The advantages of the perfusion system are (1) changes in the vessel diameter can be detected through the use of either a constant flow pump and pressure transducer or a hydrostatic reservoir and the measurement of flow through the vessel, (2) radio labeled substances can be passed through the vessel to study the effects of metabolism, and (3) the release of substances from the lumen of the vessel are passed through the outflow cannula for collection and analysis by HPLC, mass spectroscopy, radioassay or bioassay.

Regarding bioassays, two or more of these systems may be linked together to provide a cascade system to examine certain short-lived substances, depending on the flow rate throughout the system. This should provide valuable aid for research into compounds released by the endothelium, such as adrenal purines, catecholamines, EDRF and various arachidonate metabolites.

It is also possible to perform an experiment, denude the endothelium by appropriate treatment and then retest the specimen for the differences in response. The removable cap perfusion system facilitates easy transfer for silver staining for confirmation of endothelial integrity. 15873