Pharmacological studies of proctolin receptors on foregut and hindgut of Blaberus craniifer.
Proctolin (Arg-Tyr-Leu-Pro-Thr) and proctolin analogs modified at position 1, 2, or 5 caused dose dependent contractions of Blaberus fore- and hindgut. The varying contractile effects between both tissues revealed the possible presence of receptor subtypes as identified by [GABA1]-proctolin. A single population of binding sites (Kd approximately 100 nM) was deduced from Scatchard analysis. In addition, nanomolar concentrations of proctolin induced a dose-dependent hydrolysis of phosphoinositides (PIns) augmented by GTPgammaS (1 microM) on foregut membranes but no accumulation of cAMP. Proctolin induced contractions are likely mediated via a phospholipase C linked to a heptahelical receptor bound to heterotrimeric G-proteins.
Mazzocco-Manneval
C
C
Laboratoire de Neuroendocrinologie de l'insecte, ER CNRS 629, Université Bordeaux I, France.
Kuczer
M
M
Konopinska
D
D
Fournier
B
B
Loughton
B G
BG
Puiroux
J
J
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D003058:Cockroaches; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006868:Hydrolysis / Q000187:drug effects; D009479:Neuropeptides; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D018013:Receptors, Neuropeptide / Q000145:classification / Q000378:metabolism* / Q000502:physiology; D015290:Second Messenger Systems / Q000187:drug effects; D013270:Stomach / Q000737:chemistry* / Q000166:cytology / Q000187:drug effects
D009479:Neuropeptides; D018377:Neurotransmitter Agents; D009842:Oligopeptides; D010716:Phosphatidylinositols; D018013:Receptors, Neuropeptide; C011536:proctolin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases