Acid secretagogue mechanisms of a GABA-mimetic (PCPGABA) in the anesthetized rat: effects of hypothermia.

The secretagogue action of lipophilic, GABA-mimetic, beta-(p-chlorophenyl)-gamma-aminobutyric acid (PCPGABA) was studied in the rat in relation to body temperature. PCPGABA (2 to 8 mg/kg s.c.) stimulated acid output in the urethane-anesthetized rat whose core temperature ranged between 28 to 30 degrees C. However, this stimulatory effect of PCPGABA totally disappeared in the same animal whose rectal temperature was maintained at the normal unanesthetized level (37-39 degrees C), whereas the acid secretory responses to histamine and bethanechol were not modified with the change in the thermoregulation. This suggests that the thermoregulation mechanisms are implicated in acid secretagogue action of centrally acting gastric stimulants.