Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments were performed on conscious uninephrectomized dogs to determine the comparative effects of chronic intrarenal and intravenous norephrine (NE) infusion (0.27 microgram/kg/min) on the steady-state values for arterial pressure, plasma renin activity (PRA), and renal function at four levels of sodium intake (5, 40, 120 and 240 mEq/day). Arterial pressure was monitored continuously 24 hr/day with on-line computer techniques. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and plasma renin activity (PRA) were determined after sodium and water balance was achieved. During intrarenal NE infusion, ERPF and GFR decreased progressively from 15% to 30% and from 24% to 46% respectively, while renal vascular resistance increased progressively from 40% to 140% as sodium intake was increased from 10 to 240 mEq/day. Both ERPF and renal resistance, but not GFR, returned to control levels during intravenous NE infusion at each level of sodium intake and after terminating NE infusion. During intrarenal NE infusion the steady-state value for mean arterial pressure increased from a control of 105 to 118 mm Hg when the sodium intake was 10 mEq/day. Pressure then increased progressively from 118 to 135 mm Hg as the sodium intake was elevated from 10 to 240 mEq/day. Increases in arterial pressure associated with intravenous NE infusion were significantly smaller at each sodium level than those achieved with intrarenal NE infusion. At each level of sodium intake, PRA was elevated during intrarenal NE infusion and returned to control after NE infusion. Intravenous NE infusion did not increase PRA above control levels. The data are compatible with the concept that enhanced renal adrenergic activity could initiate and sustain hypertension chronically by basic alterations in renal function.
Hypertension
PMID:Changes in renal vascular sensitivity and arterial pressure associated with sodium intake during long-term intrarenal norepinephrine infusion in dogs. 39 48

The renin-angiotensin-aldosterone system, electrolyte and water balance, body fluid, and neurogenic tone and reactivity of the vasculature were studied in hypertension induced in uninephrectomized rats by repeated injection of renin-rich kidney extract and 1% saline drinking. The control rats were injected with physiological saline. Various measurements were made in conscious rats on the 10th day of the treatment. As compared with the control, plasma renin concentration and serum sodium increased significantly, while plasma aldosterone and renal excretory function did not differ. Blood volume (BV) expressed as per body weight increased significantly, but absolute BV, absolute or body weight-related plasma volume and hematocrit were not significantly different. The hypotensive effect of 1-Sar-8-Ile-angiotensin II was negligible 12 hours after the preceding injection of kidney extract. It was small but significant 1 hour after the injection. Increase in water turn-over and fractional sodium excretion occurred during the development of hypertension. Spironolactone did not significantly modify the developmental course. We observed increased depressor response to hexamethonium and increased reactivities to noradrenaline and angiotensin II (A II); these response curves relatively resembled those of spontaneously hypertensive rats. Hypertensive vascular changes were seen in the kidney and heart by histology. Thus, it was suggested that a direct vascular action of A II played a partial role in this hypertensive process while aldosterone played little role. The significance of BV increase and possible contribution of A II's other actions were discussed.
 ...
PMID:Pathophysiological studies on hypertension induced in rats by kidney extract and salt. 39 83

White and regional gray matter distributions of water, blood flow, and the protein tracer pertechnetate were measured in five normal squirrel monkeys. A second group of five monkeys, which had undergone unilateral nephrectomy six months previously, were found at the time of study to have blood pressures similar to those of the control animals but increased brain water and altered distribution of blood flow which was increased in white matter. No alteration of capillary permeability to the protein traces attended these changes, which appeared to be influenced by blood pressure. Nephrectomy without hypertension influences brain water content, perhaps because of an effect on cerebral resistance vessels. In hypertensive encephalopathy renal lesions, as well as intraluminal pressure changes, may be related to cerebral edema.
 ...
PMID:Brain water alterations after unilateral nephrectomy. A study of regional circulatory factors in squirrel monkeys. 40 49

A case characterized by a dark pigmentation of the skin with an initial hypotension and a lung tuberculosis in the remote anamnesis is described. The skin pigment was formed by lipofuscin and emosiderin, but only the former was found in the liver biopsy. Anyway, the pigment was not melanine and the surrenalic function of the patient was completely normal; therefore, an Addisonism syndrome is excluded. The patient was treated for a very long time with DOCA: this caused hypertension, probably supported by the hypervolemia triggered by the DOCA depending retenction of sodium and water. A sure diagnosis of the case was not made, but an Addisonism syndrome was certainly excluded.
 ...
PMID:[A case of melanoderma erroneously considered to be addisonian]. 43 70

A patient with a vipoma of the pancreas and persistently elevated blood levels of vasoactive intestinal polypeptide (VIP) had watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). In the untreated state, the diarrhea was never profuse. Fecal volumes ranged from 0.16 to 1.24 L/day. Attempts to correct the dehydration by fluid and electrolyte loading resulted in a massive increase in fecal water and electrolyte loss. Prednisone cured the diarrhea and was associated with a decrease in plasma VIP levels. The patient had a marked circulatory disturbance with systemic arterial hypotension and cutaneous vasodilation that caused a subnormal body temperature. Removal of the tumor led to a dramatic change in the patient's circulation. Generalized vasodilation with systemic venous and arterial hypotension gave away to vasoconstriction with severe venous and arterial hypertension. Central venous pressure rose from -4.4 to +4.0 cm H2O and arterial pressure rose from 80/55 to 195/110 mm Hg. These changes might explain the unexpected and sometimes fatal heart failure that has complicated the removal of these tumors from some patients.
 ...
PMID:Vipoma of the pancreas: observations on the diarhrhea and circulatory disturbances. 43 2

Effects of peripheral arterial chemodernervation on laryngeal reflex-induced apnea were studied in 18 piglets of either sex varying in age from 4 to 63 days. The distal trachea was cannulated with a cuffed endotracheal tube to secure a free airway and permit ventilatory measurements with a pneumotachograph. The proximal trachea was used to introduce fluids into the larynx. Water elicited apnea, bradycardia, and arterial hypertension, whereas saline caused only transient disturbances. Electrical stimulation of the superior laryngeal nerves reproduced, and conduction anesthesia ablated, the effects of water in the larynx. Carotid body contribution to respiratory drive was assessed by the ventilatory responses to increased (100%) and decreased (10%) anbient oxygen concentration. These indicated significant peripheral chemoreceptor ventilatory activity from birth with little further change in the neonatal period. Ventilatory responses to oxygen were ablated by carotid chemodenervation, but there was no change in the duration of laryngeal reflex apnea. We conclude that attenuation of laryngeal-induced apnea during postnatal development is independent of peripheral chemoreceptor activity. Our findings may have relevance to the clinical problem of sudden infant death syndrome, in which carotid body abnormalities have recently been described.
 ...
PMID:Laryngeal reflex apnea in the chemodenervated newborn piglet. 46 79

Endocrine and renal functions were studied in 149 patients with essential hypertension by measuring plasma electrolytes, renin activity, creatinine and aldoserone, as well as the urinary excretion of creatinine and sodium chloride, before and during treatment for hypertension. Half of the patients responded to trichlormethiazide (thiazide-responsive group) but the other half did not (thiazide-unresponsive group). Systolic and diastolic blood pressures increased progressively uith age in the thiazide-unresponsive group, but were lower and did not progress with age in the thiazide-responsive group. There was no consistent difference in plasma renin activity between the thiazide-responsive and the thiazide-unresponsive groups. The fluctuation of plasma renin activity in response to an excess of sodium chloride or to thiazide treatment was reduced progressively with age. Creatinine clearance decreased and the blood urea nitrogen level increased with age. The age-related decrease of plasma renin activity is discussed on the light of the age-related impairment in the ability of the kidney to excrete sodium and water.
 ...
PMID:Age-related changes in endocrine and renal function in patients with essential hypertension. 46 52

The zinc content in plasma as well as in erythrocytes was studied in 61 patients with untreated essential hypertension. They displayed an intraerythrocytic mean value of Zn2+ of 128.2 micromoles/l intracellular water, which is significantly higher than the corresponding mean of 101.5 micromoles/l from 42 normal persons. In plasma, on the other hand, the mean zinc value of the hypertensive persons was 15.2 micromoles/l plasma, i.e. well within the normal range of plasma Zn2+. Possible mechanisms underlying the elevated red cell zinc level in hypertension are discussed.
 ...
PMID:Increased red cell content of Zn2+ in essential hypertension. 47 94

A 15 year old girl presented with excessive thirst and hypertension (170/110 mm Hg). Biochemical investigations revealed serum sodium 118 meq/liter, serum osmolality 238 mosmol/liter, urine sodium 90 meq/liter, urine osmolality 700 mosmol/liter, persistenly elevated serum antidiuretic hormone (ADH) levels (5.8 to 11.9 pg/ml) and no obvious cause for the hypertension. The hypertension is, at least in part, volume-related, diminishing with fluid restriction. Features of gross water intoxication (e.g., confusion, coma) have not occurred. The etiology of the inappropriate secretion of ADH is not obvious but is not thought to be due to "resetting of osmoreceptors" as evidenced by failure to maximally dilute urine following a water load test and persistently elevated serum ADH levels. A similar patient described by Epstein and associates in 1962 is presently well with persistent features of inappropriate secretion of ADH.
 ...
PMID:Idiopathic, sustained, inappropriate secretion of ADH with associated hypertension and thirst. 47 98

Physiological levels of arginine vasopressin (AVP) were continuously infused 24 h/day into six dogs for periods ranging from 7 to 34 days. The acute and chronic responses of the mean arterial pressure (MAP), body fluid volumes, renal function indices, plasma electrolyte concentrations, plasma renin activity, and urinary electrolyte and water excretion rates were measured. MAP was unaffected acutely but rose significantly to a peak on day 9 before declining toward control. MAP was significantly and positively correlated with the plasma volume, but had a diphasic correlation with the plasma sodium concentration and the change in total body sodium. The plasma sodium concentration reached a relatively stable plateau that was maintained in spite of large changes in total body water. We conclude that AVP produces only a transient hypervolemic hypertension; that AVP is a natriuretic agent, either directly or indirectly, both acutely and chronically; and that chronically it is a more potent controller of the plasma sodium concentration than of the total body water except in extreme cases.
 ...
PMID:Acute and chronic effects of vasopressin on blood pressure, electrolytes, and fluid volumes. 47 64


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>