Effects of somatostatin on basal and stimulated pancreatic secretion in conscious rat.
The effects of somatostatin on pancreatic secretion were studied in conscious rats during diversion and recirculation of pancreatic juice. Pancreatic secretion was significantly inhibited by low doses (2 micrograms/kg/h) of somatostatin during diversion of pancreatic juice. The inhibitory effect was more marked on bicarbonate and protein output than on volume, while in bicarbonate and protein output a rebound effect was observed. These data suggest a combined inhibitory effect of somatostatin on endogenous CCK release and cholinergic mechanisms. During recirculation of pancreatic juice there was no rebound effect, thus only the inhibition of cholinergic mechanisms seems to be involved in the inhibitory effect of somatostatin. During recirculation, CCK-OP-stimulated bicarbonate and protein secretion was strongly inhibited by somatostatin. Even water secretion not stimulated by CCK-OP was significantly inhibited demonstrating a supplementary inhibitory effect on basal cholinergic mechanisms. Somatostatin decreased only slightly the synthetic secretin-stimulated water and bicarbonate secretion. The more effective inhibition of protein output was explained by an additive effect of somatostatin on basal cholinergic tone.
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D008297:Male; D010189:Pancreatic Juice / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012633:Secretin / Q000494:pharmacology; D012844:Sincalide / Q000494:pharmacology; D013004:Somatostatin / Q000494:pharmacology* / Q000502:physiology
D001639:Bicarbonates; D011506:Proteins; D012633:Secretin; D013004:Somatostatin; D012844:Sincalide