Changes in Hormonal Activities Relative to the Severity of Essential Hypertension

Abstract

Endocrine activity in patients with essential hypertension was studied by measuring the urinary excretion of catecholamines, prostaglandin E (PGE) and cyclic adenosine monophosphate (cAMP). Simultaneously, plasma renin activity, concentrations of serum sodium, potassium, blood urea nitrogen (BUN) and creatinine were determined. Systolic blood pressure and BUN increased progressively with age until the sixth decade. Urinary excretion of norepinephrine was correlated with the systolic blood pressure. In contrast, plasma renin activity and urinary excretion of PGE decreased progressively with the increase in systolic blood pressure. Although the cause of essential hypertension is not known, it is suggested that hypertension accelerates the aging process in the kidney and thus decreases renal PGE synthesis. This decrease of PGE in turn causes a reduction of plasma renin activity, possibly either by accelerating the retention of sodium and water or by failing to stimulate renin synthesis. A decrease of PGE may also potentiate the vasopressor action of norepinephrine.

Age‐Related Changes in Endocrine and Renal Function in Patients with Essential Hypertension

“…In comparison with the subjects in other studies (5, 12), most of our patients undoubtedly were ingesting an excess amount of salt, as judged by the urinary excretion of NaCl. Despite this deviation, a number of aspects were comparable to those previously reported (4, 13, 14). First, systolic and diastolic blood pressures increased progressively with age (13).…”

“…Although plasma renin activity is not a reliable criterion for the prediction of thiazide effectiveness, it is still a matter of theoretical interest to evaluate the physiologic role of renin activity in patients with essential hypertension. In a recent study (14), we again found that plasma renin activity decreased progressively with age. Yet, in the patients of this study, plasma renin activity seemed also to be governed by the salt intake.…”

“…Second, plasma renin activity was inversely correlated with the increased urinary excretion of NaCl (5, 12). Third, plasma aldosterone concentration increased progressively with the increase of plasma renin activity (12, 14). It seems, therefore, that the plasma renin‐aldosterone system was operating to control electrolyte and water in our patients.…”

Changes in Endocrine Activities Relative to Obesity in Patients with Essential Hypertension*

“…Our previous studies (4, 5) have shown that a number of endocrine changes are associated with the severity of essential hypertension. Since the blood pressure increases progressively with the increase of relative body weight, it may be hypothesized that the weight increase results in changes of endocrine activities.…”

“…Despite these accumulated evidences, it is not known why overweight is associated with a high incidence of hypertension or why weight reduction favors a decreased incidence of hypertension. Our previous studies (4, 5) repeatedly showed a number of aspects of endocrine activities associated with the severity of essential hypertension. In order to throw some light on the relation between blood pressure and obesity, a population study was made in Kijimadaira village, Nagano‐ken, Japan.…”