Purified staphylococcal alpha toxin was found to inhibit the active transport of sodium across the isolated toad bladder when applied to the serosal but not to mucosal surface. Heating or the addition of specific antitoxin abolished this effect. Low temperatures reduced this activity significantly. Application of vasopressin to the bladder serosa shortly after toxin resulted in only weak and transient stimulation of sodium transport; once maximal toxin activity had been established, exposure to the hormone was without effect. Transport in bladders previously stimulated by vasopressin was rapidly inhibited by alpha toxin. Concentrations that suppressed active sodium transport completely within 30-45 min produced a significant increase in oxygen consumption by minced bladder tissue within the same period; antitoxin neutralized this activity. 2,4-dinitrophenol also inhibited sodium transport and stimulated oxygen consumption by the toad bladder. The addition of 2,4 dinitrophenol to bladder tissue in which respiration was maximally stimulated by alpha toxin resulted in a further increase in respiratory rate. The addition of toxin to bladder tissue after its exposure to a concentration of 2,4 dinitrophenol known to uncouple oxidative phosphorylation produced a significant stabilization but no increment in respiratory rate. The data are consistent with the previously suggested action of staphylococcal alpha toxin on cell membranes and suggest that energy-dependent transport processes are inhibited. The stimulation of oxygen consumption may be due to an additional effect on oxidative phosphorylation.
James J. Rahal Jr., Martin E. Plaut, Louis Weinstein
Usage data is cumulative from October 2023 through October 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 98 | 0 |
79 | 24 | |
Scanned page | 380 | 2 |
Citation downloads | 40 | 0 |
Totals | 597 | 26 |
Total Views | 623 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.