Sympathetic stimulation acts directly on the macula densa, a group of modified cells in the distal tubules near the end of the loop of Henle and closely associated with juxtaglomerular
Renin which is secreted from juxtaglomerular
cells in the kidney acts on angiotensinogen and converts it into angiotensin I .
The decreased renal perfusion then results in stimulation of the juxtaglomerular
(J-G) cells which lie close to the glomerulus triggering the renin-angiotensin response.
The renal morphology, with the predominance of tubules and prominent juxtaglomerular
apparatus, is consistent with the adaption towards an arid habitat where the species lives and a necessity to produce highly concentrated urine.
Renal sympathetic nerves innervate the tubules, the vessels, and the juxtaglomerular
granular cells of the kidney (1).
The convoluted tubules coil like spaghetti, so that the distal convoluted tubule can have its cells against the afferent arteriole of the glomerulus, allowing for the juxtaglomerular
apparatus to form.
More rare entities include fibroma, leiomyoma, extramedullary hemato poiesis, hemangioma, and juxtaglomerular
cell tumors; however, there are no definitive imaging features of these entities that would obviate pathologic diagnosis.
Renin is an enzyme that is produced by the juxtaglomerular
apparatus of the kidney in response to low sodium flow in the distal convoluted tubule and causes the cleaving of endogenous angiotensinogen to angiotensin I.
And mechanistic links exist: Active vitamin D suppresses renin expression in the juxtaglomerular
apparatus, and vitamin D also inhibits the growth of vascular smooth muscle cells.
These results suggest that the beneficial effects of Panamanian plant extracts on the cardiovascular system do not involve effects on the [beta]1 receptors which are located in the heart and control its contractile force and rate, or the juxtaglomerular
cells of the kidney which control the release of renin which activates the renin-angiotensin system.
renin staining was present in the uric acid model (Mazzali et al.