Fixation and tissues preparation method for the localization of monoamine oxidase enzyme activity in lung and in control and transplanted pancreas

A modified method for the localization of monoamine oxidase-(MAO) enzyme activity in cells and fibres of some visceral tissues was described. As a model control and 21-day old embryonic pancreatic tissues fragments transplanted into the anterior eye-chamber of adults rats were used. After 135 days the vibroslice-sectioned slices were incubated in a solution containing tryptamine, nitroblue tetrazolium, sucrose and sodium sulphate. MOA-positive neurons and their processes were observed in the periductal and in intrainsular areas of transplanted and control tissues. MAO-positive mast cells were also detected in the lung. The method may be applied to other tissues as well.