Renal Pharmacology Flashcards
What are the 3 main endocrine functions of the kidney?
- Renin production
- Erythropoietin function and production
- Vitamin D activation and function and the control of calcium and phosphate
What is the function of erythropoietin?
- Controls red blood cell production
Where is erythropoietin mRNA transcribed?
In hypoxic cortical peritubular fibroblasts (fibroblast cells in the cortex surrounding the tubules)
What is erythropoietin gene transcription increased by?
- Hypoxia
- Low iron
- Low haematocrit
HIF - What happens under normal oxygen levels?
HIF-1a contains two prolines which undergoes hydroxylation
Von Hippel-Landau protein binds to the hydroxylated prolines and Ubiquitan Ligase Complex
Protease then is able to destroy this and recycles it.
How is vitamin D produced?
- Skin contains 7-dehydrocholesterol and exposure to sunlight forms cholecalciferol (D3)
- D3 binds to vitamin D binding protein in the blood
- Then goes into the liver where cholecalciferol (D3) is hydroxylated to 25-hydroxycholecalciferol by the enzyme 25-hydroxylase
- Within the kidney: 25-hydroxycholecalciferol is converted to active form 1,24-dihydrocholecalciferol by 1a-hydroxylase.
What is the role of vitamin D?
- Promotes calcium and phosphate uptake from intestinal lumen
- Vital for normal osteoblast and osteoclast activity
- Increases calcium reabsorption from tubules
- Maintains normal serum calcium
- Induces calcium sensor expression on parathyroid glands
- Supresses 1a-hydroxylase and promotes 24-hydroxylase in the kidney
What treatment prevents bone disease and ectopic calcification?
- 1a-hydroxylated VD replacement
- Phosphate restriction
- Phosphate binders
- Calcimemtics
- Parathyroidectomy
What is eGFR calculated from?
Creatinine, age, gender and ethnicity
What are the causes of Chronic Kidney Disease?
- Systemic disease: diabetes, hypertension, atherosclerotic disease
- Immune mediated diseases: membranous nephropathy, IgA nephropathy
- Infectious Diseases: HIV, HBV, HCV, TB
- Genetic diseases: Polycystic kidneys, cystinosis
- Arterial Disease: aterial disease
- Obstruction of the flow of urine: tumours, kidney stones, fibrosis
What is the treatment for fluid overload?
- Loop diuretics
- Salt restriction
- Fluid restriction
- If all else fails, dialysis or transplant
What is the treatment for hyperkalaemia or hypernatraemia?
- Salt restriction
- Potassium restriction
- If all else fails, dialysis or kidney transplant
What is the treatment of metabolic acidosis?
- Sodium biacrbonate
- If all else fails, dialysis or transplant
What is the treatment of hypertension?
- Salt restriction
- Diuretics
- RAS blockade
- Other antihypertensive medication
What is the treatment of uraemia? (lots of protein)
- Dialysis or transplant
- Not protein restriction as can lead to malnutrition
