The effects of vitamin B6 deprivation with 4-deoxypyridoxine in meal-fed rats.

Weanling male rats were trained to consume a control diet in one 4-hr meal a day. Rats were then fed one of three experimental diets for 7 days: (a) control diet minus B6 (-B6); (b) control diet (B6); or (c) control diet restricted to food intake of -B6 (B6R). Xanthurenic acid excretion was greater before and after a tryptophan load in -B6 than in B6R. Body weight gain, food intake, and food efficiency were not different between -B6 and B6. However, in B6R body weight gain, food intake and food efficiency were lower than that in both -B6 and B6. Serum glucose (12-16 hr after meal) and percentage body fat were similar in all three groups. No differences were found in organ size between the -B6 and both control groups indicating that short-term deprivation and deoxypyridoxine did not affect organ size. No significant differences were observed for serum growth hormone (GH), pituitary GH, serum prolactin (PRL), or pituitary PRL among the three groups. When meal fed, differences were minimized between B6 deprived and unrestricted control (B6) rats in body weight gain, food intake, food efficiency, and body composition.