Effect of histamine on respiratory movements and isolated ileum of pertussis-vaccinated mice. A negative study.

1. The sensitivity of mice, of the Swiss random bred strain, previously i.p. vaccinated with Bordetella pertussis Phase I cells, to histamine was investigated. 2. No response and no increase of the sensitivity of the respiratory system of the pertussis-vaccinated mice was observed during and after the inhaled histamine. 3. No contractions and no response of the isolated perfused ileum of the pertussis-vaccinated mice were observed after the addition of histamine. 4. No experimental or control mouse died during the whole experiment.