Time changes in Na+,K(+)-ATPase, Mg(++)-ATPase, and acetylcholinesterase activities in the rat cerebrum and cerebellum caused by stress.
Na+,K(+)-ATPase, Mg(++)-ATPase, and acetylcholinesterase activities were determined in homogenated rat cerebrum and cerebellum in unstressed animals (control) and exposed to cold and immobilization for 45-180 min. Na+,K(+)-ATPase and Mg(++)-ATPase activities were not affected within the first 80 min of stress, while they were increased about 50-70% after 120-180 min, where the maximum enzyme stimulation was observed. However, acetylcholinesterase activity was increased considerably by less than 45 min of stress and reached a plateau in 80-180 min to a higher value in the cerebrum (approximately equal to 100%) than in the cerebellum (approximately equal to 40%) related to the control. Our results suggest that: a) The stress used can stimulate acetylcholinesterase in a different way and more quickly than Na+,K(+)-ATPase and Mg(++)-ATPase; b) acetylcholinesterase in the cerebellum is stimulated to a lower level than in the cerebrum by stress, probably because of the presence of a relatively small cerebellar cholinergic innervation.
Department of Experimental Physiology, University of Athens Medical School, Greece.
S
S
Tsakiris
A N
AN
Kontopoulos
D000109:Acetylcholine / Q000502:physiology; D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002531:Cerebellum / Q000201:enzymology*; D003345:Corticosterone / Q000378:metabolism; D000242:Cyclic AMP / Q000502:physiology; D008297:Male; D009474:Neurons / Q000201:enzymology; D009638:Norepinephrine / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013312:Stress, Physiological / Q000201:enzymology*; D013564:Sympathetic Nervous System / Q000502:physiology; D013997:Time Factors
D000242:Cyclic AMP; D000110:Acetylcholinesterase; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D000109:Acetylcholine; D003345:Corticosterone; D009638:Norepinephrine