Sertoli Cells Category

It is generally believed that FSH synergizes the effect of testosterone on spermatogenesis, for which both factors are probably required. Interestingly, recent data strongly indicate that if the action of FSH is missing, normal testicular production of testosterone can compensate for this to maintain human fertility. Our data indicate that PKC activation antagonizes testosterone action […]

Hence, activation and desensitization of the TPA response seemed to follow the kinetics of classical PKC isotypes in both Sertoli cell fractions. Others have shown that the ratio of basal PKC activity in the soluble versus the particulate cell fraction of Sertoli cells increases at the onset of pubertal maturation, arguing that this represents a […]

The classical PKC isotypes (a, pI, pII, and 7) are biochemically characterized by their in vitro activation by calcium, phosphatidylserine, and diacylglycerol or its analogue TPA. The PKC isozymes reveal uneven tissue distribution. Some are widespread, such as PKCa and PKCpII, whereas PKC7 has been considered to be restricted to neural crest-derived cell types. Our […]

Regulatory responses modulated by calcium/phospholipid-dependent signaling pathways in Sertoli cells are not completely characterized. In the present study, we demonstrated TPA-dependent phosphotransferase activity in rat Sertoli cells in culture, presumably mediated by calcium/ phospholipid-dependent isomeric forms of PKC (a, p, and 7). Activation of PKC was associated with homologous induction of mRNA expression of PKC […]

Whereas baseline expression was close to unresponsive at low concentrations of TPA (10~10-10~9 M), higher concentrations (10~8-10~6 M) were associated with a reduction in the level of AR mRNA, with a half-maximal effect at 10~8 M TPA and a maximal reduction (~70%) at the highest concentrations. Analysis of mRNA expression of PKCa and PKCp was also […]

Moreover, Sertoli cells were incubated with TPA for increasing time periods (0-24 h) to examine possible regulatory effects on PKC expression (Fig. 3). Regulation of the expression level turned out to be much slower than regulation of phosphotransferase activity. The expression of PKCa mRNA in TPA-treated cells was not different from that in control cells […]

Activation and Expression of Calcium/PhospholipidDependent PKC Sertoli cells were incubated with TPA (10—7 M) for increasing time periods (5 min to 24 h), and phosphotransferase activity in the absence and presence of calcium and phosphatidylserine was analyzed in soluble and particulate cell fractions. Figure 1, displaying the enzymatic profile from the particulate cell fraction, shows […]