Effects of Linoleate and Arachidonate Deficiencies on Reproduction and Spermatogenesis in the Cat

Abstract

The inability of the cat to convert significant quantities of linoleate [18:2(9,12)] to arachidonate [20:4(5,8,11,14]) in the liver makes the cat a useful model for studying the specific physiological roles of these two fatty acids. In these studies, cats were fed purified diets that were either deficient in essential fatty acids (EFAs) or that provided linoleate with or without arachidonate. Male cats that were fed the EFA-deficient diet for approximately 2 years exhibited extensive degeneration of the testes, and the fatty acid composition of testes changed in a manner consistent with EFA deficiency. Linoleate prevented testis degeneration. Levels of arachidonate, 22:4n6, and 22:5n6 were higher in testis phospholipids of cats supplied with linoleate than in the deficient cats, indicating that the testis of the cat has the capacity to desaturate and elongate linoleate. In contrast, female cats that were fed diets lacking arachidonate were unable to bear live kittens, whether linoleate was provided in the diet or not. Arachidonate, supplied by oral supplements of ethyl arachidonate or by animal fat in the diet, significantly improved reproduction. Thus, linoleate appears to meet the requirements for spermatogenesis in males, but dietary arachidonate is essential for adequate reproduction in female cats.

Targeted disruption of hormone-sensitive lipase results in male sterility and adipocyte hypertrophy, but not in obesity

“…Because HSL catalyzes the hydrolysis of cholesterol ester and triacylglycerol, it is reasonable to speculate that cholesterol or fatty acids released by the action of HSL are required for spermatogenesis. In this concern, it is noteworthy that cholesterol contents of sperms are significantly altered during epididymal maturation (31) and that deficiency of essential fatty acids leads to extensive testicular degeneration (32). It is also possible that the male sterility arises from a disturbance of retinoid metabolism, since HSL mediates retinol ester hydrolysis (33).…”

Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations

“…Reproduction in male cats appears normal when given an all-vegetable-fat diet devoid of arachidonate (MacDonald et al 1984;JG Morris, unpublished results). The testes of toms receiving a linoleate-containing diet had higher levels of arachidonate (indicating synthesis) than in the testes of cats given a linoleate-free diet.…”

Another hormone-sensitive triglyceride lipase in fat cells?

“…mal maturation (9). Moreover, pathological states of fatty acid deficiency have been identified that result in testicular degeneration and sterility (10). Thus, a suggested role for cholesterol ester hydrolysis in spermatogenesis is now conclusively demonstrated with the HSL knockout.…”