Beta1-adrenergic agonist is a potent stimulator of alveolar fluid clearance in hyperoxic rat lungs.
Because it was still uncertain whether a stimulation of beta1-adrenoceptors accelerated alveolar fluid clearance in hyperoxic lung injury, the effect of denopamine, a selective beta1-adrenergic agonist, on alveolar fluid clearance was determined in rats exposed to 93% oxygen for 48 and 56 h. Alveolar fluid clearance was measured by the progressive increase in the concentration of Evans blue labeled albumin instilled into the alveolar spaces over 1 h at 37 degrees C in isolated rat lungs. The principle results were as follows: 1) Although lung water volume increased in rats exposed to hyperoxia for 48 and 56 h, basal alveolar fluid clearance did not change for up to 56 h; 2) Denopamine increased alveolar fluid clearance in rats exposed to hyperoxia as well as in rats without exposure to hyperoxia; 3) Denopamine primarily increased amiloride-insensitive alveolar fluid clearance in rats exposed to hyperoxia; 4) The potency of denopmaine was similar to that of terbutaline, a selective beta2-adrenergic agonist. In summary, denopamine is a potent stimulator of alveolar fluid clearance in rats exposed to hyperoxia.
Sakuma
T
T
Department of Thoracic Surgery, Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa, Japan. sakuma-t@kanazawa-med.ac.jp
Hida
M
M
Nambu
Y
Y
Osanai
K
K
Toga
H
H
Takahashi
K
K
Ohya
N
N
Inoue
M
M
Watanabe
Y
Y
D058665:Adrenergic beta-1 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001826:Body Fluids; D004983:Ethanolamines / Q000494:pharmacology*; D018496:Hyperoxia / Q000503:physiopathology*; D008297:Male; D011650:Pulmonary Alveoli; D051381:Rats; D017207:Rats, Sprague-Dawley; D013726:Terbutaline / Q000494:pharmacology*
D058665:Adrenergic beta-1 Receptor Agonists; D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D000584:Amiloride; D013726:Terbutaline; C037293:denopamine