and expression during rat spermatogenesis: a link to the very-long-chain PUFAs typical of germ cell sphingolipids.

The sphingolipids (SLs) of rodent spermatogenic cells (spermatocytes, spermatids) and spermatozoa contain nonhydroxylated and 2-hydroxylated versions of very-long-chain (C26-C32) PUFAs (n-V and h-V, respectively) not present in Sertoli cells (SCs). Here, we investigated the expression of selected fatty acid elongases [elongation of very-long-chain fatty acid protein ()], with a focus on , and a fatty acid 2-hydroxylase () in rat testes with postnatal development and germ cell differentiation. Along with and , was actively transcribed in the adult testis.

Lipid Biochemical and Biophysical Changes in Rat Spermatozoa During Isolation and Functional Activation In Vitro.

In spermatozoa isolated from rat epididymis, lipids are differentially modified after in vitro induction of capacitation (Cap) and the acrosomal reaction (AR). This study uses Laurdan fluorescence generalized polarization values (GPv) to evaluate the effect of lipid changes occurring after isolation and functional activation on sperm membrane biophysical properties. In gametes isolated in the presence of a divalent cation chelator, no lipid changes occurred and the GPv were the lowest recorded, indicating maximal membrane lipid mobility.

Uneven distribution of ceramides, sphingomyelins and glycerophospholipids between heads and tails of rat spermatozoa.

Previous work showed that rat germ cells and spermatozoa contain ceramides and sphingomyelins with high proportions of nonhydroxy and 2-hydroxy (2-OH) polyunsaturated fatty acids (PUFA) with very long chains (VLCPUFA). The aim of this study was to assess how these lipids are distributed between the heads and tails of mature spermatozoa in comparison with other membrane lipid classes. In addition to quantitative differences due to the fact that these gametes have a long, voluminous tail and a minute head, several compositional dissimilarities emerged between these two regions.

Mild testicular hyperthermia transiently increases lipid droplet accumulation and modifies sphingolipid and glycerophospholipid acyl chains in the rat testis.

Spermatogenesis is known to be vulnerable to temperature. The aim of this study was to investigate the effects on testicular lipids of the transient germ cell loss that is induced by mild testicular hyperthermia. Adult rat testes were exposed once a day to 43 °C for 15 min for 5 days and the effects were followed for several weeks.

Differentiation-related changes in lipid classes with long-chain and very long-chain polyenoic fatty acids in rat spermatogenic cells.

In rat seminiferous tubules (ST), cells that contain polar and neutral lipids with long-chain polyenoic fatty acids (PUFA) and sphingomyelins (SM) and ceramides (Cer) with very long chain (VLC) PUFA of the n-6 series coexist. In this study, pachytene spermatocytes and round spermatids were isolated to determine how these lipids change during spermatogenesis. As the amount per cell of PUFA-rich glycerophospholipids (GPL) decreased with cell size, the 22:5/20:4 ratio increased with cell differentiation.