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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.
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Although brain amines have been suggested as neurotransmitters regulating the release of hypothalamic hormones, some conflicting evidence has still to be explained. Scapagnini, Van Loon, Moberg & Ganong (1970) have implicated brain noradrenaline in the inhibitory control of adrenocorticotrophin (ACTH) secretion, based on the results of intraperitoneal injection of α-methyl-p-tyrosine. However, we found no increase in corticosterone after oral administration of α-methyl-p-tyrosine to rats (Uchimura, Kumeda, Kawabata, Maeda, Tada, Okamoto, Ogawa & Inamori, 1972).
In this study we have examined the effects of intraventricular administration of 6-hydroxydopamine (6-OHDA), a specific and long-lasting catecholamine depletor which does not cross the blood-brain barrier thus excluding the effects of serotonin, peripheral noradrenaline or peritoneal irritation. We performed the experiments 2 weeks after intraventricular administration of 6-OHDA to avoid the stress effects of the administration of 6-OHDA itself.
Male Wistar rats (125–250 g), caged singly, were used. Each rat was
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ABSTRACT
Changes in concentration of human atrial natriuretic peptide (hANP) in normal and toxaemic pregnancy were examined. The maternal plasma concentration of hANP increased gradually during normal pregnancy to a maximum of 20·0±2·4 pmol/l (mean ± s.e.m.) after week 36 of pregnancy. From week 20, the plasma concentrations of hANP were significantly higher than those in non-pregnant women (9·3±2·0 pmol/l). In toxaemia with hypertension, maternal plasma hANP levels were increased after week 26 of pregnancy (37·7±6·0 pmol/l) compared with those in normal gravida at the same time (17·1±1·6 pmol/l). Maternal plasma hANP levels in toxaemia only with oedema were not different from those in normal gravida.
J. Endocr. (1987) 114, 325–328
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Facilitative glucose transporter-1 (GLUT1) is abundant in trophoblast cells and is responsible for glucose transport in the placenta. However, the change in GLUT expression in human placenta upon trophoblast differentiation remains to be clarified. Therefore, we first examined the localization of GLUT1 and GLUT3 using human first-trimester chorionic villi. We found that GLUT1 and GLUT3 were mainly localized to syncytiotrophoblast and cytotrophoblast cells respectively. We analyzed whether placental GLUT1 and GLUT3 expression changes during differentiation using a human choriocarcinoma (BeWo) cell line which is known to show functional and morphological differentiation in response to cAMP in culture. Treatment of BeWo cells with 8-bromo-cyclicAMP (8-bromo-cAMP) increased the level of hCG secretion and induced cell fusion leading to the formation of large syncytia. Treatment of BeWo cells with 8-bromo-cAMP also resulted in a significant increase in glucose uptake on days 2-3 of culture. The stimulating effect of 8-bromo-cAMP on glucose uptake was concentration dependent. Northern and immunoblot analyses revealed that the levels of mRNA and protein of GLUT1, but not of GLUT3, were significantly increased by 8-bromo-cAMP. These findings suggest that 8-bromo-cAMP stimulates GLUT1 expression with differentiation in BeWo cells.
