Search results
Results from the WOW.Com Content Network
Aldosterone synthase, also called steroid 18-hydroxylase, corticosterone 18-monooxygenase or P450C18, is a steroid hydroxylase cytochrome P450 enzyme involved in the biosynthesis of the mineralocorticoid aldosterone and other steroids. The enzyme catalyzes sequential hydroxylations of the steroid angular methyl group at C18 after initial 11β ...
Aldosterone synthase normally is not ACTH sensitive, and is only activated by angiotensin II. [citation needed] Aldosterone causes the tubules of the kidneys to retain sodium and water. This increases the volume of fluid in the body and drives up blood pressure. [citation needed] Steroid hormones are synthesized from cholesterol within the ...
These enzymes are nearly identical (they share 11β-hydroxylation and 18-hydroxylation functions), but aldosterone synthase is also able to perform an 18-oxidation. Moreover, aldosterone synthase is found within the zona glomerulosa at the outer edge of the adrenal cortex; 11β-hydroxylase is found in the zona glomerulosa and zona fasciculata.
Measuring aldosterone alone is not considered adequate to diagnose primary hyperaldosteronism. Rather, both renin and aldosterone are measured, and a resultant aldosterone-to-renin ratio (ARR) is used for case detection. [20] [21] A high aldosterone-to-renin ratio suggests the presence of primary hyperaldosteronism. The diagnosis is made by ...
Gilbert cloud chamber, assembled An alternative view of kit contents. The lab contained a cloud chamber allowing the viewer to watch alpha particles traveling at 12,000 miles per second (19,000,000 m/s), a spinthariscope showing the results of radioactive disintegration on a fluorescent screen, and an electroscope measuring the radioactivity of different substances in the set.
In the adrenal cortex, angiotensin II acts to cause the release of aldosterone. Aldosterone acts on the tubules (e.g., the distal convoluted tubules and the cortical collecting ducts) in the kidneys, causing them to reabsorb more sodium and water from the urine. This increases blood volume and, therefore, increases blood pressure.
Hypoaldosteronism causes low sodium (hyponatremia), high potassium (hyperkalemia), and metabolic acidosis, a condition in which the body produces excess acid.These conditions are responsible for the symptoms of hypoaldosteronism, which include muscle weakness, nausea, palpitations, irregular heartbeat, and abnormal blood pressure.
The outermost layer, the zona glomerulosa is the main site for the production of aldosterone, a mineralocorticoid. The synthesis and secretion of aldosterone are mainly regulated by the renin–angiotensin–aldosterone system. The zona glomerulosa cells express a specific enzyme aldosterone synthase (also known as CYP11B2).