Temporal dynamics of acute isovolume bronchoconstriction in the rat

Bates, Jason H. T., Thomas F. Schuessler, Carrie Dolman, and David H. Eidelman. Temporal dynamics of acute isovolume bronchoconstriction in the rat. J. Appl. Physiol. 82(1): 55–62, 1997.—The time course of lung impedance changes after intravenous injection of bronchial agonist have produced significant insights into the mechanisms of bronchoconstriction in the dog (J. H. T. Bates, A.-M. Lauzon, G. S. Dechman, G. N. Maksym, and T. F. Shuessler. J. Appl. Physiol. 76: 616–626, 1994). We studied the time course of acute induced bronchoconstriction in five anesthetized paralyzed open-chest rats injected intravenously with a bolus of methacholine. For the 16 s immediately after injection, we held the lung volume constant while applying small-amplitude flow oscillations at 1.48, 5.45, and 19.69 Hz simultaneously, which provided us with continuous estimates of lung resistance (Rl) and elastance (El) at each frequency. This procedure was repeated at initial lung inflation pressures of 0.2, 0.4, and 0.6 kPa. Both R...