Luteinizing hormone (LH)-releasing hormone in third ventricular cerebrospinal fluid of the ewe: correlation with LH pulses and the LH surge

摘要: Morphological evidence suggests that LHRH may be secreted into cerebrospinal fluid (CSF), but only in the rhesus monkey has CSF been found to reflect changes occurring neuroendocrine system. This study investigated whether is detectable ovine and, if so, its release profile correlates with peripheral LH profiles during pulse and surge conditions. A polyethylene catheter was threaded through a stainless steel guide cannula previously implanted third ventricle of an ovariectomized ewe, which enabled continuous withdrawal on repeated occasions. The first experiment (n = 3) showed concentrations were unaffected by removal at rates 12, 30, 50, 100 microliters/min, second 4) established secretion pulsatile, considerable variation amplitude (6.3 +/- 1.8 pg/ml; range, 1.3-18.7 pg/ml). In 6), endogenous induced after progesterone 17 beta-estradiol administration. Although (15.3 1.3 h) (14.8 1.0 surges occurred simultaneously, greater than half-maximal levels for longer (11.0 0.6 h; P < 0.005) (6.0 0.4 h). sheep reveal presence show it expresses dynamic term coincident fluctuations. analysis also permits sampling from individuals therefore, long within-individual comparisons.