Beta-adrenergic receptors in the urinary bladder of adult and developing rats.

Specific beta-adrenergic receptors were demonstrated in the urinary bladder of adult and developing rats, by direct tissue binding with LD [125I]-cyanopindolol (CYP). The maximum number of binding sites (Bmax) was 167 +/- 25 fmol/mg membrane protein and the dissociation constant (KD) equalled 61 +/- 33 pM. The Hill slopes of the LD [125I]-CYP binding showed a single class of noncooperative receptor sites.

Effect of the calcium channel blocker nisoldipine on the progression of chronic renal failure in man.

Patients with stable renal insufficiency were randomized into two groups: (1) patients given the channel blocker nisoldipine (n = 17) and (2) placebo-treated patients (n = 17) also taking their regular antihypertensive therapy which did not include calcium blockers. Patients were already on low protein diet with a protein intake of 0.80 +/- 0.

The calcium channel blocker nisoldipine delays progression of chronic renal failure in humans (preliminary communication).

Chronic renal failure (CRF) patients with a stable course were asked to participate in a follow-up program in which they were randomized into two groups: 1) the placebo group taking their standard antihypertensive therapy without any calcium ion blocker: and 2) the nisoldipine group, those patients taking the calcium channel blocker nisoldipine as the only antihypertensive drug. The two groups had similar blood pressures on entering the study (151 +/- 21.3/90.

The control of hypertension and its effect on renal function in rat remnant kidney.

Blood pressure control and its influence on the rat remnant kidney function were studied. The deterioration in kidney function was followed for up to 20 weeks at 4-weekly intervals in four groups of 5/6th nephrectomised rats. The groups studied were: (1) Control, untreated (C), given normal rat chow containing 21% protein; (2) nisoldipine (a dihydropyridine calcium channel blocker) treated (N), given nisoldipine freshly mixed daily in normal chow (0.

Relationship between plasma renin activity and distal nephron sodium delivery and reabsorption in man.

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.

Hemodynamic effects of nifedipine in hypertension in the presence of elevated angiotensin-II and beta-adrenergic blockade.

The hemodynamic effects of the slow release form of a calcium channel blocker, nifedipine retard, in essential hypertension patients after angiotensin II (AII) infusion were studied using nuclear ventriculography. Sublingual nifedipine lowered blood pressure that had been acutely raised by an infusion of AII to its baseline level. When used for 4 weeks, nifedipine retard maintained its blood-pressure-lowering effects without a change in heart rate, both when used alone and when used in addition to beta-adrenergic blockers.

Calcium entry-blockade with verapamil in cyclosporine A plus ischemia induced acute renal failure in rats.

The possible alleviating effect of verapamil, a calcium entry blocker, on the resulting renal damage from the combination of a short episode of ischemia and CyA was studied in rats. Immediately after right nephrectomy the rats were divided into five experimental groups. Group 1: left renal pedicle clamping for 20 minutes.

Beta-adrenergic receptors on polymorphonuclear cell membranes in essential hypertension.

Beta adrenergic receptor binding sites were determined and characterized by specific binding of (+/-)[125I] iodocyanopindolol to membranes obtained from circulating polymorphonuclear leukocytes. No difference was found in the number of receptor sites and in their dissociation constants (Kd) between patients with untreated essential hypertension (EH), EH treated with drugs other than beta blockers, and in normotensive controls. The group with EH receiving treatment with beta blockers had a significantly higher receptor density and Kd as compared with all the other groups (p less than 0.

Cyclosporine and short ischaemia: a new model of experimental acute renal failure in rats.

To determine whether a mild episode of ischaemia may be a factor in the production of cyclosporine (Cys) toxicity, right nephrectomy was performed in three groups of Charles River rats: I. Ischaemia (left renal pedicle clamping) for 20 minutes, without treatment; II. Ischaemia of 20 minutes, followed by IP Cys 60 mg/kg BW/day; III.

Calcium-entry blockade and pressor effect of angiotensin II in normal and nephrectomized rats.

The pressor effect of intravascular boli of 1.5 micrograms/kg angiotensin II was studied in untreated and in verapamil-pretreated intact rats and in rats 24 h after bilateral nephrectomy. An initial i.

Beneficial effect of verapamil in ischemic acute renal failure in the rat.

To investigate the possible protective effect of Ca2+ blockers in ischemic acute renal failure (ARF), verapamil, in a dose of 10 micrograms/kg body wt/min was administered for 100 min, starting 15 min before the total occlusion of the left renal artery after right nephrectomy in rats. Mean 24-hr creatinine clearance, blood urea, and serum creatinine levels, 24 hr after declamping, were used as a measure of kidney function. These values which were 135 +/- 1.

Evidence for an extrarenal action of chlorothiazide on serum potassium.

The effects of chlorothiazide and furosemide on serum potassium were studied in fasting anuric patients maintained by chronic hemodialysis and compared to a control period when no drug was administered. Serum potassium levels were significantly lower following oral chlorothiazide (15 mg/kg body weight) than during the control period. After intravenous furosemide (1 mg/kg body weight), potassium levels were midway between those of the chlorothiazide and control periods, but statistical significance was not attained.

Lithium prevents saline deoxycorticosterone acetate (DOCA) hypertension in the rat.

Uni-nephrectomized rats drinking 1% saline instead of water, were given Doca intramuscularly, 50 mg/kg BW per week for 2 weeks. The mean blood pressure in the control group was 105 +/- 4 (+/- S.E.

beta 1-Adrenergic receptors in kidney tubular cell membrane in the rat.

We used a beta-adrenergic antagonist, (-) 3H-dihydroalprenolol, to demonstrate binding sites in purified rat kidney preparations that consistsed of plasma membranes of cells from tubules. The tubular origin of these plasma membranes was shown by electron microscopy and Na-K-ATPase enrichment. The binding was rapid (t1/2, 78 sec) and rapidly reversible (t1/2, 48 sec).