It has been suggested that
estrogen-
progestagen therapy may be useful in preventing
bleeding from gastric
angiodysplasia, a vascular lesion similar to that described in portal-hypertensive gastropathy. In this study we assessed the effects of
estrogen-
progestagen therapy on gastric microcirculation and systemic and splanchnic hemodynamics in portal-hypertensive and
sham-operated rats. One week after the
surgical procedure (partial portal vein
ligation or
sham surgery), animals were given an
intramuscular injection of a slow-release preparation of
estrogen-
progestagen or its vehicle. Two weeks later, gastric mucosal blood flow was measured by means of
hydrogen gas clearance, a morphometrical analysis of gastric mucosal blood vessels was performed and systemic and splanchnic hemodynamics were evaluated with a radiolabeled-
microspheres technique. In portal-hypertensive rats,
estrogen-
progestagen therapy induced a significant reduction in gastric mucosal blood flow, number of blood vessels and relative area of vessels. Similar changes, although of lesser magnitude, were achieved with
estrogen or
progestagen given separately and with the low dose of combined
estrogen-
progestagen.
Estrogen-
progestagen treatment also induced significant reductions in portal pressure and porto-collateral resistance without changing systemic or splanchnic hemodynamics. In contrast,
estrogen-
progestagen treatment did not induce changes in any of the parameters studied in
sham-operated rats. We conclude that long-term
estrogen-
progestagen therapy reduces the gastric
hyperemia, increased mucosal vessel density and portal pressure in portal-hypertensive rats.