THE EFFECT OF PROSTAGLANDIN E1 (PGE 1) ON THE PLASMA-LYMPH BARRIER OF THE HIND LIMB OF RABBITS AND IT S ANTAGONIZATION BY AESCIN AND LNDOMETHACIN

Abstract

kg/min PGE1 for 15 min increased the lymph flow
by between 13% and 81% for up to 45 min after
the infusion, as measured at the piarna-lymph barrier
of the hind limbs of rabbits. The lymph flow
normalized after 105 min. The ED50 for PGE 1
15 min after infusion was 19 ng/kg/min. PGE 1 did
not influence the permeation of macromolecules
(PVP, proteins) from plasma to lymph. With a dose
of 50 ng/kg/min severe side-effects appeared. The
dose of 25 ng/kg/min did not produce any haemodynamic
effects.
Intravenous injections of 0.25 to 0.8 mg/kg of aescin
or 2.5 to 20 mg/kg of indomethacin reduced the increased
lymph flow, obtained by injecting 25 ng/kg/
min of PGE" by 45% to 92% and 13% to 68% respectively
for up to 45 min after infusion of PGE1.
The dose of 20 mg/kg i.v. of indomethacin as compared
with 10 mg/kg did not show an increased efficacy
but resulted in severe side-effects. The ED 50
of aescin was 0.29 mg/kg i.v. and that of indomethacin
3.4 mg/kg i.v. 45 min after PGE1 infusion.
According to these results both aescin and indomethacin
had an antagonistic effect on the increased permeability
of the plasma-lymph barrier of the hind
limbs of rabbits ind uced by PGE1.