Biochem 2 Quiz 2 Review Sheet (No Topic List) PDF

Kidney Osmolality Equation ○ (1.86 * [Na+]) + [Glucose]/18 + [BUN]/2.8 + 9 = Osm/L Both Creatinine and BUN should be elevated to the SAME degree if there is a kidney problem Increase in Urea without increase in Creatinine (Prerenal Azotemia) ○ Decreased renal blood flow...

Kidney Osmolality Equation ○ (1.86 * [Na+]) + [Glucose]/18 + [BUN]/2.8 + 9 = Osm/L Both Creatinine and BUN should be elevated to the SAME degree if there is a kidney problem Increase in Urea without increase in Creatinine (Prerenal Azotemia) ○ Decreased renal blood flow CHF, shock, decreased renal blood volume ○ Increase protein catabolism High protein diet Fever, upper GI bleeding ○ Dehydration Urea moves with water: less water excretion → less urea excretion Jaffe Reaction ○ Creatinine + Alkaline picrate → Red-orange ○ False increase: Hemolysis, ketones, glucose, proteins, ascorbic acid ○ False decrease: Icterus Kinetic Jaffe ○ Measures rxn rate ○ MORE specific ○ ONLY ketones interfere Acute Glomerulonephritis ○ Rapid onset Inflammation to GAS, drug toxicity, SLE Hypertension, edema ○ Urine lab findings Hematuria Proteinuria ○ Plasma lab findings Increased: Creatinine, Urea, K+ Decreased Na+, CO2, Albumin  Chronic Glomerulonephritis ○ Slow onset inflammatory response**** ○ May be asymptomatic (only slightly decreased GFR) ○ Urine lab findings Slight hematuria Proteinuria ○ Plasma lab findings Increased: Urea, creatinine ○ Gradual hypertension, renal failure with lab findings similar to acute form Nephrotic Syndrome ○ Increased Glomerular basement membrane permeability ○ Generalized Edema ○ Urine lab findings SEVERE proteinuria ○ Plasma lab findings Increased: Alpha-2-globulins (AMG), Total Cholesterol, Triglycerides Decreased: Albumin and Alpha-1-globulins What hormones control water regulation and homeostasis? ○ Antidiuretic hormone (ADH) Released in distal convoluted tubule Released in collecting ducts, increases water reabsorption Released from posterior pituitary in response to increased plasma osmolality amd decreased intravascular volume Increases permeability of distal convoluted tubules and collecting ducts to water, causing increased water reabsorption Increased plasma osmolality → Thirst and increased ADH secretion Increased [urine] osmolality Decreased urine output Decreased plasma osmolality → decreased ADH secretion Decreased [urine] osmolality  Increased urine output Diabetes insipidus (neurogenic) → decreased ADH secretion/action → Dehydration ○ Aldosterone (ALD) Released by distal convoluted tubule Increases Na+ reabsorption; K+ and H+ secretion Regulation by RAS (regulates BP) Decreased plasma Na+ and blood flow → Increased ALD secretion Renin-Angiotensin: Regulate blood pressure and ALD secretion. Decreased BP → Increased ALD Potassium: Reabsorbed and excreted by distal convoluted tubule and collecting ducts; excretion controlled by aldosterone ○ Renin Regulates ALD secretion. Decreased BP → Increased RAS → Increased ALD Renin catalyzes synthesis of angiotensin Sodium: Controlled primarily by renin-angiotensin-aldosterone hormonal system, excreted from kidney ○ Erythropoietin RBC production Chronic renal failure → anemia Acts on erythroid progenitor cells in bone marrow, increasing number of RBCs ○ 1,25-Dihydroxy vitamin D3 Active form of vitamin D Determines phosphate and calcium balance and bone calcification ○ Prostaglandins Increase renal blood flow, sodium and water excretion, and renin release; oppose renal vasoconstriction Creatinine  ○ Waste product in creatine phosphate (high energy source) production. Measured to assess renal function. Is proportional to muscle mass. Can be used for TDM, and Delta check ○ Enzymatic methods Creatinase, creatine hydrolase Increased specificity compared to both Jaffes ○ False Increase Hemolysis, ketones, glucose, protein, ascorbic acid (Jaffe) Ketones (Kinetic Jaffe) ○ False Decrease: Icterus ○ Reference Range: 0.6-1.1 mg/dL ○ Increased: ERSD (plasma) ○ Corrected Creatinine Clearance Cu/Cs * Total volume/1440 * 1.73/Surface area Blood Urea Nitrogen (BUN) ○ End product of protein catabolism: AA → NH3 → Urea cycle → Urea ○ Increased urea = Azotemia → uremia ○ Methods Urease Urea → NH4+ + HCO3- Coupled enzyme reaction NADH → NAD+ (rate of disappearance of NADH measured) Indicator dye (ammonia + pH indicator) Conductimetric ○ Interferences Increased ammonia: Increased blood ammonia, contaminated reagents, glassware, water ○ Specimen Serum, plasma, pre-diluted urine No anticoag that inhibit urease (no NaF, Na-citrate) ○ Reference range: 6-23 mg/dL Uric Acid  ○ End Product in purine metabolism. Dietary and endogenous nucleic acids. Liver converts purines → uric acid ○ Methods Uricase Uric acid + O2 → allantoin + CO2 + H2O2 Couple enzymatic H2O2 + Reduced chromogen (colorless) →Oxidized chromogen (colored) + H2O ○ Interferences****** False decrease: Bilirubin, ascorbic acid ○ Increased: Gout: urates precipitates in joint fluids, renal calculi. Males 30-50 years. Primary causes: Increased purine production Secondary causes: Alcohol and drugs, increased dietary intake Increased cell breakdown: Chemotherapy, leukemia Chronic renal disease: Uric acid excretion ○ Decreased: Fanconi syndrome: Defective tubular reabsorption Electrolytes Osmotic pressure**** ○ Maintained by Na primarily Osmolal gap ○ Measured - Calculated ○ RR: < 10 mOsm/kg ○ Increased osmolal gap indicates unmeasured substance is present Alcohol, ketone Anion gap ○ Difference between unmeasured anions and unmeasured cations: (Na + K) - (Cl + HCO3/CO2) (10-20 mmol/L) (Na) - (HCO3/CO2 + Cl) (7-16 mmol/L)  ○ Increase: Increased unmeasured anions OR decrease unmeasured cations Increased anion gap metabolic acidosis Methanol Uremia DKA Paraldehyde Iron, Isoniazid, ibuprofen Lactic acidosis Ethylene glycol, ethanol Salicylates ○ Decreased: Decreased unmeasured anions OR increased unmeasured cations Hypoalbuminemia, hypergammaglobulinemia Different membranes ○ Na+ Na ionophore Na sensitive glass ○ K+ Valinomycin ○ Cl- Solid-state- AgCl2 or Ag Sulfide (Halogen) ○ Interference: Protein build-up Bicarbonate/carbonic acid ○ MOST IMPORTANT BUFFERING PAIR ○ Total CO2 Bicarbonate (95%) Dissolved CO2 (5%) Carbonic acid =