Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 211-219).

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 112-122).

Thesis--Ph. D., University of Hong Kong, 1980.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 149-171). / Microfiche. / xvi, 171 leaves, bound ill. 29 cm

Thesis (Ph.D.)--University of Hong Kong, 2001. / Includes bibliographical references. Also available in print.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 118-137).

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In the pulmonary circulation, alveolar hypoxia contributes to blood flow regulation. Hypoxic pulmonary vasoconstriction (HPV) involves both pulmonary arteries and veins, but little is known of the contractile mechanisms specific to the veins. The aim of these studies was to examine the hypoxic response in small porcine intrapulmonary veins in relation to the arterial response, and investigate the effects of hypoxia on ion conductances in single myocytes from intrapulmonary veins. In wire myography experiments, intrapulmonary veins contracted more than sizematched arteries in response to hypoxia and agonists KCl and PGF2α. Venous contractions were inhibited by removal of extracellular Ca2+ or in the presence of Clchannel blocker NFA, effects not seen in the arteries. To examine the mechanisms of venous contraction at cellular level, single pulmonary vein smooth muscle cells (PVSMC) were freshly isolated and characterised morphologically and electrophysiologically for the first time. In patch-clamp studies, hypoxia reversibly inhibited a whole-cell outward current in the presence of BKCa channel antagonist Penitrem A. By subtracting currents recorded in normoxia and hypoxia, a novel hypoxia-sensitive K+ current (IK(H)) was revealed in PVSMC. IK(H) was a rapidly activating, partially inactivating current and was sensitive to KV channel blocker 4-AP. The biophysical properties of IK(H) revealed the voltage window of current availability with a peak near the resting membrane potential of PVSMC. In conclusion, these findings highlight differences between the contractile properties of veins and arteries and reveal a significant contribution of Ca2+ influx and an NFA-sensitive conductance during venous contraction to agonists and hypoxia. Furthermore, the results suggest that a novel hypoxia-sensitive KV current contributes to membrane potential under resting conditions in PVSMC and its inhibition by hypoxia may contribute to the initiation of HPV in porcine intrapulmonary veins.