ELECTRON MICROSCOPY OF THE EFFECTS OF UNGUENTUM LYMPHATICUM ON ACUTE EXPERIMENTAL LYMPHEDEMA AND VARIOUS HIGH-PROTEIN EDEMAS

Abstract

Rats' legs and feet were studied by qualitative and
quantitative electron microscopy, including massdensitometry
of protein in the tissues and in the
initial lymphatics. The tissues were either normal ,
or had been made edematous by lymphostasis,
moderate burns, or dextran. It was found that
Unguentum lymphaticum very greatly reduced the
amount of edema in the legs with lymphostasis.
Since the concentrations of plasma protein in the
tissues and initial lymphatics, and its total amounts
in the tissues were all greatly reduced, it appears
that the cream's anti-lymphedematous activity is
via a removal of the excess protein. Since the macrophages
were greatly increased in number by the
cream (and previous work shows that selectively
poisoning these cells prevents much of the cream's
effectiveness in lymphedema). very probably it is
this increase in their numbers (and possibly their
individual proteolytic activities) which is how the
cream causes the removal of the excess protein -
via an increased proteolysis. The cream also causes
an increase in the amount of edema in the rat-foot
(after all the injuries, including lymphedema) ; however
the concentration and amount of protein in the
tissues is reduced . This is consistent with an inflow
of low protein fluid , caused by a vaso-dilatation of
the blood microcirculation of this rather specialized
tissue. All of these characteristics are very similar to
those of many of the benzo-pyrone group of drugs.