This flow is measured by the macula densa of the juxtaglomerular apparatus.

The juxtaglomerular apparatus is a microscopic structure in the kidney, which regulates the function of each nephron.

A fluid-insufficiency causes a decreased perfusion of the juxtaglomerular apparatus in the kidneys.

Another is renal artery stenosis in which the reduced blood supply across the juxtaglomerular apparatus stimulates the production of renin.

Animation of the Juxtaglomerular Apparatus Location, Structure, and Function.

One mechanism for maintaining the blood pressure is the release of a protein called renin from cells in the kidney (to be specific, the juxtaglomerular apparatus).

The macula densa region of the kidney's juxtaglomerular apparatus is another modulator of blood osmolality.

Renin is an enzyme secreted by the juxtaglomerular apparatus of the kidney and linked with aldosterone in a negative feedback loop.

The juxtaglomerular apparatus is a specialized region of the nephron responsible for production and secretion of the hormone renin, involved in the renin-angiotensin system.

Ang II also provides a negative feedback to the system by inhibiting renin release by the juxtaglomerular apparatus.

When subsequent blood flow to the kidneys is reduced, the kidneys respond by increasing the secretion of renin from the juxtaglomerular apparatus.

The enzyme renin is secreted by the kidney from specialized cells called granular cells of the juxtaglomerular apparatus in response to three stimuli:

In addition, the physical effect of thickening of the arteriolar walls in the kidney may prevent release of renin from the juxtaglomerular apparatus (Schindler & Sommers, 1966).

Inhibition of beta-1 receptors in the juxtaglomerular apparatus of the kidney inhibits the renin-angiotensin system, causing a decrease in vasoconstriction and a decrease in water retention.

The increased blood pressure will lead to increased glomerular filtration rate and cause a decrease in renin release from the granular cells of the juxtaglomerular apparatus in the kidney.

Diagnostic pointers include high urinary potassium and chloride despite low serum values, increased plasma renin, hyperplasia of the juxtaglomerular apparatus on renal biopsy, and careful exclusion of diuretic abuse.

The juxtaglomerular apparatus is named for its proximity to the glomerulus: it is found between the vascular pole of the renal corpuscle and the returning distal convoluted tubule of the same nephron.

If the perfusion of the juxtaglomerular apparatus in the kidney's macula densa decreases, then the juxtaglomerular cells (granular cells, modified pericytes in the glomerular capillary) release the enzyme renin.

Lacis cells form the juxtaglomerular apparatus in combination with two other types of cells: the macula densa of the distal convoluted tubule and juxtaglomerular cells of the afferent arteriole.

Narrowing of the arteries supplying the kidneys causes a low perfusion pressure which is detected by the juxtaglomerular apparatus (via the juxtaglomerular cells, which act as baroreceptors; located on the afferent arteriole wall).

"Hypokalemic Alkalosis, Hyperreninemia, Aldosteronism, Normal Blood Pressure and Normal Juxtaglomerular Apparatus : A New Syndrome of Renal Alkalosis," International Journal of Pediatric Nephrology 7: 99, 1986.

The highly selective aspartic protease renin is secreted from the juxtaglomerular apparatus, which is the only source of active renin, although its precursor, prorenin, can be secreted by other tissues, such as the salivary glands, brain, heart and blood vessels.

Stenosis of the renal arteries causes hypo-perfusion (decreased blood flow) of the juxtaglomerular apparatus, resulting in exaggerated secretion of renin, and high blood levels of aldosterone, eventually leading to water and salt retention and high blood pressure.

In rats, D1-like receptors are present on the juxtaglomerular apparatus and on renal tubules, while D2-like receptors are present on the renal tubules, glomeruli, postganglionic sympathetic nerve terminals, and zona glomerulosa cells of the renal cortex.

A non-contractile function is seen in specialized smooth muscle within the afferent arteriole of the juxtaglomerular apparatus, which secretes renin in response to osmotic and pressure changes, and also it is believed to secrete ATP in tubuloglomerular regulation of glomerular filtration rate.