Artery constriction

Deletion of the Cav3.1 channel in thalamocortical relay neurons prevents absence epilepsy. Block of the neuronal LVA channels alleviates certain forms of epilepsy. Deletion of Cav3.2 leads to coronary artery constriction and focal myocardial fibrosis. 

A specific cause of hypertension can be established in only 10-15% of patients. Patients in whom no specific cause of hypertension can be found are said to have essential or primary hypertension. Patients with a specific etiology are said to have secondary hypertension. It is important to consider specific causes in each case, however, because some of them are amenable to definitive surgical treatment renal artery constriction, coarctation of the aorta, pheochromocytoma, Cushing s disease, and primary aldosteronism. 

Meggs, L.G., Huang, H., Li, R, Capasso, J.M., and Anversa, P. 1991. Chronic nonocclusive coronary artery constriction in rats. 3-adrenoceptor signal transduction and ventricular failure. J. Clin. Invest. 88 1940-1946. 

Tada M, Esumi K, Yamageshi M et al. (1984) Reduction of prostaglandin synthesis as a possible cause of transient flow reduction in a partially constricted canine coronary artery. Mol Cell Biol 16 1137-1149 Uchida Y, Yoshimoto N, Murao S (1975) Cyclic fluctuations in coronary blood pressure and flow induced by coronary artery constriction. Jpn Heart J 16 454—464 Warltier DC, Lamping KA, Pelc LR, Gross GJ (1987) A canine model of thrombin-induced coronary artery thrombosis Effects of intracoronary streptokinase on regional myocardial blood flow, contractile function, and infarct size. J Pharmacol Meth 18 305-318... 

This technology of death was not lost and though we have no individual gas chambers, millions around the world today die of air pollution as the entire atmosphere is being turned into lethal gas. According to the World Health Organization (WHO), air pollution kills 3 million people annually, three times the number "who die in automobile accidents." A study published in 2000 (Lancet) demonstrated that air pollution was "responsible for more than 40,000 deaths annually" in France, Austria and Switzerland. In the U.S., "air pollution claims 70,000 lives annually." This exceeds 10 times the number of traffic fatalities and equals the annual mortality "from breast and prostate cancer combined." Air pollutants are known to produce arterial constriction and reduce... 

As we age, the body produces less and less NO, especially when LDL cholesterol levels are high, when we smoke cigarettes, when we gain weight, when we live sedentary lifestyles, and when we develop type 2 diabetes and sugar levels rise in the blood. Reduced production of NO leads to arterial constriction that limits blood flow, elevates blood pressure, increases blood clot production, and results in more rapid cell death and cardiovascular disease. For reasons yet to be determined, blacks produce less NO than whites do, which may explain why the incidence of hypertension is higher in that community. And while there is an association, we don t know whether a decreased production of NO contributes to the development of type 2 diabetes or whether that form of diabetes results in less NO. Decreased NO production has also been correlated with the early development of atherosclerosis. In 2005, Russian scientists at the Scientific Sessions of the American Heart Association reported their findings that a decline in NO production parallels increases in blood pressure from mild to severe. 

Ergotamine is a powerful oxytocic and is dangerous in pregnancy. It may precipitate angina pectoris, probably by increasing cardiac pre- and afterload (venous and arterial constriction) rather than by constricting coronary arteries. 

The effect of the sympathomimetic drugs on the pregnant uterus is Vciriable and difficult to predict, but serious fetal distress can occur, due to reduced placental blood flow as a result both of contraction of the uterine muscle (a) and arterial constriction (a). Pj-agonists are used to relax the uterus in premature labour, but unwanted cardiovascular actions can be troublesome. Sympathomimetics were particularly likely to cause cardiac arrhythmias (p, effect) in patients who received halothane anaesthesia (now much less used). 

A 60-year-old smoker was treated with interferon alfa (100 MU/week for 2 months and 9 MU/week for 15 weeks) for cutaneous melanoma. Ocular examination was normal before treatment, but he developed acute loss of peripheral vision in his left eye after 23 weeks. Examination was consistent with anterior ischemic optic neuropathy, and there was optic disc edema, a pupillary defect, and circular visual field constriction in the left eye. There was renal artery constriction in both eyes. Despite treatment with aspirin, high-dose dexamethasone, heparin, and finally withdrawal of interferon alfa, loss of visual function progressed and affected both eyes. Ciclosporin was started, but he was considered to have irreversible loss of visual function. 

Cantley LG, Spokes K, Clark B, McMahon EG, Carter J, Epstein FH Role of endothelin and prostaglandins in radiocontrast-induced renal artery constriction. Kidney Int 44 1217-23,1993... 

The primary effect of peripheral a-stimulation is vasoconstriction, whereas vasodilation is that of p-stimulation. In the heart a-receptors are less significant. P-Receptors, however, cause augmentation of both chronotropic (rate) and inotropic (contractile) activity. The excessive force with which the heart ventricle expels blood is pitted against a less stretchable arterial system, caused by arterial constriction. The net result is an increase in blood pressure—both systolic when the heart is contracting, and diastolic when it is dilated and relaxed. 

Nicolaou, K.C., Magolda, R.L., Smith, J.B., Aharony, D., Smith, E.F. and Lefer, A.M. (1979). Synthesis and biological properties of pinane-thromboxane A2, a selective inhibitor of coronary artery constriction, platelet aggregation, and thromboxane formation. Proc. Natl Acad. Sci USA, 76, 2566-2570... 

In rabbits with one kidney-one clip hypertension, treatment with indomethacin for 10 days aggravates the hypertension and causes deterioration of renal haemodynamic and excretory functions, while reducing plasma renin activity . In contrast, short-term treatment with indomethacin was reported to reduce both blood pressure and plasma renin activity in dogs with one kidney-one clip hypertension . Treatment with meclofenamate prior to and following bilateral renal artery constriction markedly attenuates, in the acute phase, the development of hypertension in rats. However, once the... 

Jackson, E.K., Gerkens, J.F., Brash, A.R. and Branch, R.A. (1982). Acute renal artery constriction increases renal prostaglandin biosynthesis and renin release in the conscious dog. ]. Pharmacol Exp. Ther., 222, 410-413... 

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