[Monoamine oxidase and acetylcholinesterase activity in the pig's digestive tract in ontogenesis]

To obtain information about the regulating nervous mechanisms of the pig alimentary canal the activity of monoaminooxidase (MAO) and acetylcholinesterase (AChE) in duodenum, jejunum and colon was studied during the embryonal and postnatal growth. The activity of monoaminooxidase was measured manometrically according to the method prepared by Kolb and that of acetylcholinesterase colorimetrically according to Hestrin's method. It was found that the activity of MAO and AChE in different parts of the pig alimentary canal was considerably differentiated during ontogenesis. Presence of these enzymes was already shown in the embryonal period. However, their activity was poor and almost on the same level in all the examined parts of intestines. Rapid increase of activity of both enzymes was immediately after pigs birth at the time between parturition and fifth day of postnatal life. In the later period of life (6-11 days after birth) there was a decrease of activity of both MAO and AChE only in duodenum. But in jejunum and colon there was a further, slight though, increase of the activity of both enzymes. Comparing the activity of MAO and AChE in the individual parts of the mature pig intestine with the embryonal and postnatal periods, it was found that in spite of the considerable increase of activity of both enzymes after birth, their level was smaller than that in the mature animals.