Effect of dopamine receptor blockade on the renal excretory response to acute volume expansion (AVE) in conscious Brattleboro rats.

Unlabelled: All the studies were performed on chronically cannulated, conscious Brattleboro rats, housed in metabolic cages under standard conditions. The renal excretory indices: diuresis (V), sodium (UNa.V), potassium (UK.

Renal excretory function, atrial natriuretic peptide (ANP) and plasma renin activity (PRA) during long-term sodium loading in rats.

The effect of chronic sodium loading on the level of plasma atrial natriuretic peptide (ANP) and on plasma renin activity (PRA), as well as on the renal excretory function was studied. Fifty-six standardly bred Long Evans rats were divided into three experimental groups: controls, rats drinking 170 mmol NaCl/l solution instead of water, and rats consuming food with high sodium content (850 mmol NaCl/kg) for 21 days. During the study, we measured the amount of fluid intake, the parameters of the renal function: diuresis (VU); sodium, potassium and cloride excretion (UNa V, UKV and UClV), and the dynamics of body mass.

Plasma renin activity in rats with renal denervation and adrenoreceptor blockers.

Plasma renin activity (PRA) was investigated by radioimmunoassay following short-term hypoxic hypoxia (45 min 10 per cent oxygen, 90 per cent nitrogen) or hypovolaemia induced by peritoneal dialysis with isotonic (305 mmol/l) glucose. The effect of the above stimuli was also followed in animals with chronic bilateral kidney denervation, beta-adrenoreceptor blockade with dl-propranolol (3 mg/kg body weight i. p.

Hypothalamic control of plasma renin activity.

The participation of the hypothalamus in the regulation of plasma renin activity (PRA) in rats was studied by applying electric stimulation to the supramammilar region (50 Hz, 1 ms, 150 muA), general hypoxia (90% N2 + 10% O2), and hypovolemia (peritoneal dialysis with 5.5% glucose) as stimuli of renin secretion. These techniques were combined with bilateral renal denervation and electrocoagulation in the supramammilar nuclei.