Phospholipid profile of rat testis, its unique high level of monolysocardiolipin and its lipolytic capabilities in vitro. A chromatographic analysis.

The phospholipid profiles of testes and heart of 1-, 3-, and 6-month-old rats and their in vitro response to the endogenous phospholipases at pH 7.4 and 38 degrees C for 60 min were analyzed by TLC technology and densitometry. A noticeable high level of monolysocardiolipin (MLCL) was shown in rat testes of all samples analyzed (1-, 3-, and 6-month-old), both control and incubated. In contrast, rat heart control samples revealed a high level of CL and no MLCL was detected. MLCL was only produced subsequent to in vitro incubation of whole tissue homogenate at pH 7.4 and 38 degrees C for 60 min, with concurrent reduction of CL. Alkenyl phosphatidyl ethanolamine (PE) was the major plasmalogen of rat testes. Following in vitro incubation, (a) a very low level of lyso PE plasmalogen was produced only in 3- and 6-month-old rat testes, (b) ceramide was also produced in all testes analyzed with concurrent reduction of sphingomyelin indicating the action of sphingomyelinase. These data clearly illustrate, for the first time, the presence of high levels of MLCL in all rat testes studied which probably is related to the physiological activity in vivo and requires further investigation.