Modulation of Acetylcholine Turnover in Brain Regions
There seems to be as yet no general agreement on the basal steady state level of A Ch in the brain. Values ranging from 7–31 nmol/g have been reported (6). Variables such as method of sacrifice, extraction and analysis, as well as activity and time of day have been implicated as the factors responsible (Table 1). From the time of decapitation until the brain tissue is homogenized and extracted acetylcholinesterase (A ChE) and choline acetyltransferase (CAT) may cause changes in the A Ch level. The use of the microwave technique as a rapid method of sacrifice and enzyme inactivation, originally introduced by Stavinoha and coworkers in 1970 (15), has increased progressively during recent years and has greatly reduced the time taken for enzyme inactivation. The aim of the present communication has been to study the influence of the time taken to enzyme inactivation on turnover of ACh in different brain regions.
KeywordsBrain Region Microwave Irradiation Sodium Pentobarbital Specific Radioactivity Choline Acetyltransferase
Unable to display preview. Download preview PDF.
- 1.Choi, R. L., Roch, M. and Jenden, D.J. (1973): Proc. West. Pharmacol. Soc. 16:188–190.Google Scholar
- 3.Hanin, I., Massarelli, R. and Costa, E. (1970): In: Drugs and Cholinergic Mechanisms in the CNS, (Eds.) E. Heilbronn and A. Winter, Fors. Forsk., Almqvist & Wiksell, Stockholm, pp. 33–54.Google Scholar
- 5.Karlen, B., Lundgren, G., Lundin, J. and Holmstedt, B. (1977): Life Sci. (in press).Google Scholar
- 7.Nordberg, A. (1977): J. Neurochem. (submitted)Google Scholar
- 8.Nordberg, A. and Sundwall, A. (1975): In: Cholinergic Mechanisms, (Ed.) P. G. Waser, Raven Press, New York, pp.229–239.Google Scholar
- 13.Saelens, J.K., Simke, J. P., Allen, M.P. and Conroy, C.A. (1973): In: Methods of Neurochemistry, Vol.4 (Ed.) R. Fried, Marcel Dekker, New York, pp. 69–95.Google Scholar
- 14.Stavinoha, W.B. and Ryan, L. C. (1965): J. Pharmacol. Exp. Ther. 150:231–235.Google Scholar
- 15.Stavinoha, W. B., Pepelko, B. and Smith, P.W. (1970): Pharmacologist 12:257.Google Scholar
- 17.Tobias, J.M., Lipton, M.A. and Lepinat, A.A. (1946): Proc. Soc. Exp. Biol. (New York) 61:51–54.Google Scholar
- 19.Trabucchi, M., Cheney, D.L., Hanin, I. and Costa, E. (1975): J. Pharmacol. Exp. Ther. 194:57–64.Google Scholar