Phospholipid and Cholesterol Content of Epididymal and Jaculated Ram Spermatozoa and Seminal Plasma in Elation to Cold Shock

Abstract

SummaryThe concentration of total phospholipid, phosphatidylcholine, phosphatidylethanolamine, and choline plasmalogen in spermatozoa from the caput epididymis of the ram was higher than in spermatozoa from the cauda. The phospholipid composition of spermatozoa from the latter region of the epididymis more closely resembled ejaculated spermatozoa.In general, the plasma of caput and cauda semen was similar in total phospholipid content and composition.The total phospholipid concentration of ejaculated seminal plasma was only about one-fifth that of the caput and cauda fluid and all phospholipid fractions were greatly reduced.The glycerylphosphorylcholine content of caput spermatozoa and seminal plasma was less than that of the corresponding semen fractions obtained from the cauda epididymis, and after ejaculation.The concentration of non-esterified cholesterol in both the spermatozoa and plasma decreased on passing from the caput to the cauda epididymis and was even less in the corresponding fractions of ejaculated semen.Spermatozoa taken from the testis and caput epididymis were little affected by cold shock whereas spermatozoa from the cauda epididymis and ampulla were much more susceptible, as judged by increased permeability to stain. It is suggested that a decrease in the phospholipid and cholesterol content of spermatozoa may be associated with an increase in the susceptibility of ram spermatozoa to cold shock as they pass through the male reproductive tract.

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.…”

Desmosterol, the main sterol in rabbit semen: distribution among semen subfractions and its role in the in vitro spermatozoa acrosome reaction and motility

“…Unlike the semen from other mammals, rabbit semen contains discrete amounts of sterol esters and the presence of desmosterol esters (representing about 44% of total sterol esters) is a unique biological finding. Sterol esterification occurs during spermatozoa transit through the epididymis in the ram [25], and this could also be true for the rabbit. In hamster and monkey spermatozoa, desmosterol is also present chiefly in the free form, and only a minor proportion is conjugated with a thiol group, exhibiting several structural (spermatozoa membrane stabilizer) and functional (modulator of capacitation, acrosin inhibitor) roles [21,24].…”

The Phospholipid Composition of Human Spermatozoa and Seminal Plasma

“…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.…”

“…Sphingomyelin is the predominant phospholipid type present in boar (Johnson et al, 1969) and human seminal plasma but in ram and bull seminal plasma (Quinn & White, 1967;Pursel & Graham, 1967), the choline phospholipids are the major fraction accounting for about half the total phospholipid. The latter phos¬ pholipid fraction comprises only about 10% of the phospholipids of human and boar seminal plasma.…”