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Biomedical subjects

Y Morimoto

Publications and source records attributed to Y Morimoto.

At least 541 records · Page 30Linked to original sources
PubMed1980

Relative potency in acute and chronic suppressive effects of prednisolone and betamethasone on the hypothalamic-pituitary-adrenal axis in man.

The relative potency in the hypothalamic-pituitary-adrenal (HPA) suppression of both prednisolone and betamethasone was examined in an acute study with normal volunteers and in a chronic study with glucocorticoid-treated patients. Circadian rhythm of plasma cortisol was studied after a single dose administration of 5 to 30 mg prednisolone or 0.5 to 3.0 mg betamethasone at 8:00 hr. Morning-rise of plasma cortisol occurred on the morning after the administration of 30 mg or less prednisolone but no morning rise was noted after the administration of 1.0 mg or more betamethasone. Plasma ACTH was slightly elevated on the morning after 30 mg prednisolone administration but showed low levels throughout the night after 3.0 mg betamethasone administration. Plasma cortisol responsiveness to ACTH was examined in patients before and during therapy with either prednisolone or betamethasone. The basal cortisol level was not suppressed and the responsiveness to ACTH remained nearly normal during long-term 5 mg prednisolone therapy, but these were completely suppressed during long-term 5 mg betamethasone therapy. The responsiveness to ACTH was nearly normal in patients receiving alternate-day therapy with prednisolone in such large doses as 50 or 60 mg every other day, but was completely suppressed in patients receiving 1.0 mg betamethasone every other day. The relative potency of betamethasone in acute and chronic suppressive effects on the HPA system seems to be much stronger than that of prednisolone in equivalent doses with comparable anti-inflammatory effects. It is also suggested that the alternate-day therapy with such long-acting steroids as betamethasone are useless in preventing HPA suppression.

Adrenocorticotropic Hormone↗
PubMed1980

Inhibition by biscoclaurine alkaloid of lipid peroxidation in biological membranes.

Biscoclaurine-type alkaloids were examined for ability to act as membrane-stabilizing agents and to protect against lipid peroxidation and deterioration of biological membrane. The following results were obtained. Biscoclaurine-type alkaloids inhibit Fe2+-induced lipid peroxidation of biological membrane. Cepharanthine protects against decrease in membrane compartmentation due to Fe2+-induced lipid peroxidation. Peroxidation of membrane lipid causes decrease in membrane fluidity but cepharanthine protects against this decrease. These protective actions are structure specific. They are also biscoclaurine-type specific and do not apply to coclaurine-type alkaloids such as papaverine. Based on these findings, the biological action of the alkaloid is discussed relative to membrane-stabilizing action and protective action against leukopenia induced by X-ray irradiation or mitomycin treatment in cancer therapy.

Alkaloids↗
PubMed1978

Increased serum oestrone and oestradiol following spironolactone administration in hypertensive men.

The present study was undertaken to evaluate long-term effects of spironolactone on basal serum oestrone, oestradiol, testosterone, LH and prolactin concentrations in hypertensive male patients. Serum prolactin response to TRH was also evaluated. Patients were divided into two groups: a conventional-dosage group, consisting of six males with essential hypertension who took 75 to 150 mg of spironolactone daily for 12 weeks, and a high-dosage group, consisting of two males with idiopathic hyperaldosteronism who took 300 mg of spironolactone daily for more than 40 weeks. In the conventional-dosage group, serum oestrone concentrations significantly increased (P less than 0.01) at 12 weeks, serum oestradiol concentrations gradually increased throughout the study period, however, the increments were not statistically significant (P less than 0.2). Basal serum testosterone, LH and prolactin concentrations were not significantly changed throughout the study period. Enhancement of serum prolactin response to TRH was not found in any of the patients in the conventional-dosage group. In the high-dosage group, serum oestrone maintained high levels from the beginning of this study, and serum oestradiol concentrations increased with the development of gynaecomastia. Serum testosterone, LH and prolactin concentrations did not show any definite change throughout the study period. Thus, long-term spironolactone treatment increased the serum levels of oestrone and oestradiol in hypertensive men followed by the development of gynaecomastia. The elevation in circulating oestrogens could well explain the oestrogenic side-effects of spironolactone treatment.

Adult↗