Effects of Neuropeptide Y on Intrarenal Hemodynamics, Plasma Renin Activity and Urinary Sodium Excretion in Rats

Nephron ◽  
1996 ◽  
Vol 73 (3) ◽  
pp. 467-472 ◽  
Keyword(s):  
Plasma Renin Activity ◽  
Neuropeptide Y ◽  
Sodium Excretion ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Renin Activity

Plasma Renin, Urinary Sodium Excretion and Vascular Disease

1974 ◽  
Vol 48 (s2) ◽  
pp. 127s-129s
Author(s):  
A. E. Doyle ◽  
K. G. Chua ◽  
S. Duffy ◽  
W. J. Louis
Keyword(s):  
Plasma Renin Activity ◽  
Urinary Excretion ◽  
Vascular Disease ◽  
Sodium Excretion ◽  
Mild Hypertension ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Renin Activity

1. Urinary sodium excretion and plasma renin activity have been measured in a group of persons with untreated mild hypertension and in a control normotensive group. 2. Preliminary analyses of the data indicate that the daily sodium excretion was significantly higher in the hypertensive group but the plasma renin activity did not correlate significantly with the urinary excretion of sodium. 3. These findings suggest that sodium intake was significantly greater in a population with mild hypertension than in a comparable normotensive group.

Acute effect of a thromboxane synthetase inhibitor on renal function in unanaesthetized sheep

1987 ◽  
Vol 73 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Allan D. Cumming ◽  
Robert M. Lindsay ◽  
J. W. D. McDonald ◽  
Adam L. Linton
Keyword(s):  
Plasma Renin Activity ◽  
Sodium Excretion ◽  
Urine Volume ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Renin Activity ◽  
Synthetase Inhibitor ◽  
Fractional Sodium Excretion ◽  
Thromboxane Synthetase

1. Eleven healthy, unanaesthetized sheep were given either a single intravenous bolus infusion of U63,577A (Upjohn), a selective thromboxane synthetase inhibitor, at a dose of 30 mg/kg (group 1, n = 6), or vehicle alone (group 2, n = 5). Animals were maintained in metabolic cages during the study, and received 150 ml of water/h and 7.5 mmol of sodium/h as Ringers lactate by intravenous infusion for 24 h before and during the study. During two 1 h control urine collections via bladder catheter, urine volume and sodium excretion closely paralleled these infusion rates. 2. In the first hour after injection of U63,577A, there were significant two- to three-fold increases in urine volume, urinary sodium excretion and fractional sodium excretion, compared with the control collections. During the subsequent 4 h, urine volume, urinary sodium excretion, and fractional sodium excretion fell to values significantly lower than in the control period. Creatinine clearance was reduced 1, 2 and 4 h post injection and returned to control values at 5 h. Urinary excretion of thromboxane B2 was significantly reduced compared with control values during the 5 h after injection of U63,577A. Excretion of 6-keto-prostaglandin F1α did not change. Plasma renin activity was significantly increased 1, 3 and 5 h after injection of U63,577A. Vehicle controls showed no change in any of the above parameters. 3. The results indicate that in healthy conscious sheep, sodium and water replete, U63,577A has a transient but significant diuretic and natriuretic effect, followed by sodium and water retention and increased plasma renin activity. The results may reflect an antidiuretic/antinatriuretic effect of thromboxane A2, or possibly diversion of cyclic endoperoxides into formation of vasodilator/natriuretic prostaglandins. These effects might be exaggerated and/or modified in conditions where arachidonic acid metabolism is stimulated.

Effect of Progesterone on Renal Sodium Handling in Man: Relation to Aldosterone Excretion and Plasma Renin Activity

1975 ◽  
Vol 49 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Suzanne Oparil ◽  
E. N. Ehrlich ◽  
M. D. Lindheimer
Keyword(s):  
Plasma Renin Activity ◽  
Sodium Excretion ◽  
Renal Plasma Flow ◽  
Free Water ◽  
Plasma Renin ◽  
Urinary Sodium ◽  
Renin Activity ◽  
Sodium Reabsorption ◽  
Renin Substrate ◽  
Sodium Handling

1. The effect of progesterone on renal haemodynamics and intrarenal sodium handling was evaluated in thirteen normal men on a constant diet. Clearances were measured during maximal water diuresis and again 4–7 days later, this time 3 h after progesterone was given intramuscularly. Seven additional studies were performed 3 days after progesterone administration. Another four tests were performed on volunteers who had manifested renal ‘escape’ from the sodium-retaining effect of deoxycorticosterone acetate. 2. In acute progesterone studies glomerular filtration rate was unchanged, whereas effective renal plasma flow increased, so that filtration fraction decreased significantly. A similar increase in urinary sodium occurred whether subjects received a low or high sodium diet. Indices which related to the distal delivery of filtrate (fractional urine flow and the sum of fractional free water and sodium clearances) increased significantly in both groups. The progesterone-induced increase in sodium excretion was not related to changes in plasma renin activity, renin substrate or urinary aldosterone. After 3 days of progesterone, the increase of sodium excretion was less than in the acute studies and urinary aldosterone increased two- to four-fold. Progesterone failed to produce an acute increase in urinary sodium in subjects hyperexpanded by administration of exogenous mineralocorticoids. 3. Results suggest that the acute natriuretic action of progesterone is in part independent of aldosterone inhibition and that progesterone may inhibit sodium reabsorption at proximal as well as distal sites in the nephron.

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