Mediators Inflamm

The airway epithelium is exposed to alcohol during drinking through direct exhalation of volatized ethanol from the bronchial circulation. Alcohol exposure leads to a rapid increase in the cilia beat frequency (CBF) of bronchial epithelial cells followed by a chronic desensitization of cilia stimulatory responses. This effect is governed in part by the nitric oxide regulation of cyclic guanosine and adenosine monophosphate-dependent protein kinases (PKG and PKA) and is not fully understood. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is implicated in the pathogenesis of several pulmonary disorders. We hypothesized that the inhibition of nitric oxide synthase by ADMA blocks alcohol-stimulated increases in CBF. To test this hypothesis, ciliated primary bovine bronchial epithelial cells (BBEC) were preincubated with ADMA (100\ue2\u20ac\u2030 \uc2\ub5M) and stimulated with 100\ue2\u20ac\u2030mM ethanol. CBF was measured and PKA assayed. By 1\ue2\u20ac\u2030hr, ethanol activated PKA, resulting in elevated CBF. Both alcohol-induced PKA activation and CBF were inhibited in the presence of ADMA. ADMA alone had no effect on PKA activity or CBF. Using a mouse model overexpressing the ADMA-degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH), we examined PKA and CBF in precision-cut mouse lung slices. Alcohol-stimulated increases in lung slice PKA and CBF were temporally enhanced in the DDAH mice versus control mice.1U54 OH010162-01/OH/NIOSH CDC HHS/United StatesK08 AA019503/AA/NIAAA NIH HHS/United StatesR00 HL088550/HL/NHLBI NIH HHS/United StatesR01 AA008769/AA/NIAAA NIH HHS/United StatesR01 AA008769/AA/NIAAA NIH HHS/United StatesR01 AA017993/AA/NIAAA NIH HHS/United StatesR01 AA017993/AA/NIAAA NIH HHS/United StatesR37 AA008769/AA/NIAAA NIH HHS/United States24307761PMC383656