Hypoxia increases bromodeoxyuridine labeling indices in bovine neonatal pulmonary arteries.

摘要: Thickening of peripheral pulmonary arteries (PA) in the hypertensive neonate has been well described morphologically, but less is known regarding role cell proliferation either normal or neonatal PA. Thus we studied DNA synthetic indices tunica media and adventitia four different sizes/generations PA normoxic calves (n = 15) exposed to hypobaric hypoxia during first 14 days life. were determined by incorporation thymidine analogue bromodeoxyuridine (BrdU). Hemodynamic studies confirmed a steady decline pressure 2 wk life progressive hypertension hypoxic group. Lungs perfusion-fixed evaluated for BrdU immunohistochemistry. (BrdU-labeled cells/1,000 cells) from highest between 4 7 postpartum decreased their lowest levels day 14. The observed smaller generations newborn. Adventitial cells exhibited same general pattern except that peak occurred earlier, at 1 days. Exposure significantly increased (P 0.001) both adventitia. smaller-generation vessels. These findings indicate fraction traversing S phase (i.e., actively replicating cycle) vasculature transition are initially high compared reported rates hilar adult rats, then decrease after birth. Further, exposure dramatically increases prolongs vascular proliferation. We conclude structural remodeling due partly