Voltage-gated calcium channels in rat Sertoli cells.
We have studied Ca2+ voltage-gated channels of immature rat Sertoli cells by measuring intracellular Ca2+ concentration and its variation following administration of various agents in fura-2-loaded, confluent monolayers in culture. Our findings indicate that the basal Ca2+ intracellular level is about 100 nM, a value that falls within the range found in most eukaryotic cells. The intracellular Ca2+ level is rapidly increased by fetal bovine serum through release of intracellularly stored Ca2+ and opening of membrane cation channels. Substantial Ca2+ influx in rat Sertoli cells seems to be mediated by voltage-gated cation channels, which are sensitive to nifedipine, nicardipine, and omega-conotoxin. To investigate whether FSH, which controls several morphological and biochemical events of prepubertal Sertoli cells, modified Ca2+ influx in this cell type, we analyzed the cell response to acute FSH administration. The results show that, although not influencing the basal concentration of Ca2+, FSH decreases intracellular calcium influx induced by membrane depolarization. Similar data were also obtained by adding dibutyryl cAMP to the external medium and by increasing endogenous cAMP.
D'Agostino
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Institute of Histology and General Embryology, University La Sapienza, Rome, Italy.
Menè
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Stefanini
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D000818:Animals; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006096:Gramicidin / Q000494:pharmacology; D015640:Ion Channel Gating; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012708:Sertoli Cells / Q000502:physiology*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; C028521:lanthanum chloride; D006096:Gramicidin; D011189:Potassium Chloride; D007811:Lanthanum; D005640:Follicle Stimulating Hormone; D002118:Calcium