Absence of Immunoreactive Luteinizing Hormone-Releasing Hormone in Ovine Cerebrospinal Fluid Collected from the Third Ventricle 1

Abstract

Summary

Cerebrospinal fluid (CSF) was collected repetitively from the third ventricle of three ovariectomized sheep. Immuno-reactive LHRH could not be detected (<100 pg/ml) in any of 70 samples of CSF collected from untreated, estradiol-treated, and LHRH-treated ewes. The LHRH im-munoassay accurately measured the hormone in extracts of ovine stalk-median eminence tissue. Furthermore, no immunoreactive LHRH was lost when synthetic LHRH was added to freshly collected CSF and stored in the manner used for the attempted measurement of endogenous LHRH. Intravenous injection of LHRH increased plasma concentrations of the hormone to 420 pg/ml but LHRH could not be detected (<100 pg/ ml) in CSF collected concurrently.