title: Platelet responses and anaphylaxis-like shock induced in mice by intravenous injection of whole cells of oral streptococci.
abstract: Intravenous injection of lyophilized whole cells of various oral streptococcal strains into muramyldipeptide (MDP)-primed C3H/HeN mice induces rapid anaphylactoid shock. Here we examined the mechanism underlying this shock. In non-primed mice, Streptococcus intermedius K-213K (SiK213) and Streptococcus constellatus T21 (ScT21) produced little or no sign of shock. In MDP-primed mice, SiK213 caused lethal shock, while ScT21 only had a weak effect. SiK213 induced decreases in blood platelets and 5-hydroxytryptamine (5HT) preceding the shock, while the effects of ScT21 were weak. The SiK213-induced 5HT decrease and shock were reduced by a complement-C5 inhibitor. These results suggest that (i). streptococcal bacterial cells can induce rapid platelet responses, (ii). complement-dependent degradation of platelets may be involved in streptococcus-induced shock, (iii). the streptococcus-induced platelet degradation or degranulation may occur largely in the systemic circulation, and (iv). platelets may play a role not only in infectious diseases caused by gram-negative bacteria, but also in diseases caused by gram-positive bacteria.
authors.affiliation: Department of Immunology, Graduate School of Dentistry, Tohoku University, Aoba-ku Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohba
authors.forename: M
authors.initials: M
authors.lastname: Shibazaki
authors.forename: T
authors.initials: T
authors.lastname: Sasano
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Takada
authors.forename: Y
authors.initials: Y
authors.lastname: Endo
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000008:administration & dosage / Q000276:immunology; D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000704:Analysis of Variance; D000707:Anaphylaxis / Q000382:microbiology*; D000818:Animals; D001792:Blood Platelets / Q000382:microbiology*; D015550:Cell Degranulation / Q000276:immunology; D003182:Complement C5 / Q000037:antagonists & inhibitors; D003169:Complement Inactivator Proteins / Q000494:pharmacology; D006877:Hydroxamic Acids / Q000494:pharmacology; D007114:Immunization; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D009055:Mouth / Q000382:microbiology; D012701:Serotonin / Q000032:analysis / Q000097:blood; D034365:Streptococcus constellatus / Q000276:immunology*; D034367:Streptococcus intermedius / Q000276:immunology*; D013921:Thrombocytopenia / Q000382:microbiology
chemical_list: D000276:Adjuvants, Immunologic; D003182:Complement C5; D003169:Complement Inactivator Proteins; D006877:Hydroxamic Acids; D008070:Lipopolysaccharides; C003486:2-methyl-3-(4-phenylpiperidino)propionohydroxamic acid hydrochloride; D012701:Serotonin; D000119:Acetylmuramyl-Alanyl-Isoglutamine