Nori Canine Angiotensin II ELISA Kit Summary

Alternative names for  angiotensin II: AII,

Alternative names for canine: Dog

Standard Curve

Kit Components
1. Pre-coated 96-well Microplate
2. Biotinylated Detection Antibody
3. Streptavidin-HRP Conjugate
4. Lyophilized Standards
5. TMB One-Step Substrate
6. Stop Solution
7. 20 x PBS
8. Assay Buffer

Other Materials Required but not Provided:
1. Microplate Reader capable of measuring absorption at 450 nm
2. Log-log graph paper or computer and software for ELISA data analysis
3. Precision pipettes (1-1000 µl)
4. Multi-channel pipettes (300 µl)
5. Distilled or deionized water

Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the datasheet.
2. Add 100 µl of Standard or samples to each well and incubate 1 h at RT.
3. Add 100 µl of Working Detection Antibody to each well and incubate 1 h at RT.
4. Add 100 µl of Working Streptavidin-HRP to each well and incubate 20 min at RT.
5. Add 100 µl of Substrate to each well and incubate 5-30 min at RT.
6. Add 50 µl of Stop Solution to each well and read at 450 nm immediately.

Background: 

Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. Angiotensin I is converted to angiotensin II (AII) through removal of two C-terminal residues by angiotensin-converting enzyme (ACE), primarily through ACE within the lung (but also present in endothelial cells, kidney epithelial cells, and the brain). Angiotensin II acts on the CNS to increase vasopressin production, and also acts on venous and arterial smooth muscle to cause vasoconstriction. Angiotensin II also increases aldosterone secretion, therefore, it acts as an endocrine, autocrine/paracrine, and intracrine hormone. Angiotensin II increases blood pressure by stimulating the Gq protein in vascular smooth muscle cells. In addition, angiotensin II acts at the Na⁺/H⁺ exchanger in the proximal tubules of the kidney to stimulate Na reabsorption and H⁺ excretion which is coupled to bicarbonate reabsorption. Angiotensin II is degraded to angiotensin III by angiotensinases located in red blood cells and the vascular beds of most tissues. It has a half-life in circulation of around 30 seconds, whereas, in tissue, it may be 15–30 minutes. Angiotensin II results in increased inotropy, chronotropy, catecholamine (norepinephrine) release, catecholamine sensitivity, aldosterone levels, vasopressin levels, and cardiac remodeling and vasoconstriction through AT1 receptors on peripheral vessels. Angiotensin II has prothrombotic potential through adhesion and aggregation of platelets and stimulation of PAI-1 and PAI-2.^[1] Angiotensin II is the most important Gq stimulator of the heart during hypertrophy, compared to endothelin-1 and α1 adrenoreceptors. Angiotensin II increases thirst sensation through the area postrema and subfornical organ of the brain,^[2] decreases the response of the baroreceptor reflex, increases the desire for salt, increases secretion of ADH from the posterior pituitary, and increases secretion of ACTH from the anterior pituitary.^[2] It also potentiates the release of norepinephrine by direct action on postganglionic sympathetic fibers. Angiotensin II acts on the adrenal cortex, causing it to release aldosterone, a hormone that causes the kidneys to retain sodium and lose potassium. Elevated plasma angiotensin II levels are responsible for the elevated aldosterone levels present during the luteal phase of the menstrual cycle. Angiotensin II has a direct effect on the proximal tubules to increase Na⁺ reabsorption. Angiotensin II causes the local release of prostaglandins, which, in turn, antagonize renal vasoconstriction.

References

1. Skurk T, et al. (2001). Hypertension. 37 (5): 1336–40.
2. Shaver SW, et al. (1989). Brain Research. 505 (2): 316–20.