Follicle-stimulating hormone-dependent estrogen secretion by rat Sertoli cells in vitro: Modulation by calcium

Talbot, James; Lambert, André; Mitchell, R. M.; Grabiński, M; Anderson, D. C.; Tsatsoulis, Agathocles; Shalet, Stephen M; Robertson, W. R.

doi:10.1530/acta.0.1250280

Cited by 9 publications

(3 citation statements)

References 14 publications

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“…In addition, these results show that ATP effects are produced at a site distal to cAMP production. Our results agree with previous observations demonstrating that PKC activity and intracellular Ca 2+ levels are involved in the regulation of aromatase activity at a site distal to cAMP accumulation (Monaco & Conti 1987, Talbot et al 1991. ATP regulation of other steroid-producing cells, like granulosa and Leydig cells, has recently been presented (Kamada et al 1994, Foresta et al 1996.…”

Section: Discussionsupporting

confidence: 92%

Effects of purinergic agonists on aromatase and gamma-glutamyl transpeptidase activities and on transferrin secretion in cultured Sertoli cells

Meroni¹,

Canepa²,

Pellizzari³

et al. 1998

Journal of Endocrinology

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To study the role of extracellular nucleosides and nucleotides in the regulation of Sertoli cells, the effects of agonists which occupy A 1 and P 2 purinergic receptors on aromatase and gamma-glutamyl transpeptidase ( -GTP) activities and on transferrin secretion were tested. Sertoli cell treatment with purinergic agonists for a prolonged period of time (72 h) resulted in an increase in aromatase activity under basal conditions. In cultures stimulated with FSH, purinergic agonists counteracted the inhibitory effect on aromatase activity that long-term treatment with FSH promoted. The effects of prolonged treatments with purinergic agonists on the other two parameters of Sertoli cell function were less pronounced. Neither -GTP activity nor transferrin secretion was modified under basal conditions. On the other hand, under conditions where cell differentiation was favored by FSH treatment, reductions in -GTP activity and transferrin secretion were usually observed. The results obtained in dbcAMPstimulated cultures suggested that A 1 agonists exert their regulatory function at the level of cAMP formation while P 2 agonists act at a more distal point. The fact that morphological changes induced by FSH were reversed by both types of agonists, while those induced by dbcAMP were only abrogated by P 2 agonists, supports this hypothesis. In summary, these results demonstrate that purinergic agonists may be important in the regulation of Sertoli cell function.

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Section: Discussionsupporting

confidence: 92%

Effects of purinergic agonists on aromatase and gamma-glutamyl transpeptidase activities and on transferrin secretion in cultured Sertoli cells

Meroni¹,

Canepa²,

Pellizzari³

et al. 1998

Journal of Endocrinology

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“…The physiological significance of the calcium regulation of Sertoli cell PG metabolism remains to be elucidated. Experiments using EGTA, verapamil, or calcium ionophore [Malléa et al, 1987;Grasso and Reichert, 1989;Talbot et al, 1991] clearly indicate that calcium antagonizes the stimulatory effect of FSH on cAMP production and aromatase activity in Sertoli cells by an unknown mechanism. In addition, we have previously demonstrated that cellular HSPG level is inversely correlated with FSH-stimulated estradiol production [Phamanthu et al, 1995[Phamanthu et al, , 1999.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of transmembrane calcium influx induces decrease in proteoglycan synthesis in immature rat sertoli cells

et al. 2000

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Beyond increased cAMP synthesis, calcium influx has been involved in signal transduction triggered by the gonadotropin follicle-stimulating hormone (FSH), the main regulator of Sertoli cells functions. In order to delineate a possible involvement of calcium in the regulation of proteoglycan synthesis, we have examined the effect of low-voltage-activated calcium channel blocker verapamil on both [(35)S]-sulfate and [(3)H]-glucosamine incorporation into proteoglycan molecules neosynthesized by cultured Sertoli cells from 20-day-old rats. Verapamil induced a dose- and time-dependent decrease in labeling of both secreted and cell-associated proteoglycans, as determined by quantitative solid-phase assay. This effect was mimicked by the addition of the calcium chelator EGTA, suggesting that verapamil effect resulted from the inhibition of transmembrane calcium influx. The decrease in apparent proteoglycan synthesis appeared to be attributable primarily to a lowering of the glycanation process, as shown by experiments using an exogenous acceptor for glycosaminoglycan synthesis. Moreover, verapamil induced a decrease in relative proportion of heparan sulfate proteoglycans in the cell layer. Pulse-chase kinetics demonstrated that verapamil also altered proteoglycan catabolism, leading to glycosaminoglycan retention in the cell layer and inhibiting the proteoglycan desulfation step. We conclude that intracellular calcium is essential to maintain Sertoli cell proteoglycan expression and could thus be involved in the repression of Sertoli cell cAMP-dependent syntheses such as estradiol production.

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“…Experiments using EGTA, verapamil, or calcium ionophore [Malléa et al, 1987;Grasso and Reichert, 1989;Talbot et al, 1991] clearly indicate that calcium antagonizes the stimulatory effect of FSH on cAMP production and aromatase activity in Sertoli cells by an unknown mechanism. In addition, we have previously demonstrated that cellular HSPG level is inversely correlated with FSH-stimulated estradiol production [Phamanthu et al, 1995[Phamanthu et al, , 1999.…”

mentioning

confidence: 99%

Inhibition of transmembrane calcium influx induces decrease in proteoglycan synthesis in immature rat sertoli cells

et al. 2000

View full text Add to dashboard Cite

Beyond increased cAMP synthesis, calcium influx has been involved in signal transduction triggered by the gonadotropin follicle-stimulating hormone (FSH), the main regulator of Sertoli cells functions. In order to delineate a possible involvement of calcium in the regulation of proteoglycan synthesis, we have examined the effect of low-voltage-activated calcium channel blocker verapamil on both [ 35 S]-sulfate and [ 3 H]-glucosamine incorporation into proteoglycan molecules neosynthesized by cultured Sertoli cells from 20-day-old rats. Verapamil induced a dose-and time-dependent decrease in labeling of both secreted and cell-associated proteoglycans, as determined by quantitative solid-phase assay. This effect was mimicked by the addition of the calcium chelator EGTA, suggesting that verapamil effect resulted from the inhibition of transmembrane calcium influx. The decrease in apparent proteoglycan synthesis appeared to be attributable primarily to a lowering of the glycanation process, as shown by experiments using an exogenous acceptor for glycosaminoglycan synthesis. Moreover, verapamil induced a decrease in relative proportion of heparan sulfate proteoglycans in the cell layer. Pulse-chase kinetics demonstrated that verapamil also altered proteoglycan catabolism, leading to glycosaminoglycan retention in the cell layer and inhibiting the proteoglycan desulfation step. We conclude that intracellular calcium is essential to maintain Sertoli cell proteoglycan expression and could thus be involved in the repression of Sertoli cell cAMP-dependent syntheses such as estradiol production.

show abstract

Follicle-stimulating hormone-dependent estrogen secretion by rat Sertoli cells in vitro: Modulation by calcium

Cited by 9 publications

References 14 publications

Effects of purinergic agonists on aromatase and gamma-glutamyl transpeptidase activities and on transferrin secretion in cultured Sertoli cells

Effects of purinergic agonists on aromatase and gamma-glutamyl transpeptidase activities and on transferrin secretion in cultured Sertoli cells

Inhibition of transmembrane calcium influx induces decrease in proteoglycan synthesis in immature rat sertoli cells

Inhibition of transmembrane calcium influx induces decrease in proteoglycan synthesis in immature rat sertoli cells

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