Salt and Fat: Determining the effects of a high salt diet on fat metabolism

In an unpublished experiment by the Skinner lab, it was observed that rats on a high fat diet put on significantly more body fat than those on a high fat/high salt diet. The purpose of this project was to investigate the effects of a high salt diet on fat metabolism. It was hypothesized that elevated dietary salt consumption altered fat deposition in one of two ways, either via increased metabolic activity of the rat or due to hyperplasia and hypertrophy of adipocytes in the white adipose tissue (WAT). To evaluate the metabolic effects of excess salt consumption, 24 female Sprague-Dawley rats were fed a high fat diet(60% fat, 0.3% sodium), high salt diet (20% fat, 8% sodium), high fat/high salt (60% fat, 8% sodium), or control (20% fat, 0.3% sodium) for 24 days beginning postnatal day 21. Each rat was placed in a locomotor box to assess overall activity on 5 separate occasions: d21, d24, d31, d34, and d37. On d27 a thermochron ibutton was inserted into the intraperitoneal cavity of the rat to measure the body temperature of the rat at designated time intervals. To evaluate adipocyte variability due to high salt diet 29 female Sprague-Dawley rats were fed an 8% salt diet, a 4% salt diet, a 2% salt diet, or a control diet (0.3% sodium) for 24 days beginning postnatal day 21. The WAT of the perirenal fat pads from each rat was collected, fixed, and prepared with an H&E stain. Adipocyte size and number from 10 μm sections were compared using Adiposoft software. Data suggests that salt does not affect physical activity or body temperature in the rats. Data from the WAT adipocyte analysis is currently being collected for analysis.