[A new natriuretic factor acting like loop diuretics. Kinetics in normal and hypertensive rats].
We have recently described that urines from salt-loaded rats contain a potent natriuretic factor acting at the Na-K-Cl cotransport system (CIF: "Cotransport Inhibitory Factor"). Here we investigated the kinetics of the urinary CIF excretion which follows an oral salt-load: (i) in normal rats, relative to that of the atrial natriuretic peptide (ANP) and (ii) in an experimental model of salt-dependent genetic hypertension (Dahl's rats). Thus, Wistar rats were orally loaded with 2% NaCl for 8 days. Urinary CIF excretion was measured by testing the inhibitory potency of urines on bumetanide-sensitive lithium efflux in lithium-loaded human erythrocytes. Plasmatic levels of ANP were measured by radioimmunoassay. Plasma ANP rapidly and transiently increased during the first 24 hs of salt-load, decreasing thereafter down to normal levels in 6-8 days. Conversely, CIF slowly increased after 24 hs up to maximal constant levels after 5 days of salt-loading. Dahl salt-sensitive rats exhibited highly significant increases in urinary CIF excretion with respect to salt-resistant rats. In the basal state (before salt-loading) urinary CIF excretion was 101 +/- 13 vs 17.6 +/- 4.5 units/day in salt-sensitive vs. salt-resistant rats (n = 7 for each group, p < 0.001). This difference was maintained after salt loading (3 380 +/- 990 vs. 456 +/- 159 units/day, p < 0.05 at day 5).(ABSTRACT TRUNCATED AT 250 WORDS)
Soler
A
A
INSERM U400, Faculté de médecine, Créteil.
Alvarez-Guerra
M
M
Alda
O
O
Garcia
C
C
Nazaret
C
C
Hannaert
P
P
Garay
R P
RP
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000493:pharmacokinetics* / Q000502:physiology; D006973:Hypertension / Q000378:metabolism; D008138:Loop of Henle / Q000378:metabolism; D008297:Male; D009318:Natriuresis; D051381:Rats; D017208:Rats, Wistar
D009320:Atrial Natriuretic Factor
Un nouveau facteur natriurétique agissant comme les diurétiques de l'anse. Comportement cinétique chez le rat normal et hypertendu.