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With the use of isolated perfused rabbit lungs (n = 152), roles of endothelium-derived relaxing factor (EDRF) in pulmonary vascular responses to hypocapnia and hypercapnia were studied. Lungs were ventilated with a gas mixture containing 1, 5, or 10% CO2 and 21% O2, adjusting the perfusate pH to 7.8, 7.4, or 7.1, respectively. Methemoglobin (MetHb), hemoglobin (Hb), methylene blue (MB), and L-argininosuccinic acid (L-ASA) were used as modulators of EDRF. To eliminate augmented shear stress, we used papaverine during hypercapnia. As a measure of EDRF, we spectrophotometrically examined nitric oxide (NO) metabolites in the perfusate. Hypocapnia and hypercapnia evoked, respectively, unsustainable vasodilatation and vasoconstriction. Hb, MB, and L-ASA, but not MetHb, produced an increase in baseline pulmonary arterial pressure (Ppa). These agents also exacerbated vasoconstriction during hypercapnia. Hypercapnia and hypocapnia caused an increase and decrease, respectively, in EDRF production. L-ASA suppressed EDRF production in hypercapnic lungs. Papaverine did not suppress EDRF production under hypercapnia. In conclusion, 1) the effects of pH on pulmonary circulation are transient, 2) the increase in Ppa caused by hypercapnia is modulated by EDRF, and 3) the pulmonary EDRF genesis is activated by hypercapnic acidosis but suppressed by hypocapnic alkalosis.
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
January 1968,
Acta physiologica Scandinavica,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
January 1993,
Fundamental & clinical pharmacology,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
October 1991,
The American journal of physiology,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
May 2002,
Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
January 1983,
Lung,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
September 1973,
The Journal of pharmacology and experimental therapeutics,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
January 1992,
Journal of applied physiology (Bethesda, Md. : 1985),
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
April 1991,
The American review of respiratory disease,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
October 2000,
Respiration physiology,
K Yamaguchi, and
T Takasugi, and
H Fujita, and
M Mori, and
Y Oyamada, and
K Suzuki, and
A Miyata, and
T Aoki, and
Y Suzuki
April 1995,
European journal of pharmacology,
