Late-pregnancy changes in peripheral plasma beta-endorphin in rhesus monkeys (Macaca mulatta).
Peripheral plasma beta-endorphin (BEP) was measured in 10 pregnant monkeys during the third trimester (14-21 weeks gestation, term = 23.5 weeks). The study was intended to identify a late-pregnancy rise in BEP that has been reported in women. Levels rose in late pregnancy only in animals that delivered within a few days of the final sample. When both BEP and beta-lipoprotein (BLP) were measured in a further group of 10 animals, the late-pregnancy BEP rise was not accompanied by a rise in BLP. Multiple regression indicated that plasma BEP was correlated with plasma cortisol but that an independent influence of gestational age could be detected. We conclude that monkeys exhibit a rise in BEP just prior to parturition that is not accompanied by increases in cortisol and BLP that would indicate general maternal pituitary activation.
Golub
M S
MS
Department of Anesthesiology, University of California, Davis.
Eisele
J H
JH
Hwang
F Y
FY
Arbabzadeh
H
H
D000818:Animals; D004723:Endorphins / Q000097:blood*; D005260:Female; D005865:Gestational Age; D006854:Hydrocortisone / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008253:Macaca mulatta; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011863:Radioimmunoassay; D013997:Time Factors
D004723:Endorphins; D008074:Lipoproteins; D006854:Hydrocortisone