Factors affecting the ability of baclofen to reduce fat intake in rats

Abstract

The GABA-B agonist baclofen has been reported to reduce the consumption of vegetable shortening, but not lard, in rats. This study sought to examine some of the factors that could account for these differences. Baclofen (0, 1.0, 1.8, 3.2 mg/kg, intraperitoneal) was tested: (i) on shortening and lard intake, (ii) under 'binge-type' and non-'binge-type' conditions, (iii) when each fat was presented alone or simultaneously, and (iv) with a 30-min or no pretreatment time. With a 30-min pretreatment time, baclofen (3.2 mg/kg, intraperitoneal) consistently reduced shortening intake under 'binge-type' and non-'binge-type' conditions, as well as when shortening was presented alone or when lard was simultaneously available. Baclofen also reduced lard intake under 'binge-type' and non-'binge-type' conditions, but only when lard was presented alone. Baclofen had no effect on chow intake. When each fat was presented alone, and with no pretreatment time, the results were less consistent; baclofen reduced shortening intake only under non-'binge-type' conditions, and lard intake only under 'binge-type' conditions, and also stimulated chow intake. In summary, the type of fat, the presentation mode (one fat presented alone or two fats simultaneously), and the time between baclofen administration and intake all influence the ability of baclofen to reduce fat intake.

Can We Selectively Reduce Appetite for Energy-Dense Foods? An Overview of Pharmacological Strategies for Modification of Food Preference Behavior

“…Subsequent studies demonstrated that the drug clearly inhibited consumption of fat, but its effect on standard food intake was ambiguous, i.e. , baclofen either did not change, decreased, or increased concomitantly the consumption of normal chow [ 255 - 258 ]. Baclofen was not able, however, to suppress the consumption of sucrose solution, and, furthermore, it increased sweet-fat food consumption [ 256 ].…”

Development of bingeing in rats altered by a small operant requirement

“…A behavioral model of binge-type eating in non-food deprived rats has been developed in which intermittent (Monday, Wednesday, Friday) access to an optional food provided in the home cage for a brief period of time from 20 min [2] to 2 h [3] promotes significantly greater (excessive) intake relative to daily access for the same brief period. These optional foods have included vegetable shortening containing trans fat [4], vegetable shortening devoid of trans fat [5], lard [6], liquid sucrose [7], different concentrations of semi-solid fat emulsions [8], different concentrations of fat/sucrose dispersions [9], and different fat concentrations in emulsions made with different biopolymers [10]. …”