[Enzymhistochemical investigations on the hypothalamo-neurohypophysial system of unmilked and milked cows (author's transl)].

The behaviour of several dehydrogenases(succino-, beta-glycerophosphate-, lactate-, alcohol-, beta-hydroxibutyric acid-, glucose-6-phosphate-, isocitronic acid-dehydrogenase, monoamino-oxidase, and gamma-aminobutyric acid-transaminase) and of several hydrolytic enzymes (non-specific esterase, lipase, acetylcholin-, butyrylcholinesterase, alkaline phosphatase and leucinaminopeptidase) was investigated in the neurons of NSO and NPV, in the infundibulum and in the neurohypophysis and the innervation of the neurons (acetylcholinesterase, monoamino-oxidase, catecholamines) by unmilked and milked cows. The milking stimulus influences the metabolism especially in the neurosecretory cells of the NPV. After the milking stimulus the activity of oxydative enzymes is above all very increased, the anaerobic way of the output of energy is after that also higher. The building up of the carbohydrates through glycolyse in the neurosecretory cells of the NPV after the milking stimulus is increased. The possible participation of the investigated hydrolytic enzymes on the metabolism of the neurosecretory cells is discussed. The neurons of the NPV were innervated for the most part adrenergic. It is discussed the participation of the enzymes succinodehydrogenase and monoaminooxidase on the hormone release in the neurohypophysis.