J. Takahara, A. Arimura, A. Schally
Aug 1, 1974
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Influential Citations
150
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Quality indicators
Journal
Endocrinology
Abstract
Since a purified porcine hypothalamic preparation with high PIF activity as tested by an in vivtro assay was found to contain a high content of catecholamines, PIF activity of this preparation and catecholamines were examined in vivo. The test samples were infused for 30 min into a hypophysial portal vessel of male rats anesthetized with urethane. Infusion of 30 ng and 300 ng of porcine PIF preparation in 5% glucose solution decreased serum prolactin levels significantly, as compared to the respective preinfusion levels. Infusion of 60 ng and 600 ng, but not 6 ng, of dopamine hydrochloride in glucose solution caused a significant reduction in prolactin levels. Administration of 6 ng, 60 ng, and 600 ng of norepinephrine bitartrate in 5% glucose also decreased serum prolactin levels. The magnitude of decrease in prolactin levels appeared to be dose-related. When dopamine hydrochloride (600 ng) and norepinephrine bitartrate (600 ng) were dissolved in 0.9% saline and infused into the rat, their PIF activity w...