Serum-Endorphine in der Perinatalperiode

Abstract

In 22 pregnant women beta-ELIR and N-terminal-beta-Lipotropin serum levels were determined by radioimmunoassay (New England Nuclear) in the last three weeks of pregnancy, at the beginning and at the end of delivery and during 48 hours after delivery. The difference between the results of the two examinations (beta-ELIR and N-terminal-beta-lipotropin) represents with close approximation the beta-endorphin concentration. In 12 patients the beta-endorphin level during delivery was significantly higher than during late pregnancy; in three cases an extremely high beta-endorphin concentration was found in pregnant women with a dystrophic infant. Therefore, beta-endorphin is discussed as an indicator for foetal distress.

The Role of Endogenous Opioids in Pregnancy and Anesthesia

“…68 Clinical findings in a group of 12 patients revealed 3 cases with extremely high β-en dorphin concentrations in pregnant women with dystrophic infants. 31 As stated earlier, in the rat, enkephalin has been shown to inhibit the angiotensin-stimulated release of oxytocin and vasopressin. 57 Another study 69 sug gests that leucine enkephalin is able to function as a stimulator of pituitary or adrenal function during fetal life.…”

“…Another hypothesis, derived from the observation that the β-endorphin level is extremely high in pregnant women with dys trophic infants, suggests that more β-endorphin is released and is so required in cases of fetal distress. 31 Simultaneous measurements of immunoreactive βendorphin and ACTH in maternal plasma and in the umbilical vein at the time of vaginal delivery demon strated elevated levels of both peptides. The new borns also had an increased ratio of β-endorphin to ACTH, the role of which is uncertain at the present time.…”

“…The levels of immunoreactive lipotropin as well as of β-endorphin appear to be higher in the luteal phase than in the follicular phase, and the serum concentration of these 2 endogenous opiates in creases progressively with advancing gestation. 4,[30][31][32][33][34] During labor these 2 peptides reach maximum val ues at the period coinciding with a cervical dilatation of 10 cm. 30 The ratio of β-LPH to γ-LPH does not change significantly throughout pregnancy, but there is a progressive fall in the β-LPH: β-endorphin ratio.…”