Lack of response to all-trans retinoic acid supplementation in adult dogs following left pneumonectomy.
We showed previously that removing 55-58% of the lung by right pneumonectomy (R-PNX) in adult dogs triggers compensatory growth of the remaining lung, but removing 42-45% of the lung by left PNX (L-PNX) does not. We also showed that, following R-PNX, supplemental all-trans retinoic acid (RA) selectively enhances alveolar capillary endothelial cell volume (Yan X, Bellotto DJ, Foster DJ, Johnson RL, Jr., Hagler HH, Estrera AS, and Hsia CC. J Appl Physiol 96: 1080-1089, 2004). We hypothesized that RA supplementation might enhance compensation following L-PNX and tested this hypothesis by administering RA (2 mg.kg(-1).day(-1), 4 days/wk) or placebo orally to litter-matched adult foxhounds for 4 mo following L-PNX. Resting lung function was measured under anesthesia. Air and tissue volumes of the remaining lung were assessed by high-resolution computed tomography scan and by detailed postmortem morphometric analysis of the fixed lung. There was no significant difference in resting lung function, lung volume, alveolar structure, or septal ultrastructure between RA and placebo treatment groups. We conclude that RA supplementation does not induce post-PNX compensatory lung growth in the absence of existing cellular growth activities initiated by other primary signals.
Yan
Xiao
X
Pulmonary and Critical Care Medicine, Dept. of Internal Medicine, 5323 Harry Hines Blvd., Dallas, TX 75390-9034, USA.
Bellotto
Dennis J
DJ
Dane
D Merrill
DM
Elmore
R Geoffrey
RG
Johnson
Robert L
RL
Estrera
Aaron S
AS
Hsia
Connie C W
CC
D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D004285:Dogs; D008176:Lung Volume Measurements; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D011013:Pneumonectomy; D011650:Pulmonary Alveoli / Q000187:drug effects* / Q000254:growth & development* / Q000502:physiology; D011652:Pulmonary Circulation / Q000187:drug effects; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed; D014212:Tretinoin / Q000494:pharmacology*
D000970:Antineoplastic Agents; D014212:Tretinoin