Response of the hypophyseal-testicular axis in monkeys to stalk-median eminence extract.

Abstract

SummaryAfter an injection or an infusion of an extract from ovine stalk-median eminence (SMEE) into the femoral vein of mature rhesus males, peripheral serum levels of luteinizing hormone (LH) and testosterone (T) were measured by radioimmunossay and competitive protein binding, respectively. Within 2 to 3 min the SMEE injection initiated a 2- to 30-fold increase in serum LH which rapidly returned to base line whereas an SMEE infusion lasting 120 min resulted in a prompt elevation of serum LH which persisted throughout the infusion period. Infusions of cerebral cortical tissue extract (CCE) caused no change in the base line values of LH (430 to 550 ng/ml LER-M-907D) although anesthesia appeared to lower levels by 10 to 25%. Preanesthesia concentrations of T were high (>12 ng/ml) in 4 of 8 trials, decreased more slowly than LH after anesthesia and CCE infusions, and began to rise later than LH, reaching a maximum of 2-to 12-fold above base line within 15 to 90 min after the beginning of SMEE administration...