This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Physiology
Renin is released when: 
Select and explain. 
A. Low phosphate, B. Low sodium, C. High phosphate, D. High sodium
B: Low sodium
Answer: B: Low sodium 
Explanation: Ans. B. Low sodiumRENIN is an enzyme that is produced and stored in the granules of the juxtaglomerular cells surrounding the afferent arterioles of glomeruli in the kidney. Following stimuli increase its secretion:* Sodium depletion* Diuretics* Hypotension* Hemorrhage* Upright posture* Dehydration* Constriction of renal artery or aorta* Cardiac failure* CirrhosisRenin is a glycoprotein synthesized as a preprohormone.