Short-term effects of mating on the accessory sex glands of the male rat

Mating in the rat was associated with a significant reduction in the tissue concentrations of the presumptive secretory products of the male accessory sex glands: prostatein and the amines, putrescine, spermidine and spermine (ventral prostate lobe), zinc (lateral prostate lobe) and fructose (coagulating gland). The amount of secretory product discharged and the time taken to restore precopulatory levels differed for the different lobes. Within 12-24 h of the mating period, the activity of ornithine decarboxylase and cytosolic oestrogen binding in the ventral prostate lobe underwent a transient increase which lasted 2-3 days. No change was observed in prolactin binding. Circulating testosterone concentrations were significantly elevated above control values 12 h after the start of mating but were significantly lower than control values at 24 h. A gradual recovery to concentrations in controls occurred over the next 2-3 days. None of these changes could be explained by alterations in gonadotrophin or prolactin release.     

A difference in the in vitro accumulation and metabolism of testosterone -1,2-3H by the rat prostate gland following incubation with ovine or bovine prolactin

The $\text{in vitro}$ actions of ovine or bovine prolactin on the accumulation and metabolism of testosterone-1,2-³H by various lobes of the rat prostate gland were examined. Ovine prolactin at a concentration of 2 IU/ml of incubation media significantly increased the accumulation of total radiosteroid by the anterior and dorsal lobes of the rat prostate gland. Although the levels of both testosterone-1,2-³H and its principle metabolite 5α-dihydrotestosterone-1,2-³H were increased by this concentration of ovine prolactin, the ratio of the two steroids was not altered. Ovine prolactin did not alter either the accumulation or metabolism of testosterone-1,2-³H by the ventral or lateral lobes of the rat prostate gland.In contrast to ovine prolactin, bovine prolactin in a wide range of concentrations (0.02–8 IU/ml) significantly reduced the accumulation of total labeled radiosteroid by the dorsal lobe of the rat prostate gland. The reduction in total radiosteroid was reflected in concomitent decreases in both testosterone-1,2-³H and 5α-dihydrotestosterone-1, 2-³H. The anterior lobe responded with similar reductions but only at relatively high concentrations of bovine prolactin (4 and 8 IU/ml). No significant alterations were observed in either the ventral or lateral lobes as a result of incubation with bovine prolactin.     

睾酮对雄家猫附性器官金属硫蛋白的诱导

睾丸切除后,家猫前列腺背叶、腹叶及尿道球腺内的金属硫蛋白（ｍｅｔａｌｏｔｈｉｏｎｅｉｎ,ＭＴ）分别下降至正常家猫的２１２％（Ｐ＜００１）、８８４％（Ｐ＞００５）和１８５％（Ｐ＜００１）,而在腹叶影响较小。睾丸切除后注射芝麻油,前列腺背叶及尿道球腺ＭＴ均未得到恢复。但若在睾丸切除后连续３ｄ注射１０μｇ／ｋｇｂｗ睾酮,两者依次恢复至６９３％和５９４％。随睾酮注射剂量增加（５、１０、１５、２０、２５μｇ／ｋｇｂｗ）,血浆睾酮的浓度、前列腺背叶及尿道球腺ＭＴ含量增高。血浆睾酮与前列腺背叶及尿道球腺ＭＴ呈正相关（Ｐ＜００１）。这些结果表明,睾酮诱导前列腺背叶及尿道球腺ＭＴ,其最适剂量为２０μｇ／ｋｇｂｗ。     

Expression of the ZNT (SLC30) family members in the epithelium of the mouse prostate during sexual maturation

A prostate contains ~10-fold higher zinc than other soft organs. The function of the prostate is to produce a zinc-enriched seminal fluid. To establish a protein expression profile for zinc transporters involved in zinc efflux and intracellular sequestration/storage in the mouse prostate during sexual maturation, ZNT expression were investigated by immunohistochemistry. Our study demonstrated that ZNT proteins were differentially expressed in the prostate during sexual maturation. ZNT1 was mainly detected on the lateral membrane of the epithelium. Other ZNTs examined resided intracellularly. Among differences were a staining of ZNT2/ZNT5 in the ER-rich area of the epithelium in the anterior lobe, a staining of ZNT2 along the lateral and apical membrane, a luminal border staining of ZNT4, a staining of ZNT5 in the Golgi area of the epithelium in the ventral lobe, a uniform expression of ZNT6 across the lobes and ages, and a staining of ZNT7 in all lobes across ages.     

The bioavailability of different zinc compounds used as human dietary supplements in rat prostate: a comparative study

The normal human prostate accumulates the highest levels of zinc (Zn) of any soft tissue in the body. The pool of zinc available to the body is known to significantly decrease with age. It is suggested that dietary Zn supplementation protects against oxidative damage and reduces the risk of cancer. Zinc sulfate and zinc gluconate were the most frequently mentioned in per os administration in studies on Zn supplementation. The major aim of the study was to compare the bioavailability of different Zn compounds (sulfate, gluconate and citrate) in the prostate after their daily administration to male rats at three different doses (3.0; 15.0; and 50.0 mg Zn/kg b.w.) for 30 days. The results show that bioavailability in the prostate differs significantly between individual zinc preparations. A significantly elevated Zn concentration in the dorso-lateral lobe of the prostate, compared to controls, was found in the rats supplemented with two compounds only: zinc gluconate and zinc citrate. However, after administration of zinc gluconate, this effect occurred even at the lowest dose. The lowest zinc bioavailability in the prostate was found in the rats administered zinc sulfate: no significant Zn increase was seen in particular zones of the prostate. To sum up, the use of zinc gluconate is worth considering as a possible means of zinc supplementation in men.     

Localization of metallothionein in the genital organs of the male rat

We studied the immunohistological localization of metallothionein (MT), a low molecular weight metal binding protein, in male rat genital organs (testis, epididymis, ejaculatory duct, seminal vesicle, coagulating gland, and prostate) by use of the avidin-biotin-peroxidase complex method. MT concentrations in testis, seminal vesicle, and prostate ranged from 15-30 micrograms/g tissue. In testis, seminiferous tubules with mature spermatozoa exhibited weak MT staining, whereas the tubules containing differentiating spermatogenic cells but not containing spermatozoa showed strong MT staining. No MT immunostaining was observed in Leydig cells. In growing rat testes, the pattern of MT immunostaining was found to change with development: MT was found in supporting cells only on Day 7, spermatogonia adjacent to basement membrane on Day 14, and spermatocytes localized in the central part of the tubules on Day 21. Strong MT immunostaining in the basal cells was a common feature in other genital tissues, except the ductus efferentes. In prostate, the strongest MT staining was found in the lateral lobe, and MT was localized in apocrine secretions in the dorsal lobe. The present results suggest a close association of MT with cell proliferation and differentiation, as well as possible involvement of MT in supply or storage of zinc ions.     

Zinc transporter expression profiles in the rat prostate following alterations in dietary zinc

Zinc plays important roles in numerous cellular activities and physiological functions. Intracellular zinc levels are strictly maintained by zinc homeostatic mechanisms. Zinc concentrations in the prostate are the highest of all soft tissues and could be important for prostate health. However, the mechanisms by which the prostate maintains high zinc levels are still unclear. In addition, the response of the prostate to alterations in dietary zinc is unknown. The current study explored cellular zinc levels and zinc transporter expression profiles in the lobes of the prostate during dietary marginal zinc depletion. Rats were given either zinc-adequate (ZA, 30 mg Zn/kg) or marginal zinc-deficient (MZD, 5 mg Zn/kg) diet for 9 weeks. In addition, a subgroup of the MZD rats was supplemented with phytase (1,500 unit/kg diet) to improve zinc bioavailability. We found that both zinc concentrations and ZnT2 expression in the prostate dorsolateral lobes were substantially higher than in the ventral lobes (P < 0.05). Marginal zinc depletion significantly decreased ZnT2 expression in the dorsolateral lobes (P < 0.05), and phytase supplementation had a trend to increase ZnT2 expression. In addition, of all measured zinc transporters, only ZnT2 mRNA abundance was significantly correlated to the zinc concentrations in the dorsolateral lobe. No correlations were found between zinc transporter expression and zinc concentrations in the ventral lobes. These results indicate that ZnT2 may play a significant role in the maintenance of zinc homeostasis in the prostate.     

Short-term effects of prolactin on prostatic function in rats with lisuride-induced hypoprolactinaemia

The effects of a single injection of ovine prolactin on prostatic function were monitored in intact, intact androgenized and castrated-androgenized rats rendered hypoprolactinaemic after 7 days of treatment with a potent dopamine agonist, lisuride. Hypoprolactinaemia was associated with reductions in ventral prostate weight, polyamine levels, lateral lobe zinc and the concentration of the ventral prostate protein prostatein, but an elevation in the level of cytosolic oestradiol binding. Whether these differences attained statistical significance depended on whether the animals were intact, intact-androgenized or castrated-androgenized. With the exception of ventral prostate weight and lateral lobe zinc concentrations, a single injection of prolactin restored or reversed these changes towards control levels within 12 h, which could not be explained by an indirect effect of the hormone on adrenal or testicular function. No effects of lisuride or prolactin were observed with regard to the content of fructose in the coagulating gland or in the degree of prolactin binding to prostatic membranes.     

Longitudinal changes in zinc transport kinetics, metallothionein and zinc transporter expression in a blood-brain barrier model in response to a moderately excessive zinc environment

A blood-brain barrier (BBB) model composed of porcine brain capillary endothelial cells (BCEC) was exposed to a moderately excessive zinc environment (50 micromol/L Zn) in cell culture, and longitudinal measurements were made of zinc transport kinetics, ZnT-1 (SLC30A1) expression and changes in the protein concentration of metallothionein (MT), ZnT-1, ZnT-2 (SLC30A2) and Zip1 (SLC39A1). Zinc release by cells of the BBB model significantly increased after 12-24 h of exposure, but decreased back to control levels after 48-96 h, as indicated by transport across the BBB from both the ablumenal (brain) and the lumenal (blood) directions. Expression of ZnT-1, the zinc export protein, increased by 169% within 12 h, but was no longer different from controls after 24 h. Likewise, ZnT-1 protein content increased transiently after 12 h of exposure, but returned to control levels by 24 h. Capacity for zinc uptake and retention increased from both the lumenal and the ablumenal directions within 12-24 h of exposure and remained elevated. MT and ZnT-2 were elevated within 12 h and remained elevated throughout the study. Zip1 was unchanged by the treatment. The BBB's response to a moderately high zinc environment was dynamic and involved multiple mechanisms. The initial response was to increase the cells' capacity to sequester zinc with additional MT and to increase zinc export with the ZnT-1 protein. But the longer-term strategy involved increasing ZnT-2 transporters, presumably to sequester zinc into intracellular vesicles as a mechanism to protect the brain and to maintain brain zinc homeostasis.     

The ultrastructure of the accessory sex organs of the male rat

Summary A systematic, comparative study of the accessory sex organs of the adult male rat was carried out after intra-aortic perfusion of the pelvic organs with glutaraldehyde. It has been revealed that although the epithelial cells of the different lobes of the prostate have many features in common, it is also apparent that the cell type of the various lobes have specific ultrastructural characteristics of its own, which morphologically distinguish it from the cell type of the other lobes. I.e.: the different lobes may be identified by their specific ultrastructural feature. It is also striking that the lobes, two-by-two, have so many morphological features in common that they may be divided in 3 subgroups. Based on the appearance of amount and localisation of the different organelles, the cells of the lateral lobe and the seminal vesicle are so alike that they morphologically may be classified as one group. Similarly, the coagulating gland and the dorsal lobe form another group, while the ventral lobe as a single form a third group. The few biochemical data from the different lobes which are accessible, seem suggestive to support this subgrouping.Since the various prostate lobes and the seminal vesicles have their homologies in man, further investigation both morphologically and biochemically should be concentrated upon the different groups instead of the single lobe.The study, which describes the different lobes and cell types in detail also show structures which have not been demonstrated within the prostatic epithelium before.     

Morphological and immunohistochemical comparison of three rat prostate lobes (lateral, dorsal and ventral) in experimental hyperprolactinemia

The prolactin plays an important role in the regulation of growth and differentiation of prostate gland besides androgens. The goal of this study was to reveal the influence of elevated prolactin concentration on epithelial cells of prostate. We compared the morphology of epithelial cells of prostate dorsal, lateral and ventral lobes and expression of androgen receptors in these cells in rats with hyperprolactinemia and in control rats. We used sexually mature male Wistar rats. The experimental rats received metoclopramide; the control group received saline in the same way. The prostate dorsal, lateral and ventral lobes were collected routinely for light and electron microscopy. The intensity of immunohistochemical reaction of androgen receptor in epithelial cells of dorsal, lateral and ventral lobes was evaluated by measure of optical density with computer image analysis. The light and electron (transmission and scanning) microscopes were used for morphological observations. Results: In experimental rats twofold increase in prolactin and twofold decrease in testosterone found. In experimental group the expression of androgen receptor was lower in columnar epithelial cells of dorsal and ventral lobes but higher in lateral one. We observed morphological abnormalities in columnar epithelial cells of lateral and dorsal lobes. The columnar epithelial cells of ventral lobes didn't show any morphological changes in hyperprolactinemia.     

Nuclear zinc in liver of cadmium and zinc treated rats

X-ray microanalysis was performed to detect quantitatively, the variation of the nuclear zinc in the liver cells of rats. The nuclear zinc concentration showed statistical decrease and increase in response to cadmium and zinc treatments, respectively. The results suggest that the liver responds differently to cadmium and zinc treatments. The difference in response to either treatment may reflect different mechanisms of zinc transport and metabolism in the liver. The difference in binding affinity of metallothionein (MT) may suggest the involvement of Mt in the metabolism and transport of zinc, an effect, which may be modified by treatment.     

Metallothionein can function as a chaperone for zinc uptake transport into prostate and liver mitochondria

In mammalian cells the cytosolic concentration of free Zn(2+) ions is extremely low (nM-fM range) and unlikely to provide an adequate pool for the uptake and accumulation of zinc in mitochondria. We previously identified a mitochondrial uptake transport process that effectively transports zinc directly from low molecular weight zinc ligands independent of and in the absence of available free Zn(2+) ions. Since metallothionein (MT) is an important ligand form of cellular zinc, we determined if Zn(7)-MT was an effective chaperone and donor for delivery and uptake of zinc by prostate and liver mitochondria. The results reveal that both intact mitochondria and mitoplasts effectively accumulated zinc from Zn(7)-MT. The study confirms and extends our previous report that the putative zinc transporter is associated with the inner mitochondrial membrane and involves a direct exchange of zinc from the ligand to the transporter. The ventral prostate cells contain no detectable MT; so that ligands (such as citrate, aspartate) other than MT are zinc donors for mitochondrial zinc accumulation. However, in liver and perhaps other cells, Zn(7)-MT is probably important in the cytosolic trafficking of zinc to the mitochondria for the uptake of zinc into the mitochondrial matrix by the putative zinc uptake transporter.     

Differential regulation of androgen receptors in the separate rat prostate lobes: androgen independent expression in the lateral lobe

In order to understand the hormonal regulation of androgen receptors (AR) in the separate lobes of the rat prostate gland, the present study examined AR levels in the ventral, dorsal and lateral prostate lobes as a function of androgen withdrawal to complete prostatic regression and subsequent testosterone replacement. In the intact rat, the 3 prostate lobes contained significantly different amounts of androgen binding sites. Mean number of total cellular AR in the ventral, dorsal and lateral lobes was 7370, 1690, and 1015 fm/mg DNA, respectively. These receptors were primarily localized within the nuclear fraction of homogenized tissue: ventral, 86%; dorsal, 83%; and lateral, 100% nuclear localization. Androgen withdrawal was initiated via castration and rats were sacrificed 1, 2, 3, 5, 7, 10 and 14 days thereafter. Nuclear AR levels fell rapidly to 5, 24 and 30% of intact values by 48 h in the ventral, dorsal and lateral lobes, respectively. Levels of nuclear AR continued to decline in the ventral and dorsal lobes to undetectable levels by Day 10. In marked contrast, lateral lobe nuclear AR began to increase on Day 3 postcastration, reaching intact values by Day 7 and 133% intact levels by Day 14. Cytosolic AR in the ventral and dorsal lobes initially increased following castration, but subsequently declined to low levels by Day 14. Cytosolic AR were not detectable in the lateral prostate at any time point following castration. To determine the nuclear AR response to testosterone at this time, 14 day castrate rats were given 2 cm testosterone implants and sacrificed 1, 3, 5, 7, 10 and 14 days thereafter. As expected, nuclear AR rapidly returned in the ventral and dorsal lobes by Day 1 and reached a plateau by Day 5. A short term response to androgen exposure occurred in the lateral lobe where an immediate 9-fold increase in nuclear AR quantity was observed; however, these levels rapidly declined to pre-implant values by Day 5 and remained at that level despite continued exposure to testosterone. These f findings indicate that while nuclear AR levels in the ventral and dorsal prostate are primarily regulated by androgens, a testosterone-independent component exists within the lateral lobe.     

Induction of metallothionein by exposure to normobaric 100% oxygen atmosphere in rats with different zinc supply

The objective of this study was to determine the effects of an oxygen enriched environment on the induction of the metalloprotein metallothionein (MT) and its relation to zinc metabolism in rats supplied with different levels of dietary zinc. Male albino rats were fed purified diets based on maize starch, egg white, saccharose and soybean oil differing in the concentration of zinc (1; 20; 100; 500 mg Zn/kg diet). At a dietary zinc supply of 1 mg/kg, the rats developed a zinc deficiency indicated by visual and biochemical parameters. At the end of the 37-day feeding period, half of the rats were exposed to 100% oxygen for 12 h.

The oxygen treatment significantly reduced plasma zinc in the zinc supplemented rats and reduced it in tendency in the zinc deficient rats. The MT concentration was increased in the zinc supplemented groups in the liver, kidney and lung. The oxygen treatment elevated the metallothionein concentration in the two high zinc supplemented groups (100 and 500 mg Zn/kg diet) in the liver. The response of the zinc concentration in plasma and of hepatic metallothionein levels to oxygen exposure indicates a role of metallothionein in zinc distribution or interactions with other trace elements to support antioxidant capacity, rather than an impact on direct scavenging activity of free radicals.     

Structural changes of the guinea pig prostatic epithelial cells after gossypol treatment

The effect of gossypol acetic acid on the prostate gland of the guinea pig was assessed ultrastructurally. The three lobes of the gland showed differences in sensitivity and reacted differently to gossypol treatment. In the lateral prostate, there was a reduction in the profile of the granular endoplasmic reticulum and dense secretory granules with a concurrent appearance of smaller clear granules and an increase in cytoplasmic filamentous bundles. The latter feature was similar to that of the coagulating gland. In the dorsal prostate, the general reaction was similar to that in the lateral prostate except that there was no increase in filamentous content. In the coagulating gland, there was a reduction or total disappearance of apical secretory blebs and an increase in lysosomes, a feature not found in the lateral and dorsal lobes. Damages to mitochondria were observed in the dorsal prostate and coagulating gland but not in the lateral prostate. It is concluded that gossypol affects not only the testis, but also alters the structure and functions of the prostate gland.     

Morphological and functional heterogeneity in the rat prostatic gland.

Ductal morphogenesis and adult ductal branching patterns were examined in the rat prostate by a microdissection method. The rat prostate consists of paired (right and left) subdivisions which correspond in large part to the classically defined lobes: ventral prostate, lateral prostate, dorsal prostate, and coagulating gland. Of particular interest was the finding that the lateral prostate consists of two different ductal zones: (1) lateral type 1 prostate with 5-7 long main ducts (resembling miniature palm trees) that extend cranially towards both the seminal vesicle and dorsal prostate to arborize near the bladder neck, and (2) lateral type 2 prostate with 5-6 short main ducts that arborize caudal to the bladder neck and give rise to compact bushy glands. Both lateral prostatic groups had a ductal-acinar organization. The adult structure of the other rat prostatic lobes was also examined, and closely resembled their mouse counterparts. The ventral prostate, which had 2-3 pairs of slender main ducts per side, and the coagulating gland, which had 1 main duct per side, was completely ductal in structure. In contrast, the dorsal prostate, which had 5-6 pairs of main ducts per side, had a ductal-acinar structure. Ductal branching morphogenesis occurred at different rates in different lobes and was essentially complete in the prostate at the 30 days. Immunocytochemical studies with an antibody to DP-1, a major secretory protein of the rat dorsal prostate, revealed that secretory function was initiated at approximately 30 days after birth in the coagulating gland, the dorsal prostate, and lateral type 1 prostate. A consistent feature of the lateral type 2 prostate was the absence of DP-1. On Western blots, DP-1 was detected in the secretion of the coagulating gland, lateral type 1 and dorsal prostate, but not in the ventral and lateral type 2 prostate. Polyacrylamide gel electrophoresis confirmed this result and demonstrated that the lateral type 2 prostate expressed several low-molecular weight secretory proteins not found in the other lobes of the prostate. On the whole, the rat prostate exhibited considerable heterogeneity both between and within lobes in developmental processes, ductal patterning, histology, and functional expression.     

Metallothionein mRNA in the testis and prostate of the rat detected by digoxigenin-labeled riboprobe

Metallothionein (MT), a cysteine-rich heavy metal-binding protein, has been considered to play a role in the homeostatic control and detoxification of heavy metals, such as zinc, copper, and cadmium. In the present study, we have utilized a digoxigenin-labeled riboprobe to localize MT mRNA only by bright-field optics in the testis and prostate of the rat. In the rat testis, MT mRNA was found predominantly in primary spermatocytes and also in secondary spermatocytes and spermatids, but not in the spermatogonia, Sertoli cells, and Leydig cells. On the other hand, MT protein was present in these spermatogenic cells as well as in spermatozoa and Sertoli cells. In the prostate, MT mRNA was found predominantly in the epithelium of the dorsolateral lobes, but not in the ventral lobe, which is in agreement with the observed localization of MT protein. The utilization of both in situ hybridization and immunohistochemical staining on the same tissue specimens show MT gene expression in specific cell types in the male genital organs.     

Morphogenesis of ductal networks in the mouse prostate

Postnatal growth and development of the glandular architecture of the ventral and dorsolateral lobes of the mouse prostate (VP and DLP) were investigated by microdissection techniques that permitted precise quantification of the numbers of primary ducts emerging from the urethra, the terminal ductal tips, and ductal branch-points. At birth both the right and left lobe of the VP consisted of 1-3 main ducts that had already undergone secondary and tertiary branching. In contrast, at birth the more complex DLP had 9-12 unbranched main ducts per lobe on both the right and left sides. During the first 15 days after birth, 80.7% of tips and 76.4% of branch-points of the adult gland formed in the VP, and 70.4% of tips and 53.6% of the branch-points formed in the DLP. Ductal branching was completed by 60 to 90 days. The DLP developed in three stages: first, formation of unbranched main ducts (first 10 days); second, distal branching of each main duct resulting in 3-5 terminal branches per main duct (10-15 days after birth); third, elaboration of intraductal mucosal infolding in distal ducts after 30 days of age. Ducts of the lateral prostate (LP), a ventrolateral subdivision of the DLP, initiated branching morphogenesis between 1 to 5 days after birth. The LP grew into and became embedded within the capsule of the VP, which may explain why the ductal architecture of these two lobes are similar. These heretofore unrecognized differences in the organogenesis and morphology of the mouse VP and DLP and the striking morphological heterogeneity both between and within the lobes of the mouse prostate may be morphological manifestations of functional heterogeneities within the prostate.     

Metalloproteinase activities expressed during development and maturation of the rat prostatic complex and seminal vesicles.

The objective of this study was to characterize proteinase activities expressed during development and maturation of the prostate gland and seminal vesicles of the rat by using gelatin-and casein-containing SDS polyacrylamide gel zymography. The prostatic complexes of 2- and 10-day-old animals and the individual lobes of the prostate (ventral, dorsolateral, and anterior [coagulating gland]) and the seminal vesicles of 15-day-old animals expressed prominent gelatinolytic activities of approximately 64, 71, and 76 kDa. These activities had properties of metalloproteinases; i.e., they were stimulated by Ca2+ and inhibited by EDTA and EGTA. They were greatly diminished by 52 days of age (immediately postpuberty) and were not detected in the dorsal lobe of the adult. Less active gelatinolytic proteinases with molecular masses of approximately 34 and 43 kDa were expressed in the developing prostatic complexes and individual lobes and seminal vesicles, but they were not detected in postpubertal animals. Weak gelatinolytic activities of 82, 85, and 89 kDa were found in the prostatic complexes; these activities were greatly diminished in all prostate lobes with sexual maturation but were expressed in the seminal vesicles at all ages. A large-molecular-mass Ca(2+)-independent proteinase of 130 kDa or greater was first detected in the dorsolateral prostate at 21 days of age. This activity was expressed in both the lateral and dorsal lobes of the adult but was greater in the lateral lobe. Proteinase activities of about 22 and 26 kDa that were not stimulated by Ca2+ were detected in the ventral prostate at 15 days of age by means of both gelatin and casein gels.(ABSTRACT TRUNCATED AT 250 WORDS)