Acetylcholinesterase and Butyrylcholinesterase Activities in Brain and Plasma of Several Species of Birds in India

Abstract

Since timely acquisition of concurrent controls is not always feasible, development of a reference data of normal cholinesterase (ChE) activities for various wildlife species particularly for birds is necessary to diagnose anticholinesterase exposure. In the present study, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in brain and plasma of several species of birds collected from Ahmedabad, India, during 2005–2007, were determined. Brain AChE activity ranged from 1.24 µmole/min/g in Indian white-backed vulture Gyps bengalensis to 2.50 µmole/min/g in koel Eudynamys scolopacea. Plasma AChE and BChE activity varied from 0.60 to 1.96 µmole/min/mL and 0.68 to 2.68 µmole/min/mL respectively. The variation in cholinesterase activity among the species of birds was highly significant (ANOVA, P < 0.05). Brain and plasma ChE activity varied 2–5 fold among the species studied. Brain AChE activity among years and between sexes was not significant. The lowest ChE activities were found in the largest species and the highest ChE activities were found in the relatively small species. The ChE activities obtained for koel, pariah kite, blue rock pigeon, Indian white-backed vulture and house crow provide a good estimate of the normal values in birds. This study is the first report of AChE and BChE activities in birds in India and constitutes a starting point for future studies that evaluate impact of pesticides. These values can be used as a baseline to evaluate the effect of anticholinesterase insecticides on birds in the field.

Keywords: AChE, BChE, birds, blood plasma, brain, normal levels