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Biomedical subjects

Y Otsuka

Publications and source records attributed to Y Otsuka.

At least 199 records · Page 11Linked to original sources
PubMed1980

Indomethacin inhibits the antihypertensive effect of captopril, SQ 14225, in low renin hypertension.

The antihypertensive mechanism of orally active angiotensin I-converting enzyme inhibitor, SQ 14225 (SQ), in low renin hypertension was investigated. In the SQ-responder with low renin hypertension, the hypotensive effect of SQ was abolished after the inhibition of endogenous prostaglandin (PG) synthesis with indomethacin, while no significant change in blood pressure was found in the SQ-responder with normal renin hypertension. These results suggest that SQ may potentiate the vasodilating PG system, contributing to the antihypertensive mechanism in SQ responders with low renin hypertension.

Adult↗
PubMed1980

Active and inactive renin after SQ 14225 (Captopril) administration.

The changes of active and inactive renin in plasma after the oral administration of 25 mg or 50 mg of SQ 14225 (Captopril) were studied in 29 hypertensive patients. Inactive renin was calculated as plasma renin activity (PRA) after cold storage minus PRA before cold storage. The patients were divided into 2 groups, responders and non-responders, according to the response of active renin to Captopril. In 9 responders, the active renin increased markedly while the inactive renin decreased. On the other hand, in 20 non-responders, both renin activities increased only slightly. These results suggest that inactive renin may be converted in vivo to active renin by Captopril.

Administration, Oral↗
PubMed1980

Management of severe hypertension with nifedipine in combination with clonidine or propranolol.

The hypotensive effect of nifedipine was studied in 9 patients with severe hypertension. After oral administration of 20 mg nifedipine mean arterial pressure (MAP) fell, reaching lowest values about 1 h p.a. The antihypertensive effect lasted 7 h. Treatment with nifedipine alone (80 mg/day) lowered MAP significantly on the first day, but it tended to rise again therealter. Addition of clonidine (450 micrograms/day) or propranolol (120 mg/day) enhanced the hypotensive effect. Furosemide (120 mg/day) was ineffective when added to the above described regimen. Without nifedipine the combine drugs failed to keep MAP down. The decrease of MAP observed when giving this combination of drugs was associated with a significant fall in total peripheral resistance and plasma renin activity, but did not alter cardiac output and blood volume. We concluded that nifedipine together with clonidine or propranolol is very effective in the management of severe hypertension.

Adult↗
PubMed1979

Estimation of urinary kininogenase activity using bovine serum low molecular weight kininogen.

Estimation of urinary kininogenase activity by radioimmunoassay of generated kinin was studied. Bovine serum low molecular weight kininogen was proved not to cross-react with kallidin antibody and also bradykinin antibody. This kininogen was used as substrate measuring urinary kininogenase activity. Separation of released kinin from the kininogen was not required in the present method. Urinary kallikrein activity was found to be significantly decreased in essential hypertension, in chronic glomerulonephritis and in patients who had received renal transplantation. On the contrary, an increase in urinary kallikrein was found in primary aldosteronism and in Bartter's syndrome. The present method was very useful for measuring kininogenase activity.

Animals↗
PubMed1979

Change in plasma renin activity by cold storage of plasma in normal subjects and patients with essential hypertension and primary aldosteronism.

The time courses of change in renin activity after cold storage of human plasma at -5 degrees C and pH 7.4 were examined in 5 normal subjects, 6 patients with essential hypertension and one female patient with primary aldosteronism before and after extirpation of the adrenal tumor. In the 5 normal subjects and 6 essential hypertensives, the gradual increase in plasma renin activity was observed until 10 days of cold storage. The same result was obtained in the case of primary aldosteronism. However, there was no increase in renin activity despite of cold storage for 10 days in plasma which was sampled from this patient 45 days after operation. These data indicate that a period of 4 days for cryoactivation of human plasma renin as has been reported by Sealey et al. is not sufficient to accomplish activation of renin by cold storage.

Adolescent↗
PubMed1979

Effect of triamterene on urinary excretion of immunoreactive prostaglandin E in essential hypertension.

The effect of triamterene on urinary excretion of prostaglandin E was studied, and the results were compared with those obtained with spironolactone. Urinary excretion of immunoreactive prostaglandin E was measured radioimmunologically. Triamterene was administered in a dose of 100 mg/day for 8 days to 7 patients with essential hypertension. Following the administration of triamterene, urinary prostaglandin E tended to increase. However, the increment was not significant. The lack of significant increase in urinary prostaglandin E excretion during the administration of triamterene contrasted with our previous finding with spironolactone, in which a significant increase in prostaglandin E excretion was observed on the first day of spironolactone administration. Urinary Na excretion and urinary Na/K ratio were significantly increased and urine volume also tended to increase following the administration of triamterene. Plasma renin activity and plasma aldosterone concentration were increased in all cases. However, there was no significant correlation between these parameters and urinary prostaglandin E. These results suggest that the effect of triamterene on renal prostaglandin E synthesis is different from that of spironolactone and that the change in urinary prostaglandin E after the administration of triamterene is not the reflection of the change in the renin-angiotensin-aldosterone system.

Adolescent↗