AJP - Endocrinology and Metabolism, Vol 248, Issue 1 70-E74, Copyright © 1985 by American Physiological Society
Effects of prior adrenalectomy on postpneumonectomy lung growth in the rat
R. A. Bennett, P. C. Colony, J. L. Addison and D. E. Rannels
The effects of adrenalectomy, with and without subsequent glucocorticoid
replacement therapy, on postpneumonectomy compensatory lung growth in the
rat were investigated. Male Sprague-Dawley rats (200-230 g) were subjected
to no operation (UNOP), left pneumonectomy (PNX), or PNX preceded by
bilateral adrenalectomy 5 days earlier (ADX/PNX). At 14 days post-PNX, when
compensatory lung growth is normally complete in 200-g rats, right lung
(RL) dry weights of PNX (263 +/- 6 mg, n = 26) and ADX/PNX (334 +/- 13 mg,
n = 25) rats were increased 58 and 101%, respectively, relative to UNOP
controls (166 +/- 5 mg, n = 10). Increases in total DNA, RNA, and protein
in the right lungs of PNX and ADX/PNX rats occurred in proportion to RL dry
mass. The increase in all parameters examined in PNX and ADX/PNX rats at 7
days post-PNX was half that at 14 days, indicating linear lung growth in
both treatment groups. The stimulatory effect of ADX on lung growth was
blocked by hydrocortisone acetate (HCA), administered intraperitoneally in
daily doses of 5 mg/kg, beginning on the day of PNX. The RL dry weights of
HCA-treated ADX/PNX rats (241 +/- 7 mg, n = 10) did not differ
significantly from the corresponding value in PNX rats (270 +/- 14 mg, n =
7). The lower RL weights in the HCA-treated rats resulted from an
inhibition of cell division, as evidenced by the total RL DNA content,
which was similar to that in PNX animals.(ABSTRACT TRUNCATED AT 250 WORDS)
