The Respiration of the Rabbit Epididymis and Its Synthesis of Glycerylphosphorylcholine

Abstract

SummaryThe synthesis of glycerylphosphorylcholine (GPO) has been studied in the caput epididymis of the rabbit in vitro using [32P]orthophosphate and choline. The incorporation of 32p or 14C into GPO was much greater than into lecithin and the ratio of 32p to 140 was much less in the GPC than in lecithin. Coenzyme A and stearate caused a ~ixty-fold stimulation of the incorporation of 32p into lecithin but only a sevenfold stimulation of incorporation into GPO. The results of these experiments are not consistent with lecithin being the major immediate precursor of GPC, in vitro.The Qo, values for caput epididymis tissue varied from a maximum of 2·2 for tissue slices to 0·5 for some homogenates. Oxygen uptake of tissue slices in Ringerglucose was similar to that in a complex medium containing most cofactors. The addition of 10 fLg/ml testosterone to the incubation mixture did not affect the oxygen uptake of either tissue slices or homogenates. However, tissue slices of mature epididymides' respired at a greater rate than those obtained from immature animals.

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

“…It is generally believed that epididymal tissue is responsible for the production of most of the GPC found in semen (Dawson, Mann, and White 1957;Dawson and Rowlands 1959;Wallace, Wales, and White 1966). The loss of fatty acids and aldehydes from spermatozoal phospholipids during their passage through the epididymis could, however, account for about 20% of the GPC in the cauda epididymis of the ram.…”

“…This causes an irreversible loss of viability which is accompanied by an increased permeability of the cell and, presumably, changes to the cell lipoprotein membrane (Wales and White 1959;White and Wales 1960). Spermatozoa obtained from the epididymis are more resistant to cold shock than ejaculated spermatozoa (Lasley and Bogart 1944;Lasley and Mayer 1944;White and Wales 1961); however, the resistance ofthe latter can be increased by adding phospholipids to semen in vitro (Kampschmidt, Mayer, and Herman 1953;Blackshaw 1954;Blackshaw and Salisbury 1957).…”

The Effects of -Chlorohydrin on the Composition of Rat and Rabbit Epididymal Plasma: A Possible Explanation of Species Difference

“…Histochemical studies (Moniem, 1972) (Dawson et al, 1957;Dawson & Rowlands, 1959;Scott et al, 1963;Wallace et al, 1966). In the present study, there was virtually no change in the activity of phosphatases in epididymal plasma of the rabbit or the rat after treatment with -chlorohydrin.…”

Localization of Alkaline Phosphatase and NADH Diaphorase in the Principal Cells of the Guinea Pig Epididymis

“…Although epididymal sperm exhibit some maturational changes on their own, it is generally accepted that the epididymis influences sperm maturation by absorbing materials from the epididymal lumen and secreting other substances into the lumen [Gunn, 1936;Mason and Shaver, 1952;Dawson et al, 1957;Dawson and Rowlands, 1959;MacMillan and Clegg, 1963;Burgos, 1964;Crabo, 1965;Nicander, 1965;Fournier, 1966;Peyre and LaPorte, 1966;Wallace et al, 1966;Friend and Farquhar, 1967;Rajalakshmi and Prasad, 1968;Glover and Nicander, 1971;Johnson and Hunter, 1972;Killian and Amann, 1973;LaPorte et al, 1975;Nican der and Malmqvist, 1977;Lea et al, 1978;Moore, 1980].…”