Gastrointestinal hormone receptors on isolated smooth muscle cells from gastric antrum of the rabbit

The regulation by gastrointestinal polypeptide hormones of contraction and relaxation of functionally isolated smooth muscle cells from gastric antrum of the rabbit has been investigated. Gastrin, cholecystokinin (CCK-8) and motilin induced a rapid contraction of isolated cells: significant response...

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Bibliographic Details
Published inBiochemical pharmacology Vol. 38; no. 17; p. 2895
Main Authors Moummi, C, Magous, R, Bali, J P
Format Journal Article
LanguageEnglish
Published England 01.09.1989
Subjects
Animals
Calcium - physiology
Cholecystokinin - antagonists & inhibitors
Cholecystokinin - metabolism
Cholecystokinin - physiology
Gastrins - metabolism
Gastrins - physiology
In Vitro Techniques
Motilin - metabolism
Motilin - physiology
Muscle Contraction
Muscle, Smooth - metabolism
Muscle, Smooth - physiology
Proglumide - pharmacology
Pyloric Antrum - cytology
Pyloric Antrum - metabolism
Rabbits
Receptors, Cell Surface - metabolism
Vasoactive Intestinal Peptide - physiology
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Summary:The regulation by gastrointestinal polypeptide hormones of contraction and relaxation of functionally isolated smooth muscle cells from gastric antrum of the rabbit has been investigated. Gastrin, cholecystokinin (CCK-8) and motilin induced a rapid contraction of isolated cells: significant response occurred within a 5-sec incubation with these peptides and maximal response (40% decrease in cell length) after 30 sec. A higher sensitivity of smooth muscle cells to gastrin and CCK-8 than to motilin stimulations was demonstrated (EC50 = 10 pM for both gastrin and CCK-8 and EC50 = 1 nM for motilin). The minimal gastrin fragment required to get full contraction was the C-terminal pentapeptide amide common to gastrin and CCK. Proglumide inhibited gastrin- or CCK-8- but not motilin-induced contractions with an IC50 of 50 microM. contraction induced by gastrin and motilin required normal levels of extracellular calcium, whereas that due to CCK-8 seemed to be independent of extracellular calcium. Vasoactive intestinal polypeptide (VIP) caused a relaxation of smooth muscle cells maximally contracted by carbachol or CCK-8 or gastrin (EC50 = 2.2 nM) with a parallel increase in intracellular cAMP content.
ISSN:0006-2952
DOI:10.1016/0006-2952(89)90447-4