IN-VITRO HUMAN GROWTH-HORMONE INCREASES HUMAN CHORIONIC-GONADOTROPIN AND PROGESTERONE SECRETION BY HUMAN PLACENTA AT TERM - EVIDENCE OF A MODULATORY ROLE BY OPIOIDS

We examined the in vitro effect of human growth hormone (hGH) on hormo ne placental production and the modulation by opioids of this function . Small placental fragments from 12 term placentas were incubated at 3 7 degrees C in a 95% air and 5% CO2 atmosphere for 4 h with various co ncentrations of hGH (1-1000 ng/ml) or naloxone (3-500 ng/ml). Both hGH and naloxone increased the concentrations of human chorionic gonadotr opin (hCG) and progesterone in the medial The effect of the hCH was do se-dependent and statistically significant at 10 ng/ml, while naloxone was able to increase hCG and progesterone production only at the high est doses (25-500 ng/ml). The concomitant treatment with ineffective d oses of naloxone and hGH was able to enhance hCG and progesterone secr etion reaching levels similar to those obtained with the highest noses of hGH alone. High naloxone concentrations significantly decreased bo th hCG and progesterone secretion induced by high doses of hGH. This s tudy confirms the relevance of growth hormone in sustaining placental endocrine activities and indicates an effect of opioids in modulating these functions.