High concentrations of oxytocin in hypophysial portal plasma.
Hypophysial portal blood was collected from pentobarbital-anesthetized male rats, and the content of oxytocin (OT) was measured by RIA. The concentration of OT in portal plasma was 1.88 +/- 0.48 ng/ml (SEM) and was at least 15 times higher than the concentration of OT in peripheral plasma samples from the same rats. Dilutions of portal plasma produced a displacement curve parallel to those of synthetic OT and posterior lobe extract. The data support a possible role for OT as a hypothalamic-releasing hormone.
D000818:Animals; D003429:Cross Reactions; D008297:Male; D010121:Oxytocin / Q000097:blood* / Q000378:metabolism; D010902:Pituitary Gland / Q000098:blood supply*; D011863:Radioimmunoassay; D051381:Rats
D010121:Oxytocin