A pilot study to evaluate the effect of splanchnic nerve stimulation on body composition and food intake in rats

Systemic sympathetic stimulation with caffeine and ephedrine increased metabolic rate, reduced food intake, and improved body composition but had systemic adverse events. We hypothesize that selective sympathetic stimulation of the upper gastrointestinal tract will preserve the advantages of systemic sympathetic stimulation without its adverse events. This study evaluated the effect of splanchnic nerve stimulation on metabolic rate, food intake, and body composition.

Sixteen Sprague Dawley rats had monopolar electrodes placed on the superior common splanchnic nerve innervating the celiac ganglia. An indifferent electrode was placed subcutaneously on the back. The animals were placed on a 60% fat diet, and eight rats were stimulated for 6 weeks. The stimulation was advanced over 3 days from 0.6 mA to 3 mA. Metabolic rate and food intake were measured daily; weight change was monitored weekly, and body composition was determined by nuclear magnetic resonance (NMR) at the end of the study. Four of the eight animals had metabolic rate measured three times over 2-day periods at 0 mA, 1 mA, and 3 mA of stimulation in a metabolic chamber.

Except for the first week of stimulation, there was no difference in body weight between the stimulated and control groups. Cumulative food intake was less in the stimulated group (p<0. 001). The lean-to-fat ratio was greater in the stimulated group (p<0. 01), and the animals that received incremental stimulation showed significantly augmented metabolic rate (p<0. 02).

Splanchnic nerve stimulation decreased food intake, increased metabolic rate, and improved body composition.