Environmental and Nutritional Pathology Flashcards
What is the difference between phase I and phase II reactions?
Phase I:
- Oxidation/ Reduction reactions
- Hydrolysis
- Ex: monooxygenase systems, peroxidase-dependent cooxidation
Phase II:
- Conjugations/ Additions
- Glucuronidation
- Sulfation
- Methylation
What enzyme system converts benzo [a] pyrene (found in tobacco smoke) to an epoxide that covalently binds and damages DNA? What phase reaction is this?
Cytochrome P-450 dependent monooxygenase system
Phase I
Liver
What enzyme system metabolizes Nicotine and other amides? What phase reaction is this?
flavin-containing monooxygenase system
Phase I
Liver
What enzyme system metabolizes naphthylamine to its carcinogenic derivative? (There are two.) What phase reaction?
- Peroxidase- dependent cooxidation
- Phase I
- Catalyzed by prostaglandin-H synthase
- seminal vesicles, kidney, liver
- P-450 followed by glucuronidation
- Phase I and II
- secondary metabolite excreted in urine, carcinogen, causes bladder cancer
What metabolic reaction is used to process inorganic mercury? What is the resulting molecule? What organ systems are affected?
- Biomethylation => methyl mercury
- Organ systems:
- uptake by GI
- crosses BBB (brain damage)
- crosses placenta
How are drugs metabolized by glutathione conjugation excreted?
bile and urine
What carcinogens are present in tobacco and what organs do they affect?
- tar
- aromatic hydrocarbons
- cancer of mouth, larynx, lungs
- N-nitrosonicotine
- cancer of esophagus
- 4-aminobiphenyl and 2-naphthylamine
- bladder cancer
What are the physiological effects of nicotine?
- increased HR and BP
- increased coronary artery blood flow
- Increased cardiac outbut (increased O2 demand)
- Mobilization of FFA
What are the most common diseases associated with smoking?
- Lung Cancer
- emphysema/ COPD
- MI
- Systemic atherosclerosis
What receptors does ethanol act on?
- GABA
- N-methyl-aspartate
- Opioid receptors
How is ethanol metabolized?
- enzyme: alcohol dehydrogenase in gastric mucosa
- end product: acetaldehyde
What are the effects of ethanol on the liver?
- Steatosis
- Peripheral fat catabolism
- Lipid synthesis
- Hepatitis
- Fever, hepatomegaly, and jaundice
- Mallory bodies (fat and hyalin accumulation)
- Cirrhosis
- Path: Necrosis and fibrosis
- Symptoms: muscle wasting, ascites, GI bleed
What does the presence of Mallory bodies in the liver signal?
Acute Alcoholic Hepatitis
(fat and hyaline accumulation)
What are the effects of ethanol on the CNS?
- Cause:
- thiamine (Vit B1) deficiency
- Path:
- Neuronal degeneration
- Cerebellar atrophy
- Syndromes:
- Wernike and Korsakoff syndromes
- Symptoms:
- Ataxia
- Ophthalmoplegia
- Nystagmus
- Amnesia
What are the effects of ethanol on the CV system?
- Cardiomyopathy
- HTN
- From increased release of catecholamines
What are the effects of ethanol on the GI tract?
- Cause
- impaired absorption of nutrients
- Result:
- Gastritis
- Pancreatitis
What are the effects of ethanol on skeletal muscle?
- Rhabdomyolysis from a breakdown of myoglobin
What are the effects of ethanol on the reproductive system?
- Testicular atrophy
- Decreased fertility
- Spontaneous abortion
What types of cancer are caused by ethanol?
- Oral cavity
- Pharynx
- Esophagus
- Breast
- Liver
- esp. in combination with HBV/ HCV
What are the symptoms of Fetal Alcohol Syndrome?
- Growth and mental retardation
- microcephaly
- facial dysmorphology
- malformation of brain, heart, GU tract
- atrial septal defects
What are the metabolites of Methanol? What are the side effects of ingestion?
- Metabolites:
- Formaldehyde
- Formic Acid
- SE
- Metabolic acidosis
- Vomiting
- Blurred vision
- Respiratory distress
What is the treatment for Methanol poisoning?
Ethanol
(competes with alcohol dehydrogenase)
What are the metabolites of Ethylene Glycol? What are the side effects of ingestion?
- Metabolites
- Glyceraldehyde
- Oxalic acid
- SE
- Vomiting
- Seizure
- Renal tubular necrosis
- accumulation of oxalate crystals
What is the treatment for ethylene glycol poisoning?
Ethanol
(competes for aldehyde dehydrogenase)