THE REGULATION OF PULMONARY VASCULAR TONE

1 The ability to manipulate pharmacologically pulmonary vascular tone independent of effects on systemic blood vessels is a desirable object ive. Elucidation of the biochemical mechanisms underlying hypoxia-indu ced pulmonary vasoconstriction (HPV) may permit preferential targeting of the pulmonary circulation. 2 Here we review our studies of the rol e of locally synthesized candidate vasoactive factors in HPV. In addit ion, we present data demonstrating an attenuated presser response to h ypoxia in the pulmonary circulation of Fischer 344 rats compared with the Wistar-Kyoto (WKY) rat strain. 3 We propose that a systematic geno me-wide search using the HPV phenotype and a panel of highly informati ve microsatellite markers will elucidate the genetic loci underlying t he difference in susceptibility to HPV in these two rat strains and pr ovide a valuable and novel insight into the factors that determine the HPV response.