Intraluminal prostaglandin stimulation and bile salt inhibition of basal acid secretion in the instilled rat stomach.
To determine the effect of prostaglandin on acid secretion and the effectiveness of cytoprotection afforded by prostaglandins against bile salt damage, the stomachs of anesthetized rats were exteriorized and cannulated for determination of net acid output (H+) and electrical potential difference (PD). The stomachs were successively instilled with acid buffer, 5 mM and 15 mM sodium taurocholate (NaTC) with or without 3.3 X 10-6M 16, 16-dimethyl prostaglandin E2 (dmPGE2). With dmPGE2 present in the instillate, H+ was twice as large in the control period. Exposure to 5mM NaTC reduced H+ by 63% and abolished the stimulatory effect of dmPGE2. Subsequent exposure to 15mM NaTC depressed H+ further. In the absence of dmPGE2, NaTC reduced H+ to equivalent rates. The PD was unaffected by NaTC in the presence of dmPGE2 and lowered by 45% in the absence of dmPGE2. It may be concluded that 1) prostaglandins stimulate rather than inhibit basal H+ in vivo, and 2) prostaglandins provide weak protection against the ionic actions of conjugated bile salts instilled in the stomach.
D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology*; D005260:Female; D005750:Gastric Juice / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology*; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D013270:Stomach / Q000502:physiology*; D013656:Taurocholic Acid / Q000494:pharmacology
D001647:Bile Acids and Salts; D011459:Prostaglandins E, Synthetic; D013656:Taurocholic Acid