Circulation, Vol 65, 924-927, Copyright © 1982 by American Heart Association
WC Reeves, D Cunningham, EJ Schwiter, A Abt, S Skarlatos, MA Wood and L Whitesell
The ability of methylprednisolone (MP) and ibuprofen (IB) to reduce the
severity of the late state of radiation-induced heart disease was assessed
in 57 New Zealand white rabbits. Before and shortly after cardiac
irradiation, 15 rabbits received i.v. MP, 30 mg/kg twice daily for 3 days,
and 15 others received IB, 12.5 mg/kg twice daily for 2 days. No drug was
administered to 14 irradiated rabbits, and neither irradiation nor drugs
were administered to 13 rabbits that served as controls, All 15 rabbits
treated with MP and 13 of the 15 treated with IB lived for 100 days. Only
seven of the untreated, irradiated rabbits lived that long. Longevity of
each treated group of rabbits was better (p less than 0.01 and 0.05) than
that of the untreated, irradiated rabbits. Surviving rabbits were killed
100 days after irradiation. Pericarditis (p less than 0.05) and pericardial
effusion (p less than 0.01) were less frequent in the treated, irradiated
groups than in the untreated, irradiated rabbits. At least some rabbits in
each irradiated group had microscopic evidence of myocardial fibrosis. The
fibrosis was quantitated by determination of myocardial hydroxyproline
concentrations (MHP). MHP concentration in the untreated, irradiated
rabbits was greater than in those treated with MP (p less than 0.05) or IB
(p less than 0.01) and in the untreated, unirradiated rabbits (p less than
0.01). Early administration of MP or IB retarded the development of
myocardial fibrosis, pericarditis and pericardial effusion, and improved
survival in this experimental model of radiation- induced heart disease.
ARTICLES
Myocardial hydroxyproline reduced by early administration of methylprednisolone or ibuprofen to rabbits with radiation-induced heart disease