Zocchi L, Agostoni E, Cremaschi D
Istituto di Fisiologia Umana I, Università di Milano, Italy.
Respir Physiol. 1995 Apr;100(1):7-13. doi: 10.1016/0034-5687(94)00120-o.
The beta-agonist terbutaline increases the net rate of liquid absorption from hydrothoraces with albumin-Ringer solution: since beta-agonists decrease lymphatic drainage, the effect of terbutaline seems due to an increase in solute-coupled liquid absorption, (Zocchi et al. 1994 Respir. Physiol. 97:347-356). In this research we determined in anesthetized rabbits the rate of volume change in albumin-Ringer hydrothoraces of different size with amiloride plus terbutaline, and compared it with that previously obtained in hydrothoraces with amiloride alone. The net rate of liquid absorption was 0.09 ml/h greater (P < 0.01) with amiloride plus terbutaline than with amiloride alone. This indicates that terbutaline activates an amiloride-insensitive mechanism of Na+ transport. The increase in net rate of liquid absorption produced by terbutaline persisted with bumetanide 10(-6) M and SITS 10(-4) M, disappeared almost completely with bumetanide 10(-5) M, and completely with furosemide 10(-3) M. These findings suggest that the mechanism activated by terbutaline, when the amiloride-sensitive mechanisms of the pleura have been blocked, is a Na(+)-K(+)-2 Cl- or Na(+)-Cl- symport little sensitive to bumetanide.
β-激动剂特布他林可增加白蛋白-林格液对胸腔积液的液体吸收净速率：由于β-激动剂会减少淋巴引流，特布他林的作用似乎是由于溶质耦联的液体吸收增加所致（佐基等人，1994年，《呼吸生理学》97:347 - 356）。在本研究中，我们在麻醉的兔子身上测定了不同大小的白蛋白-林格胸腔积液在使用阿米洛利加特布他林时的体积变化率，并将其与之前仅使用阿米洛利时胸腔积液的体积变化率进行比较。使用阿米洛利加特布他林时的液体吸收净速率比仅使用阿米洛利时高0.09 ml/h（P < 0.01）。这表明特布他林激活了一种对阿米洛利不敏感的Na⁺转运机制。特布他林所产生的液体吸收净速率增加在布美他尼10⁻⁶ M和SITS 10⁻⁴ M时持续存在，在布美他尼10⁻⁵ M时几乎完全消失，在呋塞米10⁻³ M时完全消失。这些发现表明，当胸膜对阿米洛利敏感的机制被阻断时，特布他林激活的机制是一种对布美他尼不太敏感的Na⁺-K⁺-2Cl⁻或Na⁺-Cl⁻同向转运体。
