Effect of chronic renal failure and parathyroid hormone on phospholipid content of brain synaptosomes

The effects of 21 days of chronic renal failure (CRF) with and without excess parathyroid hormone (PTH) and those of 21 days administration of intact PTH on phospholipids and cholesterol contents of rat brain synaptosomes were examined. CRF and PTH treatment were associated with a significant (P less than 0.01-0.02) reduction in the synaptosomal contents of total phospholipids, phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidylethanolamine (PE). Parathyroidectomy (PTX) prior to the induction of CRF prevented the decrements in the synaptosomal contents of total phospholipids, PI, PS, and PE. The synaptosomal contents of these phospholipids in CRF-PTX rats were not different from those in normal rats despite CRF. There were no significant changes in the cholesterol content of the synaptosomes in the various experimental groups of animals. The data show that CRF affects synaptosomal metabolism of total phospholipids, PI, PS, and PE, and these derangements are due to the state of secondary hyperparathyroidism of renal failure. The decrements in the content of PI, PS, and PE could be, at least in part, responsible for the previously reported abnormalities in the neurotransmitter functions of brain synaptosomes in CRF and could underlie some of the abnormalities in central nervous system dysfunction in uremia.