Alteration of mercuric chloride-induced autoimmune glomerulonephritis in brown-Norway rats by herring oil, evening primrose oil and OKY-046 a selective TXA-synthetase inhibitor

Abstract

Repeated subcutaneous (SC) injections of mercuric chloride (MC) in Brown Norway (BN) rats induce an autoimmune glomerulonephritis (GN) due to antiglomerular basement membrane (BM) antibody deposition in the glomeruli. The aim of this study was to investigate the effects on MC-induced autoimmune GN of OKY-046, a selective TXA-synthetase inhibitor herring oil (HO), which is rich in eicosapentaenoic acid (EPA) (5.6%) precursor of the three series of prostaglandins (PGs) and of (inactive) thromboxane (TXA3), and evening primrose oil (EPO), which is rich in linoleic acid (LA) (72%) and gamma-linolenic acid (GLNA) (9%), precursors of the one series of PGs, mainly PGE1, and of (inactive) TXA1. The administration of OKY-046 significantly inhibited proteinuria, partially prevented fibrin thrombi (FT) formation in the glomeruli, decreased urinary TXB, enhanced 6ketoPGF excretion and, increased survival rate of the animals from 60% (group receiving only MC) to 86%. However, OKY-046 did not prevent body weight (BW) loss or the development and deposition of IgG in the glomeruli. Increased intake of HO (80 days prior and throughout the experiment) and avoidance of arachidonic acid (AA) intake produced an effect comparable to that of OKY-046 in the rats. Furthermore, HO significantly inhibited the deposition of IgG in the glomeruli, increased the survival rate of the animals to 100% and further enhanced the increased urinary PGE excretion induced by MC. However, HO did not prevent BW loss in the animals. Increased intake of EPO and avoidance of AA intake produced an effect comparable to that of HO. Additionally, EPO completely prevented BW loss induced by MC in these animals. These findings suggest that the metabolites of AA, EPA and GLNA play an important role either in the development or in the modulation of this model of MC induced GN.