Modulation of endotoxin-induced andrological alterations by flunixin meglumine in the boar

Flunixin meglumine (FM), an inhibitor of the cyclo-oxygenase pathway of the prostaglandin synthesis, was used to evaluate the andrological changes following an endotoxin (ET) administration in the boar. FM was injected as a single dose 10 min prior to an ET injection. Blood plasma was analysed for the contents of 15-ketodihydroprostaglandin (PG) F2 alpha LH, testosterone and cortisol. Twelve h after the ET administration, the boars were castrated and the testes examined by light and electron microscopy. The results were compared between controls, ET-, FM- and FM+ET-treated boars. An increase in 15-ketodihydro-PGF2 alpha levels was seen following ET administration. Pretreatment with FM decreased the levels of 15-ketodihydro-PGF2 alpha during 2 h. Following the ET administration a voluminous increase in testosterone levels as well as changed LH levels were seen. Similar alterations in hormonal levels were observed also after pretreatment with FM, however, delayed about 2 h, and during this time a marked decrease in testosterone levels was seen. In the testes an infiltration of polymorphonuclear neutrophils (PMN) in the interstitium and histological changes among the Leydig cells were seen after ET injection. Pretreatment with FM reduced the number of invading PMN and the Leydig cells appeared less affected. The results show that FM modulated the negative effects of ET on the testicular function in the boar, indicating that the initiation of the arachidonic acid cascade was of importance for the induction of the alterations following an ET injection.