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PIROG, EDYTA C.; CLARK, RICHARD V.; COLLINS, DELWOOD C.
doi: 10.1002/j.1939-4640.1993.tb00360.xpmid: N/A
ABSTRACT: UDP‐glucuronyl transferase (UDPGT) activity was determined for androgens in tissue minces and microsomal fractions from the liver and extrahepatic tissues (kidney, skin, prostate, and preputial glands) of the male rat. Liver microsomes showed the highest UDPGT activity with each of the androgens tested (Vmax = 7, 3, and 10 nmol/minute/mg protein for testosterone, androsterone, and androstanediol, respectively). UDPGT activity (Vmax) for androstanediol in the liver was 102‐fold higher than in the kidney and 103‐fold higher than in the skin and prostate. UDPGT activity for androgens was not detected in microsomes from preputial glands. Furthermore, no body site distribution was found for androgen UDPGT activity in skin microsomes. The Michaelis‐Menten constant (Km) for UDPGT in liver microsomes was 20.4, 12.2, and 2.2 μ, respectively, for testosterone, androstanediol, and androsterone. Kidney microsomes showed a Km of 19.4 and 26.9 μ, respectively, for androstanediol and androsterone. The Km for testosterone was very high in the kidney (138 μ), suggesting that it was a poor substrate. In microsomes from the skin and prostate, the Km was very high (range 43–162 μ) for all three androgen substrates, suggesting that these androgens were not the preferred substrates for UDPGT in these tissues.
RAYCHOUDHURY, SAMIR S.; BLACKSHAW, ALAN W.; IRVING, MICHAEL G.
doi: 10.1002/j.1939-4640.1993.tb00362.xpmid: N/A
ABSTRACT: Previous investigators have suggested metabolic cooperation between Sertoli and peritubular cells. This study concerns Sertoli cell and peritubular myoid cell interactions in terms of synthesis of one of the main testicular extracellular matrix (ECM) constituents, glycosaminoglycans (GAG). We have tested the effect of hormones and other regulatory agents such as a combination of FSH, insulin, retinol, and testosterone (FIRT) on monocultures of Sertoli and peritubular myoid cells, and have examined whether or not coculture of Sertoli and peritubular myoid cells substitutes for the stimulation by FIRT. Cocultures of Sertoli and testicular peritubular myoid cells showed significant increases in the levels of secreted protein and sulfoprotein, as well as in cell‐associated GAG synthesis in untreated cultures. This indicates cell‐cell cooperation between Sertoli and peritubular myoid cells in the testis in terms of sulfated protein and GAG synthesis. Addition of the hormone mixture and retinol (FIRT) stimulated cell‐associated and ECM‐associated GAG in peritubular myoid cells, suggesting a role of circulating hormones in ECM production by peritubular myoid cells in vivo. Cocultures of Sertoli and myoid cells substituted for the stimulatory response of FIRT on peritubular myoid cells, predominantly in terms of cell‐associated GAG synthesis, which again emphasizes that the paracrine regulation of testicular ECM synthesis is dependent on Sertoli‐myoid cell cooperation.
FALSETTI, COSTANZA; BALDI, ELISABETTA; KRAUSZ, CSILLA; CASANO, ROSARIA; FAILLI, PAOLA; FORTI, GIANNI
doi: 10.1002/j.1939-4640.1993.tb00364.xpmid: N/A
ABSTRACT: Spermatozoa from oligozoospermic subjects are characterized by a reduced in vitro ability to penetrate hamster oocytes and by a decreased responsiveness to physiological stimuli that trigger the acrosome reaction. One of the first steps in the induction of the acrosome reaction is an increase of intracellular free calcium concentrations ([Ca2+],). It has been recently shown that progesterone (P) is able to increase [Ca2+], in capacitated human sperm at concentrations similar to those found in follicular fluid. We evaluated sperm [Ca2+], increase in response to P (0.1 μg/ml) in 19 normo‐ and 17 oligozoospermic subjects. The average percentage of [Ca2+], increase over the basal level was significantly lower in spermatozoa from oligozoospermic subjects when compared to normozoospermic subjects (138.7 ± 8.22% increase in oligo‐ versus 263.3 ± 39.7% increase in normozoospermic subjects; P < 0.001). Progesterone‐stimulated [Ca2+], increase was significantly correlated with sperm motility (r = 0.54), sperm concentration (r = 0.96), and sperm morphology (% of normal forms) (r = 0.49). In addition, P induced a significant increase of acrosome‐reacted spermatozoa in normospermic patients (n = 10), whereas no significant effect was observed in spermatozoa from oligozoospermic men (n = 7). Taken together, these results indicate that spermatozoa from oligozoospermic men have a reduced ability to initiate the cascade of events that lead to the acrosome reaction in response to a physiological stimulus, such as P, and might contribute to explaining the reduced fertilizing capacity of these patients.
VERI, JOHN‐PAUL; HERMQ, LOUIS; ROBAIRE, BERNARD
doi: 10.1002/j.1939-4640.1993.tb00366.xpmid: N/A
ABSTRACT: Glutathione S‐transferases (GSTs) are a family of isozymes that catalyze the conjugation of glutathione (GSH), a tripeptide found in all mammalian cells; this function plays a protective role, as the addition of GSH to an etectrophile generally forms a less toxic product. The pi class of GSTs contains homodimers of the Yf subunit, also known as Yp or rat subunit 7; this subunit is found in high concentrations in the testis and epididymis. The objective of the present study was to localize immunocytochemically the Yf subunit in the testis and in the various regions of the epididymis using light, electron, and confocal microscopy. In the testis, immunoperoxidase staining was localized exclusively to Sertoli and Leydig cells. The low cuboidal epithelial cells of the rete testis and the sparse ciliated cells of the ductuli afferentes were also immunoreactive. A distinct pattern of immunostaining for the Yf subunit was observed in the different regions of the epididymis. The proximal area of the initial segment showed intense reactivity localized to epithelial basal cells. Basal cells in the middle area of the initial segment were also reactive, as were a second unidentified population of cells located in the apical region of the epithelium. The epithelium, including both principal and basal cells, in the distal initial segment, intermediate zone, and proximal caput epididymidis showed a weak, moderate, or strong degree of reactivity, respectively. In the distal caput epididymidis, however, principal cells showed a checkerboard‐like pattern of immunoreactivity, with some eels being intensely stained or faintly stained, whereas others were unreactive. Strikingly, in the corpus and proximal cauda epididymidis, intense immunostaining was localized exclusively over the epithelial basal cells. As viewed in the light and confocal microscope, the intensely stained basal cells showed extensive processes that covered most of the base of the epididymal tubule. Upon quantitation of the immunogold labeling density (the number of gold particles/μ2) in principal and basal cells of the different regions of the epididymis, we observed a sharp decline in immunogold labeling of principal cells coupled with a dramatic increase in labeling of basal cells as we progressed along the tissue, particularly in the transition from the caput to the corpus epididymidis. This study constitutes the first demonstration of a protein that is selectively expressed Hi epithelial basal cells of the corpus and proximal cauda epididymidis. The intense immunoreactivity for this pi GST subunit in basal cells, coupled with the discovery of their extensive processes and overall organization, leads us to speculate that these cells may be involved in the protection of the epididymal epithelium from electrophilic attack.
PEACOCK, N. R.; SWERDLOFF, R. S.; BERMAN, N.; GILLEY, R. M.; TICE, T. R.; BHASIN, S.
doi: 10.1002/j.1939-4640.1993.tb00367.xpmid: N/A
ABSTRACT: This study examined the pharmacokinetics (the time course and pattern of testosterone release) and pharmacodynamics (effects on accessory sex organ weights, and serum LH and FSH levels) of a biodegradable testosterone microsphere formulation in the male rat. Two hundred seventy‐five 55‐day‐old, sexually mature male rats underwent surgical orchiectomy or sham surgery and were divided into five groups as follows, to receive placebo or testosterone microsphere systems designed to release 25, 75, or 225 μg/day testosterone: group I: intact age‐matched controls, sham operated, placebo microspheres; group II: surgically orchiectomized, placebo microspheres; group III: surgically orchiectomized, 25 μg/day testosterone microspheres; group IV: surgically orchiectomized, 75 μg/day testosterone microspheres; and group V: surgically orchiectomized, 225 μg/day testosterone microspheres.
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