Requirement of Pretone by Thromboxane A<SUB>2</SUB> for Hypoxic Pulmonary Vasoconstriction in Precision-cut Lung Slices of Rat
Requirement of Pretone by Thromboxane A<SUB>2</SUB> for Hypoxic Pulmonary Vasoconstriction in Precision-cut Lung Slices of Rat
- Su Jung Park Hae Young Yoo Hye Jin Kim Jin Kyoung Kim Yin-Hua Zhang Sung Joon Kim
- 대한생리학회-대한약리학회
- The Korean Journal of Physiology & Pharmacology
- 제16권 제1호
- 등재여부 : KCI등재
- 2012.01
- 59 - 64 (6 pages)
Hypoxic pulmonary vasoconstriction (HPV) is physiologically important response for preventing mismatching between ventilation and perfusion in lungs. The HPV of isolated pulmonary arteries (HPV-PA) usually require a partial pretone by thromboxane agonist (U46619). Because the HPV of ventilated/perfused lungs (HPV-lung) can be triggered without pretone conditioning, we suspected that a putative tissue factor might be responsible for the pretone of HPV. Here we investigated whether HPV can be also observed in precision-cut lung slices (PCLS) from rats. The HPV in PCLS also required partial contraction by U46619. In addition, K<sup>+</sup> channel blockers (4AP and TEA) required U46619- pretone to induce significant contraction of PA in PCLS. In contrast, the airways in PCLS showed reversible contraction in response to the K<sup>+</sup> channel blockers without pretone conditioning. Also, the airways showed no hypoxic constriction but a relaxation under the partial pretone by U46619. The airways in PCLS showed reliable, concentration-dependent contraction by metacholine (EC<sub>50</sub>, ∼210 nM). In summary, the HPV in PCLS is more similar to isolated PA than V/P lungs. The metacholine- induced constriction of bronchioles suggested that the PLCS might be also useful for studying airway physiology in situ.