Search PubMedSearch

PubMed · 3189315

Daily exposure to forty percent oxygen causes a decrease in platelet count.

Abstract

A study was undertaken to evaluate a previous observation made in this laboratory that hyperoxic treadmill training is associated with a decrease in the circulating platelet count (PLT). The subjects studied breathed air containing 40% oxygen for 30 min/day, 5 days/week, for 6 weeks, while at rest in the seated position. Such exposure resulted in a consistent fall in PLT between day 1 and day 5 of each week (P less than .01). In addition, there was a progressive decline in PLT over the 6 weeks of exposure to the hyperoxic air, PLT being inversely correlated with the duration of hyperoxic exposure (rs = -0.886, P less than .02). The total decrease in PLT over the 6 weeks was 56 +/- 46 x 10(9) l(-1) (P less than .025). Not surprisingly, these changes were mirrored in the plateletcrit (Pct). The decrease in PLT did not appear to be secondary to either hemodilution or reduced erythropoietic stimulation. The mechanism of production and the biological significance of these changes remain to be elucidated.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A F Meintjes, R D Baynes, G G Rogers, B V Mendelow. 1988. Daily exposure to forty percent oxygen causes a decrease in platelet count.. https://doi.org/10.1002/ajh.2830290405

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Modulation of pulmonary immune defense mechanisms by sulfuric acid: effects on macrophage-derived tumor necrosis factor and superoxide.

There is considerable interest in the potential health effects resulting from inhalation of acidic aerosols. However, except for well documented irritant effects and acid-induced changes in lung clearance function, other potential health effects have not been well defined. This study was designed to provide further insight regarding the relationship of sulfuric acid aerosol to the pathogenesis of respiratory disease by describing the effects of inhaled acid on the release and/or activity of biologically active mediators critical for maintaining pulmonary immunocompetence and resistance against infectious diseases. Results of this study demonstrated that a single inhalation exposure of rabbits to environmentally relevant and higher concentrations of sulfuric acid depresses the release/activity of lipopolysaccharide-stimulated tumor necrosis factor-alpha and also reduces the ability of pulmonary macrophages to produce superoxide anion radical in response to opsonised zymosan. These findings should be considered when evaluating the health risks associated with sulfuric acid exposure.

Administration, Inhalation

Protection against bradykinin-induced bronchoconstriction in asthmatic patients by neurokinin receptor antagonist.

Axon reflex mechanisms may be involved in the pathogenesis of asthma, but there has been no direct evidence that endogenous tachykinins cause bronchoconstriction in asthmatic subjects. We have studied the effect of a tachykinin receptor antagonist (FK-224) on bronchoconstriction induced by inhalation of bradykinin in asthmatic patients. In a double-blind, placebo-controlled, crossover trial, ten subjects with stable asthma were given FK-224 (4 mg) or placebo by inhalation 20 min before challenge with bradykinin (0-1250 micrograms/ml, five breaths of each concentration) given with 5 min intervals. Bradykinin caused dose-dependent bronchoconstriction in all subjects. FK-224 significantly opposed the bronchoconstrictor effect; the geometric mean of the cumulative concentration required to elicit a 35% fall in specific airway conductance was 5.3 micrograms/ml after placebo and 40 micrograms/ml after FK-224 (p < 0.001). Inhalation of bradykinin caused coughing in three subjects, which was inhibited by FK-224 in all three. Antagonism of the tachykinin receptor by FK-224 greatly inhibited both bronchoconstriction and coughing induced by bradykinin in asthmatic patients, suggesting that tachykinin release from the airway sensory nerves is involved in responses to bradykinin. Tachykinin receptor antagonists may be useful in the treatment of asthma.

Administration, Inhalation

[Obstructive respiratory tract diseases--new standards in therapy].

AIMS: Presentation of modern-day therapeutic procedures in various stages of obstructive airway diseases. MAIN TOPICS: Subacute bronchitis and hypersensitivity of the bronchial system are early symptoms of obstructive diseases of the airways. Highly effective prophylactic treatment includes adrenocortical hormones (ACH) (corticosteroid) inhalation and antibiotics used individually or in combination for a variety of indications, are now available. In cases of manifest airway obstruction (Stage B), bronchodilators are additionally required. Of those presently available, the beta 2 sympathicomimetics head the list. For anticholinergics and theophylline there are additional indications. If the resulting response is unsatisfactory, oral ACH must be employed in addition to ACH inhalation and bronchodilators. Cromoglycate administered for a period of four to six weeks should always be tried. In the stage of severe exacerbation (C), intravenous water-soluble ACH in combination with antibiotics, are necessary. The entire spectrum of bronchodilators should also be utilized. Functional analysis during treatment prevents under- or overtreatment. CONCLUSIONS: In particular in the early stages, the aim of treatment of obstructive airway diseases is prophylactic.

Administration, Inhalation