[Age differences in topic concentrations and activity of H2- and B2-receptors in the larynx and trachea].
H2- and B2-receptors concentrations and activity were measured in 12 adult (6-7-month-old) and 12 young (1.5-2-month-old) rabbits by vascular reactions to histamine and bradykinin with and without prior usage of relevant specific receptor blocker. The findings suggest that concentration and activity of H2- and B2-receptors in young animals are the highest in the larynx. In mature animals-partially in trachea. With aging these concentrations and activity diminish in the larynx and rise in the trachea, the changes of B2-receptors are more significant.