ANF receptors at the glomerular level in reno-vascular hypertension in rats

The effect that hypertension may have on plasma, atrial ANF levels and on isolate rat renal glomeruli ANF receptors was investigated. Different models of renal hypertension were studied: 1-K, 1-C (BP = 177 +/- 7 mmHg), 2-K, 1-C (BP = 158 +/- 3 mmHg) and their respective controls (BP = 100 +/- 2 mmHg). At this stage of hypertension (two weeks) plasma ANF was 56 +/- 9 and 25 +/- 2 pg/ml in 2-K, 1-C and controls respectively and 124 +/- 22 vs 35 +/- 4 pg/ml in 1-K, 1-C and controls. Atrial ANF content was lower in hypertensive animals. A marked up-regulation of the glomerular ANF receptor density was observed in 2-K, 1-C animals. In the right kidney we found 840 fmol/mg protein and 540 fmol/mg protein, and in the left 1,070 fmol/mg protein against 608 fmol/mg protein in 2-K, 1-C and control animals respectively. No change was observed in glomerular ANF receptor density in 1-K, 1-C animals. We have then demonstrated that glomerular ANF receptor density is higher in 2-K, 1-C hypertensive than in normotensive animals. It could be possible, however, that the receptor density may change during the evolution of high blood pressure in the models of experimental hypertension currently studied.