Peripheral vessels

This mechanism of action unlike the previously discussed ones, would account for the delay in onset of the hypertensive action. It would also fit in well with the results from the comparative studies, that provided sufficient drug is given to adequately block the cardiac 3-receptors, all 3-blockers are roughly equally effective. A further point which may possibly explain why the cardioselective drug ICI 66082 is marginally more effective than the non-selective propranolol, is that the former could assist the relaxation of the peripheral vessels by not blocking the vascular 3-receptors. 

Schildberg and Fleckenstein observed that calciumantagonists can advantageously influence the peripheric vessels and those of the heart.With the 4-aryldihydropyridine-3,5-dicarboxylic esters 4 (Scheme 1.1) that have such effects, the first pharmaceutical products synthesized by Hantzsch reactions were independently introduced by the Bayer and Smith Cline French. ... 

Figure 1.13 Communication to and from the cardiovascular centre in the brain. The cardiovascular centre controls changes in the output from the heart (cardiac output) and the flow of blood through peripheral b ssues and organs. It is the efferent neurones that transfer informab on from the brain to the heart and peripheral vessels. The afferent neurones transfer informab on from the heart and other b ssues, e.g. muscle, to the centre. Informab on transfers from the major arteries, the coronary arteries and peripheral muscles to the brain. There is also informab on transfer within the brain and within the muscle.

Diltiazem reduces the transmembrane influx of calcium ions into cells of cardiac muscle and smooth musculature of vessels. It causes dilation of coronary and peripheral vessels. 

Nicardipin relaxes smooth musculature of vessels, lowers resistance of coronary and peripheral vessels, increases blood flow in vessels of the brain, causes a moderate and stable hypotensive effect, and reduces the myocardial need for oxygen. 

In a number of cases, furosemide has proven more effective than other diuretics. Besides a diuretic effect, it also dilates peripheral vessels. It is frequently used in combination with other antihypertensive drugs. Synonyms of this drag are lazix, lazizix, franil, urosemide, and many others. 

Unlike other adrenoblockers, labetalol lowers blood pressure more by lowering resistance of peripheral vessels than by suppressing myocardial function. This, along with a reduction in pressure, fails to change heart rate. Currently, eight of the most frequently used j8-adrenoblock-ers in medicine are used for hypertension therapy, and their syntheses are described in Chapter 12. They are propranolol (12.1.3), metoprolol (12.1.5), acebutol (12.1.6), athenolol (12.1.7), nadolol (12.1.8), pindolol (12.1.9), timolol (12.1.10), and labetalol (12.1.12). 

In addition to being used as antianginal and antiarrhythmic agents, calcium channel blockers are used to treat weak and moderate hypertension. These drugs prevent calcium ions from entering into the smooth muscle cells of peripheral vessels, and they cause relaxation of peripheral vessels, which leads to lowering of arterial blood pressure. In clinically used doses, calcium channel blockers relax smooth musculature of arteries and have little effect on veins. In doses that relax smooth musculature, calcium channel blockers have relatively little effect on cardiac contractility. 

The drugs of this class (hydralazine and sodium nitroprusside) lower arterial blood pressure primarily by direct spasmolytic action on smooth musculature of arterioles, which leads to a reduction of resistance of peripheral vessels by causing dilation. Diastolic pressure is usually lowered more than the systolic pressure. 

Hydralazine exhibits an antihypertensive effect by directly relaxing smooth muscles of the vessels. It has an effect on arterial vessels while having a minimal effect on venous vessels. As a result, resistance of peripheral vessels decreases, and blood pressure is reduced (diastolic more than systolic). 

Pharmacology Salicylates have analgesic, antipyretic, anti-inflammatory, and antirheumatic effects. Salicylates lower elevated body temperature through vasodilation of peripheral vessels, thus enhancing dissipation of excess heat. The anti-inflammatory and analgesic activity may be mediated through inhibition of the prostaglandin synthetase enzyme complex. 

ACE). Hence, angiotensin II production is inhibited. Decrease in angiotensin II results in dilatation of peripheral vessels leading to a reduction in systemic vascular resistance and a decreased aldosterone secretion. They can be administered safely in patients of hypertension with diabetes mellitus or bronchial asthma. ACE inhibitors are efficacious drugs, are well tolerated and are useful antihypertensive drugs. ACE inhibitors are also used in coronary artery... 

Weakness and dizziness It may arise due to postural hypotension especially if patient is standing in a single position for a while. This is because, venoddatation results in venous pooling i.e. accumulation of blood in peripheral vessels leads to postural hypotension. 

Although the responses depicted in curves A, B, and C of Figure 2-15 approximate the shape of a simple Michaelis-Menten relation (transformed to a logarithmic plot), some clinical responses do not. Extremely steep dose-response curves (eg, curve D) may have important clinical consequences if the upper portion of the curve represents an undesirable extent of response (eg, coma caused by a sedative-hypnotic). Steep dose-response curves in patients can result from cooperative interactions of several different actions of a drug (eg, effects on brain, heart, and peripheral vessels, all contributing to lowering of blood pressure). 

Vasodilators Peripheral vasculature Lower vascular resistance by directly vasodilating peripheral vessels... 

Thrombolytic drugs (streptokinase, t-PA, others) usually do not have a direct impact on physical therapy or occupational therapy. Thrombolytics are typically given in acute situations, immediately following myocardial infarction. Therapists may, however, benefit indirectly from the effects of these drugs because patients may recover faster and more completely from heart attacks. Thrombolytics may also help reopen occluded peripheral vessels, thus improving tissue perfusion and wound healing in rehabilitation patients. 

Human peripheral vessels D2-likeJ. 2 Haeusler et al. 1992 Mannelli et al. 1997... 

Ref. (61)]. The interim results confirmed the feasibility and safety of using E2F-I decoy. Analysis of the secondary endpoints using quantitative coronary angiography and three-dimensional intravascular ultrasound demonstrated increased patency and adaptive vessel remodeling characterized by reduction in neointimal size and volume in the treated group one year after treatment, leading to 40% reduction in critical stenosis. These results will now need to be confirmed in adequately sampled and powered phase III studies in patients with coronary and peripheral vessel disease in order to further... 

These elfects on cerebrovascular events and on intermittent claudication suggest that simvastatin and other elfective lipid-lowering treatments may have a general antiatherosclerotic elfect not limited to the coronary bed. Definitive evidence on the elfects of statin therapy in stroke prevention and peripheral vessel disease is likely to be provided by the Heart Protection Study (MRC/BHF Heart Protection Study Collaborative Group, 1999). As noted above, this UK study has randomized over 20,000 patients aged up to 80 to simvastatin 40 mg or placebo, and the 5-year treatment period is scheduled for completion in 2001. Among these patients are 3288 patients with a history of cerebrovascular disease. Because of its size and the broad array of patient types randomized, this study should also provide reliable evidence of the elfect of simvastatin on coronary morbidity and mortality in women, elderly patients, patients with low levels of LDL and HDL cholesterol, patients with peripheral vascular disease, and diabetic patients with or without coronary disease (MRC/BHF Heart Protection Study Collaborative Group, 1999). 

Bradykinin 87 and kallidin (Lys-bradykinin-decapeptide), which are split off from the kininogen in the plasma by trypsin and kallikrein respectively (Fig. 10), hardly differ in their pharmacological activity. The most important effect of the kinins is a dilation of the peripheral vessels, which leads to an improved blood flow, in the kidneys for example, and therefore increases diuresis. By acting on the formation of angiotensin II, kinins can contribute to the regulation of blood pressure. Moreover, kinins cause a contraction of the bronchial muscle. 

A decoction of dried twigs of cinnamon can produce an antipyretic effect in mice. Studies conducted in anaesthetized dogs and guinea pigs indicated that cinnamaldehyde, or sodium cinnamate, also produced the hypothermic and antipyretic effects (Chinese Materia Medica, 1996). It also causes a hypotensive effect, which is due mainly to vasodilation of peripheral vessels. Cinnamaldehyde produced an analgesic effect in mice (Wang, 1985). 

A chemical that acts on the /3-andrenergic receptors in the myocardium and peripheral vessels. 

There were relatively few developments for the next 70 years. However, in 1946, a Portuguese surgeon, Cid Dos Santos, introduced thromboendarterectomy for restoration of flow in peripheral vessels (Dos Santos 1976). The first successful reconstruction of the carotid artery was performed by Carrea, Molins and Murphy in Buenos Aires in 1951 (Carrea et al. 1955). However, this was not an endarterectomy. Rather they performed an end-to-end anastomosis of the left external carotid artery and the distal internal carotid artery (ICA) in a man aged 41 years with a recently symptomatic severe carotid stenosis. 

---