Hormones angiotensins

The renin-angiotensin-aldosterone system (RAAS) generates the peptide hormone angiotensin II and subsequently the mineralocorticoid aldosterone, which both exert considerable impact on blood pressure ( blood pressure control) and fluid homeostasis, and... 

In addition to their involvement in excretion and metabolism, the kidneys also have endocrine functions. They produce the hormones erythropoietin and calcitriol and play a decisive part in producing the hormone angiotensin II by releasing the enzyme renin. Renal prostaglandins (see p. 390) have a local effect on Na resorption. 

The peptide hormone angiotensin II is not synthesized in a hormonal gland, but in the blood. The kidneys take part in this process by releasing the enzyme renin. 

Examples of the way these two entirely different approaches compliment each other are developing in conformation studies with the hormones angiotensin, oxytocin, and vasopressin. In 1964 Craig, Harfenist, and Paladini (7) published the comparative half-escape times shown in Table I in 0.01N acetic acid and another series in Table II using a different membrane less porous and not as selective as the first. Oxytocin and vasopressin are cyclic octapeptides with an S-S linkage closing the ring at the 1-6 positions (5, 6). Their size is thus limited except for the side... 

Circulating Hormones Angiotensin Calcitonin Glucagon Insulin Leptin... 

Angiotensin II receptors are widely distributed in the body. Like the receptors for other peptide hormones, angiotensin II receptors are located on the plasma membrane of target cells, and this permits rapid onset of the various actions of angiotensin II. 

Metalloproteases include carboxypeptidase [1, 29, 30], ACE (a dipeptidyl carboxypeptidase) [13, 31] and a variety of matrix metalloproteases (matrixins or MMPs) [1, 32, 33]. ACE catalyzes the formation of the vasoconstrictive hormone angiotensin II from angiotensin I, some ACE inhibitors being important anti-hypertensive drugs [13, 31]. 

The metalloprotease ACE catalyses the conversion of angiotensin I to the vasoconstrictive hormone angiotensin II. ACE inhibitors are widely used as anti-hypertensive drugs and a variety of plant-derived peptides are ACE inhibitors (Table 13.4). 

Stimuli for Drinking. Thirst stimulation and the act of drinking are basic physiological responses. The three major circumstances known to stimulate thirst and drinking are (1) a deficit of body water (hypohydration and hypovolemia), (2) an increase in the osmolality of the extracellular fluid volume (hyperosmolality and hyperosmotemia), and (3) consumption of dry food (prandial thirst) (50). These three factors can function independently, but they are often interactive e.g., a hypovolemic subject is often hyperosmotic. In addition, the hormone angiotensin II acts as a stimulant for drinking (dipsogen) in animals, and possibly in man (51). 

A 42-year-old man who for 2 years had taken a supplement containing vitamin D2 had a serum calcium concentration of 3.75 mmol/1 and a serum calcifediol concentration of 487 ng/ml (reference range 9 7). He had normal concentrations of calcitriol, parathyroid hormone, angiotensin-converting enzyme, and thyroid hormone, and had normal bone marrow, radiography, and CT of the chest, neck, and abdomen. Vitamin D2... 

Peptide hormone angiotensins peptide analogs (various)... 

Trandolapril is an angiotensin-converting enzyme (ACE) inhibitor that reduces the formation of the vasopressor hormone angiotensin II by inhibiting ACE. It Results in decreased BP and reduced sodium reabsorption and potassium retention. Heart failure post-MMeft-ventricular dysfunction post-MI used for stable patients who have... 

Peptide hormones Angiotensin Bradykinin Substance P Endothelin Gastrin... 

Aminoglycosides Androgenic hormones Angiotensin converting enzyme inhibitors Captopril, enalapril Angiotensin receptor antagonists ... 

The hormone angiotensin causes a rise in blood pressure through its action at the angiotensin receptors. The first compounds that were discovered to control hypertension by blocking this pathway were peptide analogues of angiotensin, for example the octapeptide, saralasin. As might be expected, these had poor... 

Some short peptides, of around ten amino acids, are hormones. Angiotensin II, for example, is a peptide that causes blood pressure to rise—a very necessary thing in some situations but too much and too often leads to heart attacks and strokes. 

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