PubMed · 4132834
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L J Bruce-Chwatt. 1974-05-04. Letter: No provocation without foundation.. https://doi.org/10.1016/s0140-6736(74)90532-7
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Physiological leucocytosis refers to an increase in the number of circulating leucocytes which occurs either in response to physical exercise or to increased levels of adrenalin in otherwise healthy human beings. The mechanism underlying this phenomenon and its physiological implications are not known. The article briefly sums up 99 years of research in this field. It is concluded that adrenalin is the most important mediator in the regulation of the leucocytosis. Before entering the circulating blood the leucocytes are stored intra- and/or extra-vascularly in several organs, including the lungs, spleen, lymphatic tissue and haematopoietic bone marrow. Evidence is also presented indicating changed activity at the level of the individual leucocyte during physiological leucocytosis.
In patients with cirrhosis, the significance of elevated plasma catecholamine concentrations is unclear. Thus we investigated the relationship between plasma catecholamine concentrations and the hemodynamic effect of pindolol (an index of sympathetic vascular tone) in 10 patients with cirrhosis. Systemic and splanchnic hemodynamics and plasma catecholamine concentrations in the pulmonary artery and the splanchnic veins (hepatic and azygos veins) were studied before and after the oral administration of pindolol (20 mg). In basal conditions patients exhibited a hyperkinetic circulatory syndrome and elevated plasma catecholamine concentrations. Alterations in basal hemodynamics were correlated with plasma epinephrine concentrations but not with norepinephrine. Pindolol administration significantly decreased heart rate and increased right atrial pressure. After pindolol administration, individual hemodynamic changes (cardiac index, systemic vascular resistance, wedged hepatic venous pressure) were significantly correlated with plasma catecholamine concentrations. In conclusion, this study shows that in cirrhotic patients epinephrine may play a role in hemodynamic alterations, and plasma catecholamine concentrations are an index of sympathetic vascular tone.
Two free radical generating systems, xanthine oxidase/hypoxanthine or phenazine methosulfate/NADH, were exposed to air plus He, N2, or Ar at partial pressures ranging from 0.2 to 6.0 MPa, and the rates of production of superoxide, hydroxyl, singlet O2, and H2O2 were measured. All three inert gases acted similarly to enhance the production of superoxide radicals by facilitating interactions between iron and H2O2, or O2 and organic radicals. These reactions occurred at quite low gas partial pressures, only 0.28 MPa, and hydrostatic pressures of up to 6.0 MPa had no effect on radical reactions. Enhanced radical production may be the basis for the inhibition of cellular growth mediated by inert gases, and inert gas enhancement of O2 toxicity.