RESUMO
The effects of extracts of airborne particulate matter (APM) on morphology and mediator release from enriched basophils (HBC) and from purified neutrophils of pollen-allergic and nonallergic individuals were investigated. APM was collected on glass fiber filter sheets using high volume samplers HVS150. After preparing an aqueous extract, in which allergens are absent, followed by extraction of organic substances, the mediator-releasing activity of the APM extracts was studied under defined and physiological in vitro conditions. The results indicate that APM potentiates anti-IgE-induced histamine release (HR) and that this enhancement is significantly higher in HBC samples from pollen allergic donors than from nonallergic individuals. Electronmicroscopy of APM-exposed HBC reveals basophil degranulation in addition to strong activation of platelets and neutrophils, the latter sticking onto the surface of HBC and forming clusters with them. Incubation of purified PMN with APM prior to zymosan stimulation showed that these substances also enhance the release of LTB4, LTC4, PGE2 and IL-8. The results show that substances adsorbed to APM interfere with mediator cells of the allergic inflammation and exhibit 'priming' effects on them. Therefore, exposure of individuals to high concentrations of APM can provoke enhancement in symptoms of allergy and continuation of allergic inflammation.
RESUMO
Rats were kept for 30 days in an O2-N2-mixture of gradually reduced O2 (18 leads to 6 Vol%) and constant CO2 (0.5 Vol percent). This induces a selective hypertrophy of the right ventricle and the ratio ventricular/body weight (g/kg) increased from 0.6 to 1.4 while it remained constant in the left heart. In the right and left ventricles of control animals the contents of myocardial ATP (4.0 muM/g) and of phosphocreatine (CP) (5.8 muM/g) were the same. These values were not significantly changed by hypertrophy. In the control animals, a single test-dose of isoproterenol (30 mg/kg), subcutaneously administered 2 hr before the heart was removed, caused a diminution of the ATP-content by 15 percent in the right ventricle and by 40 percent in the left. The CP-content was reduced by 40 percent on the right and by 50 percent on the left side. In the hypertrophied right ventricle, however, there was no major decrease in ATP and CP following the isoproterenol injection. In the nonhypertrophied left heart the response to isoproterenol was still detectable but much less than normal. As the chronotropic and hypotensive effects of isoproterenol were also lessened in the hypoxic animals it is concluded that a general reduction in the responsiveness to beta-adrenergic stimulation has occurred.
