Evidence for a Periodic Release of LH in Castrated Male and Female Rats1

作者：VERNON L. GAY, Nandini A. Sheth · 发表于：Endocrinology · 年份：1972 · DOI：10.1210/endo-90-1-158 · 被引用次数：186 · 研究领域：Growth Hormone and Insulin-like Growth Factors、Pituitary Gland Disorders and Treatments、Hypothalamic control of reproductive hormones

Radioimmunoassay systems were used to measure LH and FSH concentrations in sequential samples of whole blood obtained at frequent (2–10 minute) intervals from cannulated rats which had been castrated at least 45 days earlier. In castrated rats of both sexes, plasma LH patterns were characterized by brief periods of rapid increase, alternating with more prolonged periods during which LH levels decreased at a rate comparable to the disappearance rate (“halflife”) for LH following hypophysectomy. Plasma LH concentrations, which varied from 80 to 300 ng B160/ml, were consistently greater than levels measured in intact males or diestrous females ( @ 5 ng/ml) and consistently less than maximum levels associated with ovulation (400–800 ng/ml). These data suggest that LH is released at regular intervals ranging from 20 minutes to one hour and that the periodicity of this LH release is reasonably consistent within individual castrated rats during 2 to 3 hour intervals. It appears that there are periods of time during which the pituitary of the castrated rat releases little or no LH. In the same rats, serum FSH levels were more stable and demonstrated few fluctuations which could be detected in our assay system. (Endocrinology90: 158, 1972)