Overt Vitamin B-6 Deficiency Affects Rat Pancreatic Digestive Enzyme and Glutathione Reductase Activities

Abstract

Previous reports suggest that vitamin B-6 deficiency contributes to pancreatic insufficiency. However, the susceptibility of pancreatic function to marginal vitamin B-6 intake has not been defined. The present study examines digestive enzyme activity and steady-state mRNA levels, as well as antioxidant enzyme status from rats fed different vitamin B-6 diets. Groups (n = 12) of adult female Long-Evans rats were assigned to five dietary groups and fed their respective diets for 6 wk. Control and food-restricted rats were fed the control diet (7 mg pyridoxine/kg diet) freely, or food intake was restricted to the lowest intake of the experimental groups. The experimental groups were fed purified diets containing 0 (deficient), 0.25 or 1 (marginal) mg pyridoxine/kg diet. Plasma amylase and pancreatic amylase, trypsin and chymotrypsin activities were significantly lower in deficient rats compared with rats fed the control diet. Lower enzyme activities were accompanied by 83 and 55% lower amylase and trypsinogen mRNA levels compared with levels in rats fed the control diet. Other than low glutathione reductase in deficient rats, pancreatic antioxidant enzyme activity was similar in all dietary groups. These data suggest that the exocrine pancreas is impaired by vitamin B-6 deficiency, but marginal pyridoxine intake maintains function.