Lymphatic collecting ducts are thin walled valved vessels which contract spontaneously and propel lymph by means of these
regular well coordinated contractions. They have a sympathetic noradrenergic innervation stimulation of which increases their frequency of contraction and thus increases lymph flow. In
addition to the alpha receptors which mediate this excitatory response, lymphatic smooth muscle also has beta receptors,
stimulation of which inhibits flow by decreasing the frequency and force of spontaneous contractions. This project seeks to make the first detailed study of the mechanism of these responses. The expertise of three European laboratories will be combined to apply modern biophysical and biochemical techniques to
elucidate: the properties and distribution of the membrane
receptors; the nature of the coupling of these to intracellular second messengers and; the way in which the latter mediators affect the vessel's electrical and mechanical responses.
The results should be invaluable in furthering our understanding of this very important but little understood circulation and for providing a rational basis for the design of drugs to drugs to control the lymph pump.