Esterase Polymorphism in Camel ( Camelus Dromedaries ) Tissues and Comparison with Other Mammalian Species

The activity of carboxyl esterase (CE) and the distribution of esterase isozymes in camel, cow, goat, rabbit, rat, and sheep tissue aqueous extracts were examined using methyl butyrate (MB) as substrate for measuring activity and non denaturant polyacrylamide gel stain after electrophoresis (PAGE) using α-naphthyI acerate (NA) as the substrate. The order of esterase activity was liver > lung > kidney > third stomach > intestine > spleen > heart > plasma > red blood cells. Camel tissues : heart, intestine, kidney, liver, lung, spleen, and stomach exhibited esterase specific activity (ESA) for MB, in µmol/min/g wet tissue, as : 0.67, 2.28, 4.61, 146.0, 29.2, 1.18, and 2.58, respectively. The esterase activity in these tissue extracts exhibited on the gel 3, 5, 1, 3, 2, 3, and 6 bands, respectively. Camel RBC and blood plasma showed no activity in gel electrophoresis. However, camel blood plasma yielded ESA of 0.42 using MB as substrate. Therefore it is concluded that camel serum albumin completely lacks serum esterase-like activity. The range of ESA values in tissue extracts of cow, goat, rabbit rat, and sheep are as lowest to highest : Heart, 2.26 in goat to 3.75 in rabbit; intestine, 1.46 in cow to 12.8 in rat; kidney, 1.45 in cow to 14.6 in rabbit ; liver, 73.4 in cow to 343 in rabbit ; lung, 1.35 in goat to 14.6 in rat; spleen, 2.54 in cow to 3.44 in rat; stomach, 1.37 in cow to 3.13 in goat; RBC, 0 in all; plasma, 0.64 in cow to 3.99 in rat. The number of activity bands on the gel by each tissue ranged from one for cow kidney and spleen to nine for sheep intestine and stomach.