title: Regional distribution of acetylcholinesterase in the right atria of humans and dogs.
abstract: The regional distribution of acetylcholinesterase in the right atrium was determined by quantitative chemical measurements on hearts obtained from 14 infant and 9 adult humans of autopsy, and 9 adult dogs after termination of acute animal experiments. The atrium and interatrial septum were dissected, and the appendage was cut along its fold from the ventricular border to the superior vena cava. The atrium was cut into 20 consecutive sections. Homogenates (10% w/v) were prepared, centrifuged, and the supernatants were used for the enzyme assay by the method of Ellman. The acetylcholinesterase concentration [AChE] was mapped by section, or the sections were grouped into areas and mapped. The results show that: 1) in the dog, [AChE] is significantly higher in the nodal regions as compared to the appendicular areas, which contain the lowest [AChE]; 2) in the human, the [AChE] distribution pattern is qualitatively similar between the adult and infant, and in contrast to the dog, the appendicular areas contain the highest [AChE]; 3) for all areas studied, human infant [AChE] levels are significantly higher than human adult levels for corresponding areas. It is concluded that there is a distinct species difference between the regional distribution of the [AChE] in human and canine right atrium. Also, within humans, there is an age-related difference in the quantitative [AChE] levels. These species and age-related differences may reflect a varying pattern of distribution of the vagus nerve between the two species studied.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D004285:Dogs; D006325:Heart Atria / Q000032:analysis / Q000033:anatomy & histology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009206:Myocardium / Q000201:enzymology*; D013045:Species Specificity
chemical_list: D000110:Acetylcholinesterase