Effect of cholecystokinin octapeptide and somatostatin on the motility of guinea pig and canine gallbladder.
Species differences have been observed in the effect of cholecystokinin octapeptide (CCK OP) on the canine and guinea pig gallbladder smooth muscle motility. 1. CCK OP was more potent stimulant in canine than in guinea pig gallbladder smooth muscles. Its pD2 values were 10 and 9.2, respectively. 2. The acetylcholine (10(-4) M)-induced maximum contractions in canine gallbladder muscle strips were by 50% lower as compared to the CCK OP (10(-8) M) maximum responses while in guinea pig gallbladder muscle strips the acetylcholine (ACh) maximum responses were by 20% lower than the CCK OP maximum responses. 3. CCK OP increased [3H]ACh release by 27% in canine gallbladder and by 40% in guinea pig gallbladder. 4. Somatostatin (SOM) had not any direct myogenic effect in guinea pig and canine gallbladder but it decreased [3H]ACh release from gallbladder intrinsic cholinergic neurons.
Rakovska
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A
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Milenov
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K
Bocheva
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A
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D005260:Female; D005704:Gallbladder / Q000187:drug effects*; D006168:Guinea Pigs; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D012844:Sincalide / Q000494:pharmacology*; D013004:Somatostatin / Q000494:pharmacology*; D013045:Species Specificity
D013004:Somatostatin; D012844:Sincalide; D000109:Acetylcholine