src: It is believed that there are two mechanisms involved in the injury process caused by smoking, the vasoconstrictor activity promoted by nicotine and the carboxyhemoglobin increase COHb in the blood, being both related to low tissue oxygenation.
tgt: Acredita-se que existam dois mecanismos envolvidos no processo de lesão pelo fumo, a ação vasoconstritora promovida pela nicotina e o acréscimo de carboxihemoglobina COHb no sangue, estando ambas relacionadas à baixa oxigenação tecidual.