Pharmacological study of signal transduction during stimulation of prothoracic glands from Manduca sexta |
| |
Authors: | Birkenbeil |
| |
Institution: | S?chsische Akademie der Wissenschaften zu Leipzig, AG Neurohormonale Wirkungsmechanismen, Erbert-Str.1 PF 100322, 07703, Jena, Germany |
| |
Abstract: | Cytosolic free calcium, Ca(2+)](i), measured in individual prothoracic gland cells of Manduca sexta with Fura-2 was increased by prothoracicotropic hormone, PTTH, and by mastoparan, a wasp venom peptide, activating G proteins. The effect on Ca(2+)](i) of mastoparan and of PTTH was inhibited by cadmium and the antagonist of T-type calcium channels, amiloride, and not influenced by the L-type calcium channel blocker nitrendipine, suggesting that the same or similar plasma membrane channels are involved in the action of mastoparan and of PTTH. Pertussis toxin prevented the mastoparan-induced increase of Ca(2+)](i), whereas the effect of PTTH is not influenced by pertussis toxin. Intracellular addition of GDP-beta-S failed to inhibit the PTTH-stimulated increase in Ca(2+)](i) suggesting that G proteins are not involved in the stimulatory mechanism of PTTH. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|