Histamine Sensitivity in Mice of Different Ages after Bordetella pertussis Treatment or Adrenalectomy

Summary The Rocky Mountain Laboratory strain of mouse which is resistant to the effect of histamine sensitizing factor from Bordetella pertussis (HSF) at 3 to 5 weeks of age became susceptible to this effect by the age of 8 weeks. The LD50 of histamine in HSF inoculated 3-week-old mice was 6.8 mg per mouse (524 mg/kg), while in 9-week-old mice it was less than 0.5 mg per mouse (<18.5 mg/kg). The LD50 of histamine in the 3-week-old control mice was 18.4 mg per mouse (1417 mg/kg), while in 9-week-old animals it was 19.3 mg per mouse (715 mg/kg). Development of histamine sensitivity after adrenalectomy was also found to be affected by age: LD50 of histamine for 4- to 5-week-old mice was 11.3 mg per mouse while it was only 0.7 mg for 10- to 12-week-old mice. Some physiological change related to aging must occur in these mice to bring about the change in susceptibility to histamine sensitization after HSF inoculation. This change appears to be related to the adrenal hormones, but the relationship is not clearly understood.