Response of Rhesus Monkeys to LRH Throughout the Ovarian Cycle

Abstract

ABSTRACT Rhesus monkeys with regular cycles were injected with synthetic LRH at doses ranging from 0.2–400 μg. LH response was measured by radioimmunoassay. Twelve out of 14 monkeys responded while 2 remained consistently unresponsive. No clear dose response curve could be established for doses of LRH ranging from 0.2–100 μg. With higher doses, LH release was sustained for a longer period of time. LRH was administered at various phases of the ovarian cycle. LH release was greatest during the midcycle surge in all monkeys. No differences in response were seen during the entire follicular phase up to and including the day preceding the LH surge. LH release during the luteal phase was variable, being comparable in some monkeys to that seen at midcycle. It is concluded that synthetic LRH will release LH in rhesus monkeys. The persistent refractoriness of some animals, with otherwise normal reproductive function, remains unexplained. Responsiveness to LRH during the ovarian cycle cannot be correlated with the ...