Alterations in testicular function after endotoxin injection in the boar

Abstract

Twelve mature boars were injected intravenously with endotoxin from Salmonella typhimurium. Blood plasma was analysed for 15-ketodihydro-PGF2 alpha, LH and testosterone. The boars were castrated at various times after endotoxin administration and the testes examined by light and electron microscopy. The levels of 15-ketodihydro-PGF2 alpha and LH rose immediately after endotoxin injection followed by an increase in testosterone levels, and in five boars a second increase in LH levels was observed. Morphological examination of the testes revealed infiltration of polymorphonuclear neutrophils (PMN) into the testicular interstitium. The Leydig and myoid cells showed morphological changes. Alterations were also present in the seminiferous epithelium among Sertoli cells, spermatocytes and spermatids. The results indicate that endotoxins can exert a negative effect on testicular function in the boar. Except for the initial increase in LH levels, which is not clearly understood, the hormonal changes are thought to be mediated by alterations in Leydig cell function. The alterations further support previous findings in the boar, and indicate that there is short-term, moderate damage to the seminiferous epithelium following endotoxin injection.

Pro‐Inflammatory and Oxidative Stress Pathways which Compromise Sperm Motility and Survival May Be Altered by L‐Carnitine

“…Serum IL-2 level also showed a marked increase in LPS-treated rats. These data are in harmony with the previous studies which revealed that infection and inflammation after administration of bacterial LPS lead to inhibition of testicular steroidogenesis and disruption of spermatogenesis in animals treated with LPS9,33 or with septic agents that generate LPS 18. Moreover, it has been reported that LPS administration resulted in the disruption of the blood-testis barrier and increased infiltration of white blood cells (WBCs) with subsequent production of ROS and activation of NO synthase 12.…”

“…It has been established that a condition similar to infection can be produced in vivo by administration of bacterial LPS. In that regard LPS administration was found to inhibit testicular steroidogenesis and the disruption of spermatogenesis in animals 9. Cytokines are good candidates for involvement in the local control exerted between germ and Sertoli cell activity 10.…”

Bacterial Lipopolysaccharide-Induced Inflammation Compromises Testicular Function at Multiple Levelsin Vivo1

“…Infection and inflammation can be reproduced in vivo by administration of bacterial lipopolysaccharides (LPS), and several studies have observed inhibition of testicular steroidogenesis and disruption of spermatogenesis in animals treated with LPS (4,5) or with septic agents that generate LPS (6). Studies in mice using relatively high doses of LPS in vivo have demonstrated that Leydig cell steroidogenesis is inhibited via reduced synthesis of the cholesterol transport protein, steroidogenic acute regulatory protein (StAR), and of the steroidogenic enzymes, cholesterol side-chain cleavage enzyme, 17␣-hydroxylase/C 17,20 -lyase, and 3␤-hydroxysteroid dehydrogenase within several hours after injection (7)(8)(9).…”

Differential effects of dexamethasone treatment on lipopolysaccharide-induced testicular inflammation and reproductive hormone inhibition in adult rats

“…Several laboratories, including our own, have investigated this process using animal models of inflammation induced by injections of lipopolysaccharide (LPS), a bacterial outer cell wall molecule that activates the inflammatory functions of monocytes and macrophages (Wallgren et al 1993, Refojo et al 1998, O'Bryan et al 2000. Inhibition of both anterior pituitary secretion of luteinizing hormone (LH) and Leydig cell testosterone secretion have been observed in these models.…”