Proline oxidase inhibition by free fatty acids of rat pancreas

Proline oxidase activity was not measurable in pancreas homogenate but was measurable in pancreas slices. Moreover, added pancreas homogenate inhibited proline oxidase activity in rat liver mitochondria and several other tissues. The partially purified inhibitor from pancreas also inhibited the activity of glutamate, glucose 6-phosphate, NADH and succinate dehydrogenases. The inhibition was reversed by the addition of bovine serum albumin. Further studies to identify the inhibitor indicated that it consisted of free fatty acids that were enzymatically released after homogenization of pancreas. The free fatty acids released appeared to be derived primarily from triglycerides.