beta-Endorphin is present in high concentration in the hypophysial portal vessels of rats.
beta-Endorphin-like immunoreactivity (beta-ELI) was measured in hypophysial portal and arterial blood of intact, adrenalectomized and hypophysectomized rats. beta-ELI levels were 61 times higher in the long portal vessels than in the general circulation. Circulating, and especially portal, levels of beta-ELI were significantly increased after adrenalectomy. After removal of the pituitary gland, the mean level of beta-ELI in portal blood was significantly lower than in intact rats. beta-ELI in portal blood displayed the same chromatographic properties as synthetic beta-endorphin.
D000315:Adrenalectomy; D000818:Animals; D004723:Endorphins / Q000097:blood*; D007016:Hypophysectomy; D007030:Hypothalamo-Hypophyseal System / Q000098:blood supply*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
D004723:Endorphins; D001615:beta-Endorphin