Acute effects of adenosine triphosphates, cyclic 3',5'-adenosine monophosphates, and follicle-stimulating hormone on cytosolic calcium level in cultured immature rat Ssertoli cells.
The ability of ATP and FSH to induce intracellular calcium [Ca(2+)](i) changes in Sertoli cells is imperfectly understood and reports are conflicting. We have applied the single-cell microfluorometry technique with the calcium probe indo-1 to investigate [Ca(2+)](i) in individual cultured Sertoli cells. When cells were exposed to ATP, cAMP, and FSH, a fast and biphasic increase in [Ca(2+)](i) was obtained in 100%, 70%, and 56% of cells, respectively. Caffeine did not activate Ca(2+) mobilization, while thapsigargin suppressed the peak response. External calcium free-EGTA buffer suppressed the plateau phase, while blockers of voltage-operated Ca(2+) channels did not abolish the response to cAMP and ATP. We conclude that the three messengers mobilized Ca(2+) from intracellular thapsigargin-sensitive stores, which induced a subsequent Ca(2+) influx from the extracellular medium by a voltage-independent Ca(2+) entry. The well-documented mechanisms by which these messengers act on cells support the idea that they release Ca(2+) from smooth endoplasmic reticulum by two different pathways, or that FSH and cAMP first release ATP, which then acts on cells. Among the cells, 77% and 80% responded, respectively, to FSH and cAMP by a delayed long-lasting decrease in [Ca(2+)](i) that was never recorded in the presence of ATP. This suggests that FSH and cAMP also promote a slow redistribution of [Ca(2+)](i) from the exchangeable pool to the bound nonexchangeable pools. Involvement of voltage-operated and voltage-independent calcium channels in the response of Sertoli cells to ATP, FSH, and cAMP is discussed.
Laboratoire de Physiologie des Régulations Cellulaires, UMR 6558, UFR Sciences, 86022-Poitiers-Cedex, France.
N
N
Lalevée
C
C
Rogier
F
F
Becq
M
M
Joffre
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D003600:Cytosol / Q000378:metabolism*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012708:Sertoli Cells / Q000187:drug effects / Q000378:metabolism*; D013873:Thionucleotides / Q000494:pharmacology
D013873:Thionucleotides; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000255:Adenosine Triphosphate; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D002118:Calcium