Lymphoedema, macrophages and benzopyrones.

The role of macrophages in lymphoedema is discussed, with particular reference to post mastectomy lymphoedema. In the latter, the normal course of events is detailed using clinical and experimental evidence. Particular importance is placed on the events of the latent phase since it is during this time that important changes are occurring in the functioning of the blood-tissue-lymph system. These changes are not usually demonstrable clinically until the end of the latent phase when lymphoedema becomes manifest. Evidence suggests that the majority of these changes can be linked with changes in the functioning of the members of the mononuclear phagocytic system. Of particular importance is the disruption to the normal tissue remodelling processes as we know in lymphoedema the delicate balance between the deposition and lysis of collagenous fibres is shifted in favour of deposition--thus fibrosis occurs. The basic mechanisms behind such changes are discussed. A group of drugs, called the benzopyrones have been shown both clinically and experimentally to be of benefit in reducing most forms of high protein oedemas including lymphoedema. It is shown that they can do this by stimulating the rather depressed functioning of the members of the mononuclear phagotic system. The exact mechanism of action of these drugs is discussed with particular emphasis on coumarin which is one of the components of Venalot.