Impact of fructose rich diet (FRD) administration in the early post-pubertal progesterone-primed female rat.

CASTROGIOVANNI D; ALZAMENDI A; GAILLARD RC; SPINEDI E; GIOVAMBATTISTA A

Washington DC, USA.

Congreso; 2009 Obesity Society Annual Scientific Meeting; 2009

NAASO

The aim of this study was to evaluate the effect of FRD administration in rats primed (at age 60 days) with progesterone (P4; im, 2 mg/200 ml corn oil) or vehicle (controls; CT). Individually housed rats from CT and P4 groups (n=7/8 rats per group) received commercial pellet-diet and water ad libitum between ages 60-99 days. Between days 100 and 120 of age, rats were ad libitum fed with a FRD (10 % w/v fructose in water) for drinking and commercial-pellet diet until experimentation. Rat body weight (BW) and food intake were daily monitored between days 60 and 99 in CT and P4 rats; and, BW, food intake and fluid intake were daily monitored between days 100 and 120 in CT-FRD and P4-FRD rats. Rats were euthanized (age 120 days, 09:00-09:30 h) and trunk blood was collected; immediately after parametrial (PM) fat pads were dissected, weighted and kept frozen. Plasma concentrations of various metabolic markers were measured. Our results indicate that no differences among groups accounted for BWs, either when examined before or after FRD administration. Normalized PM fat pad weight (g/100 g BW) and average of total daily calorie intake (even when discriminated by source) were similar P4-FRD and CT-FRD rats. While P4-FRD displayed enhanced plasma total cholesterol levels (p<0.05 vs. CT-FRD rats), circulating concentrations of non-esterified fatty acid, triglyceride, glucose, insulin and adiponectin were similar in both groups. Conversely, the plasmatic levels of leptin and plasminogen activator inhibitor-1 (expressed in ng/ml, or normalized as in either ng/ml/100 g BW or ng/ml/g PM fat) were significantly (p<0.05) higher and lower, respectively, in P4-FRD than in CT-FRD rats. Interestingly, PM fat leptin and adiponectin mRNAs were significantly (p<0.05) higher in P4-FRD than in CT-FRD rats. Our data indicate that various adaptive metabolic mechanisms involved in FRD intake-induced allostasis seem to be dependent on a previously and transiently established high P4 endogenous environment. Importantly, and because of certain paracrine effects, a distorted profile of PM fat adipokine gene expression could be playing a modulatory role in the female reproductive function, at early post-pubertal age. Thus, this study strongly encourages researchers to further develop studies on the effect of sex steroid-diet interaction on PM adipocyte endocrine function at early reproductive age. (Supported by PICT200701051; PIP11220080100704; and FRPE0709)