Modulation by chronic nifedipine of plasma atrial natriuretic peptide, cell Na+ transport and plasma volume in rats with renal hypertension.
The influence of a 6-week treatment of female Wistar rats with one-kidney, one clip (1-K, 1 C) renal hypertension, with the calcium antagonist nifedipine on plasma volume, red cell Na+ handling and plasma atrial natriuretic peptide immunoreactivity (ANP-IR) was studied. Measurements were performed at 2 and 6 weeks after surgery. In 1-K, 1 C rats plasma volume was increased and red cell Na+ pump activity was reduced only after 2 weeks. Blood pressure, heart weights and plasma ANP were massively increased after both 2 and 6 weeks. 1-K, 1 C-rats treated with nifedipine had normal plasma volume, plasma ANP, and red cell Na+ pump activity in comparison with sham-operated rats. Increases in blood pressure and heart weights were attenuated. It is concluded that 1-K, 1 C hypertension in the rat is associated with cardiomegaly, rise in plasma ANP, initial hypervolemia and depression of the membrane Na+ pump. Nifedipine prevents the occurrence of hypervolemia and secondary phenomena such as rises in plasma ANP and cardiomegaly. This may play an important contributory role in the prevention of pathological sequelae.
Knorr
A M
AM
Bayer AG, Institute for Pharmacology, Wuppertal, Federal Republic of Germany.
Laguna
C
C
Stasch
J P
JP
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006978:Hypertension, Renovascular / Q000188:drug therapy*; D009543:Nifedipine / Q000627:therapeutic use*; D010953:Plasma Volume / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D015222:Sodium Channels / Q000187:drug effects*
D015222:Sodium Channels; D009320:Atrial Natriuretic Factor; D009543:Nifedipine