Fatty acid proportions (% of total fatty acids) of cardiac sarcoplasmic reticulum phospholipids (means ± standard deviation), ratio of certain fatty acid proportions, and unsaturation index (“UI”) of summer hamsters (“Summer”, n = 7), non-hibernating winter hamsters (“Winter”, n = 7), and hibernating hamsters during entrance into a torpor bout (“Cooling”, n = 9), during deep torpor (“Torpid”, n = 18) and during inter-bout arousal (“IBA”, n = 13).

<p>The unsaturation index was calculated as followed: UI = Σ [(% each fatty acid) (no. double bonds/fatty acid)]. Groups differing significantly with p<0.05 (Tukey’s post-hoc comparisons) are denoted by different superscripts.