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R J Simon

Publications and source records attributed to R J Simon.

46 records · Page 3Linked to original sources
PubMedDate not supplied

Human embryonal extracts modulate placental function in the first trimester: effects of visceral tissues upon chorionic gonadotropin and progesterone secretion.

We investigated the effect of human first trimester fetal visceral organ extracts upon placental function, as evidenced by secretion of human chorionic gonadotropin and progesterone in explant cultures of 7-10 weeks gestational age trophoblast. Certain alcohol/water or water extracted embryonal tissues, in highly diluted solutions (1:100-1:2,000 final) had significant effects upon secretion of both hormones. The alcohol/water extract produced an opposite effect. This inhibitory effect was also seen when pulses of the water extract were added to the superfused trophoblast. Both heat inactivation at 57 degrees C and treatment with 10 microM p-chloromercurobenzoate eliminated the inhibitory effect, which suggests that the compounds in question are proteinaceous. Also dialysis with exclusion of less than 8,000 daltons abolished the inhibitory effect seen with the untreated water extract. The alcohol/water lung extract at 9 weeks inhibited, while at 10 weeks it stimulated P4 secretion. The water extracted lung had no effect upon P4 secretion. The alcohol/water extract of kidney had no consistent effect upon hCG secretion. The water extract effect was inhibitory. The effect of alcohol/water extract at 9 weeks upon P4 secretion was inhibitory while at 11 weeks it was stimulatory. The water extract had no effect upon P4 secretion. Both alcohol/water and water extracted adrenal inhibited hCG secretion. The alcohol/water extract also increased P4 secretion, while the water extract had no effect. The alcohol/water and water extract liver had no effect upon hCG secretion. The effect of alcohol/water upon P4 secretion was markedly stimulatory, while the water extract had no effect. In conclusion, fetal visceral organs in very dilute concentrations have a significant effect upon placental hormonal secretion in vitro. In case of the lung, the active compound(s) appears to be a protein with a molecular weight of less than 8,000 daltons. The role of the human embryo in modulating early trophoblastic function is suggested.

Adrenal Glands↗
PubMedDate not supplied

Human embryo modulates placental function in the first trimester; effects of neural tissues upon chorionic gonadotropin and progesterone secretion.

We investigated the effect of embryonal neural and adrenal tissues (7-14 weeks gestational age) upon beta hCG secretion by homologous placental explants in static and dynamic cultures. In static co-culture significant inhibition by SC and brain was noted at 7-9 weeks. Similarly, in superfusion, using a novel co-chambering technique there was a significant reduction in the area under the curve but not peak frequency of spontaneous pulsatile beta hCG secretion. Incubations with neural tissues 11 weeks and above caused a stimulatory effect upon beta hCG secretion in both models. The effect of adrenal tissue in static cultures was different, namely slightly inhibitory at 7-9 weeks and inhibitory at 11 weeks and above. In superfusion, the effect of adrenal tissue was not significant. Extracted neural tissue 7-9 weeks incubated with placental explants exhibited inhibitory effects upon beta hCG secretion as well. Buffer-based extracts of neural tissues effect was more pronounced than alcohol-based extracts regarding beta hCG secretion. The effect of extracts was dose-dependent and effects were noted up until a 2000-fold dilution. In contrast, the buffer SC extract had no effect on progesterone (P) secretion while the alcohol extract effect was inhibitory at 7-9 weeks and stimulatory at greater than 11 weeks. Superfused explants pattern of beta hCG secretion was inhibited by one minute pulse of the SC buffer extract. In conclusion, the human neural tissue of embryonal origin may modulate placental hCG and P secretion during early pregnancy.

Adrenal Glands↗