Question

Excretion of dilute urine is due to
(a) More secretion of aldosterone
(b) Less secretion of vasopressin
(c) Less secretion of glucagon
(d) More secretion of insulin

Answer 1

Hint: It plays a central role in the control of blood pressure, primarily by increasing the amount of salt (sodium) reabsorbed into the bloodstream and increasing the amount of potassium excreted in the urine by acting on organs such as the kidney and colon.

Complete answer:
The hormone that the adrenal gland produces is aldosterone. Aldosterone in our body regulates sodium and potassium. When the adrenal gland releases excess aldosterone, it allows the body to lose potassium and retain sodium. This results in the excretion of diluted urine.
Aldosterone is part of a group of related hormones that make up the system of renin-angiotensin-aldosterone. If there is a reduction in blood flow to the kidneys following the loss of blood volume or a decline in blood pressure ( e.g. due to hemorrhage), activation of this mechanism occurs. Renin is an enzyme that induces a series of chemical reactions to produce angiotensin II, which in turn triggers the release of aldosterone. Aldosterone allows salt and water reabsorption to increase from the kidney into the bloodstream, thereby increasing the volume of blood, restoring salt levels, and blood pressure.

Additional information: Original 5-mg injections. In potassium excretion from $o.7\mu Eq/min - 1.6\mu Eq/min$ and in urine flow from 1.4 to 2.2 ml, glucagon contributed to statistically significant mean rises in sodium excretion from $84.8\mu Eq/min to 210.4\mu Eq/min$. Every minute. Second and third glucagon (3 mg to 10 mg.) injections.
A potent insulin secretion inhibitor induces an increase in the excretion of urinary sodium. Plasma insulin levels decreased from 144 nmol/l to 79 nmol/l (or 20 mU/l -11 mU/l) by 45 percent within the first hour after somatostatin infusion. A minor, temporary decrease in urinary sodium excretion was associated with this.
Circulating ADH works on the cardiovascular system and the kidney. By increasing the reabsorption of water in the kidneys, ADH decreases urine volume. ADH activates vascular smooth muscle contraction, arteriolar constriction, and peripheral vasoconstriction.
So, the correct answer is ‘(a) More secretion of aldosterone’.

Note: Via V2 receptors, AVP works on renal collecting ducts to increase water permeability (a cAMP-dependent mechanism), resulting in decreased urine formation (hence the antidiuretic activity of 'antidiuretic hormone'). This boosts the amount of blood, cardiac production, and arterial pressure.