Plasma beta-endorphin in perinatal asphyxia and respiratory difficulties in newborn infants.
The effects of intrauterine stress and birth asphyxia on the plasma concentration of beta-endorphin (beta-E) in cord blood and in venous blood at the age of 2 h was investigated in newborn infants. Term infants with acute birth asphyxia (n = 11), infants born to mothers with preeclampsia (n = 15), and prematures with respiratory difficulties (n = 4) were entered into the study. Twenty control infants were studied; 12 were born after spontaneous delivery and eight after elective cesarean section. After normal spontaneous delivery, the plasma beta-E level decreased significantly, the median values being 17 pmol/liter at birth and 9.3 pmol/liter at the age of 2 h, whereas after elective cesarean section it remained unchanged (13 and 13 pmol/liter, respectively). In acute asphyxia the plasma beta-E level varied widely at birth, from 9.7 to 108 pmol/liter. At the age of 2 h, the beta-E level was high (26 to 83 pmol/liter) in those asphyctic infants who required prolonged mechanical ventilation, but it fell to the range of 1.6-13 pmol/liter when the infant recovered rapidly. The beta-E level was not increased in the preeclampsia group, not even in small for gestational age infants. In preterm newborn infants with respiratory difficulties, a significant postnatal rise of plasma beta-E level was found, the beta-E value varying from 7.3 to 16 pmol/liter at birth and from 61 to 168 pmol/liter at the age of 2 h. These results indicate that increased beta-E secretion is associated with respiratory difficulties in the newborn infant.
D001034:Apgar Score; D001237:Asphyxia / Q000097:blood*; D004723:Endorphins / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood*; D010927:Placental Insufficiency / Q000097:blood / Q000150:complications; D011247:Pregnancy; D012120:Respiration Disorders / Q000097:blood* / Q000209:etiology; D001615:beta-Endorphin
D004723:Endorphins; D001615:beta-Endorphin