Effects of intracisternal TRH on basal acid output and serum gastrin in hyperthyroid rats

ABSTRACT

Rats were made hyperthyroid by oral levothyroxine therapy to evaluate the role of thyrotropin-releasing hormone [TRH] as a central neurotransmitter for the changes of basal acid output [BAO] in the state of thyroid dysfunction. It was shown that [BAO] decreases with the concomitant elevation of serum gastrin level. Elevated serum gastrin in hyperthyroid rats returned to base line by intragastric infusion of 0.1 N hydrochloric acid [HCL]. In the next step, intracisternal injection of TRH to another group of hyperthyroid rats increased BAO and decreased serum gastrin level. It is concluded that decreased central TRH as a consequence of hyperthyroidism [negative feedback], decreases [BAO] which secondarily leads to hypergastrinemia