Weights Of Accessory Sex Glands Research Articles

Effects of olfactory bulbectomy, melatonin, and/or pinealectomy on three sublines of the Dunning R3327 rat prostatic adenocarcinoma.

Conventional antiandrogen therapy for prostatic cancer generally results in the death of androgen-dependent cells, resulting in shrinkage of the tumor, followed by regrowth of the tumor as androgen-insensitive cells take over. Because of reported antigonadotropic and antineoplastic effects of the pineal hormone melatonin (MEL), we hypothesized that this indole might provide an effective therapy for prostate cancer, as it would be effective against both populations of tumor cells. We used three sublines of the Dunning R3327 rat prostatic adenocarcinoma to determine whether MEL could suppress the growth of these tumors and, if so, by what mechanisms this occurs. In one experiments, we compared the growth of a well-differentiated slow-growing Dunning tumor in rats given MEL combined with the potentiating procedure olfactory bulbectomy (BULBX), with that in rats pinealectomized (PINX) or untreated. Tumor growth in BULBX-MEL rats was significantly suppressed over that in the other two groups, as were the weights of the gonads and accessory sex glands. Tumor morphology, DNA concentration, and androgen receptor concentration and distribution were identical in untreated controls and in BULBX-MEL rats, suggesting that the treatment affected all populations of tumor cells equally. With another strain of well-differentiated slow-growing Dunning tumor, we examined the effects of MEL in rats with and without BULBX. Reproductive parameters were not suppressed in BULBX-MEL rats and, while there was a trend toward slower tumor growth in this group, this was not significant. Intact rats given MEL grew larger tumors than did control rats but, again, differences were not significant. In a third experiment, we examined a fast-growing androgen-insensitive anaplastic Dunning tumor. PINX was without effect on this tumor, but BULBX-MEL resulted in a significant suppression of one of the constants in the logistic equation fitted to the growth curves. This indicates that there were some direct antitumor effects of BULBX-MEL on this tumor strain. We conclude that MEL suppresses growth of some Dunning tumor strains.

Effect of active immunization against LHRH or LH in boars: reproductive consequences and performance traits.

Forty crossbred boars were equally divided into eight groups at birth. Four groups were immunized (200 micrograms/boar) at 12 wk of age against either luteinizing hormone-releasing hormone (LHRH) conjugated to human serum globulin (LHRH-hSG) in complete Freund's adjuvant (CFA), LHRH-hSG in muramyldipeptide adjuvant (PEP), procine luteinizing hormone (LH) conjugated to hSG (pLH-hSG) in CFA or ovine LH (oLH) in CFA. Equal doses of boosters were given in either PEP or incomplete Freund's adjuvant (IFA) at 16 and 18 wk of age. Two groups of boars were immunized with either hSG + CFA or hSG + PEP (adjuvant controls). Two groups were castrated either at the time of weaning (castrate weaning) or at 16 wk when immunized boars were given their first booster injections (castrate booster). All pigs were slaughtered at 24 wk of age. Serum levels of LH and testosterone (T), LHRH or LH antibody titers, as well as testicular and accessory sex gland weights and histology were determined. By wk 16, LHRH antibody titers began to rise in those boars immunized against LHRH-hSG. Luteinizing hormone-releasing hormone antibody titers on wk 18, 20 and 22 were greater than those at wk 16. By 22 wk of age, LHRH-hSG boars had non-detectable plasma LH and T and reduced weights of testes and acessory sex glands. Boars immunized against oLH did not respond to treatment, whereas pLH-hSG boars showed a reduction in serum T levels and accessory sex gland weights. Immunization had no effect on average daily gain, hot carcass weights or loin eye area.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of short‐day photoperiods and of castration on the structural integrity of the ventral and dorsal prostates of the Syrian hamster (Mesocricetus auratus)

Short-day photoperiods and castration both cause reductions in the weights of male accessory sex glands. In the Syrian hamster, we have found that the ventral prostate loses less weight following these treatments than does the dorsal prostate. In this paper, we report on the effects of the pineal and of castration on the structural integrity of these glands, as assessed by stereological techniques. Short days result in little alteration to the ventral prostate or its acinar composition. The typical acinus is narrower following 10 weeks in short days. The ventral prostate also responds to castration with a narrower acinus, and, in addition, it shows a decrease in the epithelial volume fraction and increases in those of the lumen and muscular stroma. In neither case is there a change in the proportion of the gland consisting of acinar or interacinar components. Short-day photoperiods and castration generally show similar effects in the dorsal prostate. In both cases, there are increases in the proportion of the gland made up of interacinar tissue. Within the acini, there are decreases in the volume fractions of lumen and large increases in those of lamina propria and muscular stroma. Following both treatments, typical acini are narrower and show reduction in the thickness of the epithelium and increases in the thickness of the lamina propria and muscular stroma.Thus, in the ventral prostate, both short days and castration lead to subtle changes which are different with each treatment and which differ from those that occur in the dorsal prostate. In the dorsal prostate, there are relative increases in the proportions of nonepithelial elements following both of these treatments. These results are discussed in relation to the mode of action of the pineal in causing accessory sex gland regression.

The effects of estradiol, tamoxifen, and testosterone on the weights and histology of the epididymis and accessory sex organs of sexually immature rabbits.

The effects of estradiol benzoate (EB), testosterone propionate (TP), and Tamoxifen, alone or in combination, on the weight and morphology of the male accessory sex glands were studied in intact and in castrated immature rabbits. TP treatments (2 mg/kg) exerted a stimulatory effect on the glands, resulting in a significant increase in the weight of the epididymis, the proprostate, and the prostate of castrated rabbits, and of the bulbourethral glands of both intact and castrated rabbits, and in marked morphological changes in all the glands. the epithelium was stimulated but retained its pseudostratified columnar appearance and resembled more the epithelium of normal mature males than that of age matched controls. The bulbourethral glands were the most responsive and the vesicular gland the least responsive to androgen treatment. The response of the glands to EB (25 micrograms/kg) was characterized by significant weight increases in all the glands of both castrated and intact rabbits, hypertrophy of the musculo-fibrous components and proliferation of the basal layer of the epithelium leading to squamous metaplasia and leukocytic infiltration. Hyperplasia of the fibromuscular stroma was most evident in the cauda epididymidis and in the vesicular gland. Squamous metaplasia and leukocytic infiltration were most evident in the ejaculatory duct and in the structures adjacent to it. The antiestrogen, Tamoxifen (250 micrograms/kg), and TP (2 mg/kg) given in conjunction with EB (25 micrograms/kg) tended to reduce the weight increase caused by estrogen, but the decrease was significant in only a few instances. Tamoxifen (250 micrograms/kg) administered alone stimulated the epithelium of the accessory sex glands and induced squamous metaplasia, but did not induce hyperplasia of the fibromuscular stroma. The study demonstrates that accessory sex glands display a consistent pattern of differential sensitivity to both androgens and estrogens and that these hormones exert their action on different cell types within the organ.

Comparison of the Antispermatogenic Effects of a New D-Homo-Steroid and Testosterone in Rabbits

In comparison to testosterone, 18 beta-hydroxy-18 alpha-methyl-16 alpha-methylene-D-homo-5 alpha-androstane-3-one (D-homo-S) shows more pronounced anti-gonadotrophic than androgenic properties in rats. The present study was initiated in rabbits to investigate the potential of D-homo-S to suppress spermatogenesis. D-homo-S in sesame oil was administered at the doses of 0.1 (DI), 3 (D II) or 10 mg (D III) per rabbit each day for 8 weeks. During treatment serum testosterone, sperm concentration and quality of sperm motility decreased, whereas sex drive, semen volume and seminal plasma concentrations of fructose and zinc were not changed in any of the groups. Testicular weight and intratesticular testosterone concentration decreased significantly in groups D II and D III, while weights of accessory sex glands increased in those groups. Testosterone in the same dose regimen did not suppress sperm count, motility or serum testosterone, however, seminal plasma zinc concentration in group T III and fructose in group TI increased. Testicular weight and intratesticular testosterone concentration decreased in group TIII only. On the other hand, the weight of the accessory sex glands increased in the same group. In conclusion, D-homo-S suppresses spermatogenesis and increases accessory sex gland weights at doses, when testosterone is still ineffective. Thus, in rabbits D-homo-S appears to be a more potent androgen than testosterone but a dissociation between antigonadotrophic and androgenic properties could not be observed.

Teratogenic effects of benomyl in the Wistar rat and CD-1 mouse, with emphasis on the route of administration

Benomyl, a systemic fungicide whose molecular basis of action is inhibition of tubulin polymerization, was administered during organogenesis via the dietary and gavage routes to pregnant Wistar rats, and via the gavage route to pregnant CD-1 mice. Benomyl was fetotoxic and teratogenic in both species via the po route of administration, producing a broad spectrum of malformations at a dose of 62.5 mg/kg/day in the rat and 100 mg/kg/day in the mouse. Via the dietary route of administration, benomyl produced fetotoxicity, but no teratogenic effects. The fetotoxic potential of benomyl from dietary exposure was approximately an order of magnitude less effective than from gavage exposure. Benomyl did not affect postnatal growth, viability, or locomotor activity at subteratogenic doses. The most sensitive indicator of perinatal exposure to benomyl via the po route of administration was a permanent reduction in testes and accessory sex gland weight noted in male offspring of dams receiving 31.2 mg/kg/day benomyl during gestation and lactation. No effects on any parameters were evident in rats receiving 15.6 mg/kg/day by po gavage. The relevance of the two routes of administration for risk extrapolation is discussed.

Testosterone regulation of luteinizing hormone and follicle stimulating hormone secretion in young male lambs.

Polydimethylsiloxane (Silastic) capsules containing crystalline testosterone were implanted subcutaneously in castrate lambs and evaluated for their ability to (1) provide stable, physiological concentrations of serum testosterone and (2) regulate secretion of LH and FSH. Testosterone was nondectable (< .2 ng/ml) between 12 and 24 weeks of age in the serum of castrate lambs implanted with empty capsules but was increased at those ages in lambs implanted with 20 cm (1.2 +/- .1 and .5 +/- .1 ng/ml), 60 cm (2.8 +/- .1 and .9 +/- .1 ng/ml) and 180 cm (6.6 +/- .3 and 1.9 +/- .2 ng/ml) of testosterone-filed Silastic tubing. Serum concentrations of LH and FSH were suppressed by exogenous testosterone and did not exceed concentrations in intact control rams as long as serum testosterone concentrations were greater than 1 ng/ml. In conclusion, simultaneous suppression of serum LH and FSH by concentrations of testosterone that cause a dose-dependent stimulatory effect on accessory sex gland weights indicates that testosterone is a physiological regulator of gonadotropin secretion in ram lambs. Although testosterone per se may not be directly responsible for negative feedback on LH and FSH secretion, the results presented herein question the need for a nonsteroidal "inhibin-like" testicular hormone to regulate FSH in lambs.

Chronic methadone administration to male rats: Tolerance to adverse effects on sires and their progeny

Previous studies have shown that acute administration of methadone to male rats prior to mating results in adverse effects on their progeny, particularly decreased birth weights and increased neonatal mortality. Rather than chronic administration accentuating these effects, results of the present study indicate that tolerance developed so that no adverse effects were found in offspring sired after 21–32 days of methadone administration. In the sire, maintenance of normal weights of accessory sex glands after 4 months of daily methadone suggests that tolerance developed to the CNS effect(s) responsible for the depressed serum LH and testosterone levels found after acute administration of narcotics. In contrast, tolerance did not developed to the inhibition of weight gain produced by methadone administration. No evidence for a dominant lethal effect could be found after chronic methadone administration, in contrast to suggestive evidence for this effect found in previous experiments after acute methadone administration.

Action of androgen and estrone implants on sexual behavior and reproductive organs of castrated male rabbits

Sexually mature but inexperienced male rabbits were castrated, immediately implanted with either testosterone (T), estrone (E 1), dihydrotestosterone (DHT), T + E 1, or DHT + E 1, and tested for male sexual behavior. Other castrates were not implanted, and testing was either begun immediately (Ca-I) or delayed for 4 weeks (Ca-D). Intact males served as controls (C). Latency to mount a teaser female and to ejaculate into an artificial vagina was tested twice in a morning three times per week for 8 weeks. Then, animals were sacrificed, and reproductive organs were measured. The Ca-I group responded slowly to sexual training and ceased nearly all sexual activity by 8 weeks, whereas the Ca-D males seldom displayed interest in the teaser female. Intact controls and the T and T + E 1, groups all responded to the teaser and mounted and ejaculated within a few seconds. DHT and E 1, individually maintained the sexual activity of castrates equivalent to that of C for 4–5 weeks, but the time required to mount and, particularly, to ejaculate increased thereafter. The results with DHT + E 1 were equivocal in that castrates with this hormone combination sustained sexual activity equivalent to that of the controls for 7 weeks, but one animal in particular became sexually inactive the last week of the experiment. Penis weight was at least partially maintained in all implanted castrates. Accessory sex gland weight was smallest in the DHT group and was significantly increased in the T + E 1 and DHT + E 1 groups. The largest ejaculates of fluid were obtained in the group receiving E 1 alone. These results may be interpreted to indicate a role of both androgen and estrogen centrally and peripherally in the rabbit.

Inhibition and maintenance of spermatogenesis in rats implanted with polydimethylsiloxane capsules containing various androgens.

SUMMARY Polydimethylsiloxane (PDS) capsules providing surface areas of 50, 75, 100, 200, 400 and 2000 mm2 were filled with testosterone, testosterone cypionate (TC), or testosterone propionate (TP) and were implanted (s.c.) into sexually mature rats for 56 days to determine the efficacy of this mode of androgen administration in suppressing or maintaining spermatogenesis. Rats that received 75 mm2 capsules of TP and 200 mm2 capsules of testosterone or TC were azoospermic and had a 45–50% reduction in testicular weight. Moreover, immunoreactive serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations declined eightfold below control values, but plasma testosterone titres and the dry weight of the accessory sex glands were not affected (P &gt; 0·10). Conversely, 2000 mm2 capsules of testosterone, TC or TP maintained testicular weight and induced accessory sex gland hypertrophy as well as a five- to eightfold increase in the concentration of plasma testosterone. The relative number of germ cells at stage VII of the cycle of the seminiferous epithelium was not affected (P &gt; 0·15) by 2000 mm2 testosterone capsules even though immunoreactive serum LH and FSH concentrations remained at least eight-fold below control values. Similar implants containing TC or TP maintained germ cell numbers within 83% of control testes. The results establish that PDS capsules releasing 'low' doses of testosterone, TC or TP induce azoospermia without affecting plasma testosterone concentration or accessory sex gland weight, and that similar capsules releasing 'high' doses of testosterone maintained spermatogenesis quantitatively up to and including step 7 of spermiogenesis.

Long-term testicular responses to blinding in rats

Gonadal responses to the blinding of one month old rats have been studied at 1,2,3,5,7,9, and 12 month intervals post-surgically. Testosterone in both testicular vein and peripheral venous plasma was measured by radioimmunoassay and spermatogenesis was evaluated by means of differential germ cell counting. The weights of endocrines and accessory sex glands were routinely recorded. Blinding was without effect upon gametogenic function of the testis, at all intervals of study. Testicular venous levels of testosterone in intact rats showed a ‘post-pubertal spurt’ followed by a more pronounced ‘seasonal peak’ and the latter was paralleled by a similar peak in peripheral testosterone. Blinding led to suppression of the post-puberal surge in testicular secretion but testicular vein levels of the hormones were not significantly altered from control values for the remainder of the investigation. In contrast, testosterone concentrations in peripheral plasma of blinded rats were more consistently lower than in control animals until 12 months post-surgery. Atrophic responses of the accessory sex glands to blinding occurred during the initial periods of the study but these had totally disappeared by 9 months. Taken together, the results illustrate a somewhat small degree of gonadal dependency upon photic input in the male rat, particularly when compared with responses reported for the hamster subjected to similar experimental conditions.

Effect of testosterone polydimethyl-siloxane implants upon sperm production, libido and accessory sex organ function in rabbits.

Summary. Testosterone-filled polydimethylsiloxane (PDS) capsules (0·245 mm wall thickness) were placed subcutaneously in normal adult male rabbits to assess the relationship between the surface area of the implant and the amount of testosterone released. Testosterone release was quantified in terms of plasma testosterone concentrations and other biological endpoints such as libido, accessory sex organ weight, seminal fructose and citric acid levels and spermatogenic activity. Subcutaneous placement of PDS capsules ranging from 100 to 800 mm2 in surface area had no measurable (P>0·25) effect on (1) plasma testosterone concentrations, (2) libido, (3) accessory sex gland weight, and (4) the concentrations of fructose and citric acid in seminal fluid. The total daily sperm production and the number of step-6 spermatids decreased linearly with each successive increase in capsule surface area. It was concluded that testosterone-filled PDS capsules (800 mm2) induced azoospermia in rabbits without any significant (P>0·25) alteration in either plasma testosterone or the weight and secretory activity of the accessory sex glands.

Relationship between blood levels of testosterone and accessory sex gland weights in impala ( Aepyceros melampus)

1. 1. In twenty-two male impala, plasma testosterone levels have been compared with weights of seminal vesicles and bulbourethral glands. 2. 2. The results show that single measurements of circulating testosterone are unrelated to weights of accessory sex glands. 3. 3. This finding may be explained if it is assumed that plasma testosterone levels fluctuate more rapidly than the accessory glands can respond. 4. 4. In light of this evidence, it seems necessary to modify the view that plasma concentrations of testosterone bear a direct relationship to its physiologic effect on target organs.

Plasma testosterone and accessory sex glands in normal and cryptorchid rats.

SUMMARY Plasma testosterone concentration and the weights of the seminal vesicles and ventral prostate gland were measured in normal and cryptorchid Fischer rats at 3, 4·5, 7·5 and 13·5 months of age, and in normal parabionts and cryptorchid parabionts of 13·5 months of age. Testosterone was measured individually by a protein-binding method. In normal rats, all parameters rose to a maximum at 7·5 months of age, then levelled off or declined at 13·5 months of age. In cryptorchid rats, a similar pattern at a lower level was found for accessory sex gland weight, but plasma testosterone levels showed a progressive decline from an above normal level at 3 months to a subnormal level at 13·5 months of age. Cryptorchid parabionts were less responsive to gonadotrophin stimulation from union with a castrated partner than normal parabionts. The present study showed that plasma testosterone levels in normal and cryptorchid rats are age-related. It also showed that the pattern of plasma testosterone levels observed in cryptorchid rats is different from that seen in normal rats. Accessory sex gland weight is also age-related but is not a reliable index of plasma testosterone levels.