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Biomedical subjects

E Murakami

Publications and source records attributed to E Murakami.

At least 127 records · Page 7Linked to original sources
PubMed1981

Treatment of severe hypertension and hypertensive emergency with nifedipine, a calcium antagonistic agent.

Nifedipine, the Ca++ antagonistic coronary vasodilator, was administered by oral, sublingual and enema routes. 1) In 6 severe hypertensive patients (systolic pressure greater than or equal to 200 mmHg, diastolic greater than or equal to 120 mmHg), nifedipine, administered orally, induced prompt and reliable fall of arterial pressure (systolic pressure: -28% of control level, diastolic: -27%). 2) In 10 patients with hypertensive emergencies, including malignant hypertension, intracranial bleeding, hypertensive encephalopathy and acute hypertensive heart failure, sublingual and enema administration of nifedipine were performed with excellent hypotensive efficacy. 3) Pressure began to fall within 5--15 min, 30 min and 30--60 min after sublingual (or dissolved), enema and oral (capsule), respectively, and reached its lowest levels in the next 10--20 min. The fall of pressure lasts for 2--4 hours. 4) In the combination of nifedipine with alpha-methyldopa, antihypertensive response in short-term was increased about +11% over nifedipine alone and lasted for 8 hours. In combination with beta-blocker (propranolol), hypotensive efficacy increased +39% over nifedipine alone, but the effective duration of this combination was the same as nifedipine alone. 5) Side effects, including dryness of the mouth and burning sensation in face and legs, were observed in few patients.

Administration, Oral↗
PubMed1980

Effects of prostaglandins on renin substrate production by the liver.

1. The effects of prostaglandin (PG) E1, PGE2 and PGF2 alpha on plasma renin substrate concentration in rats and renin substrate production by perfused rat liver were investigated. 2. After bilateral nephrectomy, both plasma renin substrate concentration and renin substrate production were remarkably elevated. 3. The increase in plasma renin substrate level and production of renin substrate by the liver after nephrectomy was markedly suppressed by the treatment with PGE1 or PGE2. 4. In contrast PGF2 alpha had no suppressive effect on renin substrate synthesis. 5. These findings suggest that PGE1 and PGE2 might be inhibitory factors in the regulation of renin substrate synthesis.

Angiotensinogen↗
PubMed1980

Pathophysiological characteristics of labile hypertensive patients determined by the cold pressor test.

Hemodynamic changes during the cold pressor test were examined in Type I labile (juvenile labile) hypertensive patients, Type II labile (middle aged labile) hypertensive patients, established hypertensive patients and normal subjects. In normal, Type I labile hypertensive and established hypertensive subjects, the pressor response during the test was accounted for chiefly by a rise in peripheral resistance. In Type II labile hypertensive patients, an increase in blood pressure during cold stimuli was accompanied by an augmented cardiac output. Therefore, Type II labile hypertension is separated clearly from other types of hypertension with respect to hemodynamic changes during the test. In Type II labile hypertensive patients, however, diazepam reduced an increase in cardiac output during the test, resulting in hemodynamic changes similar to those of normal subjects. After atropinization, the hemodynamic pattern of Type I and established hypertensives changed similar to that of Type II labile patients during the cold pressor test. It is concluded that an excessive cardiac output caused by the cold stimuli is a distinctive hemodynamic characteristics of Type II labile hypertensive patients, and this distinctive hemodynamic characteristics might be due to the decreased parasympathetic tone.

Adult↗
PubMed1980

Effects of insulin and glucagon on production of renin substrate by the isolated rat liver.

An isolated rat liver perfusion system was used to study the effects of insulin and glucagon on renin substrate production. Normal livers synthesized renin substrate at a rate of 28.3 +/- 3.8 (S.E.M.) ng angiotensin I equiv./g liver each h (n = 8). The addition of insulin (more than 0.1 i.u.) to the perfusion significantly enhanced the production of renin substrate which was about twofold higher than normal control values (P less than 0.001). However, glucagon (20 micrograms) did not affect the synthesis of renin substrate. These results indicated that insulin promoted the synthesis of renin substrate by the isolated rat liver.

Angiotensinogen↗
PubMed1980

Reduced responses of renin release to three different stimuli in essential hypertensive patients of stage II (WHO stage classification).

The responses of renin release to three different stimuli, such as 1) head-up tilt, 2) administration of loop diuretics(bumetanide) and 3) low sodium diet + administration of bumetanide + ambulation were examined in essential hypertensive patients and normotensive subjects. Essential hypertensive patients were classified as stage I and II according to WHO stage classification. Groups studied were age-matched. The responses of renin release to three stimuli did not significantly differ in normotensive subjects (n = 13, 42 +/- 2(SEM) years old) and essential hypertensive patients of stage I (n = 15, 44 +/- 2). However, essential hypertensive patients of stage II (n = 20, 44 +/- 1) showed significantly lower responses of renin release to all three stimuli than essential hypertensive patients of stage I and normotensive subjects. The results suggest that the suppression of renin release is related in part to the development of hypertension.

Adult↗
PubMed1980

Production of blood capillary contracting substance after administration of estrogen to rabbit.

Estradiol was continuously injected to female rabbits with a daily dose of 10,000 units for 50 days, and androgen was similarly given to male rabbits. Samples were obtained from livers of these rabbits according to the method of "placental capillary contracting substance", and their capillary contracting activities were determined. A substance showing a high activity was obtained from the liver of the rabbit treated with estradiol. A capillary contracting substance was also extracted from the urine of pregnant women, but it was hardly obtained from the urine of normal men.

Androgens↗
PubMed1979

Spinal cord ischemia and left atrial myxoma.

A 62-year-old man had an acute, transient, flaccid paraplegia. Examination showed a primary cardiac tumor with emboli to major branches of the aorta. A myxoma was removed from the left atrium, and normal function returned. Left atrial myxoma should be suspected as a cause for embolism to the CNS.

Embolism↗
PubMed1979

No evidence for the existence of a species-specific renin substrate in plasma from normal and bilaterally nephrectomized rats.

Renin substrate in plasma from normal and biolaterally nephrectomized rats was measured using an excess of rat or rabbit renin which had the same pressor activity when directly assayed in the rat. The amounts of angiotensin I generated with an excess of rat renin were similar to those generated with an excess of rabbit renin in plasma from normal and bilaterally nephrectomized rats. Further addition of an excess of homologous renin to the incubation mixture did not generate more angiotensin I from normal and bilaterally nephrectomized rat plasma which had been incubated before with an excess of rabbit renin. The isoelectric focusing profiles of plasma renin substrate from normal and bilaterally nephrectomized rats were almost identical using an excess of either rat or rabbit renin. It is concluded that there is no species-specific renin substrate for homologous renin in normal or bilaterally nephrectomized rats.

Angiotensin I↗
PubMed1979

Hemodynamic effects of sublingual nifedipine in congestive heart failure.

Hemodynamic response of nifedipine in 11 patients with congestive heart failure was examined. Thirty minutes after sublingual administration of nifedipine, CI and SVI were increased together with a decrease in PAEDP and TSVRI. The increase in CI was proportional to the decrease in TSVRI. Twenty-four hours after continuous administration of nifedipine, however, six of 11 patients did not show the improvement of left ventricular function. These results indicate that sublingual administration of nifedipine is effective in the short-term therapy of the patients with a markedly decreased cardiac output and an increased systemic vascular resistance.

Administration, Oral↗