Adverse Effects of Dietary and Furosemide-Induced Sodium Depletion on Thermoregulation in Rats
Abstract
In this study the diuretic furosemide was used in combination with dietary sodium (Na) restriction, to produce varying degrees of circulatory hyponatremia to quantify the effects of moderate to severe Na-depletion on heat tolerance in a validated, heat stressed rat model. Male Sprague-Dawley rats (500 g) were subjected to a Na-depletion regimen as follows: group I (control) had free access to a normal diet and tap water; group II consumed the normal diet and tap water but was treated with the diuretic furosemide (10 mg/kg/day, ip); group III had free access to a Na-free diet and deionized drinking water; group IV consumed the same Na-free diet and electrolyte-free water but was also treated with furosemide. Both the dietary and drug manipulations effected significant (p<.05) negative Na and water balance and hyponatremia in the experimental groups. Group IV consistently exhibited the greatest decrements. Following four days of depletion all four groups were acutely exposed to a 42 C environmental heat stress during which time rectal temperature increased. It is concluded that in the sedentary rat Na deprivation and diuretic treatment can elicit a 25-50% reduction in heat tolerance which is partially due to electrolyte depletion and hypohydration. These data suggest that during environmental heat stress uncompensated negative Na balance may predispose an individual to heat illnesses. Keywords: Aldosterone, Plasma volume. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1988
- Accession Number
- ADA212081
Entities
People
- Lawrence De Garavilla
- Michael J. Durkot
- Natalie Leva
- Ralph P. Francesconi
- Thomas M. Ihley
Organizations
- United States Army Research Institute of Environmental Medicine