ABSTRACT
We present evidence that Bacillus anthracis lethal toxin (LT) suppresses rather than induces proinflammatory cytokine production in macrophages. Suppression is observed with extremely low levels of LT and involves inhibition of transcription of cytokine messenger RNA. Thus, LT may contribute to anthrax pathogenesis by suppressing the inflammatory response.
Subject(s)
Antigens, Bacterial , Bacillus anthracis/pathogenicity , Bacterial Toxins/toxicity , Cytokines/biosynthesis , Macrophages/drug effects , Animals , Cell Line , Cytokines/genetics , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Mice , RNA, Messenger/analysisABSTRACT
The relative potency of penbutolol, a new beta adrenergic receptor blocking agent, was compared with propranolol by a four-point assay on healthy male subjects. A dose-response relationship to intravenous doses of propranolol in the microgram range was obtained during a steady state of infusion of epinephrine. Two subjects underwent the entire assay according to the Latin square design and four others each underwent one schedule of design on different days. The potency of penbutolol thus assessed was consistent with reported results. This study emphasizes the importance of intersubject variation and differential receptor sensitivity in individuals. The use of epinephrine as a beta receptor adrenergic agonist for evaluation of selective beta adrenergic receptor blocking activities is discussed.
