Inflammation Capillary dilation

These steioids aie capable of preventing or suppressing the development of the sweUing, redness, local heat, and tenderness which characterize inflammation. They inhibit not only the acute symptoms of the inflammatory process, such as edema, fibrin deposition, and capillary dilatation, but also the chronic manifestations. There is evidence that glucocorticoids induce the synthesis of a protein that inhibits phosphoHpase A 2 (60), diminishing the release of arachidonic acid from phosphoHpids (Fig. 2), thereby reducing chemotaxis and inflammation. 

Antiinflammatory and immunosuppressive effects Glucocorticoids suppress all types of inflammation, hypersensitization and allergic reactions. They suppress the edema, capillary dilatation, migration of leukocytes, capillary permeability in the inflamed area. 

Muscle cells release kallikrein during inflammation causing formation of active kinin peptides (bradykinin and kallidin) from kininogen [65, 66]. Kinins are peptide hormones that produce vasodilation, increase capillary permeability, and cause pain and infiltration of neutrophils. There is a direct correlation between the amount of kinin in plasma or tissues and the degree of inflammation. Vascular dilation causes increased blood flow to infection [67, 68], Bik inhibits formation of kinins and vascular dilation by kallikrein, thereby inhibiting smooth muscle contraction [69-71],... 

Erythematous Flushing of the skin caused by dilation of the capillaries. It is often a sign of inflammation and infection. 

Because Treponema pallidum is sensitive to penicillin G, this antibiotic is the drug of choice for treatment of syphilis and syphilitic eye disease (see Table 11-1). Syphilitic eye disease can include interstitial keratitis (stromal inflammation and vascularization), episcleritis, scleritis, nongranulomatous or granulomatous iritis, iris papules (collections of dilated capillaries in the iris), chorioretinitis, papillitis, retinal vasculitis, and exudative retinal detachment. Probenecid can be added to procaine penicillin to decrease excretion of the penicillin by the kidneys, thus causing an increase in penicillin plasma levels. Penicillins are not used for the treatment of minor ocular infections such as blepharitis and conjimctivitis... 

Histologically, cholestasis is moderate, focal and irregular, and the biliary capillaries are dilated, displaying biliary thrombi. Bile pigments may be detectable in the liver cells. Cell necroses and signs of inflammation are absent. 

A previously healthy 63-year-old man, who had taken quinidine gluconate 972 mg/day for 9 months, developed diffuse edematous erythema on the extensive surfaces of the hands, arms, and face, with marked accentuation over the joints. His nail-fold capillaries were dilated and the shoulder abductors were shghtly weak. His erythrocyte sedimentation rate was shghtly raised (29 mm/hour) and there was a positive ANA titer (1 640) with a speckled pattern. There were no antibodies to Sm, ribonucleoprotein, SSA or SSB antigens, or histones. There was no evidence of inflammatory myopathy on electromyography, and a skin biopsy showed a mild, superficial, perivascular, lymphocytic inflammation with positive direct immunofluorescence for IgG and IgM at the dermoepidermal junction. There was no evidence of malignancy. All these abnormalities resolved rapidly after quinidine withdrawal. 

NSAIDs that preferentially inhibit COX-2 more than COX-1 (Vioxx and Celebrex) target the pain associated with inflammation such as rheumatoid or osteoarthritis with fewer stomach problems because prostaglandin I2 is synthesized by COX-1 in the stomach. In the heart, continuous muscular movements cause capillary wear. Cytokines induce COX-2 to make prostaglandin I2 which dilates the capillaries and prevents excessive blood clotting by thromboxane A4, a COX-1 enzyme product. A COX-2 inhibitor stops prostaglandin I2 synthesis. The heart capillaries do not dilate and there is a greater risk of coronary artery obstruction (heart attacks). 

An irritant can be a gas, liquid, or fine particulate matter. Ammonia is a familiar and common irritant. Irritants injure the body by inflaming the tissues at the point of contact. Heat, redness, swelling, and pain are signs of inflammation. Mild irritants cause the capillaries to dilate and fill with blood, causing the redness and increased heat. The permeability of the capillary walls change, and fluid passes from the blood into the spaces between the tissues and causes swelling and pain. Strong irritants can produce blisters. 

Vasodiiation Dilation of the capillary and venule walls during an acute inflammation. 

Basophils are another type of granulocytes with numerous granules that stain darkly with basic dyes. They measure 8—10 pm in diameter and make up only about 1% of WBCs. Basophils migrate to injury sites and cross the capillary endothelium to accumulate in the damaged tissue, where they discharge granules that contain histamine (dilates blood vessels) and heparin (prevents clotting). They enhance local inflammation at the sites of injury and other chemicals that attract eosinophils and other basophils to the area of injury. 

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