Seasonal variations in acetylcholine content and the levels of cholinergic enzymes in the alimentary tract and heart of Rana esculenta L.
The acetylcholine (ACh) content and the relative levels of choline-acetyltransferase (ChAT) and acetylcholinesterase (AChE) were measured in the stomach and intestinal musculature and in the heart muscles of frogs (Rana esculenta L.) during hibernation (January-stage 1), low activity (April-stage 2) and high activity period (July-stage 3). The ACh content doubled in the stomach from stage 1 to 2, then little change occurred. In the intestine, the ACh content changed little during the stages, while slightly decreased levels were found in the heart from stage 1 to 3. A significant increase in the level of ACh was found in the brain during the entire period. The level of ChAT increased in all tissue samples during the time. The AChE level was not significantly different during the stages in the stomach and intestine. In the heart, a 2.5 fold increase was measured in April compared with January, followed by a sharp decrease to half of the April level by July. In the brain, the activity of this enzyme increased continuously from January to July. The results show that these important cholinergic parameters change differentially in different organs in this poikilotherm animal during the year, presumably resulting in a fine control of the viscera, probably in cooperation with other autonomic transmitter systems.
Gábriel
R
R
Department of Zoology, Attila József University, Szeged, Hungary.
Budai
D
D
D000109:Acetylcholine / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D006605:Hibernation / Q000502:physiology*; D006706:Homeostasis; D007413:Intestinal Mucosa / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011898:Ranidae / Q000378:metabolism*
D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase; D000109:Acetylcholine