TOX 300 Lecture Notes - Lecture 19: Dna Repair, Genotoxicity, Xenobiotic
Document Summary
They are all redox active elements, especially arsenic. The carcinogen may undergo a few metabolic steps to become the ultimate carcinogen, one that damages dna. When the initiated cell replicates, that is the progression phase. The mutated dna may have activated the oncogenic proteins and/or inactivated the tumor suppressor proteins: proto-oncogenes becomes an oncogene. Spontaneous dna damage (from uv rays, ros, etc. : the nongenotoxic carcinogen will either promote replication or inhibit apoptosis from occurring. The survival of the mutated dna may have activated the oncogenic proteins and/or inactivated the tumor suppressor proteins. 3 major systems affected: liver hepatotoxicity, kidney nephrotoxicity, lung respiratory tract toxicity. The portal vein brings in blood from the stomach and intestines into the liver. Hepatocytes are arranged in rows w/ sinusoids in between: bile canaliculi are associated w/ the hepatocytes. Hepatic artery brings oxygenated blood to the liver. Kupffer cell = resident macrophages; protects us from pathogens.
