Target Organ Toxicity Flashcards
why is the liver so susceptible to toxicity arising from xenobiotic exposure?
lots of metabolism; lots of perfusion; enterohepatic cycling; first pass effect; binding proteins; active transport pumps; high rates of cell mitosis;
what is BUN?
blood urea nitrogen– increased urea in blood indicates reduced GFR
what is GFR?
glomerular filtration rate
3 regions of the respiratory system
nasal passages; conducting airways (trachea and bronchi); gas exchange region (alveoli)
sources of lung damage
oxidative stress (ozone–from motor vehicle exhaust); gases and vapours; particles and aerosols
what is PM2.5
particulate matter less than 2.5 um – associate with human respiratory tract toxicity– including death
What are the toxic responses of the liver?
steatosis; necrosis; cholestasis; cirrhosis; carcinogenesis
what is steatosis?
fatty liver; >5% fat accumulation in liver; can be due to chronic or acute exposure; reversible; –>e.g ethanol (binge drinking or chronic drinking); c
what is the clinical marker of steatosis?
serum triglycerides (storage form of lipids);
what is necrosis?
focal (central, midzone, or peripheral) or massive (throughout the river); usually acute exposure; irreversible; involves decreased ATP or altered Ca regulation;
what are some examples of liver necrosis-causing agents?
acetominophen (Tylenol); produces active quinonamine– produces ROS; CCl4 (carbon tetrachloride); liquid at R; disinfectant
what is a biomarker for liver necrosis?
gamma glutamyl transpeptidase; GGT in blood plasma
what is cholestasis of the liver?
canicular cholestasis–decreased bile formation and biliary secretion;
symptoms of liver cholestasis?
jaundice–>due to excess bilirubin in blood
examples of xenobiotics that cause liver cholestasis?
ethanol, certain metals, steroids, certain drug
clinical marker of liver cholestasis?
GGT and plasma bilirubin