The Annals of Thoracic Surgery, Vol 57, 652-656, Copyright © 1994 by The Society of Thoracic Surgeons
Effect of methylprednisolone on angiogenesis in syngeneic rat tracheal grafts
DE Smith, TK Waddell, KN DeCampos, AS Slutsky and GA Patterson
Department of Surgery, University of Toronto, Ontario, Canada.
Airway anastomotic complications remain a cause of morbidity after clinical
lung transplantation. The use of corticosteroid therapy to control
pulmonary rejection has raised concern over delayed airway healing. We
therefore investigated the hypothesis that the effects of
methylprednisolone (MP) impair the revascularization and epithelial
regeneration of heterotopic syngeneic tracheal isografts. Lewis rat
tracheal segments were wrapped in omentum and implanted in the abdomen of
recipient rats. All recipients received cyclosporin A (CsA) (5 mg.kg-
1.day-1) and were randomly allocated into three groups of 12 rats each
according to the daily MP dose: group II, no MP; group III, 1 mg.kg-
1.day-1; and group IV, 2 mg.kg-1.day-1. In each group, 6 animals were
sacrificed after 7 and 14 days. Normal, untreated rats served as controls
(group I). Epithelial regeneration was assessed histologically by a blinded
subjective scoring system and by measurement of epithelial thickness.
Tracheal revascularization was quantitated in terms of the number of blood
vessels per square millimeter of tracheal wall and the vessel area was
quantitated in terms of the percentage of the tracheal wall area. In
animals treated with MP and CsA, the trachea exhibited significantly better
regeneration after 14 days than it did in animals treated only with CsA.
Epithelial regeneration was improved between 7 and 14 days in the groups
treated with MP (group III, p = 0.01; group IV, p = 0.04). The epithelial
thickness for all three study groups was significantly greater than that in
the control group and returned toward normal after 14 days.(ABSTRACT
TRUNCATED AT 250 WORDS)
