Effects of the mammalian vasoconstrictor peptide, endothelin-1, on Tetrahymena pyriformis GL, and the immunocytological detection of endogenous endothelin-like activity.
The vasoconstrictor endothelin-1 (ET-1) is shown to have significant physiological effects on a unicellular organism, Tetrahymena pyriformis. These responses include: (1) A significant increase in intracellular [Ca2+] induced by 10(-10) M ET-1; (2) Increased chemotaxis, maximal at 10(-10) M; and (3) A small inhibition of proliferation at the 10(-13)-10(-12) M concentration range. Immunocytochemical detection of endogenous ET-1 using rabbit antibodies directed against human or porcine ET-1 indicates that this is a further example of the widening group of vertebrate hormones now known to be synthesized by Tetrahymena. These observations suggest that hormones are of considerable antiquity in their phylogenetic appearance and have been highly conserved throughout evolution.
Department of Biology, Semmelweis University of Medicine, Budapest, Hungary.
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Köhidai
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Csaba
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002633:Chemotaxis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000494:pharmacology*; D007150:Immunohistochemistry; D010587:Phagocytosis / Q000187:drug effects; D011817:Rabbits; D013768:Tetrahymena / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D016232:Endothelins; D002118:Calcium