Hormone
Hormone
Hormone
Parathyroid Hormone
  • Protein hormone produced by chief cells of the parathyroid gland
  • Secretion stimulated by a decrease in serum calcium levels
  • Normal levels are 1.3 – 6.8 pmol/L
  • Acts to increase serum calcium and decrease serum phosphate levels through a number of mechanisms:
  • Kidney: Increases calcium reabsorption
  • Bone: Mobilises calcium from bone stores by stimulating osteoclast activity and inhibiting osteoblast activity
  • GI Tract: Increases GI absorption of calcium and phosphate indirectly by production active vitamin D metabolites