Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.15 (renin)
 35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Relationships between frequency of renal nerve stimulation (RNS) and renal blood flow (RBF), glomerular filtration rate (GFR), and plasma renin activities (PRA) were evaluated in anesthetized dogs placed on low (5 meq/day)-, normal (40 meq/day)-, and high (200 meq/day)-sodium chloride diets. Arterial pressure, RBF, GFR, and renal venous and arterial PRA were determined before and during direct electrical RNS at 0.5, 1.0, and 2.0 Hz (15 V, 1.0 ms). Dogs on low sodium intakes increased renal venous PRA at 0.5, 1.0-, and 2.0-Hz RNS, whereas dogs on normal sodium intakes did not increase renal venous PRA until RNS reached 2.0 Hz. High sodium dogs did not increase PRA at any frequency of RNS tested. RNS at 0.5 Hz was not associated with any changes in GFR or RBF in any of the groups. Dogs on normal sodium and high sodium intakes decreased both GFR and RBF during 1.0- and 2.0-Hz RNS. Low-sodium dogs, however, only decreased GFR and RBF during 2.0-Hz RNS, and these hemodynamic responses were significantly less than 2.0-Hz GFR and RBF responses of high sodium dogs. These data indicate that renal vasoconstrictor responses to RNS are potentiated, and renin release responses to RNS are reduced by elevation of sodium chloride intake. We suggest that during low sodium intake, activation of sympathetic nerve activity elicits an enhanced renin release response, whereas the renal vasculature may be protected against neurogenic vasoconstriction.
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PMID:Effects of altered NaCl intake on renal hemodynamic and renin release responses to RNS. 331 1

Taste sensitivity and preference for sodium chloride in bread and pea soup were assessed before and after haemodialysis in 12 female chronic renal failure patients. Blood samples were also taken pre- and post-dialysis and analysed for zinc, sodium and renin. The patients demonstrated an increased sensitivity to, and decreased preference for, sodium chloride in both bread and pea soup following dialysis. These taste changes were found to correlate with pre- to post-dialysis changes in the zinc levels in the blood. Patients receiving a more severely sodium-restricted diet showed a greater sensitivity to the taste of sodium chloride in the foods tested. Renin levels dropped in all patients following dialysis, the size of the change correlating with the size of the change in body weight.
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PMID:Effects of haemodialysis on taste for salt in relation to changes in blood constituents. 332 41

The effects of oral calcium loading on blood pressure (BP) of DOCA (deoxycorticosterone acetate)-salt hypertensive rats (D-S rats) were investigated. Calcium loading was performed by adding 1% CaCl2 (calcium chloride) to the drinking water. Calcium loading attenuated the development of high BP in D-S rats, and at the end of a two week experiment, BP was 141 +/- 3 (calcium treated) vs. 174 +/- 7 mmHg (non-calcium treated) (p less than 0.01). However, calcium loading did not cause any changes in BP in normotensive rats. Further, in established D-S rats [after four weeks of DOCA and 1% NaCl (sodium chloride) treatment], calcium loading for 4 weeks also reduced BP [144 +/- 6 (calcium treated) vs. 181 +/- 4 mmHg (non-calcium treated), p less than 0.01, at the end of experiment]. With calcium treatment, there were no significant changes in sodium-water balance, plasma levels of epinephrine and norepinephrine, plasma renin activity, plasma aldosterone concentration and serum electrolytes both in developing and established D-S rats. The depressor mechanism of calcium loading was studied by observing vascular responsiveness to norepinephrine both in whole body and in hind limb preparations. Vascular reactivity in both developing and established D-S rats was significantly attenuated by calcium treatment. These results suggest that the antihypertensive effects of calcium treatment in D-S rats are mainly caused by attenuation of vascular reactivity.
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PMID:Effects of calcium loading in DOCA-salt hypertensive rats. 332 56

The relationship between plasma renin activity and distal tubular sodium delivery and reabsorption was examined in man. Distal sodium delivery and reabsorption were measured during hypotonic volume expansion by the free water clearance method, or during hydropenia or isotonic volume expansion by the lithium clearance method. The maximal water diuresis method and the lithium clearance method both showed a negative correlation between plasma renin activity and distal sodium delivery and reabsorption. Only with the lithium clearance method, however, was it possible to measure plasma renin activity, distal sodium delivery and reabsorption in hydropenia without disturbances of water and electrolyte balance and plasma renin activity level. In hydropenia the plasma renin activity was higher and the fractional distal sodium delivery and reabsorption lower than during volume expansion. Our results support the idea that sodium chloride reabsorption at the macula densa region is negatively correlated to the plasma renin activity in man.
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PMID:Relationship between plasma renin activity and distal nephron sodium delivery and reabsorption in man. 332 59

Interactions between sodium and calcium metabolism and the renin angiotensin system (RAS) have been studied. In rats drinking highly palatable 0.5% sodium chloride solution for a 6 month period, plasma angiotensin II (p[AII]) levels after 6 months did not differ from control animals drinking water. However, plasma ionized calcium (p[iCa]) levels were significantly reduced compared to controls. In a third group of animals which drank saline, but consumed a calcium supplemented chow (2% calcium by weight vs. 1%), p[AII] was significantly elevated above both other groups. Further experiments were performed to study short term (4 weeks) changes in calcium intake and p[AII] levels. Diets contained high (4%), normal (1%) and low (0.05%) calcium content. All animals drank water. Plasma total calcium (p[tCa]) and p[iCa] concentration were elevated in the 4% calcium group compared with 1% calcium. In the 0.05% calcium group, p[iCa] was significantly reduced compared with the 1% group. Compared with the 1% calcium group, 4% calcium animals showed significant elevation of p[AII] levels. A slight, insignificant elevation was observed in 0.05% calcium rats compared with those consuming 1% calcium. A final experiment studied animals on the same calcium intakes (0.05, 1 and 4%), but consuming 0.5% saline in place of water. No differences in p[iCa], p[tCa] or p[AII] were observed in these experiments. However, consumption of saline lead to the expected reduction in p[AII] levels which was absent after 6 months in the earlier studies, indicating that normal levels of p[AII] in saline drinkers after 6 months was not a measurement error.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma angiotensin II: interdependence on sodium and calcium homeostasis. 337 34

Arterial blood pressure and renal function of both clipped and non-clipped kidneys of benign two-kidney, one clip (2K1C) Goldblatt hypertension were evaluated in order to determine whether high-salt intake alters the course of the development and magnitude of hypertension or influences renal function. The administration of 0.9% sodium chloride as a drinking solution for 3 weeks suppressed plasma renin activity (PRA) and kidney renin content of the clipped kidney to normal values. Despite suppression of PRA and kidney renin content, the saline-drinking clipped rats still developed hypertension of the same magnitude as the water-drinking clipped rats. However, the onset of hypertension was delayed by 4 days. Urine flow, glomerular filtration rate (GFR) and sodium excretion rate from the clipped kidneys of the saline-drinking clipped rats were higher than the corresponding values in the water-drinking rats, and approached those observed in control animals. Thus, the high-salt intake which was associated with suppression of the activity of the renin-angiotensin system delayed the onset of, but not the final magnitude of, the hypertension. In addition, kidney function in the clipped kidneys of saline-drinking clipped rats was enhanced compared with that observed in the water-drinking clipped rats.
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PMID:Arterial pressure and renal function in two-kidney, one clip Goldblatt hypertensive rats maintained on a high-salt intake. 351 64

The changes occurring in several components of the rat renin-angiotensin system (RAS) were studied for the brief postnatal period, between the fourth and tenth week of life. The parameters were: plasma renin activity (PRA), plasma renin concentration (PRC), plasma renin substrate (PRS) and the plasma angiotensin II concentration (AII). A gradual decrease in PRA with age was noticed. Between the fourth and the eighth weeks of life, this was attributed to a corresponding decline in both PRC and PRS. However, between the eighth and tenth weeks, no changes in PRA could be detected, but PRC and PRS increased, perhaps as a consequence of the changes in renal function and the AII increase observed. In this second period, simultaneously with the RAS changes described, there was reduced sodium chloride excretion as the glomerular filtration rate (GFR) stabilized. The data presented suggest that this postnatal period is critical, in rats, for the maturation of the RAS component control mechanisms; they appear to be closely related to the development of the renal function.
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PMID:Postnatal development of renin-angiotensin system in rats. 352 Jul 18

A technique was designed to study renin release from superfused rat glomeruli with short attached arterioles (SAG), from single glomeruli with long attached arterioles (LAG), and from single afferent arterioles (AA). The preparations obtained by magnetic isolation and microdissection were superfused individually, and the renin release was measured by an ultramicroradioimmunoassay with a detection limit of 3 X 10(-9) Goldblatt units. The renin content of one SAG was about one-fifth of that contained in one AA. Isoprenaline (10(-5) M) did not change renin release from SAG, whereas renin release from AA and LAG increased threefold (P less than 0.01). A 30-mosmol/kg reduction in medium sodium chloride concentration increased renin release from SAG 50% (P less than 0.01). This challenge caused no change in renin release from AA. It is concluded that the isoprenaline-sensitive juxtaglomerular (JG) cells are located in the afferent arteriole only at some distance from the glomerulus, whereas those cells sensitive to sodium chloride are located within and/or close to the glomerulus.
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PMID:Renin release from different parts of rat afferent arterioles in vitro. 352 63

Type II pseudohypoaldosteronism is an uncommonly reported disorder. The authors recently evaluated a patient who in many respects appeared to have this syndrome. He had hyperkalemia, a normal glomerular filtration rate, "normal" serum and urinary aldosterone levels, and low plasma renin activity. In addition, he had a hyperchloremic metabolic acidosis and hypertension. Fractional excretion of potassium was reduced in response to sodium chloride loading. However, renal potassium excretion in response to administration of sodium sulfate was normal. Thiazide diuretic restored the serum potassium, the low bicarbonate, and blood pressure to normal. He developed marked natriuresis and kaliuresis in response to high-dose exogenous mineralocorticoid. The magnitude of the kaliuretic response achieved to exogenous mineralocorticoid has been reported only once previously.
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PMID:Mineralocorticoid-induced kaliuresis in type-II pseudohypoaldosteronism. 352 61

We have suggested that inhibition of renin release by sodium chloride is related to increased absorptive solute transport in the loop of Henle. In the rat, we have shown that reduced chloride transport in the loop is associated with increased renin release. Based on indirect evidence, it has been suggested that chlorpropamide (CPMD) increases loop solute transport. This study directly evaluates the effect of CPMD on loop chloride transport and plasma renin activity (PRA) in the male Sprague-Dawley rat. Loop of Henle chloride reabsorption (measured by recollection micropuncture) and PRA were determined before and after acute infusion of CPMD (N = 8) or vehicle (N = 8). Although delivery to the loop was not significantly changed, CPMD increased (P less than 0.05) absolute loop chloride reabsorption from 1798 pEq/min +/- 200 SE to 2453 pEq/min +/- 206 SE. PRA was decreased (P less than 0.01) from 9.2 ng/ml/hr +/- 1.0 SE to 5.6 ng/ml/hr +/- 0.8 SE following CPMD infusion. Comparable vehicle infusion did not alter loop chloride reabsorption or PRA. Arterial pressure, and whole kidney and single nephron glomerular filtration rates were unchanged following infusion of CPMD or vehicle. These results demonstrate that an increase in loop chloride reabsorption is associated with a decrease in renin release. This observation is consistent with the hypothesis that renin release is inversely related to the magnitude of chloride transport in the thick ascending limb of the loop of Henle.
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PMID:Effects of chlorpropamide on loop of Henle function and plasma renin. 353 61


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