The acute effect of NO synthase (NOS) inhibition on pulmonary arteriolar tone was assessed in a transgenic mouse model (TgAD) of AD (C57BL/6‐Tg(Thy1‐APPSwDutIowa)BWevn/Mmjax) and age‐matched wild‐type controls (C57BL/6J). This evidence concerns the gene THY1 and Alzheimer disease.