[Distribution of catecholamine-containing nerve cells in the walls of the major vessels of the lamprey, Lampetra fluviatilis].

Using histochemical fluorescence technique, two types of adrenergic nervous cells, i.e. small with intense fluorescence and large with weak fluorescence, have been detected in tissues and walls of the main blood vessels in the lamprey Lampetra fluviatilis. The first type of cells is distributed along the whole vascular net concentrating mainly in branching nodes. The second type of cells was found only in the adventitial layer of the dorsal aorta and intestinal artery. Adrenergic nervous cells are also present in the walls of the main veins. Possibility of presence of catecholamines of different nature in the bodies of the nerve cells is discussed.