Atrial natriuretic factor: specific binding to renal glomeruli during the development of two-kidney, one clip hypertension in the rat

Blood pressure (BP), atrial and plasma concentrations of atrial natriuretic factor (ANF), hematocrit and renal glomerular ANF receptors were studied during the development of hypertension in two-kidney, one clip (2-K, 1C) rats and were compared with normotensive controls. Plasma ANF was elevated in the 2-K, 1C group in all stages of hypertension, even after 3 weeks when BP, although higher than in sham-operated animals, had not yet reached arbitrarily-set hypertensive levels. At this time, hematocrit was higher in the hypertensive rats than in the controls, but the difference later disappeared. Lower atrial ANF concentrations were observed in the 2-K, 1C group at week 3, but only in the right atrium. No difference in ANF levels was noted in either the left or right atrium between hypertensive and normotensive animals 5 and 7 weeks after clipping. The glomerular ANF receptor population was markedly smaller in the clipped left kidney of 2-K, 1C rats during all stages of hypertension, and in the untouched right kidney at 5 and 7 weeks after surgery, but was larger in the non-clipped right kidney in the pre-hypertensive phase (3 weeks). It is concluded that receptor density changes during the evolution of high BP in the 2-K, 1C Goldblatt model of experimental hypertension. Our data suggest that the increases and decreases in density of renal glomerular ANF receptors may play a role in the differential handling of sodium by the clipped and non-clipped kidney during the various stages of development of 2-K, 1C hypertension in the rat.