Role of fatty acid oxidation in mechanism of action of gastric secretagogues.
The role of beta-oxidation in the mechanism of stimulation of acid secretion was examined in toad gastric mucosa in vitro. The incubation with 4-pentenoate selectively inhibited in a dose-dependent manner the rate of 14CO2 formation from [1-14C]octanoate. Pretreatment with 20 mM 4-pentenoate sharply reduced the respiratory and secretory responses to theophylline and histamine. Tracer studies showed a major utilization of exogenous octanoate over glucose and pyruvate by the in vitro toad gastric mucosa. Theophylline and histamine stimulated by 69% the rate of octanoate oxidation. Over 60% of the increments in oxygen uptake produced by theophylline and histamine accounted for the increments in octanoate oxidation, whereas glucose and pyruvate together accounted for less than 25%. Octanoate-dependent respiration was shown to correlate with octanoate oxidation under both inhibition with 4-pentenoate and stimulation with theophylline. Theophylline stimulated by 25% the rate of octanoate oxidation in Cl--free glucuronate-nutrient solutions. The present work provides further evidence for the primary role of fatty acid oxidation in the mechanism of acid secretion in amphibian.
D000818:Animals; D002024:Bufo marinus / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005750:Gastric Juice / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D006633:Histamine Antagonists; D066298:In Vitro Techniques; D010101:Oxygen Consumption; D010421:Pentanoic Acids / Q000494:pharmacology*; D013806:Theophylline / Q000037:antagonists & inhibitors; D014631:Valerates / Q000494:pharmacology*
D006633:Histamine Antagonists; D010421:Pentanoic Acids; D014631:Valerates; D013806:Theophylline