Tissue remodeling of rat pulmonary artery in hypoxic breathing. I. Changesof morphology, zero-stress state, and gene expression

The remodeling of the pulmonary arterial tissue in response to a step chang e of the oxygen concentration in the gas in which a rat lives was recorded as function of time and function of O-2 concentration. Three steps of chang ing rom 20.9% to 17.2%, 13.6%, and 10% O-2 were imposed. Earlier work in ou r laboratory has shown that pulmonary arterial tissue remodeling is signifi cant in the first 24 h after a step change of oxygen tension. Hence we made measurements in this period. Furthermore, data were obtained for tissue re modeling of circumferential and axial lengths of the pulmonary arteries. We recorded the activities of gone expressions in the lung tissues by microar ray, determined the dose response curves of gene expression in the homogeni zed whole lungs with respect to four levels Of O-2 concentration, and obtai ned the time courses of gene expression in the lung parenchyma in 30 days a fter a step decrease Of O-2 concentration from 20.9% to 10%. We would like to suggest that the correlation of gene expression with physiological funct ion parameters, i.e., time, O-2 tension, blood pressure, opening angle, wal l thicknesses, etc., is the way to narrow down the search for specific gene s for specific physiological functions. (C) 2001 Biomedical Engineering Soc iety.