Adrenergic neurons: are they present on microvessels in cheek pouches of hamsters?

Catecholaminergic innervation was investigated in the cheek pouch, mesentery, and cremaster muscle of the hamster. These tissues were removed from normal hamsters after anesthetization with sodium pentobarbital. They were prepared immediately for visualization of catecholamines by using a glyoxylic acid fluorescent technique. Visualization was accomplished via a Zeiss fluorescent microscope with a 470-nm barrier and a 420-nm excitation filter. No fluorescence was observed in or around the microvessels of the cheek pouch; however, intense fluorescence was demonstrated around and along microvessels in the mesentery and cremaster muscle. Thus, within the limitations of this technique, this study demonstrates that local catecholamines, either as a component of adrenergic neurons or a part of the local tissue milieu, are nondetectable in the microvessels within the cheek pouch as compared to mesenteric and muscle tissue of the hamster.