SUMMARY

Human chorionic somatomammotrophin (HCS), progesterone, and unconjugated oestradiol and oestriol were measured in the plasma of 13 patients with intact hydatidiform moles from week 9 to 19 of pregnancy and in 89 normal women from week 5 to 20 of pregnancy. Plasma α-foetoprotein (AFP) was also measured in 9 out of 13 patients and in 23 of the normal women from week 13 to 20 of pregnancy. All the compounds were measured by radioimmunoassay. The plasma HCS concentration in 35 samples from 13 patients with hydatidiform moles ranged from 10 to 910 ng/ml; this was lower than that in normal pregnancy of corresponding duration in eight patients, within the normal range in four patients and high in one patient. The plasma progesterone concentration ranged from 17·5 to 79·2 ng/ ml: it was higher than that in normal pregnancy in eight patients and within the normal range in five patients. The plasma unconjugated oestradiol concentration ranged from 1·82 to 8·10 ng/ml: it was higher than normal in six patients and within the normal range in seven patients. The plasma unconjugated oestriol concentration ranged from 0·168 to 1·37 ng/ml, the levels at 15–19 weeks of gestation being significantly lower than those in normal pregnancy at this time (P < 0·005). Plasma AFP was not detectable in the nine patients (< 10 ng/ml) whereas it ranged from 10 to 80 ng/ml in 18 out of 23 women in week 13–20 of normal pregnancy. The present results suggest that both plasma oestriol and AFP could be helpful in the diagnosis of hydatidiform mole at about 12–14 weeks though diagnosis could not be made with absolute certainty.

The present study was undertaken to investigate whether human chorionic gonadotropin (hCG) beta-core fragment (hCG beta cf) was directly produced by gestational trophoblastic tumors. Immunoreactivity of hCG beta cf was demonstrated in the extracts as well as in the culture media of hydatidiform mole tissues. It was also present in the extracts of choriocarcinoma tissues, and its molar concentration exceeded that of intact hCG. The presence of hCG beta cf was then confirmed by gel chromatography and Western blot analysis. Immunohistochemistry showed localization of hCG beta cf immunoreactivity to the syncytiotrophoblasts and scattered cells in the stroma of mole tissue, and to syncytiotrophoblastic cells in choriocarcinoma. Immunoreactivity of hCG beta cf was also detected in the sera of the patients with gestational trophoblastic disease, although the hCG beta cf/hCG ratio was less than one hundredth of that in the tissue extracts. Serial measurement of serum hCG beta cf levels after mole evacuation showed that they declined much more rapidly than those of hCG and became undetectable in the patients with subsequent spontaneous resolution, while hCG beta cf remained or became detectable before the rise of hCG was observed in the patients with subsequent persistent trophoblastic disease. Taken together, these results suggest that hCG beta cf is directly produced by gestational trophoblastic tumors, and monitoring of hCG beta cf in the serum after mole evacuation may be useful for early prediction of subsequent development of postmolar persistent trophoblastic disease.

ABSTRACT

We have previously demonstrated that retinoic acid (RA) as well as thyroid hormone stimulates GH gene expression. To clarify the relationship between the action of RA and thyroid hormone, pituitary-specific gene expression was investigated further in rat pituitary cells.

Rat clonal pituitary cells, GH₃, were treated with RA with or without tri-iodothyronine (T₃) for up to 3 days. After treatment with 10–1000 nmol RA/1 with or without 0·1–10 nmol T₃/1, medium was collected for radioimmunoassay and cells were subjected to RNA extraction, and GH and prolactin gene expression was analysed using ³²P-labelled rat GH and rat prolactin cDNA probes respectively. The data demonstrated the dose–responsive manner of the stimulatory effects of RA and T₃ on GH secretion with T₃-depleted media. The action of RA was additive to that of T₃ for GH secretion when maximum effective doses of RA or T₃ were used. Using dot blot and Northern gel analysis, it was shown that RA increased GH mRNA levels in T₃-depleted media, and that this action of RA was additive to that of T₃ on the induction of GH mRNA levels. In contrast, neither RA nor T₃ stimulated the secretion of prolactin and prolactin mRNA levels in these cells.

Our results indicate that RA stimulates GH mRNA increment and GH secretion in T₃-depleted media, and that the stimulatory effect of RA is additive to the maximum effective dose of T₃.

Journal of Endocrinology (1990) 125, 251–256

ABSTRACT

To determine the effects of atrial natriuretic polypeptide (ANP) on plasma levels of ACTH, cortisol, aldosterone and dehydroepiandrosterone (DHEA), synthetic human α-ANP (hα-ANP) was infused i.v. into eight normotensive, disease-free volunteers, at a dose and duration previously found to be sufficient to produce apparent cardiovascular and renal effects.

The mean basal concentration of plasma ACTH determined by radioimmunoassay was 18·2 ± 3·1 ng/l. Plasma ACTH concentrations tended to be decreased during the infusion in all subjects. However, the change in plasma ACTH concentrations during infusion of hα-ANP was essentially the same as that during the infusion of saline. The mean plasma cortisol concentration was significantly suppressed from 25 to 40 min after the end of synthetic hα-ANP infusion. At 90 min after infusion, the mean plasma level of cortisol reverted to the pretreatment level. There was a non-significant increase in plasma renin activity following the infusion. The mean plasma aldosterone concentration was reduced by 15% (P < 0·05) during the infusion and returned to preinfusion levels 10 min after termination of the infusion, after which the mean plasma concentration declined to the level seen during infusion. Administration of hα-ANP had no significant influence on plasma DHEA concentrations, but there was a tendency to decrease during the infusion.

Our data suggest that synthetic hα-ANP inhibits adrenocortical steroidogenesis in man.

J. Endocr. (1986) 110, 287–292