The endogenous respiration rate of unstarved cultured cells of Acer pseudoplatanus L. is markedly stimulated by 2,4-dinitrophenol. Pyruvate is also stimulatory but to a lesser degree than dinitrophenol. Exogenously supplied sugars cause no short-term stimulation. Pyruvate does not enhance the elevated rate of 0, uptake in the presence of dinitrophenol but does cause additionatl CO2 evolution. T...

INTRODUCTION The principal factor initiating increased cardiac output during exercise, the "work stimulus," still is not fully understood (1). Both mechanical and metabolic factors have been identified with the "work stimulus." The former have been related to the stimulation of mechanical sensory receptors inside the muscles or tendons, and This work was presented in part at the Annual Meeting ...

Studies of the adenosine triphosphate-adcnosine diphosphate exchange reaction of phosphorylating submitochondrial particles first described by Cooper and Lehninger (l), and subsequently studied in detail by Bronk and Kielley (2), and Wadkins and Lehninger (3) have provided evidence that this exchange reaction is a manifestation of the terminal step of oxidative phosphorylation in which ADP reac...

Simultaneous preconcentration of phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol was improved by using olive wood (OW) washed with ethanol then pyrolyzed at 200°C as preconcentrating sorbent. Various OW sorbents were prepared by either washing OW (with ethanol, ether, dichloromethane, tetrahydrofuran or n-hexane); or by pyrolysis (at 1...

Effects of inhibitors of phosphorylation on the oxidation of succinate and of l-malate were investigated with tightly coupled mitochondria isolated from mung bean hypocotyls. When mitochondria were incubated with 2,4-dinitrophenol, or carbonyl cyanide m-chlorophenylhydrazone prior to the addition of substrate, the uncoupling effects of these chemicals were relatively small. This is probably cau...

1. The release of growth hormone from isolated fragments of rat anterior pituitary tissue incubated in vitro was studied by employing a double-antibody radioimmunoassay. 2. In the absence of added stimuli, two phases of hormone release could be distinguished, an early phase of 2h duration and a subsequent late phase. In the early phase, hormone release was rapid but could be significantly decre...