Vsnmr. Karamsetty et al., THE EFFECTS OF CHRONIC HYPOXIA ON THE PHARMACOLOGICAL RESPONSIVENESS OF THE PULMONARY-ARTERY, Pharmacology & therapeutics, 68(2), 1995, pp. 233-246
Chronic hypoxia (CH) is associated with several cardiopulmonary disord
ers. In vitro and in vivo studies have established the morphological c
hanges, but yielded conflicting results about the functional changes i
nduced by CH in the pulmonary vascular bed. CH increases the responsiv
eness to endothelium-dependent vasodilators in perfused lungs; however
, in artery rings, a reduction is found in endothelium-dependent vasod
ilation. In CH, vasoconstriction induced by endothelin-l is enhanced a
nd vasodilation produced by atrial natriuretic peptide and Kf channel
openers is increased. Vasoconstriction produced by acute hypoxia can b
e either enhanced or reduced by CH, depending on the experimental prot
ocol. An understanding of the functional changes associated with CH is
particularly important for a rational approach to the treatment of di
sorders associated with CH.