THE LEVELS AND POSSIBLE INVOLVEMENT OF LEUKOTRIENE-B4 AND PROSTAGLANDIN-F2-ALPHA IN THE CONTROL OF INTERSTITIAL FLUID VOLUME IN THE RAT TESTIS

The possible involvement of two arachidonic acid metabolites, prostaglandin F2α (PGF2α) and leukotriene B4 (LTB4), in the stimulatory effect of human chorioni gonadotrophin (hCG) on the volume of interstitial fluid (IF) in the rat testis ha been investigated. Administration of hCG caused a time‐ and dose‐dependen increase in the IF levels of PGF2α while LTB4 showed no clear dose‐dependence but did decrease significantly at 2–8 h after injection of 100 IU hCG. Administra tion of ethane dimethane sulphonate (EDS), which specifically destroys Leydi cells, decreased the volume of IF but the IF levels of LTB4 and PGF2α were unchanged. This indicates that although the absence of Leydig cells results i significant changes in IF volume, LTB4 and PGF2α are probably not involved in these changes. Furthermore, these findings suggest that Leydig cells are not th only contributors to LTB4 and prostaglandins E2 and F2α in testicular IF. In rats injected peripherally with hCG, intratesticular administration of the cyclo oxygenase inhibitor, indomethacin, decreased PGF2α, levels in IF after 2 and 4 ’ but not at later times. However, no inhibitory effect of indomethacin on the hCG stimulated increase in IF volume was detected; indeed, at 2 h after injection o indomethacin + hCG there was a significant increase in IF volume in the indomethacin‐injected testis. It is concluded that, although prostaglandins am LTB4 are secreted into IF in the rat testis, these arachidonic acid metabolites ar apparently not the primary mediators of the increase in IF volume that follows hCC treatment. Copyright © 1990, Wiley Blackwell. All rights reserved