Protein and Lipid Profile of Different Epididymal Regions and Their Contents in Rattus rattus L.

Abstract

To study the molecular composition of epididymis and its contents, protein and lipid concentration and their profile in its three segments; caput, corpus and cauda was analyzed. The amounts of proteins, lipids and phospholipids was highest in the tissues of caput epididymis as compared to corpus and cauda as well as protein content was higher in caput fluid too. However, their concentration in spermatozoa was highest in those from cauda as compared to other regions. The SDS-PAGE profile of epididymal tissue, its fluid and spermatozoa separately collected from these regions revealed the presence of high (205 and >205 kDa), medium (66, 70, 90, 97.4, 100, 125, 151 kDa) and low (3, 6.5, 8.6, 14.3, 16, 17, 20, 32.5, 43, 54 kDa) molecular weight proteins. A protein of molecular weight 16/17 kDa was present in tissue and fluid of caput only but in spermatozoa from all the three regions which shows its origin from secretory activity of caput and incorporation as such in spermatozoa. However, 100 and 125 kDa proteins were present in tissues of all epididymal regions and appeared as an altered (90/97.4 kDa) protein in spermatozoa from all the three regions. Thin Layer Chromatographic studies of phospholipids in epididymal tissues and its contents in three regions revealed the presence of phosphatidyl choline, phosphatidyl serine, phosphatidyl inositol, sphingomyelin, phosphatidyl glycerol, phosphatidyl ethanolamine and cardiolipin.