Bronchial reactivities in guinea pigs to acetylcholine or histamine exposure.
The bronchial reactivities in Hartley guinea pigs to acetylcholine (ACh) or histamine (Hist) were investigated, and the following results obtained; 1. Eight-week-old animals were exposed to ACh and Hist. A significant relationship was observed between the concentrations of the chemicals and the time needed to produce falling down (TNPFD) due to the asthmatic reaction to ACh and Hist. 2. Eight-week-old animals were exposed to 0.1% ACh and 0.05% Hist, for which the mean TNPFD +/- standard error were 377 +/- 33 sec and 122 +/- 5 sec respectivity. However, no difference in reactivity between male and female animals was noted. 3. Eight- and 9-week-old animals were exposed to 0.01% ACh and 0.025% Hist. A positive correlation was observed (r = 0.736, p less than 0.01) between the TNPFD for ACh and that for Hist. 4. Growing animals from 2 weeks to 20 weeks old were exposed to 0.08% ACh and 0.025% Hist. After inhalation of both chemicals, 6-week-old animals showed the greatest prolongation of mean TNPFD (lowest sensitivity). 5. Eight-week-old animals were exposed to 0.08% ACh and 0.025% Hist. With both of these chemicals, a positive correlation was observed between TNPFD and dose threshold (ACh r = 0.886, p less than 0.001; Hist r = 0.891, p less than 0.001).
Mikami
H
H
Institute of Bio-Active Science, Nippon-Zoki Pharmaceutical Co., Ltd., Hyogo, Japan.
Nishibata
R
R
Kawamoto
Y
Y
Ino
T
T
D000109:Acetylcholine / Q000276:immunology; D000367:Age Factors; D000818:Animals; D001249:Asthma / Q000139:chemically induced*; D001980:Bronchi / Q000276:immunology*; D001985:Bronchial Provocation Tests; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D006632:Histamine / Q000276:immunology; D008297:Male; D013997:Time Factors
D006632:Histamine; D000109:Acetylcholine