Atrial-natriuretic-peptide receptors in glomerular cryosections of renal malignant and spontaneously hypertensive rats.
ANP-receptors affinities (KD) and capacities (Bmax) were assayed in cryosections of glomeruli from 'malignant' hypertensive rats (2K-1C) and spontaneously hypertensive rats (PHR). Plasma ANP concentration was twofold higher in 2K-1C (P < 0.05) and PHR (P < 0.02) than in the respective controls, KD and Bmax for rANP99-126 and ANP103-123 did not differ. ANP mediated cGAMP release in 2K-1C rats was also unaffected. ANP-C glomerular receptors (i.e. displacement of tracer binding with ANP103-123) were not down-regulated and had unchanged peptide binding affinity in either kidney of rats with 'malignant' hypertension and in PHR. The difference between Bmax for rANP99-126 and Bmax for rANP103-123 (ANP-A receptor binding) indicates moderate up-regulation of ANP-A receptors in the clipped, and down-regulation in the contralateral kidney of 2K-1C (2K-1C, right vs. left, P < 0.05). Since [ANP]pl, and also Bmax and KD for ANP were similar in both hypertension models investigated, changes of the [ANP]pl/ANP-receptor system can not completely explain the marked natriuresis of rats with 'malignant' hypertension.
Marin-Grez
M
M
Physiologisches Institut, Ludwigs-Maximilians-Universität München, Germany.
Grigelat
C
C
Heinz-Erian
P
P
Heim
J M
JM
Klein
H G
HG
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects; D006162:Guanylate Cyclase / Q000378:metabolism; D006973:Hypertension / Q000235:genetics / Q000378:metabolism*; D006974:Hypertension, Malignant / Q000378:metabolism*; D006978:Hypertension, Renovascular / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009318:Natriuresis / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism*
D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor