Effect of prolonged high salt intake on atrial natriuretic factor's kinetics in rats.
Plasma atrial natriuretic factor (ANF) paradoxically decreases after 5 weeks (but not after 3 weeks) of 8% NaCl intake in normotensive rats. As this phenomenon remains unaccounted for by changes in ANF production, we studied the disappearance of [125I]ANF(99-126) from the circulation as an alternative explanation of plasma ANF decline. Following 5 weeks (but not 3 weeks) of an 8% NaCl diet, plasma concentrations of [125I]ANF were significantly decreased and metabolic clearance rate and volume of distribution were increased compared to control rats fed a 0.8% NaCl diet. By studying [125I]ANF tissue uptake we noted significantly greater peptide uptake after 5 weeks (but not after 3 weeks) of high salt consumption in several tissues. We hypothesize that prolonged (at least 5 weeks) 8% NaCl ingestion increases the density and/or affinity of ANF binding sites. These changes may be responsible for the previously observed decline in plasma ANF concentrations after a prolonged high salt intake.
Widimsky
J
J
Laboratory of the Autonomic Nervous System, Hôtel-Dieu Hospital, Montréal, Québec, Canada.
Debinski
W
W
Kuchel
O
O
Buu
N T
NT
Du Souich
P
P
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000493:pharmacokinetics; D001810:Blood Volume / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D010446:Peptide Fragments / Q000493:pharmacokinetics; D051381:Rats; D011919:Rats, Inbred Strains; D012982:Sodium, Dietary / Q000494:pharmacology*; D013997:Time Factors; D014018:Tissue Distribution / Q000187:drug effects
D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D012982:Sodium, Dietary; D009320:Atrial Natriuretic Factor