Biomedical subjects

K Masuo

Publications and source records attributed to K Masuo.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Plasma norepinephrine and dietary sodium intake in normal subjects and patients with essential hypertension.

To evaluate the relationship between sodium intake and the activity of the sympathetic nervous system in patients with essential hypertension, plasma catecholamine levels were measured in 49 essential hypertensive patients and 38 age-matched normal subjects under regular-, high-, and low-sodium diets (mean 24-hour sodium excretions; 116 +/- 8, 267 +/- 29, 31 +/- 7 mEq/day, respectively). The levels of plasma norepinephrine were significantly (p less than 0.01) higher in hypertensive patients than in normal subjects. However, they were significantly reduced by high-sodium intake and increased by low-sodium intake in both patients and controls. The percent decrease and change in the absolute plasma norepinephrine levels from low- to high-sodium states were greater in normal subjects than in the hypertensive patients. The results are interpreted as indicating that an abnormal relationship exists between sodium intake and the activity of sympathetic nervous system in patients with essential hypertension.

Adult↗

PubMedDate not supplied

Increased plasma norepinephrine in young patients with essential hypertension under three sodium intakes.

Increased sympathetic nerve activity may play an important role in the pathogenesis of essential hypertension. It is well known that both dietary sodium intake and age influence the plasma norepinephrine (NE) concentration. The present study was undertaken to evaluate the effects of age on sympathetic nerve activity in patients with essential hypertension and normal control subjects under low-, regular-, and high-sodium regimens (mean 24-hour sodium excretions: 30 +/- 4, 116 +/- 7,280 +/- 15 mEq, respectively). Plasma NE and epinephrine (E) were analyzed by trihydroxyindole methods after high-performance liquid chromatography separation. Subjects were categorized by age into young (less than or equal to 40 yrs), middle-aged (40-60 years), and old (greater than or equal to 60 years) subgroups. Mean plasma NE in hypertensive patients was significantly higher (p less than 0.01) than in normal subjects on each of the sodium regimens. In normal control subjects, there was a significant positive correlation between age and plasma NE with all three sodium intakes. However, no correlation was seen in hypertensive patients on any of the sodium regimens, because in the young subgroup of hypertensive patients the mean plasma NE was significantly higher than that of normal control subjects. These results suggest that the increased sympathetic nerve activity plays an important role in the pathogenesis of essential hypertension, especially in young patients.

Adult↗

PubMedDate not supplied

Pilot study of a new angiotensin II receptor antagonist, TCV-116: effects of a single oral dose on blood pressure in patients with essential hypertension.

After a 1-week placebo control period, six hypertensive patients (mean age, 67 years) each received single doses of 1, 2.5, and 5 mg of TCV-116 at 2- to 3- day intervals. Systolic and diastolic blood pressures were significantly lower after the final dose (5 mg) of TCV-116 than on the last day of the placebo period. Blood pressures were decreased after each dose of TCV-116 in a dose-dependent fashion from 2 hours after administration and reached a nadir at 4 to 6 hours. After 2.5 and 5 mg of TCV-116, the hypotensive effect was sustained for 24 hours. Pulse rate did not change significantly. Plasma renin activity and angiotensin I levels increased in a dose-dependent fashion after TCV-116, but the changes were not significant. No changes were noted in plasma aldosterone or angiotensin II levels. One patient reported mild light-headedness after 5 mg of TCV-116. No other side effects or abnormal laboratory tests results were noted. It appears that TCV-116 is a safe and effective antihypertensive agent.

Aged↗

PubMedDate not supplied

Antihypertensive efficacy of FK906, a novel human renin inhibitor.

The antihypertensive efficacy of a newly developed orally active human renin inhibitor (FK906) was evaluated in 14 patients with essential hypertension aged 40 to 83 years (mean, 64 years). After a 1-week placebo run-in period, 25 mg of FK906 was given twice daily; this was increased up to 100 mg twice daily until sufficient blood pressure reduction was obtained. No adverse effects were observed in any patients. Supine blood pressure was decreased from 169 +/- 3/97 +/- 1 mmHg to 153 +/- 5/87 +/- 3 mmHg at 25 mg twice daily (n = 14), to 142 +/- 5/78 +/- 3 mmHg at 50 mg twice daily (n = 12), P < 0.01), and to 137 +/- 10/77 +/- 8 mmHg at 100 mg twice daily (n = 6, P < 0.01). The hypotensive effect was sustained over 24 hours. Pulse rate did not change. Plasma renin activity and angiotensin I were decreased after FK906 administration only in patients with increased plasma renin activity. The hypotensive effects of FK906 were not correlated with baseline plasma renin activity. Suppression of the noncirculating tissue renin-angiotensin system may account for the hypotensive action of FK906. The results suggest that FK906 is a promising antihypertensive drug in patients of all ages and with different plasma renin levels.

Adult↗