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T T Hung

Publications and source records attributed to T T Hung.

23 records · Page 2Linked to original sources
PubMed1983

Effects of epidural anesthesia during labor on maternal plasma beta-endorphin levels.

Plasma beta-endorphin (beta-EP) was measured in 48 women. Twenty-three were in labor. In 13 of the 23 patients in labor, beta-EP was determined prior to and after complete onset of epidural anesthesia, and in 10 women, who served as controls, prior to and after injection of saline into the epidural space as part of the loss of resistance technique, but before injection of the local anesthetic. Venous blood also was obtained for plasma beta-EP determinations from 10 healthy non-pregnant women and from 15 patients scheduled for elective repeat cesarean section and who were not in labor. Human beta-EP was determined by radioimmunoassay following silicic acid extraction of plasma samples and separation of the beta-EP fraction by gel chromatography. In the 10 non-pregnant volunteers, plasma beta-EP averaged 11.3 +/- 1.5 fmol/ml (mean +/- SE) as compared with 43.7 +/- 6.5 fmol/ml observed in the 15 women with term pregnancies who were not in labor (P less than 0.005). In the 13 patients in labor who underwent epidural anesthesia, plasma beta-EP concentrations decreased (P less than 0.005) from 54.5 +/- 9.0 to 28.2 +/- 3.5 fmol/ml, whereas there was no significant change in plasma beta-EP levels in the 10 controls who averaged 64 +/- 20.5 and 55.8 +/- 13.6 fmol/ml prior to and following saline injection. These data confirm that plasma beta-EP levels are significantly higher in women with term pregnancies in labor than in non-pregnant women and also demonstrate that epidural anesthesia during labor is accompanied by a significant decrease in maternal plasma beta-EP concentrations.

Adult↗
PubMed1982

beta-Endorphin and beta-lipotropin concentrations in umbilical cord blood.

Antisera suitable for human beta-endorphin and beta-lipotropin radioimmunoassay were developed, and radioimmunoassays were established to measure these peptides in umbilical cord plasma, with silicic acid extraction and gel chromatography used to separate the beta-endorphin from the beta-lipotropin fraction. These two peptides were determined in umbilical venous plasma from 64 newborn infants. Umbilical vein beta-endorphin and beta-lipotropin concentrations averaged 38.5 +/- 3.2 and 50.4 +/- 4.1 (+/- SE) fmoles/ml in the 54 newborn infants without and 115 +/- 18 and 110 +/- 25 fmoles/ml in the 10 newborn infants with apparent fetal distress. Neither the presence or absence of labor nor the route or mode of delivery was found to affect umbilical vein beta-endorphin or beta-lipotropin concentrations. However, cord plasma levels of both peptides were significantly elevated in conjunction with fetal distress, as evidenced by prolonged bradycardia, late and prolonged variable fetal heart rate decelerations, or fetal acidosis. In 18 of 22 pairs of simultaneously measured umbilical venous and arterial beta-endorphin and beta-lipotropin concentrations in newborn infants without apparent intrapartum distress, the venous beta-endorphin concentrations, which averaged 40.4 +/- 3.5 fmoles/ml, were significantly higher than the arterial beta-endorphin levels, with a mean of 28.5 +/- 4.2 fmoles/ml. No significant umbilical arteriovenous concentration difference could be observed for beta-lipotropin. This suggests that at least a portion of the coad plasma beta-endorphin is derived from the placenta. The ratio of umbilical arterial to venous beta-endorphin concentrations rose as the absolute cord plasma beta-endorphin levels increased. Furthermore, both the molar umbilical venous and arterial beta-lipotropin to beta-endorphin ratios decreased significantly in association with intrapartum fetal distress. These data indicate tat the stress-related increase in umbilical plasma beta-endorphin exceeds that of beta-lipotropin and may be, at least in part, of fetal origin. Umbilical venous beta-endorphin and beta-lipotropin levels of neonates whose mothers did not receive meperidine or other narcotics agents did not differ from those of neonates whose mothers were given meperidine or other narcotics during labor. Our data, in conjunction with those of others, are consistent with the hypothesis that fetal hypoxia causes the release of neurotransmitters such as beta-endorphin, which may modulate the regulation of fetal heart rate patterns.

Chromatography, Gel↗