Erythropoietin, renin, and calcitriol are three hormones secreted by the kidneys.
The peptide hormones erythropoietin and renin are secreted by the kidney’s juxtaglomerular cells.
Calcitriol is a steroid hormone produced by the cells of the nephron’s proximal tubules.
Erythropoietin
It induces the generation of RBC from haematopoietic stem cells in the bone marrow, which is stimulated by hypoxia (insufficient oxygen supply to the tissues).
Renin
Reduced blood pressure and low salt levels are stimuli for the kidney to produce renin.
Renin is an important component of the renin-angiotensin-aldosterone pathway and has enzymatic activity (RAAS).
The RAAS is responsible for controlling cardiac output and arterial pressure.
Renin’s primary role in the RAAS system is to convert angiotensinogen to angiotensin I. (proteolytic activity).
Calcitriol
Calcitriol (1,25-dihydroxycholecalciferol) is vitamin D’s active form.
It increases calcium absorption by stimulating the synthesis of calcium-binding protein in the intestine.
As a result, it plays a crucial role in bone mineralization (bone formation)
Final Answer:
Erythropoietin, renin, and calcitriol are three hormones secreted by the kidneys.