The acute-phase response to turpentine-induced abscesses in malnourished rats at different environmental temperatures

Abstract

An assessment was made of the independent effect of environmental temperature (13, 21, and 30°C) and either protein deficiency or energy deficiency on the metabolic response of rats that had aseptic abscesses induced by subcutaneous injections of turpentine. Measurements of food intake, α 2-macroglobulin (α 2-M; a major acute-phase protein in the rat), albumin, and various circulating metabolites were made 48 hours after turpentine injection in animals acclimatized at 13, 21, and 30°C and compared with pair-fed controls. Despite differences in basal circulating albumin concentrations between controls and protein deficient rats ( P<.001), turpentine produced a similar reduction in all groups of animals (∼ 10 g/L), independent of environmental temperature. The α 2-M response to turpentine was attenuated in all protein-deficient animals and also in the energy-restricted animals at 13°C. The increase in circulating 3-hydroxybutyrate (BOH) and nonesterified fatty acid (NEFA) concentrations, which normally occur with reduced dietary intake, was reduced in the turpentine-injected animals to an extent that depended on prior dietary intake. It is concluded that the metabolic response, particularly the acute-phase protein response, to a standard form of “injury” is affected by protein deficiency and possibly by energy restriction under adverse environmental temperature.