Cotlier E
Int Ophthalmol. 1979 Feb;1(2):123-8. doi: 10.1007/BF00154199.
Bicarbonate was found to stimulate ATP breakdown by rabbit or cat ciliary body-iris homogenates. Maximum HCO3- stimulation of ATPase with Tris-Hepes buffer occured at pH 8.0. Acid pH and chloride ions in the media reduced the activity of the HCO3--stimulated ATPase. The Km for ATP was 0.55 mmolar and for HCO3-, 20 mmlar. HCO3- ATPase was not inhibited by acetazolamide added to in vitro. It is postulated that ATPase represents the linkage step of energy donor mechanism and active CT secretion in acid aqueous humors (human, cat.) or HCO3- secretion in alkaline aqueous humor (rabbit, guinea pig). Inhibition of Cl- or HCO3- secretion by acetazolamide results from decreased intracellular HCO3- levels which, in turn, reduces the stimulation of the HCO3- ATPase.
发现碳酸氢盐可刺激兔或猫睫状体-虹膜匀浆中的ATP分解。在Tris-HEPES缓冲液中，HCO₃⁻对ATP酶的最大刺激作用发生在pH 8.0时。培养基中的酸性pH值和氯离子会降低HCO₃⁻刺激的ATP酶的活性。ATP的Km值为0.55毫摩尔，HCO₃⁻的Km值为20毫摩尔。体外添加乙酰唑胺不会抑制HCO₃⁻-ATP酶。据推测，ATP酶代表了能量供体机制与酸性房水（人、猫）中活性氯离子分泌或碱性房水（兔、豚鼠）中HCO₃⁻分泌之间的连接步骤。乙酰唑胺对氯离子或HCO₃⁻分泌的抑制作用是由于细胞内HCO₃⁻水平降低，进而减少了对HCO₃⁻-ATP酶的刺激。
