Effects of cigarette smoking on metabolic events in the lung.

Nicotine and cigarette smoke extract show acute physiological effects: increasing tracheal pressure (PTR), pulmonary artery pressure (PPA), systemic blood pressure (PSYST), and left atrium pressure (PLA); and decreasing cardiac output (QAORTA) and blood flow to the left lower lobe (QLLL). In addition, cigarette smoking induces bronchoconstriction, thus decreasing peak flow, FVC, and FEV1.0 in healthy subjects. It has also been demonstrated that cigarette smoking caused temporary slowing of mucociliary clearance in the lung and that cigarette smoke increases the activity of aryl hydrocarbon hydroxylase which metabolizes benzo[alpha]pyrene. We demonstrated that serum angiotensin I converting enzyme (ACE) activity showed a significant increase immediately after smoking and returned to the control level 20 min after smoking. We also demonstrated that plasma histamine levels showed a marked decrease after smoking. Furthermore, the effects of cigarette smoke and related substances on prostaglandin, thromboxane, testosterone, cyclic nucleotides metabolism, and protein synthesis were also investigated.