Cyclic AMP modulates part of the relaxant action of calcitonin gene-related peptide in guinea pig gallbladder strips.
Calcitonin gene-related peptide (CGRP) has been shown to relax cholecystokinin-induced tension in guinea pig gallbladder strips. This relaxation is dependent on the concentration of CGRP, and is primarily due to the opening of ATP sensitive K+ channels; however, other mechanisms may also be involved. Studies using forskolin, 8-bromoadenosine 3', 5' cyclic monophosphate, dibutyryl cAMP, cholera toxin, and Rp-adenosine 3', 5'-cyclic monophosphothioate triethylamine, which measured changes in tension suggest that cAMP may be involved in mediating the actions of CGRP. Radioimmunoassay of strips precontracted with cholecystokinin octapeptide (CCK) and either treated with CGRP or its solvent demonstrated that cAMP concentrations increased with CGRP treatment. The results of these studies demonstrate that CGRP acts through multiple mechanisms to induce relaxation of guinea pig gallbladder strips precontracted with CCK.
Kline
L W
LW
Department of Oral Health Sciences, University of Alberta, Edmonton, Canada. lkline@gpu.srv.ualberta.ca
Pang
P K
PK
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism / Q000494:pharmacology*; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005704:Gallbladder; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology
D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D013873:Thionucleotides; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; C016957:adenosine-3',5'-cyclic phosphorothioate; D003994:Bucladesine; D002766:Cholecystokinin; D002772:Cholera Toxin; D000242:Cyclic AMP; D015740:Calcitonin Gene-Related Peptide