Perturbation and age-related changes in the fatty acid pattern of soleus muscle phospholipids and triglycerides in rats depleted in long-chain polyunsaturated ω3 fatty acids

Abstract

Altered D-glucose metabolism prevails in the soleus muscle of rats depleted in long-chain polyunsaturated omega3 fatty acids (omega3). In these animals, the prior intravenous injection of an omega3-rich medium-chain triglyceride:fish oil emulsion (omega3-FO rats), as compared to that of an omega3-poor medium-chain triglyceride:olive oil emulsion (omega3-OO rats), may either correct or aggravate selected metabolic variables. This study deals with the fatty acid pattern of soleus phospholipids and triglycerides in control animals versus omega3-depleted rats not injected with any lipid emulsion (omega3-NI rats) and in omega3-OO versus omega3-FO rats. In each group of omega3-depleted rats, age-related changes were also monitored. The omega3-depleted rats displayed low long-chain polyunsaturated omega3 fatty acid content, facilitated metabolism of long-chain polyunsaturated omega6 fatty acids, and increased Delta9-desaturase activity. Both the age-related changes in lipid variables and those attributable to the prior intravenous injection of the omega3-rich lipid emulsion consisted either in a move towards normalization or in the opposite direction, i.e. towards aggravation of the defect found in the omega3-depleted rats. Emphasis is placed, therefore, on the unusual situation found in the soleus muscle of omega3-depleted rats, in which both lipid and metabolic variables may be either favourably or adversely affected by the same environmental factor(s).