Rice germinates equally well when incubated in air and in nitrogen. It was therefore chosen for a comparative study of the effect of oxygen status in a single organism upon the activity of conventional metabolic poisons. Inhibitor activity was based upon the concentration required for 50% inhibition of germination. The inhibitors were: AgNO(3), HgCl(2), phenylmercuric acetate, iodoacetamide, KC...

Effects of D 600, papaverine and KCN on sustained contracture induced by 20 mM KCl in a Na+-free sucrose- or Tris-substituted solution were investigated in the taenia coli of guinea pigs. D 600 (10(-5) M) and papaverine (10(-4) M), added after 40 min incubation in the 20 mM KCl sucrose solution, relaxed the muscle by 88.2 +/- 8.0% (mean +/- S.E., n = 4) and 78.8 +/- 6.3% (n = 4), respectively. ...

Aerobic respiration of Streptococcus pyogenes and pneumococcus Type 1 are strongly inhibited by KCN, NaN(3), and Na(2)S. The anaerobic glycolysis of glucose by pneumococcus is also inhibited by KCN and NaN(3). Streptococcus pyogenes, E. coli, pneumococcus Type 1, B. subtilis, B. proteus, and Staphylococcus aureus did not catalyze the oxygen uptake by p-phenylenediamine in the presence of added ...

The stomata in the abaxial epidermis of Vicia faba were examined for the location of redox systems using tetrazolium salts. Three distinct redox systems could be demonstrated: chloroplast, mitochondrial, and plasmalemma. The chloroplast activity required light and NADP. Mitochondrial activity required added NADH and was suppressed by preincubation with KCN. The plasmalemma redox system in guard...

The alternative oxidase (AOX) of plant mitochondria transfers electrons from the ubiquinone pool to oxygen without energy conservation. AOX can use reductant in excess of cytochrome pathway capacity, preventing reactive oxygen species (ROS) formation from an over-reduced ubiquinone pool, and thus may be involved in acclimation to oxidative stresses. The AOX connection with mitochondrial ROS has...

In this study the effects of paraquat on the aerobic metabolism and viability of isolated rabbit alveolar macrophages and lung fibroblasts were investigated, and compared with the effects of other known metabolic inhibitors, i.e. sodium fluoride (NaF) and potassium cyanide (KCN). The manometrically and polarographically determined endogenous oxygen consumption of lavaged alveolar macrophages co...

The contribution of peroxisomes to palmitate beta-oxidation in rat heart was estimated by either inhibiting mitochondrial beta-oxidation or measuring the activity of acyl-CoA oxidase. When respiratory inhibitors such as KCN or antimycin plus rotenone, or inhibitors of mitochondrial fatty acid uptake such as 2-tetradecylglycidic acid or 2-bromopalmitate, were used, degrees of inhibitions ranging...

Evidence is presented showing that the dissimilation of carbohydrate reserves in two strains of bakers' yeast, Saccharomyces cerevisiae, is a purely respiratory process. Endogenous respiration is KCN-labile. Our own experiments together with various accounts and data given in the literature show that the same "oxygen-transporting mechanism" functions in both endogenous and exogenous metabolism....

Peripheral chemoreceptors located in the carotid bodies are the primary sensors of systemic hypoxia. Although the pattern of responses elicited by peripheral chemoreceptor activation is well established in rats, lambs, and rabbits, the cardiovascular responses to peripheral chemoreflex activation in conscious mice have not been delineated. Here we report that stimulation of peripheral chemorece...

The pattern of Fos-like immunoreactivity (FLI) in the periaqueductal gray (PAG) associated with activation of arterial chemoreceptors versus baroreceptor afferents was examined in urethane-anesthetized rats. Chemoreflex responses elicited by repeat intravenous injections of potassium cyanide (KCN; 90 microg/kg) significantly increased FLI in all columns of the PAG relative to saline-injected an...