology and ultrastructure of the male internal reproductive tracts from three species of Camponotus, representing three subgenera. This study is the first to provide ultrastructural information on the testes (including spermatogenesis and spermiogenesis), seminal vesicles, and accessory glands in ants. Testes contain about ten follicles each, and each follicle is capable of producing hundreds of cysts in which spermatozoa develop. Structural evidence of meiosis in late pupal testes includes cytoplasmic bridges between spermatocytes, centriole elimination, and fusion of mitochondria. Developing spermatids are in close contact with cyst cells in the region of the acrosome. Mature spermatozoa are similar in ultrastructure to those described previously for two other subfamilies of ants (Myrmicinae and Dolichoderinae). The ultrastructure of the seminal vesicle suggests that it is not merely a passive organ for sperm storage. Large numbers of both mitochondria and membranous whorls suggest a pH-regulating and/or hormonal function. The accessory gland is made up of secretory cells that contain a diversity of secretory granules. SDS-PAGE reveals several proteins found in the accessory glands but absent in the adjacent genitalia. Preliminary analyses indicate that carbohydrate is an important component of accessory gland secretions.

Additive and/or synergistic effects of 5 alpha-dihydrotestosterone, dexamethasone, and triiodo-L-thyronine on induction of proteinases and epidermal growth factor in the submandibular gland of hypophysectomized mice

The effects of androgen, glucocorticoid, and thyroid hormones on levels of proteinase isozymes and epidermal growth factor (EGF) in the submandibular glands of hypophysectomized (Hypox) mice were investigated. Total proteinase activity in males was decreased by hypophysectomy and increased by single or combined injection of the three hormones into these mice. 5 alpha-Dihydrotestosterone (DHT) had the strongest effect, and dexamethasone (Dex) the least. By isoelectric focusing, proteinases extracted from the submandibular gland of untreated male and female mice were fractionated into four isozymes with pI values of 4.8 (proteinase-F), 5.8 (proteinase-D), 6.2 (proteinase-A), and 10.0 (proteinase-P). In Hypox mice (both sexes), there was only a single isozyme, proteinase-F. Proteinase-D, -A, and -P were induced in the submandibular gland of Hypox males by injections of DHT, Dex, and/or T3; the percent ratio of activity of each of these isozymes induced by these hormones, given either singly or in combination, was almost parallel among the three isozymes. Synergistic effects were observed between T3 and Dex, and additive effects between T3 and DHT. The increase in proteinase isozyme activities by concomitant injections of T3 and Dex was about 2 times more than the additive values. The changes in proteinase-F upon hormone injection were complicated. In females, the enzyme activity was decreased by hypophysectomy and increased by DHT administration. In males, on the other hand, it was increased by hypophysectomy and suppressed by T3 or T3 plus steroid hormones. The EGF level in the submandibular gland was decreased to about 1/800th (males) or 1/90th (females) of its normal level by hypophysectomy. Its level in the Hypox animal was greatly increased by all three hormones, given singly or in combination. Synergism was also observed between T3 and steroid hormones; DHT plus T3 and T3 plus Dex induced EGF 6 times and 9 times, respectively, more than the additive values. These values were much greater than those for the induction of proteinase-D, -A, and -P by combined injections of T3 and steroids. The present results suggest that the genes coding for proteinase-A, -D, and -P are located close to each other and that the onset of their expression may be controlled by the same regulatory mechanism. By contrast, the gene for proteinase-F may be mapped to a different locus or regulated differently. The mechanism of induction of EGF by T3, DHT, and Dex appears to be similar to but not completely the same as that for proteinase-D, -A, and -P.

Evaluation of the co-mutagenicity of ethanol and Δ9-tetrahydrocannabinol with Trenimon

The mutagenic potential of chronic treatments of male CF-1 mice with ethanol and delta 9-tetrahydrocannibinol (THC), and their comutagenic potential with a known mutagenic agent, Trenimon, were examined. This was accomplished by measuring the frequency of dominant lethal mutations arising from mating of treated males with nontreated females. Adult male mice were treated with 5% (v/v) ethanol as part of a liquid diet (28% ethanol-derived calories) for five weeks; 10 mg/kg body weight (p.o.) THC every two days for five weeks; a single injection of Trenimon (0.125 mg/kg, i.p.) on day 28 of diet treatment; and all combinations of treatments. The control group was pair-fed a liquid diet in which isocaloric sucrose replaced ethanol; these males were also given sesame oil (vehicle for THC) and saline (vehicle for Trenimon) on the same schedule as that for the treated males. Neither body weights nor hematocrits were adversely affected by any treatment. Both ethanol and Trenimon treatments resulted in a small (8-9%; p less than 0.05) decrease in testicular weight. The effect of combined treatment with ethanol and Trenimon was roughly additive. Treatment with THC had no effect on testicular weight. Seminal vesicle weights were not affected by any treatment. Treatments were without significant effect on fertility, as measured by the frequency of males producing pregnancies. Ethanol and Trenimon treatments produced approximately 3- and 7-fold increases, respectively in the frequencies of preimplantational loss over that seen for the control group (7.3%), resulting in significant ethanol and Trenimon effects (p less than 0.001). No interactive effects of ethanol and Trenimon treatments were noted. Frequencies of dead fetuses per pregnancy in the ethanol- and Trenimon-treated groups were increased approximately 2.5- and 4-fold, respectively, over the control value of approximately 16%. However, the effect of combined treatments was not greater than that due to Trenimon alone, resulting in Trenimon and ethanol effects (p less than 0.001) and ethanol-Trenimon interaction (p less than 0.001). The calculated mutation index resulting from each treatment yielded significant (p less than 0.001) ethanol- and Trenimon-induced effects. In contrast to effects of ethanol and Trenimon treatments, THC, given alone, or in combination with ethanol and/or Trenimon, had no effect on either preimplantational loss, fetal mortality or the resulting mutation index. The data suggest that chronic ethanol treatment, at levels resulting in minimal fertility impairment, increases the frequency of dominant lethal mutations. In contrast, chronic treatment with THC, as administered in the present study, appears to be without effect.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of microcapsules of luteinizing hormone-releasing hormone antagonist SB-75 and somatostatin analog RC-160 on endocrine status and tumor growth in the Dunning R-3327H rat prostate cancer model

Inhibitory effects of sustained delivery systems (microcapsules) of the modern antagonist of luteinizing hormone-releasing hormone [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]LH-RH (SB-75) or the potent somatostatin analog D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) were investigated in the Dunning R-3327H rat prostate cancer model. In the first experiment, the treatment was started 4 months after tumor transplantation, when the tumors measured approximately 2 cm3. Tumor volumes and weights were significantly reduced by SB-75 microcapsules releasing 48 micrograms/day or RC-160 microcapsules releasing 38 micrograms/day given alone, as compared with the control. The combination of these two analogs showed a synergistic effect. In the second experiment, the treatment was started 7 months after tumor transplantation, when the tumors were well developed and measured about 16 cm3. In addition to a significant reduction in volume, weight, and growth rate of tumors, histological signs of tumor regression were found in the groups treated with SB-75 microcapsules releasing 72 micrograms/day given alone or in combination with RC-160 microcapsules releasing 76 micrograms/day, but not with RC-160 alone. No synergistic effect of the combination therapy was found in the second experiment. Serum testosterone levels decreased to undetectable levels and LH levels were also diminished within 2 weeks by administration of SB-75 alone or in combination with RC-160. In both experiments, the weights of testes, ventral prostate, and seminal vesicles were greatly reduced by administration of SB-75 alone or in combination with RC-160. Our results suggest that the combined therapy with microcapsules of SB-75 and RC-160, started soon after the diagnosis of prostate cancer is made, could improve therapeutic response.

Morphometric and stereological study of the seminal vesicle of the guinea pig

The seminal vesicle of the guinea pig has been widely used as a model for the study of hormonal action on the male accessory sex organ, but there have been few attempts to quantify their cellular and tissue components. In the present study, the seminal vesicle of the guinea pig was described in the form of a morphometric model. Tissue samples were taken from the distal, middle and proximal regions of the gland and processed for light microscopy. Using a combination of a stereological point-counting technique and direct measurement, the relative volumes of different components (lumen, epithelium, lamina propria and fibromuscular layer) were determined. The relative numbers of the secretory cells and basal cells were also estimated. Following the estimation of the average size of the seminal vesicle, the relative volume of different components and the relative number of secretory cells were transformed into absolute data on a per average seminal vesicle basis. Similarly, the average sizes of the secretory cells and nuclei were also determined. The quantitative data generated from the present study will serve as a baseline for further studies of the seminal vesicle of the guinea pig. The techniques used in the present study are easy to apply, and data generated were objective and reproducible.

Comparative effects of chronic administration of the non-steroidal antiandrogens flutamide and Casodex on the reproductive system of the adult male rat

The effects of chronic blockade of androgen action by the antiandrogens flutamide and Casodex on serum and pituitary concentrations of LH and FSH, serum and testicular androgen levels, reproductive organ weights, and on spermatogenesis were compared in the adult rat. Animals were treated for 3 and 8 weeks with vehicle, Casodex (20 mg.kg-1.(day)-1, flutamide (20 mg.kg-1.(day)-1) and GnRH antagonist (150 micrograms/day, Detirelix). Treatment with GnRH antagonist suppressed gonadotropin and testosterone production, reduced the weights of testes, epididymides and seminal vesicles, and inhibited germ cell development. Flutamide administration markedly elevated serum and pituitary levels of gonadotropins as well as serum and testicular androgen concentrations. Casodex-induced elevation of gonadotropin concentrations was less pronounced and serum and testicular levels of androgens did not change significantly. The reduction of seminal vesicle weights was similar after Casodex and GnRH antagonist treatment, whereas flutamide was less effective. Testicular weight and spermatogenesis (assessed by light microscopical and flow-cytometric analysis) remained unaffected by Casodex and flutamide. It is concluded, that 1. Casodex, in contrast to flutamide, is a peripherally selective antiandrogen, and 2. Casodex influences release of gonadotropins into circulation less than flutamide. Therefore this antiandrogen might be useful clinically for selectively blocking androgen actions in the accessory sex glands.

Sectional anatomy of the pelvis in the male rat with ultrasound correlations

Ten-week-old male Wistar rats were used for sectional anatomy and ultrasonic diagnosis of the pelvis. The prostate and the urinary bladder were identified easily on longitudinal section by ultrasound examination. The prostate (ventral, lateral, and dorsal lobes) was located in the midline of the pelvis cavity on transverse sections and the caudal side of the urinary bladder on longitudinal sections. The urinary bladder was positioned at the cranial side of the prostate on longitudinal sections and in the midline of the pelvis cavity on transverse sections. The seminal vesicles were located at right and left positions of the urinary bladder. Ultrasonic diagnosis was estimated to be useful for experimental studies and we hope that ultrasound techniques may reduce the number of rats used for the treatment of prostate and urinary bladder cancers.

Effect of diabetes mellitus on epididymal enzymes of adult rats

Diabetes mellitus caused significant reduction in serum testosterone and accessory sex glands weight. The sperm content of epididymal regions also decreased. Among the epididymal regions, the cauda epididymidal tissue alone showed significant reduction in Na(+)-K+ ATPase activity. However, Mg2+ ATPase activity was lowered in caput epididymidis only. Specific activity of Ca2+ ATPase significantly decreased in caput and cauda epididymides. All three ATPases decreased significantly in caput epididymidal spermatozoa leaving cauda epididymidal spermatozoa unaffected. Specific activity of alkaline phosphatase was suppressed in caput epididymidis and in the spermatozoa collected from caput and cauda epididymides, while the acid phosphatase was unaffected. In general, the results are suggestive of definite influence of diabetes on epididymal phosphatases which is region specific. Diabetes induced decrease in phosphatases may have an impact on secretory and absorptive functions of epididymis and thus on sperm maturation.

Thermoregulation, growth, and reproduction in Alaskan collared lemmings: role of short day and cold

To assess factors controlling seasonal thermoregulatory and reproductive changes, collared lemmings (Dicrostonyx groenlandicus) were exposed for 16 wk to long day (LD, 22 h light: 2 h dark) and warm (15 +/- 3 degrees C), LD and cold (1 +/- 0.5 degrees C), short day (SD, 4 h light: 20 h dark) and warm, SD and cold or acclimatized to outdoor winter conditions (OUT). Hair length and color, body mass, and food intake were monitored weekly. Resting metabolic rates (RMR) and nonshivering thermogenesis (NST) were estimated several times by measuring oxygen consumption before and after norepinephrine injections. Body composition and reproductive condition were determined at the end of the experiment. SD and OUT groups had a 15.8% lower (P less than 0.01) RMR at 7 degrees C than the LD groups. Lower thermal conductance in SD and OUT animals appears due to molt to white winter pelage, which occurred by week 3 in SD but not in LD groups. Neither SD, cold, nor OUT altered NST or reproductive morphology. SD-exposed lemmings showed 19.2% greater growth than those in LD, resulting primarily from a 29.2 and 15.0% increase in lean and ash components, respectively. Cold exposure increased food intake by 34.7%. Results suggest that the pineal gland, which mediates SD effects, may influence molt and growth but not NST or reproductive morphology.

The effects of a brain-enhanced estradiol delivery system on testosterone and androgen-dependent tissues. I. Dose-response and time-course evaluation

The primary objective underlying hormone treatment of prostatic adenocarcinoma is to induce an effective androgen deprivation, and high dose estrogen therapy is as effective as surgical castration in abolishing the growth-promoting effects of androgens on prostatic tissue. An estradiol-chemical delivery system (E2-CDS), with sustained release of E2 in the brain, may be potentially useful in the treatment of prostatic cancer by virtue of the need for lower or less frequent doses of the estrogen. In this study we evaluated the dose- and time-dependent effects of the E2-CDS vs. 17 beta-E2 on serum testosterone (T) and weights of androgen-dependent tissues in male rats. Rats received a single iv injection of E2-CDS (0.1, 0.5, or 1.0 mg/kg), equimolar doses of 17 beta-E2, or the drug's vehicle. Sera and tissues were collected 1, 7, 14, or 21 days later for determination of hormone levels and tissue weights. The E2-CDS exhibited a dose- and time-dependent suppression of serum T and weights of the ventral prostate and seminal vesicles. In contrast, 17 beta-E2 had no significant effect on serum T or growth of these androgen-dependent tissues. Serum T levels were significantly reduced by 98%, 82%, and 59% at 1, 7, and 14 days, respectively, with the 1.0 mg/kg dose of E2-CDS. The E2-CDS significantly reduced prostate weight by 45% and 50% (1.0- and 0.5-mg/kg doses, respectively) 7 days and by 27% (0.5 mg/kg dose) 14 days after treatment. Similarly, seminal vesicle weights were reduced by 14-20% on day 1, maximally reduced by 39-48% on day 7, and still reduced by 24-36% on day 14 compared with the control levels. Weights of these tissues returned to control levels by day 21. Serum E2 was elevated through 7 days by E2-CDS or on day 1 only by 17 beta-E2. PRL secretion was stimulated for 1 week by both forms of estrogen. Anterior pituitary weights were increased by the E2-CDS through 14 days, while 17 beta-E2 had no significant effect. These data indicate that the E2-CDS causes chronic suppression of serum T, which subsequently results in regression of androgen-dependent tissue weight.

The effects of a brain-enhanced estradiol delivery system on testosterone and androgen-dependent tissues. II. The role of testosterone

The present study was undertaken to evaluate the efficacy of an estradiol-chemical delivery system (E2-CDS) for the brain vs. estradiol benzoate (E2-BNZ) in suppressing serum testosterone (T) and weights of the ventral prostate and seminal vesicle in male rats. Also, the role of serum T in the weight reduction of androgen-dependent tissues observed after E2-CDS treatment was further evaluated in these studies. Intact male rats received a single iv injection of either E2-CDS at a dose of 1.0 mg/kg or an equimolar dose of E2-BNZ (0.95 mg/kg). Sera and tissue samples were collected 1, 7, 14, or 21 days after injection for determination of hormones and tissue weights. A single injection of E2-CDS suppressed serum T levels by 96%, 83%, 46%, or 63% 1, 7, 14, or 21 days after treatment, respectively. In contrast, an equimolar dose of E2-BNZ had no significant effect on serum T at any sampling time examined. Prostate weight was maximally reduced by 53% at 7 days and remained significantly suppressed by more than 31% throughout the 21-day time course. Similarly, seminal vesicle weight was reduced by 14% on day 1, maximally reduced by 41% on day 7 and remained significantly suppressed through day 21. In contrast, E2-BNZ was ineffective in inducing weight changes in either of these tissues. Serum PRL was significantly elevated through day 14, while E2 was elevated through day 7 by E2-CDS. Both the anterior pituitary and adrenal gland weights were stimulated by E2-CDS treatment. Testis weight was moderately reduced by both esters. In a subsequent study serum T was reduced by 98% and 97% 1 and 7 days, respectively, after E2-CDS treatment, and weights of the ventral prostate and seminal vesicle were reduced by 47% and 40%, respectively, at 7 days. In contrast, in rats treated with Silastic capsules containing T, the expected E2-CDS-induced weight regression was prevented in both prostate and seminal vesicles. These data indicate that the prolonged effects of E2-CDS on weights of androgen-dependent tissues are caused by its ability to produce profound suppression of the serum T concentration.

Recovery of pituitary-gonadal function in male and female rats after prolonged administration of a potent antagonist of luteinizing hormone-releasing hormone (SB-75)

The reversibility of the antifertility effects induced by long-term administration of the LH-RH antagonistic analog [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]-LH-RH (SB-75) was investigated in male and female rats. Male rats were implanted with osmotic minipumps releasing 50 micrograms of SB-75/day for 60 days. The control rats were implanted with minipumps containing only vehicle. The treatment with the antagonist caused a significant decrease in the weights of the testes, seminal vesicles and ventral prostates (p less than 0.01) and reduced serum LH and testosterone levels (p less than 0.01). The histology of the testes from the treated rats showed that spermatogenesis was totally depressed. No mature elongated or round spermatids were found in the seminiferous tubules, spermatocytes being the most advanced germ cell form in 100% of the testicular tubules. These changes indicate that a total spermatogenetic arrest occurred in the treated animals. Ninety days after cessation of treatment with the LH-RH antagonist, there was a complete recovery of the weights of the testes, seminal vesicles and ventral prostates and LH and testosterone returned to control levels. Histological studies revealed a complete recovery of spermatogenesis, with 99.2% of seminiferous tubules containing mature elongated spermatids. Immediately after the discontinuation of treatment with SB-75, a significant down-regulation of the pituitary LH-RH receptors was found, but 90 days later, this phenomenon was completely reversed. Female rats were injected every 3 weeks for 6 weeks with SB-75 microcapsules, at a dose calculated to release 27 micrograms/day of the antagonist. The treatment with SB-75 disrupted the normal estrous cycle. Body weights were not affected, but ovarian and uterine weights were significantly decreased (p less than 0.01 and p less than 0.05, respectively) in the animals treated with the antagonist. Treated rats had significantly lower LH (p less than 0.05) and estradiol (p less than 0.01) levels than controls. The histology of the ovaries from the SB-75-treated group showed that the ratio of small to large maturing follicles increased significantly (p less than 0.01) and corpora lutea were absent. Two months after the cessation of treatment, a complete recovery in the organ weights and in hormonal levels was observed and no histological differences were found between the ovaries in treated and untreated rats. These collective results indicate that the suppression of gonadal function induced by the treatment with LH-RH antagonist SB-75 is completely reversible both in male and female animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Fructolysis effect of 50% ethanolic extract of Mentha arvensis Linn. (leaves) in seminal vesicles of rat

50% ethanolic extract of Mentha arvensis Linn. (leaves) has been found to reduce the fructose synthesis in seminal vesicles; as a result of which the viability of spermatozoa seems to be altered. Fertility testing revealed sterile matings till 30 days of last treatment.

Antifertility effects of sulfapyridine on male hamsters

Sulfapyridine was administered to mature male golden hamsters either by impregnation in feed pellets, or by subcutaneous injection as a solution in dimethylsulfoxide. The average litter size for control males was 8.3 +/- 3.3 (n = 13) vs. 4.2 +/- 2.7 (n = 11) for sulfapyridine-fed treated animals. Histology of the testis and epididymis was normal and sperm were normal in morphology and motility. Subcutaneous injection of sulfapyridine caused much more dramatic inhibition of male fertility than was achieved by feeding the drug. Sulfapyridine (750 mg/kg body weight in 0.2 ml DMSO) injected subcutaneously for 60 days was effective in reducing testis size and sperm quality. Histology of testes showed spermatogenic arrest at young spermatids. Two classes of animals were found in both sulfapyridine-fed and -injected treatment groups. One class was relatively resistant to the antifertility effects of the drugs. This difference may reflect differing abilities of the animals to convert sulfapyridine to an active form or to excrete its metabolites.

[Pharmacological studies on Bombyx mori L]

The toxicity of the Bombyx mori extract is very low. It can promote the growth of under-aged male mice, and increase markedly the weight of the prostate glands, seminal vesicles and preputial glands in castrated rats of mice. The results of the experiments have shown that Bombyx mori has androgen-like action.

MR imaging of the seminal vesicles

MR imaging (0.35 and 1.50 T) was used to assess the appearance of the seminal vesicles. The size and signal intensity of normal seminal vesicles vary with the age of the subject. In general, on T2-weighted images, the signal intensity of normal seminal vesicles is lower than that of fat in prepubertal children, similar to or higher than that of fat in adults, and similar to or lower than that of fat in patients older than 70 years of age. Endocrine and radiation therapy will influence the size and signal intensity of the seminal vesicles. The purpose of the essay is to illustrate the spectrum of seminal vesicle disease, including congenital anomalies, inflammation, and neoplastic disease. Although MR imaging is helpful in depicting seminal vesicle abnormalities, it does not allow differentiation of benign from malignant disease, distinction of hemorrhage due to tumor invasion from postbiopsy changes, or distinguishing between glandular obstruction due to tumor infiltration and mechanical compression.

Production of corticosterone and testosterone in scorbutic mutant rats: difference of in vivo production between adrenal gland and testis

Effects of deficiency in ascorbic acid on in vivo production of corticosterone and testosterone were examined using a mutant strain of rats unable to synthesize ascorbic acid. The adrenal weight of scorbutic rats was larger, and corticosterone levels in plasma and adrenal tissues were higher than those of ascorbic acid-supplied (ascorbutic) rats. Acute and chronic stimulation with ACTH increased corticosterone levels in both ascorbutic and scorbutic rats. In contrast, weights of seminal vesicles and ventral prostates in unstimulated scorbutic rats were smaller, and testosterone levels in plasma and testicular tissues were lower than those in ascorbutic rats. Acute stimulation with hCG increased testosterone levels only slightly in plasma and not in testicular tissues of scorbutic rats, when testosterone levels in ascorbutic rats reached a maximum. Chronic stimulation with hCG increased testosterone levels remarkably in both ascorbutic and scorbutic rats. These findings seem to indicate that ascorbic acid is not essential for the synthesis of steroid hormones. The scurvy seems to increase plasma ACTH levels secondary to the stress, resulting in the stimulation of the adrenals. In contrast, a prolonged deficiency in ascorbic acid appears to decrease plasma gonadotropin levels, and may reduce the sensitivity of testes to gonadotropins.

Gender effects and central opioid analgesia

Central morphine analgesia is significantly greater in male than in female rats. Since mu and delta opioid receptor subtypes have been implicated in supraspinal analgesia, the present study evaluated whether gender or adult gonadectomy altered (a) analgesia on the tail-flick and jump tests following central administration of the mu-selective agonist, [D-Ala2, Me-Phe4, Gly(ol)5] enkephalin (DAMGO) and the delta-selective agonist, [D-Ser2,Leu5] enkephalin-Thr6 (DSLET) and (b) mu1, mu2 and delta opioid receptor binding. Sham-operated male rats displayed significantly greater magnitudes of peak and total analgesia than sham-operated females on the tail-flick test following DAMGO, but not DSLET. Gender differences were not observed for DAMGO and DSLET analgesia on the jump test. Gonadectomy failed to consistently affect either DAMGO or DSLET analgesia. Regression analyses failed to reflect significant shifts in the dose-response functions for either agonist on either measure. Gender differences were not observed for mu1, mu2, or delta binding in hypothalamus or cortex. These data are compared with analgesic responses sensitive to gender differences.

Hormonal manipulation of the prenatal environment alters reproductive morphology and increases longevity in autoimmune NZB/W mice

Steroid hormones, which affect development of reproductive traits, alter immune responses in rodents and appear to control severity of disease in F1 hybrid NZB/W mice, an animal model of systemic lupus erythematosus. We tested the hypothesis that exposure of NZB/W fetuses to altered hormonal environments would influence subsequent expression of autoimmune renal disease and affect longevity. NZB females, pregnant with NZB/W fetuses, were treated from Days 13-18 of gestation with testosterone or the antiandrogen, flutamide. Similar treatments were carried out in C57BL/6 dams mated to DBA/2 males to permit comparison with nonautoimmune hybrid mice. Serum concentrations of testosterone were greater in testosterone-implanted dams of both strains, but concentrations of estradiol were greater only in C57BL/6 dams treated with flutamide. Alpha fetoprotein (AFP), which binds estrogen and modulates immune responsiveness, was greater in serum from both groups of testosterone-treated dams, while flutamide treatment increased serum AFP only in NZB dams. We conclude that factors governing circulating estradiol and AFP differed in pregnant NZB and C57BL/6 females. Morphological analyses confirmed effects of hormonal manipulation on the developing fetuses. Testosterone implants resulted in female offspring with greater anogenital spaces, and treatment of dams with flutamide eliminated the expected difference between anogenital spaces in females and males. Effects of altered prenatal hormonal environments on immune-mediated disease in NZB/W offspring were examined in a longevity study. Early deaths were delayed in NZB/W females produced by flutamide-treated dams. An unexpected result was observed in NZB/W males. Male offspring from both testosterone- and flutamide-treated mothers lived longer than males from control dams. This paradox suggested that a characteristic shared by both groups of treated NZB dams had similar effects on the developing fetuses. It is proposed that elevated concentrations of AFP modulated the course of autoimmune disease and contributed to increased longevity in NZB/W offspring of treated dams.

[Androgen-like and anabolic action of Antheraea pernyi Guerin-Meneville Pas]

It has been found that the ethyl acetate extract isolated from Antheraea pernyi Pas is able to increase the weight of prostate-semina and levator ani muscle-bulbocavarnosus muscle of castrated mice. In addition, the extract also accelerates the growth of younger male mice and enhances the contents of RNA, DNA and protein in the liver tissue of mice. It has been determined that beta-ecdysone is one of the effective constituents for the androgen-like and anabolic action.

Expressions of sulfated glycoprotein 2 and pSvr-1 genes and involution of steroid hormone-dependent rat tissues

To further survey the molecular mechanisms underlying the involution of steroid hormone-dependent rat tissues, we undertook experiments to test whether or not any significant correlation between the tissue involution and expressions of rat sulfated glycoprotein 2 (SGP-2) and pSvr-1 genes, which had been initially cloned from the Sertoli cells and the seminal vesicles, respectively, and then identified as androgen repressed messages both in the ventral prostate and in the seminal vesicles, could be observed in steroid hormone-dependent rat tissues. Expressions of these genes were stimulated within 48 h after castration of animals both in the ventral prostate and in the seminal vesicles as reported previously, but not significantly altered by ovariectomy in the uterus. Expressions of these genes in the thymus were significantly repressed by the administration of dexamethasone and/or cycloheximide. Although the roles of expressions of SGP-2 and pSvr-1 genes in steroid hormone-dependent tissues remain unclear, their presence might become useful molecular markers of tissue involution not only in androgen-dependent rat tissues but also in glucocorticoid-dependent ones, and also provide excellent model systems for the study of negative regulation mechanism of gene expression by steroid hormones.

Effects of estrogen on growth of androgen-responsive rat prostatic tumor (R 3327)

It has been known that estrogen has synergistic effects with androgen on growth of normal male accessory sex organs of rats. The present study was therefore undertaken to examine the effects of estrogen on androgen-responsive rat Dunning R 3327 prostatic tumor. The weight of male accessory sex organs was suppressed by estrogen on growth of treatment, but synergistic effects of estrogen and androgen on these organs were seen following combined treatment with androgen and estrogen. In contrast to the effects of estrogen on accessory sex organs, estrogen influenced a R 3327 tumor only in the negative direction regardless of whether androgen was injected simultaneously or not. When the dihydrotestosterone injection was reduced from 500 to 100 micrograms/rat/day after the tumor appeared as subcutaneous nodules, the weight of the accessory sex organs was similar to that of the control animals. However, this amount of dihydrotestosterone increased tumor growth equally when compared to those treated with a pharmacological dose of dihydrotestosterone. Therefore, the response of R 3327 tumor to androgen was different from that of the accessory sex organs.

Effect of lithium chloride on testicular steroidogenesis and gametogenesis in immature male rats

The present study was performed on immature male rats aged 35 days. Subcutaneous injections of lithium chloride at a daily dose of 2.0 mg/kg for 15 days resulted in significant inhibition of spermatogenesis at stage VII of the seminiferous epithelial cycle. Spermatogonia A, preleptotene spermatocytes and step 7 spermatids were decreased in number in comparison to controls. Serum levels of FSH, LH, PRL, and testosterone were decreased. Activities of testicular delta 5-3 beta-hydroxysteroid dehydrogenase and 17 beta-hydroxysteroid dehydrogenase were suppressed along with a low caudal epididymal sperm count in comparison with controls. When the treatment was prolonged for 20 and 25 days, it showed an additional significant diminution in accessory sex organ weights and number of midpachytene spermatocytes at stage VII in comparison to control animals of corresponding age. It is concluded that lithium has an adverse effect on testicular function in immature rats by reducing serum levels of FSH, LH, PRL, and testosterone. Furthermore, since hormonal changes and altered spermatogenic activities were evident when the serum concentration of lithium was within the therapeutic range, our data may have some potential clinical implications.

Seasonal changes in plasma concentrations of gonadotropins and in the responsiveness of the pituitary and testis to GnRH in a desert rodent, the sand rat (Psammomys obesus)

The male sand rat (Psammomys obesus), captured alive in the Sahara desert in the area of Béni-Abbès (Algeria), exhibited seasonal changes in plasma concentrations of LH, characterized by an increase in early summer. Administration of a standard dose of GnRH (200 ng/100 g body weight) failed to elicit significant season-dependent changes in LH release, whereas the increase in plasma testosterone was maximum in June-July and quite small between November and March-April. The present results suggest that the summer seasonal onset of the testicular endocrine activity of the sand rat is due to increases both in LH release and in testis sensitivity to gonadotropin.

Effect of sleep deprivation on the physiological status of rat testis

The effect of alteration of central turnover of monoamines on the intratesticular mechanisms in the testis of rats was studied after REM sleep-deprivation. The reduction in the weights of ventral prostate, seminal vesicles and decreased activity of beta-glucuronidase in kidney reflected decreased availability of testosterone to the target organs. Decreased activities of lysosomal enzymes, acid phosphatase and beta-glucuronidase were associated with a decreased steroidogenic activity in the testis. The active mediation of lysosomal enzymes in the testicular function under altered condition was indicated.

Regional differences in the prostate of the neonatally estrogenized mouse

Neonatal estrogenization of the mouse with diethylstilbestrol resulted in time-of-exposure and dose-dependent inhibition of the growth of the prostatic lobes observed at the age of 2 mon. The critical time was the days 1-6 of postnatal life. In neonatally estrogenized (neoDES) mice, responses to 5 alpha-dihydrotestosterone in terms of nuclear 3H-thymidine labelling were altered concomitantly with the inhibition of growth and were in accordance with changes in the relative volumes of epithelium, glandular lumina, and interacinar stroma. Secondary estrogen treatment of neoDES mice with 17 beta-estradiol did not increase 3H-thymidine labelling in the prostate of control or neoDES mice. However, it induced squamous epithelial metaplasia in periurethral collecting ducts and proximal parts of coagulating glands of neoDES animals. In control mice only slight epithelial hyperplasia could be observed after similar treatment. Estrogen receptors, located immunocytochemically in nuclei of stromal cell, corresponded with the sites of increased estrogen sensitivity, observed as metaplastic transformation. When the neoDES animals aged, epithelial hyperplasia and dysplasia could be observed at distinct prostatic sites, ie, the periurethral collecting ducts and the coagulating glands and periurethral glands, and stromal inflammation become more extensive. Almost identical location of the epithelial changes and the altered estrogen response is suggestive of causal relationship.

Ultrasonographic characteristics of the seminal vesicles after ejaculation

A total of 12 men from a sperm donor bank underwent transrectal ultrasonography before and after ejaculation to investigate possible changes that could influence interpretation of seminal vesicle ultrasonography. The mean length of the seminal vesicles was 2.98 cm. before and 2.95 cm. after ejaculation. The anteroposterior diameter decreased only from 0.59 to 0.52 cm. Minimal differences were noted between the right and left seminal vesicles, and the greatest variation in size in an individual was only 3 mm. These results indicate that interpretation of seminal vesicle anatomy as seen by ultrasonography does not depend upon the temporal relationship to ejaculation.

Influence of photoinhibition, photostimulation and prolactin on pituitary and hypothalamic nuclear androgen receptors in the male hamster

Testosterone (T) feedback sensitivity is markedly altered in adult male golden hamsters following exposure to short photoperiods (SD). Using a technique which measures total androgen receptors within the cell nucleus, the present study examined pituitary and hypothalamic nuclear androgen receptor levels in animals exposed to (1) long days (LD) or SD in the presence and absence of a constant T level supplied via a Silastic implant, (2) photostimulation following SD-induced testicular regression and (3) short-term prolactin injections following SD-induced testicular regression. Short photoperiods were associated with a drop in nuclear androgen receptor levels which was correlated with a decline in circulating T. When constant T was supplied to gonadectomized hamsters, those exposed to SD possessed higher pituitary and similar hypothalamic nuclear androgen receptor levels than those exposed to LD. As expected, plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were greatly reduced in SD-exposed, castrated, T-treated hamsters as compared to LD-exposed, castrated, T-treated animals. Photostimulation of intact SD-exposed hamsters for 5 or 10 days was associated with a decline in pituitary nuclear androgen receptors. Prolactin treatment caused no noticeable change in pituitary or hypothalamic androgen receptors even though plasma LH and FSH levels were significantly increased. These results support the hypothesis that altered T feedback mechanisms controlling LH and FSH release following chronic exposure to SD may be related to an alteration in the amount of androgen receptors present in the anterior pituitary.

Endocrinological studies on TAP-144-SR, a sustained-release formulation of a potent GnRH agonist (D-Leu6-[des-Gly10-NH2]-GnRH ethylamide), in male rats

The paradoxical effects of TAP-144-SR, a biodegradable sustained-release formulation of a potent GnRH agonist (TAP-144, leuprolide acetate) were evaluated in male rats by comparing its potency with that of TAP-144 solution. A single sc injection of TAP-144-SR (equivalent to 0.1 mg/kg/day as TAP-144), prepared by encapsulating the agonist in microcapsules of copoly (DL-lactic/glycolic acid), suppressed serum levels of androgens, and the levels remained suppressed for 4 weeks. The potency of the paradoxical effects of TAP-144-SR was evaluated 4 weeks after treatment by comparing it with that of TAP-144 solution administered daily for 4 weeks. Both daily injections of TAP-144 solution and a single injection of TAP-144-SR (equivalent to 0.02, 0.2 or 2 mg/kg/day as TAP-144) decreased the weight of the testes, prostates and seminal vesicles in a dose-dependent manner in a 4-week assay in male rats. TAP-144-SR was more effective than TAP-144 solution in reducing these organ weights. Serum and pituitary concentrations of LH and FSH and serum testosterone levels were also lower in TAP-144-SR-treated than in TAP-144 solution-treated rats. These results indicate that the paradoxical effects were more extensive upon TAP-144-SR treatment, suggesting that maintaining constant serum TAP-144 levels results in more extensive desensitization of the pituitary and testes. These results also suggest advantages of TAP-144-SR over TAP-144 solution in both efficacy and convenience as an anti-prostatic tumor agent.

Ultrasound anatomy of the prostate: the normal gland and anatomical variations

Knowledge of the normal prostatic anatomy is paramount to understanding the pathological conditions of the gland observed on ultrasound imaging. Through transverse and sagittal histological sections of normal prostates, model ultrasound images of the prostate and periprostatic tissues were constructed. Various shades of gray were assigned to these structures depending upon the histological composition. We found that ultrasonic characteristics of the normal prostate and its surrounding tissues could be predicted accurately by knowledge of the histology of these structures. Histological sections of 100 prostates from patients who underwent transrectal ultrasound and subsequent radical prostatectomy for prostate cancer were examined. The congenital anatomical variations observed in this group are described histologically and sonographically. Caudal formation of the ejaculatory ducts within the central zone occurred in 18% of the cases, abnormal posterior penetration of the ejaculatory ducts at the rectal surface in 12% and abnormally large muscle bundles with the ejaculatory duct sheath in 6%. Concomitant ejaculatory duct and seminal vesicle dilatation was observed in 5% of the patients, whereas dilated ejaculatory ducts alone, dilated seminal vesicles alone and cystic utricles each were seen in 2%.

Effect of gossypol on rats maintained on protein deficient and low potassium diets

Sexually mature male albino rats were divided into four groups of 5 animals each. Animals of group I served as control, whereas animals of group II received gossypol (20 mg/kg body weight/day) for 45 days. Animals of groups III and IV were maintained on protein deficient diet. Animals of group IV received 20 mg/kg gossypol in addition to the protein deficient diet. Animals of group III and IV received protein deficient diet for 45 days before initiating gossypol treatment. The total period of maintaining the animals on protein deficient diet was 90 days. In another experiment, the same experimental protocol was followed except that the animals were maintained on low potassium diet instead of protein deficient diet. A significant decrease in body weight of animals was observed following protein deficient and gossypol (group IV) treatment. Testis weight decreased significantly in the animals of group III (protein deficient) and group IV (protein deficient + gossypol). Similar observations were made in the animals maintained on low potassium diet. In both the experiments, sperm motility was reduced significantly. Histologically, in the testis of animals of group IV (protein deficient + gossypol) almost all the tubules were disorganised and vacuolated and total arrest of spermatogenesis could be observed in majority of the tubules.

Magnetic resonance imaging of the normal prostate at 1.5 T

Prostatic magnetic resonance images of 22 male volunteers less than 30 years old and with no known genito-urinary tract disease were obtained at 1.5 T. Normal anatomical features of the prostate were studied with spin-echo techniques. Different zones of the normal gland are shown by T2-weighted images: the anterior fibromuscular fascia, the central prostate, the peripheral prostate and the periurethral zone can be differentiated. The normal prostate gland is shown on T1-weighted images as a homogeneous appearance. It is important to recognize the normal zonal anatomy of the prostate since prostatic disorders arise in different anatomical zones.

Androgen-induced changes in nuclear pore number and in tight junctions in rat seminal vesicle epithelium

The numbers of nuclear pore complexes and tight junctions were quantified in the seminal vesicle epithelial cells of castrated and castrated-plus-androgen-treated male rats, which received subcutaneous pellets of testosterone propionate (1 mg/kg body weight) for 1 week. Seminal vesicle weights were 0.284 +/- 0.02 g for castrated, 1.006 +/- 0.006 g for androgen-treated, and 0.918 +/- 0.04 g for untreated groups. Tissue samples were processed for light or electron microscopy and for freeze-fracture techniques. Nuclear areas were measured: controls were 279.34 +/- 8 microns 2; these increased significantly (P less than .001) in castrated-plus-androgen-treated rats (324.66 +/- 11 microns 2) and decreased (P less than .001) in castrated animals (173.14 +/- 6.3 microns 2). Nuclear pore density increased (P less than .001) in castrated-plus-androgen-stimulated rats (5.38 +/- 0.24 pores/microns 2) (control: 4.78 +/- 0.14 pores/microns 2), and decreased (P less than .001) in castrated rats (3.16 +/- 0.14 pores/microns 2). A significant (P less than .001) increase in numbers of tight junction strands that extended in the lateral cell membranes was detected in castrated-plus-androgen-treated rats vs. controls or castrated-only animals.

Endocrine effects of a new histamine H2-receptor antagonist, nizatidine (LY139037), in the male rat

A new orally active histamine H2-receptor antagonist, nizatidine (LY139037), was evaluated in male rats for effects on mechanisms regulating accessory sex organ growth and function. Cimetidine antagonized androgen binding to cytosolic receptors in vitro while nizatidine had no effect. Nizatidine and cimetidine were administered at the ED50, 5 X ED50, or 10 X ED50 doses for inhibition of gastric acid secretion previously determined using in vivo dog and rat models. The relative potencies of both agents to antagonize histamine H2-receptor-mediated gastric acid secretory responses have been confirmed in human clinical trials. Neither nizatidine nor cimetidine antagonized the in vivo uptake or nuclear translocation of radiolabeled androgen into the hypothalamic-preoptic-amygdala, pituitary, or ventral prostate. Nizatidine, given at doses equal to and 10 X the ED50 gastric acid secretion inhibitory values, and cimetidine (10 X ED50 value) had no effect on the response of male accessory sex organs to a submaximally stimulating dose of androgen in castrated rats. High doses of dietary nizatidine (greater than 500 mg/kg-day) administered for 6 months did not alter intact rat male accessory sex organ weights or circulating androgen levels relative to untreated controls. Acute administration of either nizatidine or cimetidine produced transient elevations in plasma prolactin (PRL) levels. Cimetidine was more potent and consistent than nizatidine in producing these increases in circulating PRL. The data described herein support the contention that unlike cimetidine, nizatidine is not a pharmacological antagonist of androgen action and has less of a stimulatory effect upon plasma prolactin. Taken together, these studies indicate that in the male rat, nizatidine exhibits a large therapeutic index between its gastric antisecretory activity and potential endocrinological effects.

Effects of chronic ethanol diet on pituitary-testicular function of the rat

We studied the effects of a 6% ethanol liquid diet administered for 5 wk on the pituitary-gonadal function of adult male rats. Because ethanol is known to reduce body weight, we used sucrose-fed animals as controls. No significant differences in body, testis, or prostate weights were found between the rats exposed to ethanol and their sucrose-fed controls at the end of the 5-week treatment. Seminal vesicle weights decreased significantly (p less than 0.05) in the ethanol-treated group. Serum and testicular testosterone concentrations were significantly reduced in the ethanol-treated group, to 43.6% and 48.3% of levels in the sucrose-fed controls, respectively (p less than 0.05). Serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels of the ethanol-treated rats were 37.9% and 41.3%, respectively, of those of the sucrose-fed controls (p less than 0.01-0.05). The pituitary levels of these hormones were similar to those of controls, but the ratios of pituitary LH and FSH to their serum levels were clearly increased after ethanol exposure, to 492% and 206.1%, respectively (p less than 0.05). In contrast, pituitary prolactin (PRL) of the ethanol-treated rats was decreased to 40.2% (p less than 0.01) of sucrose-fed controls. Testicular content of LH receptors was significantly reduced (to 77.0% of controls; p less than 0.01), but content of FSH receptors was slightly increased by the ethanol diet (to 121.5% of sucrose-fed controls; p less than 0.05). No ethanol-associated changes were apparent in testicular PRL and gonadotropin-releasing hormone (GnRH) receptors or in pituitary GnRH receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Indolo[2,1-a]isoquinolines. Syntheses, steroid hormone receptor binding affinities, and cytostatic activity

A number of acetoxy-substituted 5,6-dihydroindolo[2,1-a]isoquinolines were synthesized and tested for binding affinity for steroid hormone receptors. All of the derivatives bind to the estrogen receptor with RBA values ranging from 1.5 to 17 (17 beta-estradiol = 100). Some of them show binding affinities for the androgen receptor as well. In the mouse uterine weight test, the tetracycles proved to be weak estrogens with partial antagonistic activity. All of the compounds were tested in vitro for cytostatic activity with hormone-independent MDA-MB 231 and hormone-dependent MCF-7 breast cancer cells. A cytostatic effect was found in both cell lines. The comparison of results exhibited a stronger inhibitory effect on MCF-7 cells only for compounds with high binding affinity for the estrogen receptor. For those derivatives, it can be assumed that the growth inhibition is partly mediated by the estrogen receptor.

Greater inhibitory effects for testosterone than castration in rat thyroid tumorigenesis initiated by N-bis(2-hydroxypropyl)nitrosamine

The effects of testosterone and castration on thyroid tumorigenesis subsequent to initiation by N-bis(2-hydroxypropyl)nitrosamine (DHPN) were investigated in male Wistar rats. Following 2 weekly i.p. injections of DHPN at the dose of 210 mg/100 g body weight, testosterone was administered in the diet at concentrations of 0.15% or 0.03% for 28 weeks. Castration was performed on a separate group of animals 1 week after the final injection of DHPN. The incidence of thyroid adenomas and carcinomas were 69% (9/13) and 15% (2/13), respectively, in rats treated with DHPN alone, 0% (0/15) and 6% (1/15) in rats treated with DHPN and 0.15% testosterone, 13% (2/15) and 13% (2/15) in rats treated with DHPN and 0.03% testosterone and 33% (5/15) and 33% (5/15) in the castrated animals initiated by DHPN. The reduction in adenoma development associated with testosterone treatment was significant at both concentrations. In contrast, only a tendency for decrease of thyroid tumor incidence was observed in rats castrated.

Transrectal ultrasonography in disorders of the seminal vesicles and ejaculatory ducts

Ultrasonography is an inexpensive, noninvasive, and reliable means of evaluating the integrity of the distal seminal tract. A variety of rare congenital anomalies can be demonstrated by ultrasound applied either transabdominally or by the transrectal route. Ultrasonography provides a unique insight into the function and pathology of ejaculation that may affect fertility and may well produce new diagnostic criteria to explain some of the more unusual symptoms encountered by urologists in general practice.

Roles of prepubertal androgen, estrogen or androgen plus prolactin on androgen-induced proliferative response of seminal vesicles in adult mice

Male mice castrated on day 0 after birth were pretreated daily with testosterone propionate (TP, 4 micrograms/g body weight), 17 beta-estradiol (E2, 0.2 micrograms/g body weight) or vehicle for 21 days starting from day 20. In another experiment, male mice were castrated on day 25; two pituitaries from 60-day-old females were immediately grafted under the capsule of the left kidney in one group. The castrated mice with or without grafts were pretreated daily with TP (4 or 20 micrograms/g body weight) for 36 days starting from day 25, and the left kidney was removed on day 60. Daily TP injections (4 micrograms/g body weight) were started again at 30 days after the end of pretreatments to examine androgen-induced proliferation, and incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles was used as an index of proliferation. In the neonatally castrated mice, both TP and E2 pretreatments given during the prepubertal period significantly increased seminal vesicle weight even long after the end of the pretreatments. However, androgen-induced proliferative response found in the neonatally castrated adult mice (poor response; long duration with a low peak) was changed to that found in mice castrated at adulthood (good response; short duration with a high peak) by the TP pretreatment only but not at all by the E2 pretreatment. In the mice castrated on day 25, a pharmacological dose of TP or TP plus hyperprolactin could not enhance or change the adult castration type of androgen-induced proliferation induced by physiological prepubertal androgens, although both treatments significantly enhanced the prepubertal growth of the seminal vesicles.

Seminal vesicle imaging

The purpose of this paper is to enhance the understanding of CT, MRI and US images of the seminal vesicles. Accurate interpretation of images requires knowledge of normal anatomy, embryology and pathology. Anatomy and a spectrum of abnormalities are reviewed and discussed. Cases are from an analysis of clinical and surgical files to show the diagnostic features of various cystic diseases of the seminal vesicles. Tissue characteristics of the seminal vesicles on CT, MRI and US images are emphasized.

Effect of androgen pretreatments at adulthood on androgen-induced proliferative response of seminal vesicles in neonatally castrated mice

Male mice were castrated on days 0 and 60 after birth. The majority of the neonatally castrated mice were pretreated with androgen; the mice were given daily injections of testosterone propionate (TP; 4 or 8 micrograms/g body wt) for 20 or 30 days starting from day 60. Daily injections of TP (4 micrograms/g body wt) to examine androgen-induced proliferation were started from day 30 or 60 after the end of TP pretreatments or from day 60 after castration; on various days after starting TP injections, the weight and the incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles were determined as indices for proliferation. The seminal vesicles of neonatally castrated adult mice were characterized by long duration of androgen-induced proliferation (greater than 20 days) with a low peak (neonatal castration type), whereas the seminal vesicles of adult castrated mice were characterized by short duration of proliferation (10 days) with a high peak (adult castration type). In neonatally castrated adult mice, the neonatal castration type of androgen-induced proliferation was changed largely to the adult castration type when pretreatment with 8 micrograms/g body wt of TP had been given for 30 days. However, this effect gradually disappeared when the mice had been pretreated with decreasing amounts of TP for a shorter period. The present findings suggest that the defect in the androgen-induced proliferative response of mouse seminal vesicles induced by the absence of neonatal and prepubertal testicular androgens can be compensated by androgens given in adulthood, if enough androgen is given for a sufficiently long time.

Effect of castration on epididymal sperm storage in male musk shrews (Suncus murinus) and mice (Mus musculus)

Reproductively mature male musk shrews and mice were bilaterally castrated. Epididymal sperm numbers and motility were assessed 0, 2, 4 and 6 weeks after surgery. Seminal vesicle weights and plasma concentrations of total androgens were also measured. In male musk shrews, 30% of the original epididymal sperm numbers were still present 2 weeks after castration and motile spermatozoa were present in 2 of 7 individuals. By 4 and 6 weeks after castration the numbers of spermatozoa remaining declined to about 10% and no sperm motility was noted. Seminal vesicle weights were maintained at about 30% of their original size even up to 6 weeks after castration. In male mice, epididymal sperm numbers, seminal vesicle weights, and androgen levels declined more dramatically after castration. Although androgen concentrations in gonadally intact male musk shrews were approximately 50% of the values in male mice, after castration the concentrations in musk shrews were approximately 2-fold higher than in mice at all times. The results suggest that post-castration retention of epididymal sperm and seminal vesicle weights in the male musk shrew as compared with male mice, is facilitated either by a relatively greater adrenal contribution to circulating androgen levels and/or greater target tissue sensitivity.

Histophysiological changes of sex organs in methylmercury intoxicated mice

Methylmercury (MeHg) treatment intramuscularly at doses of 10 and 20 micrograms separately/day/mouse for 30 days affected the weight of body and organs like testes, vas deferens and seminal vesicles in mice. Diminution of testosterone in serum was also associated with an accumulation of cholesterol in testes and reduction in seminal vesicle fructose. Altered spermatogenesis and Leydig cell morphology in testes and the changes in histoarchitecture of seminal vesicle and vas deferens indicated androgen deficiency in treated mice. Thus, the data suggested that MeHg administration to mice induced androgen deprived effect to target organs probably by blocking Leydig cell function.

Antagonism of androgen and estrogen effects in guinea pig seminal vesicle epithelium and fibromuscular stroma by keoxifene (LY156758)

Using separated epithelium (SVE) and fibromuscular stroma (SVM) of guinea pig seminal vesicle, the antihormonal effects of daily subcutaneous administration (14 and 28 days) of the benzothiophene keoxifene (LY156758; [6-hydroxy-2-(4-hydroxyphenyl)benzo(b) thien-3-yl] [4-(2-1-piperidinyl) ethoxyl] phenyl) methanone hydrochloride) in intact, castrate, and androgen/estrogen-maintained castrate animals was evaluated. The compound was devoid of agonist activity in castrated males, in that the compound had no stimulatory effect on SVM wet weight or DNA content. In vitro cytosolic binding of [3H]estradiol (E2) in the SVM was decreased in a concentration-dependent manner by keoxifene, but the compound did not perturb the binding of [3H]dihydrotestosterone (DHT) in the SVM or SVE. Likewise, keoxifene administration to castrated males treated with exogenous steroids antagonized the estrogen-induced hyperplastic response of the SVM, whereas no interference with androgen-induced growth of the SVM or SVE was observed. Keoxifene treatment of intact male guinea pigs produced regression of the androgen-sensitive SVE as well as the androgen/estrogen-sensitive SVM. Keoxifene-induced decreases in guinea pig serum testosterone levels were associated with this activity. Histological analysis of the seminal vesicle under these conditions suggests androgen deprivation. These findings indicate that keoxifene is a physiological antagonist of androgen action in the intact male guinea pig. The pure estrogen antagonist properties of keoxifene and its ability to decrease accessory sex organ epithelium and fibromuscular stroma in vivo suggest potential applications of the benzothiophenes in the medical management of prostatic neoplasia.

Histological studies on the effects of pineal 5-methoxyindoles on the reproductive organs of the male golden hamster

The effects of late-afternoon injections of melatonin (MEL), 5-methoxytryptamine (MTN), 5-methoxytryptophol (MTOL), and 5-methoxyindole-3-acetic acid (MIAA) on testicular and seminal vesicular histology in the golden hamster were examined. MEL, MTN, and MTOL injections caused a reduction in the diameters of seminiferous tubules and an inhibition of spermatogenesis. Testicular regression ranged from a decrease in the abundance of late spermatids and mature spermatozoa in some animals to an almost complete loss of spermatogenesis in others. Sertoli cells were more resistant to the treatment than other cellular components of the seminiferous tubules. Leydig cells were reduced in size, showed a great reduction in cytoplasm, and possessed shrunken and angular nuclei. The epithelial cells of seminal vesicles were reduced in size and became cuboidal or low columnar. Some secretory cells possessed pyknotic nuclei and had minimal secretory activity. MTN and MTOL appeared to be more potent than MEL in inducing the aforementioned changes, whereas MIAA failed to exert similar effects.

Serum androgen levels in senescent Cr1:CD-1 (ICR)BR mice: effects of castration and testosterone treatment

Serum levels of dehydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone were measured in intact, orchiectomized and orchiectomized-androgen-treated CD-1 mice. Although dehydroepiandrosterone was not detectable in the serum of old mice, approximately half of the very substantial serum concentration of this hormone found in the mature mice appeared to be of adrenal origin. In contrast to dehydroepiandrosterone, serum levels of testosterone and, when detectable, the other androgens, were the same in mature and senescent intact males. Serum levels responded similarly to castration and testosterone replacement. Seminal vesicle weights reflected the similar serum androgen levels found in both age groups. The results indicate that there is neither an age-associated decline in the serum concentration of testosterone nor an apparent alteration in the hepatic and/or peripheral metabolism of testosterone in aging CD-1 male mice.

Regulation of pituitary alpha-subunit, beta-luteinizing hormone and prolactin messenger ribonucleic acid by gonadotropin-releasing hormone and estradiol in hypogonadal mice

We have investigated the effects of three different GnRH injection regimens and the effects of estradiol benzoate (EB) on expression of the common alpha-subunit, beta-LH, and PRL genes in male and female hpg mice. GnRH was injected once daily (100 ng), every 2 h (100 ng) or every 30 min (25 ng), and EB (10 micrograms) was injected once daily. The effects of continuous exposure to the superactive agonist D-Trp6-GnRH released from microcapsules were also studied. Northern blot analysis showed that administration of GnRH increased alpha-subunit mRNA levels 2- to 10-fold in male and female hpg but not normal mice and had no significant effect on beta-LH or beta-TSH mRNA levels. The greatest increase in alpha-mRNA occurred when 100 ng GnRH were injected every 2 h and could be detected within 6 h of the first GnRH injection. More frequent injections (25 ng every 30 min) were less effective in increasing alpha-mRNA, as was prolonged exposure to the D-Trp6-GnRH superagonist. The increase in alpha-mRNA was associated with an increase in pituitary FSH content of similar magnitude. Continuous exposure of the pituitary gland to D-Trp6-GnRH (approximately 1500 ng/day) resulted in a smaller (2-fold) increase in alpha-mRNA and pituitary FSH content, suggesting that desensitization had occurred. EB had little effect on beta-LH mRNA and did not alter alpha-mRNA levels or affect the increase in alpha-mRNA caused by GnRH. Injection of GnRH every 2 h increased pituitary PRL mRNA levels in female but not male hpg mice, probably due to an indirect effect resulting from increased estrogen secretion. We conclude that GnRH administration to hpg mice significantly increases alpha-subunit but not beta-LH mRNA levels and that maximal effects occur with 100 ng GnRH injections every 2 h. Although EB does have direct effects upon pituitary gonadotropin content in hpg mice, the absence of significant changes in alpha- and beta-LH mRNA suggests that these effects may be largely posttranscriptional.

Castration levels of plasma testosterone have potent stimulatory effects on androgen-sensitive parameters in the rat prostate

In order to assess the biological significance of low serum androgens comparable to those which remain after castration in men treated for prostate cancer. Silastic depots continuously releasing predetermined doses of testosterone (T) have been implanted into castrated adult male rats in the absence or presence of simultaneous treatment with the pure antiandrogen Flutamide. Quite remarkably, a 3- to 5-fold increase in prostate weight (P less than or equal to 0.001) was observed at plasma T concentrations comparable to those found in the serum of castrated men. Although of lower magnitude, castration levels of plasma T also caused a significant stimulation of seminal vesicle weight (P less than 0.01). This dramatic stimulatory influence of "castration" levels of plasma T on ventral prostate and seminal vesicle weight can be explained by the 13- to 15-fold higher intraprostatic level of the active androgen dihydrotestosterone (DHT) compared to the plasma T concentration. In fact, a near-maximal intraprostatic concentration of DHT is reached at concentrations of plasma T of 0.2-0.5 ng/ml and a positive correlation was found between prostatic DHT concentration and ventral prostate weight. Prostatic growth and DHT concentrations were also positively correlated with ornithine decarboxylase (ODC) activity, an enzyme highly sensitive to androgens in the rat ventral prostate. In fact, a dramatic (30-fold) increase in ODC activity was observed at plasma T values corresponding to those found in castrated men. The level of prostatic beta 2-adrenergic receptors fell within 10 days of castration and an increase in beta 2-adrenergic receptor concentration was observed with low doses of T, thus indicating that beta 2-adrenoreceptor levels are also a sensitive parameter of androgenic activity in the rat prostate.(ABSTRACT TRUNCATED AT 250 WORDS)