calcitriol

Examples of calcitriol in the following topics:

• Intracellular Hormone Receptors

  • For example, the active vitamin D metabolite, calcitriol, mediates its biological effects by binding to the vitamin D receptor (VDR), which is principally located in the nuclei of target cells.
  • The binding of calcitriol to the VDR allows the VDR to act as a transcription factor that modulates the gene expression of transport proteins that are involved in calcium absorption in the intestine.

• Bone and Calcium Homeostasis

  • Part of the calcidiol is converted by the kidneys to calcitriol, the biologically active form of vitamin D.

• Dialysis

  • The kidneys also function as a part of the endocrine system, producing erythropoietin and calcitriol.
  • Erythropoietin is involved in the production of red blood cells and calcitriol plays a role in bone formation.

• Hormonal Control of Blood Calcium Levels

  • PTH triggers the formation of calcitriol, an active form of vitamin D, which acts on the intestines to increase absorption of dietary calcium.

• Parathyroid Glands

  • Finally, PTH stimulates synthesis and secretion of calcitriol by the kidneys, which enhances Ca2+ absorption by the digestive system.

• Organs with Secondary Endocrine Functions

  • The kidneys also release calcitriol, which aids in the absorption of calcium (Ca2+) and phosphate ions.

• Location and External Anatomy of the Kidneys

  • In addition, the kidneys produce hormones including calcitriol, erythropoietin, and the enzyme renin, which are involved in renal and hemotological physiological processes.