ON INNERVATION OF ARTERIO-VENOUS ANASTOMOSES

The innervation of the glomera caudalia of the rat was studied by fluorescence technique for the demonstration of monoamines, the acetyicholinesterase reaction and myelin staining methods. Thin nerve fibres exhibiting only weak acetyicholinesterase activity become more clearly visible when additionally stained with methylene blue. The glomus caudale is not only innervated by a cholinergic network but also - as could be expected from physiological data - by an adrenergic plexus of similar density. The densest innervation is found in that part of the glomus which is characterized by the presence of epitheloid cells. Furthermore cholinergic and some myelinated nerve fibres originating from nerves beside the A. caudalis media run to this part of the glomus. The hypothesis of a central regulation of the terminal vascular bed is discussed. Attention is directed to the possibility of an additional local regulation by histamin derived from large numbers of mast cells found in the adventitia of the epitheloid cell-containing part of the glomus. © 1969 Springer-Verlag.