Butyrylcholinesterase blood plasma concentrations of Common Swifts (Apus apus)

Butyrylcholinesterase (BChE), known as pseudocholinesterase or plasma cholinesterase, is a non-specific cholinesterase enzyme synthesised in the liver. The function of this enzyme is unknown in detail and is primarily discussed as a safeguarding system for Acetylcholinesterase (AChE). In a retrospective analysis of results of blood chemistry investigations of wild bird patients of the Clinic for Small Mammals, Reptiles and Birds, University of Veterinary Medicine Hannover, Foundation, Germany, BChE plasma concentrations of the Common Swift (Apus apus) and a possible influence of the body condition and age were determined. Blood values of adult (n = 33) and juvenile (n = 50) Common Swifts were analysed. BChE was determined by dry chemistry analyser Kodak Ektachem DTSC II module® with slides with butyrylthiocholin as substrate and measured at 400 nm by reflectance spectrophotometry during 5-min incubation at 37 °C. The Common Swift could be determined as a species with very high BChE blood plasma concentrations compared to other insectivore species. The arithmetic mean ± standard deviation (SD) for adult swifts amounted to 27,189.28 U/l ± 10,852.94 and that for juvenile/fledged swifts to 25,986.54 U/l ± 9573.28. A remarkable influence of the body condition on this BChE plasma concentration could be observed. In cases of malnutrition, a highly significant decrease of BChE activity could be found. For example, BChE concentrations of adult swifts in a poor body condition with reduced total protein and albumin blood plasma concentrations without liver diseases, arithmetic mean ± SD, 14,837.13 U/ l ± 7944.45, illustrate this impact.