title: Immediate cell signal induced by laminin in rat sertoli cells.
abstract: Rat Sertoli cells in primary culture have been studied for their ability to respond to extracellular matrix macromolecules by increases of [Ca(2+)](i). We observed that cells seeded on glass coverslips, loaded with the intracellular Ca(2+) indicator fura-2, responded to laminin, but not to fibronectin, with an immediate [Ca(2+)](i) raise, with a peak followed by a prolonged plateau. [Ca(2+)](i) increases were dependent upon Ca(2+) influx across the plasma membrane and Ca(2+) release from intracellular Ca(2+) pools. Ca(2+) influx was inhibited by extracellular Ca(2+) removal by EGTA, and by treatment with La(3+), or with the L-type voltage operated Ca(2+) channel blocker, nifedipine. Ca(2+) release from intracellular Ca(2+) storing organelles, was inhibited by the microsomal Ca(2+)-ATPase blocker thapsigargin. Responses were mimicked by synthetic peptides carrying the Arg-Gly-Asp adhesion sequence, but not by the control Arg-Gly-Glu-containing peptide, in which aspartic acid was replaced by glutamic acid. Laminin-dependent [Ca(2+)](i) increases were down-regulated by the follicle-stimulating hormone. However, this occurred only when cells were not subjected to homotypic cell-cell contact, and responded to the hormone with a significant [Ca(2+)](i) elevation. These results indicate that laminin may regulate Sertoli cells by intracellular signals that perturb Ca(2+) homeostasis. This role may be related to an effect exerted by the seminiferous epithelium basement membrane on the regulation of spermatogenesis.
authors.affiliation: Istituto Dermopatico dell'Immacolata, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Taranta
authors.forename: A
authors.initials: A
authors.lastname: Teti
authors.forename: M
authors.initials: M
authors.lastname: Stefanini
authors.forename: A
authors.initials: A
authors.lastname: D'Agostino
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D002478:Cells, Cultured; D005353:Fibronectins / Q000494:pharmacology; D007797:Laminin / Q000378:metabolism* / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D012708:Sertoli Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D015220:Calcium Channels; D005353:Fibronectins; D007797:Laminin; C121346:laminin 1; D007811:Lanthanum; D002118:Calcium