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Biomedical subjects

H Morikawa

Publications and source records attributed to H Morikawa.

At least 163 records · Page 9Linked to original sources
PubMed1976

An enzymologic study of corpora lutea in early pregnant rats treated with abortifacient agents.

Luteal metabolism was investigated in corpora lutea of early pregnant rats treated with four abortifacient agents. In corpora lutea of rats treated with prostaglandin F2alpha or of rats 1 day postpartum, glucose-6-phosphate dehydrogenase (G6PDH) activity increased 140 to 170% and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) was activated to significantly high levels, whereas malic enzyme activity decreased to 29% of control values. In aminoglutethimide-treated rats, the activities of G6PDH and malic enzyme decreased, while 20alpha-HSD activity was maintained at a very low level. With the increased dose, complete abortion was observed. In corpora lutea of these aborted rats, 20alpha-HSD was activated moderately and G6PDH values were slightly higher than control values, whereas malic enzyme activity fell to lower levels. All rats treated with clomiphene citrate aborted within 63 hours after the last injection. The activities of G6PDH, malic enzyme, and ATP citrate lyase in these corpora lutea decreased to 66, 68, and 72% of control levels, respectively; 20alpha-HSD activity was maintained at a very low level, and activities of 3beta-hydroxysteroid dehydrogenase, 6-phosphogluconate dehydrogenase, and pyruvate kinase were not appreciably altered. These findings indicated that, at the beginning of luteolysis and fetal resorption, the activities of steroidogenic enzymes decreased and 20alpha-HSD was not yet activated. Therefore, we could gauge the early changes of luteolysis by measuring the activities of G6PDH, MALIC ENZYME, AND ATP citrate lyase as well as 20alpha-HSD.

ATP Citrate (pro-S)-Lyase↗
PubMed1976

Growth hormone, prolactin and chorionic somatomammotropin in normal and molar pregnancy.

Twenty patients with molar pregnancy, ten normal pregnant women and ten healthy non-pregnant women were given 30 g of arginine intravenously. The serum concentration of growth hormone, prolactin and chorionic somatomammotropin (CS) was determined by radioimmunoassay. In addition, serum 17beta-estradiol, estriol and progesterone were also measured. Arginine infusion induced a sharp rise of GH in patients with molar pregnancy and in nonpregnant subjects, but the response in normal pregnancy was blunted. The response of PRL was high in patients with molar pregnancy, blunted in normal pregnancy and very small in nonpregnant subjects. CS did not respond at all to arginine infusion both in normal pregnancy and molar pregnancy. The high response to argine of PRL, normal response of GH and low baseline secretion and no response of CS may be characteristic of molar pregnancy.

Arginine↗
PubMed1975

Lipolytic action of human chorionic somatomammotropin.

Human chorionic somatomammotropin extracted and purified from placenta at term was proved to have a lipolytic action in the epididymal fat pad of rats. The following mechanism appears to be involved in the lipolytic action of the hormone; human chorionic somatomammotropin activates adenyl cyclase, thereby increasing the concentration of cyclic AMP in the tissue, which, in turn, activates protein kinase to lead to the activation of hormone sensitive lipase.

Adenylyl Cyclases↗