Arteries vasoconstriction

Activation of both the RAAS and the SNS also contribute to vasoconstriction in an attempt to redistribute blood flow from peripheral organs such as the kidneys to coronary and cerebral circulation.7 However, arterial vasoconstriction leads to impaired forward ejection of blood from the heart due to an increase in afterload. This results in a decrease in CO and continued stimulation of compensatory responses, creating a vicious cycle of neurohormonal activation. 

Amphotericin B-induced ARF occurs in as many as 40% to 65% of patients treated with the conventional desoxycholate formulation.30 Nephrotoxicity is due to renal arterial vasoconstriction and distal renal tubule cell damage. Risk factors include high doses, treatment for at least 7 days, preexisting kidney dysfunction, and concomitant use of other nephrotoxic drugs.31 Three lipid-based formulations of amphotericin B have been developed in an attempt to decrease the incidence of ARF amphotericin B lipid complex, amphotericin colloidal dispersion, and liposomal amphotericin B. The range of... 

Amant, C., Hamon, M., Bauters, C., et al. (1997) The angiotensin 11 type 1 receptor gene polymorphism is associated with coronary artery vasoconstriction. J. Am. Coll. Cardiol. 29, 486 90. 

Both drugs are partial agonists at a-adrenergic receptors and at some serotonin and dopamine receptors they also can inhibit the release of endotheUal-derived relaxation factor. They may induce arterial vasoconstriction and have minor actions on the central nervous system. Their a-adrenergic blocking activity is relatively weak compared with those of other ergot alkaloids. 

Increased vascular permeability and oedema Pulmonary artery vasoconstriction Coronary artery vasoconstriction Activation vagal afferent nerves in airways Bronchospasm Gut contraction... 

Associated with arterial vasoconstriction, and release of serotonin... 

Smooth-muscle contraction. Vasoconstriction of coronary artery, vasoconstriction of veins, decreased motility of GI smooth muscle... 

BETA-BLOCKERS ERGOT DERIVATIVES Three reported cases of arterial vasoconstriction and one of T BP occurred when ergotamine or methysergide was added to propanolol or oxprenolol Ergotamine can cause peripheral vasospasm, and absence of beta-adrenergic activity can t the risk of vasoconstriction Ergot derivatives and beta-blockers are often co-administered without trouble however, monitor BP at least weekly until stable (watch for t BP) and warn patients to stop the ergot derivative and seek medical attention if they develop cold, painful feet... 

In severe cyanide poisonings, autonomic shock due to the release of biogenic amines plays a role. The coronary arterial vasoconstriction, resulting in an increase in central venous pressure, leads to the observed shock-hke state that is not attributable to inhibition of cytochrome oxidase (Vick and Froehlich, 1985). In the liver CN is metabohzed by rhodanese to thiocyanate, which is excreted in the urine. 

The hypertensive crisis that can follow the withdrawal of clonidine can be accentuated by beta-blockers. It has also been reported that when beta-blockers are used in conjunction with drugs that cause arterial vasoconstriction they can have an additional effect on peripheral perfusion, which can be hazardous. Thus, combining beta-blockers with ergot alkaloids, as has been recommended for migraine, can cause severe peripheral ischemia and even tissue necrosis (408). 

Severe acute pulmonary vasoconstriction with cardiovascular collapse was identified in 1983 and subsequent studies showed that the incidence of protamine-induced pulmonary artery vasoconstriction was about 1.5% after cardiac surgery (3). Protamine-induced pulmonary artery vasoconstriction is accompanied by generation of large quantities of thromboxane A2, a potent vasoconstrictor (3). 

P. Golino, M. Buja, Y. Shcng-Kun, J. McNatt and J. T. Willerson, Failure of nitroglycerin and diltiazem to reduce platelet-mediated vasoconstriction in dogs with coronary artery stenosis and endothelial injury further evidence for thromboxane A2 and serotonin as mediators of coronary artery vasoconstriction in vivo, J Am Coll Cardiol 15, 718-726 (1990). 

Phenylephrine (neo-synephrine, others) is a selective receptor agonist it activates receptors only at much higher concentrations. The drug causes marked arterial vasoconstriction during intravenous infusion. Phenylephrine also is used as a nasal decongestant and as a mydriatic in various nasal and ophthalmic formulations (see Chapter 63 for ophthalmic uses). 

The ATj and AT2 receptors have little sequence homology. Most of the known biological effects of Angll are mediated by the AT receptor. Consistent with its functional preeminence, the ATj-receptor gene contains a polymorphism (AII66C) that is associated with hypertension, hypertrophic cardiomyopathy, coronary artery vasoconstriction, and aortic stiffness, while preeclampsia is associated with the development of activating autoantibodies against the ATj receptor. Potential roles for the AT receptor include antiproliferative, proapoptotic, vasodilatory, and antihypertensive effects. 

Liu J Q, Folz R J (2004). Extracellular superoxide enhances 5-HT-induced murine pulmonary artery vasoconstriction. Am. J. Physiol. Lung. Cell. Mol. Physiol. 287 Llll-118. 

The mechanisms of kidney injury include direct tubular epithelial cell toxicity with increased tubular permeability and necrosis, as well as arterial vasoconstriction and ischemic injury (Fanos and Cataldi 2000). Overall, the combined effects of increased cell energy and oxygen requirements due to greater cell membrane permeability, and reduced cellular oxygen delivery due to renal vasoconstriction, results in renal medullary tubular epithelial cell necrosis and kidney injury. Risk factors include CKD, higher average daily doses, volume depletion, and concomitant administration of diuretics and other nephrotoxins (e.g., cyclosporine) (Deray 2002 Costa and Nucci 2001). Rapid infusions of amphotericin B have the potential... 

Brook RD (2008) Cardiovascular effects of air pollution. Clin Sci 115 175-187 Brook RD, Brook JR, Urch B et al (2002) Inhalation of fine particulate air pollution and ozone causes acute arterial vasoconstriction in healthy adults. Circulation 105 1534-1536 Brook RD, Brook JR, Rajagopalan S (2003) Air pollution the heart of the problem. Cuir Hypertens Rep 5 32-39... 

The circulatory collapse was attributed by the authors to the combined effects of the injected vasopressin and the nicotine from the transdermal patch. Both of these drugs can increase afterload and cause coronary artery vasoconstriction, which the authors suggest may have decreased the blood supply to the heart and resulted in cardiac depression. ... 

Acute ischemia caused by severe arterial vasoconstriction within the kidney... 

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