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Biomedical subjects

T Saruta

Publications and source records attributed to T Saruta.

At least 595 records · Page 33Linked to original sources

Hypertension induced by adrenocortical dysfunction--hypertension in 17 alpha-hydroxylase deficiency and metopirone-induced hypertension.

Hypertension in 17 alpha-hydroxylase deficiency was studied by comparing it with hypertension in Cushing syndrome or that in primary aldosteronism. Furthermore, the role of endogenous increases of ACTH, deoxycorticosterone, and 18 alpha-hydroxy-deoxycorticosterone upon blood pressure was studied in rats by administerating metopirone. Hypertension in 17 alpha-hydroxylase deficiency was considered to be more similar to that in primary aldosteronism from the studies on renin components, pressor responses to angiotensin II and norepinephrine, and renin responses to stimulations. Plasma catecholamines were slightly decreased in 17 alpha-hydroxylase deficiency. The hypertension was alleviated by the administeration of dexamethasone in 2 of 3 patients with 17 alpha-hydroxylase deficiency. However, in the remaining one who had an accelerated hypertension and normal renin, the hypertension was not alleviated by dexamethasone. In the animal studies, hypertension induced by metopirone was accelerated by salt loading of uni-lateral nephrectomy plus salt loading. In those rats, plasma ACTH, and deoxycorticosterone were markedly increased.

Adrenal Hyperplasia, Congenital↗

Role of renin-angiotensin system in the controls of blood pressure and aldosterone in patients with cirrhosis and ascites.

In an attempt to evaluate the role of renin-angiotensin system in the contols of blood pressure and aldosterone secretion in the patients with cirrhosis and asictes, 7 patients were infused of an antagonist of angiotensin II, Sar-1 Ile-8 angiotensin II, intravenously to inhibit the action of renin-angiotensin system and to observe changes in arterial pressure and plasma aldosterone. In 1 patient with recent onset of severe ascites and high plasma renin activity, blood pressure and plasma aldosterone decreased during the infusion. In contrast, mild rise in blood pressure and various changes in plasma aldosterone were observed in the other 6 patients with normal plasma renin activity. These results suggest variable angiotensin dependency in the controls of blood pressure and plasma aldosterone in the patients with cirrhosis and ascites according to the stage of the disease, the states of sodium and water balance and/or palasma renin activity.

Adult↗

Effect of estrogen upon the juxtaglomerular apparatus and the renin-angiotensin system in rats.

Administration of 1.5 mg/kg of estriol intramuscularly and 15 mg/kg of stilbestrol disulfate intraperitoneally daily for 15 days caused an increase in plasma renin substrate (PRS), accompanied by an increase in plasma renin activity (PRA) and a slight decrease in plasma renin concentration (PRC). Contrary to the slight suppression of PRC, juxtaglomerular granulation index (JGI) was significantly increased in rats treated by estrogen. In the rats which developed hypertension by estrogen PRA, PRC and JGI were a little higher than those in the rats which remained normotensive after the same estrogon treatment, but these differences were not statistically significant. Therefore, it seems rather difficult to attribute the development of estrogen hypertension only to the quantitative changes in the renin-angiotensin system.

Angiotensins↗

The renal lesion associated with total lipodystrophy.

This report concerns a 41-year-old man with total lipodystrophy associated with a specific renal disorder. He had massive proteinuria, mild azotemia and a normal level of serum complement in addition to the generalized loss of subcutaneous fatty tissue. Results of 1 50-gm glucose tolerance test indicated a high fasting insulin level with an exaggerated response to glucose. Hypoglycemic responses to exogenous insulin were reduced. Renal biopsy revealed changes consistent with glomerular lipidosis. This case is unique in that the renal lesion was not the Kimmelstiel-Wilson pathologic change atributable to abnormal glucose metabolism.

Adult↗

Effects of angiotensin III (DES-1-asp-angiotensin II) and angiotensin III analogue (DES-1-asp-8-ile-angiotensin II) upon adrenal steroidogenesis and blood pressure.

Effects of angiotensin III and angiotensin III analogue upon adrenal steroidogenesis and blood pressure were studied in rats, rabbits and a man. Pressor effect of angiotensin III was about one fifth of that of angiotensin II in all the species. Degradation rate of pressor effect of angiotensin III in plasma was more rapid than that of angiotensin II. Different from the effects of angiotensin III upon blood pressure, its effect upon aldosterone was similar to that of angiotensin II. The effect of angiotensin III upon other adrenal steroids, such as DOC and cortisol, however, seemed to be slightly less than that of angiotensin II. Angiotensin III producted an additive effect to that of ACTH, but it didn't produce an additive effect to that of angiotensin II. Angiotensin III analogue, itself, stimulated adrenal steroidogenesis, but it inhibited the effects of angiotensin III and angiotensin II upon aldosterone. Effects of ACTH upon plasma DOC and cortisol were not inhibited by angiotenesin III analogue, but the effect of ACTH upon aldosterone was blunted slightly.

Adrenal Cortex↗

Benign desoxycorticosterone-producing adrenal tumor.

A woman with a benign tumor of the left adrenal cortex had a six-year history of hypertension. Serum potassium level and plasma renin activity were low. Plasma aldosterone and cortisol levels were low normal, and plasma desoxycorticosterone (DOC) level was extremely high. Iodine 131-labeled cholesterol accumulated in the tumor in the left upper quadrant of the abdomen. At laparotomy, a benign adrenal tumor was excised; thereafter, the blood pressure and plasma DOC levels returned to normal. We believe that this is the first case of a benign DOC-producing adrenal tumor.

Adrenal Gland Neoplasms↗

Effects of furosemide and chlorothiazide on blood pressure and plasma renin activity.

Short (2 weeks) and long (12 weeks) term effects of furosemide and chlorothiazide on blood pressure, plasma renin activity, and uric acid concentration were studied in 69 hypertensive patients. Both treatments caused significant reductions in blood pressure and increases in plasma renin activity and uric acid at 2 and 12 weeks in 6) normal renin patients; there was no difference between the effects of furosemide and that of chlorothiazide. Reduction in blood pressure in eight low renin patients who showed smaller changes in plasma renin activity and uric acid was not significant at 2 weeks but significant after 12 weeks of treatment.

Adult↗

Renin release and the juxtaglomerular apparatus in chronic renal failure due to glomerulonephritis.

Changes in renin release with decreasing renal function and juxtaglomerular apparatus in chronic renal failure due to glomerulonephritis were studied. Renin production was still remaining in the contracted kidneys and its release could be stimulated by various stimulations, although the macula densa didn't seem to play an important role in renin release in the contracted kidneys.

Adolescent↗

The mechanism of low-renin hypertension: aldosterone response to sodium restriction and upright posture, angiotensin II, ACTH and potassium in patients with hypertension.

Plasma renin activity and aldosterone were measured simultaneously in 67 out-patients with essential hypertension. High aldosterone was more often in patients with high renin, and low levels of aldosterone were usual in those with low and normal renin. In order to study the mechanism by which aldosterone and renin acitvity are suppressed in low-renin hypertension, 25 patients (13 normal-renin hypertensives, 10 low-renin patients including 4 non-responders and two DOC excess hypertensives) were investigated as inpatients. Plasma renin activity, aldosterone and cortisol were determined by the following stimualtions with 3 days of sodium restriction and 2 hours of upright posture, angiotensin II infusion (at a dose which increased 20mmHg of diastolic blood pressure), ACTH administration (rapid i.m. injection of 0.25 mg of alpha 1-24 preparation) and potassium infusion (30 meq of potassium i.v.). Responses of aldosterone in normal-renin hypertensives to all stimulations were 3-5 fold increases from bases line values. Low-renin hypertensives except two of four non-responders showed the responses similar to those in normal-renin patients. The responses of two of the non-responders were similar to those in DOC excess hypertensives who showed reduced responses of aldosterone to some of these stimulations. Thus, it seems that low-renin hypertension is a clinical entity caused by a variety of mechanisms, and the mechanism by which low-renin hypertension is induced is not explained by one factor such as an unknown mineralocorticoid.

Adrenocorticotropic Hormone↗

[Effects of low salt plus upright posture, angiotensin II, ACTH, and potassium upon plasma renin activity, aldosterone, and cortisol (author's transl)].

In order to study the control system of plasma aldosterone in human, we examined the effects of low salt plus upright posture, angiotensin II, ACTH and potassium upon plasma renin activity, aldosterone and cortisol in five subjects who were supposed to be normal. All of the procedures, low salt diet with below 3 g of salt and 2 hr-upright posture, 0.25 mg of Cortrosyn, angiotensin infusion to increase 20mmHG of diastolic pressure for an hour, and 30 mEq of potassium infusion stimulated plasma aldosterone significantly. Furthermore, in each subject the degrees of response to each of these stimulations were almost same. In an old woman aged 68, responses to all of stimulations were significantly lower than those in other subjects. Plasma cortisol was significantly stimulated by ACTH, but slightly reduced by potassium infusion. From these results, it is certain that plasma aldosteron levels are easily affected by a small amount of changes in angiotensin, ACTH, potassium and sodium. However, responses of aldosterone to these changes seem to be decreased in old subjects.

Adrenocorticotropic Hormone↗

A case of secondary aldosteronism induced by pheochromocytoma.

A case of secondary aldosteronism caused by a pheochromocytoma containing a large amount of norepinephrine is described. The increased level of angiotensin induced by norepinephrine seems to play an important role in the development of secondary aldosteronism.

Adrenal Gland Neoplasms↗