If a child is diagnosed with posterior urethral valves and chronic kidney disease, what hormone level is likely to be increased?

• A. Renin
• B. Aldosterone
• C. Angiotensin
• D. Adrenaline

Answer: (C)

In the context of a child diagnosed with posterior urethral valves and chronic kidney disease, the likely increase in hormone levels is related to the body’s response to decreased renal function and subsequent changes in blood flow and pressure.

Chronic kidney disease (CKD) often leads to impaired filtration and reduced blood flow in the kidneys, prompting the activation of the renin-angiotensin-aldosterone system (RAAS). From this activation, renin is secreted by the juxtaglomerular cells of the kidneys in response to low blood pressure, low sodium concentration, or sympathetic nervous system stimulation. Renin then converts angiotensinogen (produced by the liver) into angiotensin I, which is further converted to angiotensin II primarily by the action of angiotensin-converting enzyme (ACE) in the lungs.

Angiotensin II plays several critical roles: it causes vasoconstriction, directly increasing blood pressure, and stimulates the secretion of aldosterone from the adrenal cortex, which promotes sodium and water retention to increase blood volume and pressure. Therefore, in the case of posterior urethral valves leading to urinary obstruction and chronic kidney disease, there is a compensatory increase in renin, which in turn leads to