Fine structural aspects of lymphoedema in various tissues and the effects of treatment with coumarin and troxerutin.

The fine structural changes produced by lymphoedema, and by its treatment by coumarin and rutin were studied in the facial skin, parotid glands, ciliary bodies and cerebral cortices of rats, after the ligation of their cervical lymphatics. Both the true initial lymphatics (in the first two sites) and the prelymphatics (in the other two) behaved similarly, as did the tissue around them. There was much protein and oedema fluid during lymphoedema, which were markedly reduced by the drugs, separately and in combination. The very dilated lymphatics in the facial skin had many open endothelial intercellular junctions: the better supported ones in the parotid did not dilate so much and had no open junctions, although they normally possess some. It is suggested that the raised intralymphatic pressures, plus the smaller amount of dilatation permitted in this site, caused the junctions to be sealed closed. Fenestrae seemed to have little effect on the amount of lymphoedema, nor did it appear to affect their numbers.