Hyperphagia modifies FA profiles of plasma phospholipids, plasma FFA, and adipose tissue TAG.

ABSTRACT

Hyperphagia was achieved by continuous intracerebroventricular infusion of a melanocortin receptor antagonist (HS024; Neosystem, Strasbourg, France) in rats. The effects of hyperphagia on FA composition and concentration of plasma phospholipids (PL), plasma FFA, and adipose tissue TAG were studied in rats for 8 d [short-term hyperphagia (STH); n = 8], or 28 d [long-term hyperphagia (LTH); n = 9]. The control rats were treated with artificial cerebrospinal fluid for 8 d (n = 8) or 28 d (n = 10). The rats were fed the same regular diet. In STH rats the plasma PL and fasting plasma FFA contained higher concentrations of saturated FA (SFA) and monounsaturated FA (MUFA), and plasma FFA contained lower n-6 PUFA than in the control rats. In LTH rats the plasma PL contained higher concentrations of SFA, MUFA, and n-3 PUFA and higher proportions of 161n-7 and 181n-9 at the expense of 182n-6 than in the control rats. In LTH rats the abundant dietary intake of 182n-6 did not enrich 182n-6 of the plasma PL or adipose tissue TAG. In LTH rats the fasting plasma FFA contained more than twofold higher concentrations of SFA and MUFA, and higher proportions of 161n-7 and 181n-9 at the expense of 182n-6 than in the control rats. This animal obesity model shows that LTH affects the FA composition and concentration of plasma PL, plasma FFA, and adipose tissue TAG, a result consistent with changes associated with increased risk of various diseases in humans. These results also demonstrate that LTH alters the FA composition of plasma PL and adipose tissue TAG in a way that does not reflect the FA composition of dietary fat.