Modification of skeletal muscle sarcoplasmic reticulum fatty acyl composition during arousal from hibernation

Abstract

The fatty acyl composition of sarcoplasmic reticulum was analyzed in skeletal muscle from hibernating and aroused Richardson's ground squirrels, Spermophilus richardsonii.

Total levels of monounsaturated fatty acyl groups increased in the phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI) fractions of aroused animals. Docosahexaenoic acid (22:6n-3) was lower in all phospholipids while the ratio $\text{20:4}\text{22:6}$ was higher in aroused animals.

These changes in fatty acyl composition have the potential to alter SR Ca²⁺-ATPase activity and Ca²⁺ uptake efficiency during the energetically demanding arousal process.