Lipid composition and metabolism in testicular and ejaculated ram spermatozoa

Abstract

1. Spermatozoa collected directly from the testis of the conscious ram contain 25% more phospholipid than ejaculated spermatozoa. The concentration of lecithin, phosphatidylethanolamine and ethanolamine plasmalogen was greater in testicular spermatozoa; little difference was observed in choline plasmalogen. Both types of spermatozoa had significant amounts of cardiolipin and alkyl ether phospholipid. 2. The fatty acids in the phospholipid extracted from testicular spermatozoa have a very high content of palmitic acid. The phospholipids of ejaculated spermatozoa contained less palmitic acid, but more myristic acid. 3. Ejaculated spermatozoa contained less acyl ester and cholesterol. It is suggested that lipids are a source of substrate for spermatozoa during their passage through the epididymis. 4. Testicular spermatozoa when incubated with [U-(14)C]glucose incorporated more radioactivity into the glycerol part of the phospholipid and neutral lipid fractions than did ejaculated cells. The distribution of radioactivity in the individual phospholipids and neutral lipids was similar for both cell types. No radioactivity was detected in choline plasmalogen, which accounted for approx. 40% of the total phospholipid. 5. Testicular spermatozoa incorporated more radioactivity from glucose into formate than into acetate, whereas a higher proportion of radioactivity was found in acetate in ejaculated cells. 6. The implications of these lipid changes in the process of spermatozoal maturation are discussed.

The Effect of Cold Shock and Freeze-Thawing on Release of Phospholipids by Ram, Bull, and Boar Spermatozoa

“…The results presented here for the ram are in reasonable agreement with those of Scott et al (1967) and Neill and Masters (1972) and those for boar spermatozoa agree with the data of Johnson et al (1969). Differences between present findings and some of those mentioned in Section I are probably due to differences in the amount of total phospholipid extracted and the analytical techniques employed.…”

The Proteins of Bovine Spermatozoa From the Caput and Cauda Epididymidis

“…The results of the present study confirm that the decrease in the dry matter content of spermatozoa, which occurs during maturation (Lavon, Volcani & Danon, 1970) (Scott, Dawson & Rowlands, 1963;Dawson & Scott, 1964;Grogan et al, 1966;Pickett, Komarek, Gebauer, Benson & Gibson, 1967;Quinn & White, 1967;Scott & Dawson, 1968;Lavon et al, 1970) and was assumed to be the result of their utilization as a source of energy in the absence of carbohydrates (Quinn & White, 1967;Scott et al, 1967). It seems likely that a parallel degradation occurs in the related proteins during the maturation process.…”

The Phospholipid Composition of Human Spermatozoa and Seminal Plasma

“…The amount of phospholipid extracted from human spermatozoa is similar to the amount extracted from the ram (Scott et al, 1967) and bull (Pursel & Graham, 1967) despite the use of different extraction procedures, but is lower than the figures quoted for the boar (Johnson et al, 1969;Poulos et al, 1972 Stanley (1957) in at least three other species (Poulos et al, 1972).…”

“…The phospholipid composition of human spermatozoa appears to resemble that of the boar more closely (Johnson et al, 1969;Poulos et al, 1972) than that of the ram (Scott et al, 1967;Quinn & White, 1967) or bull (Masaki & Hartree, 1962;Pursel & Graham, 1967). Choline plasmalogen comprises only 3% and 10% of human and boar sperm phospholipids, respectively, whereas it is by far the major component of ram and bull spermatozoa.…”

“…Although a considerable amount of information has been amassed on the phospholipid composition of the spermatozoa of ram (Hartree & Mann, 1961 ;Scott, Voglmayr & Setchell, 1967), bull (Pursel & Graham, 1967) and boar (Grogan, Mayer & Sikes, 1966;Johnson, Gerrits & Young, 1969), little work has been carried out on the phospholipid composition of human spermatozoa. This may be at least partially due to the low sperm concentration of human semen which necessitates the use of large numbers of ejaculates before sufficient lipid material can be isolated and analysed.…”