Effects of dietary sodium chloride intake on renal function and blood pressure in cats with normal and reduced renal function.
OBJECTIVE
To determine effects of variations in dietary intake of sodium chloride (NaCl) on systemic arterial blood pressure (ABP) in cats with normal and reduced renal function.


METHODS
21 adult cats (7 with intact kidneys [control cats; group C], 7 with unilateral renal infarction with contralateral nephrectomy [remnant-kidney model; group RK], and 7 with unilateral renal infarction and contralateral renal wrapping and concurrent oral administration of amlodipine [remnant-wrap model; group WA]).


METHODS
All cats were sequentially fed 3 diets that differed only in NaCl content (50, 100, or 200 mg of Na/kg); each diet was fed for 7 days. The ABP was recorded continuously by radiotelemetry, and renal function (glomerular filtration rate [GFR]) was determined on the sixth day of each feeding period.


RESULTS
Dietary supplementation with NaCl did not affect ABP, but it increased GFR in groups C and WA. The renin-angiotensin-aldosterone axis was activated in groups RK and WA at the lowest NaCl intake, but supplementation with NaCl suppressed this activation in group WA. The lowest NaCl intake was associated with hypokalemia and a high fractional excretion of potassium that decreased in response to supplementation with NaCl. Arterial baroreceptor resetting was evident after chronic hypertension but was not modified by dietary supplementation with NaCl.


CONCLUSIONS
Low NaCl intake was associated with inappropriate kaliuresis, reduced GFR, and activation of the renin-angiotensin-aldosterone axis without evidence of a beneficial effect on ABP. Therefore, this common dietary maneuver could contribute to hypokalemic nephropathy and progressive renal injury in cats.
Buranakarl
Chollada
C
Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
Mathur
Sheerin
S
Brown
Scott A
SA
D000704:Analysis of Variance; D000818:Animals; D001774:Blood Chemical Analysis; D001794:Blood Pressure / Q000187:drug effects*; D002371:Cat Diseases / Q000503:physiopathology*; D002415:Cats; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000662:veterinary*; D009392:Nephrectomy; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D013686:Telemetry; D016482:Urinalysis
D017673:Sodium Chloride, Dietary