Ventilatory function, cellular composition in bronchoalveolar lavage (BAL) fluid and release of chemical mediators from leucocytes were examined in 25 older asthmatics (mean age 66.7 years) and 25 younger asthmatics (mean age 45.1 years) in relation to clinical asthma types. 1. Ventilatory function tests showed that the values of ventilatory parameters such as % MMF, % V(50) and % V(25) were lower in older subjects than in younger subjects, and a significant difference was found in the % V(50) value between the two age groups. Regarding clinical asthma types, the values of % MMF, % V(50), and V(25) were significantly lower in both younger and older subjects with type II. 2. In analysis of cellular composition in BAL fluid, the proportion of BAL lymphocytes was significantly lower in type II older subjects than in younger subjects with the same type. A significantly increased proportion of BAL neutrophils was observed in both younger and older subjects with type II. 3. The release of leukotriene C(4) (LTC(4)) from leucocytes was significantly lower in type II older subjects than in younger subjects with the same type, and LTC(4) release in patients with type II was also significantly lower than that in those with other asthma types in both younger and older subjects. The release of histamine and leukotriene B(4) (LTB(4)) from leucocytes was not significantly different between the two age groups. These results demonstrate that ventilatory function, cellular composition in BAL fluid, and the release of chemical mediators from leucocytes are affected by aging and clinical asthma types.25例の老年者気管支喘息と25例の若壮年者喘息症例を対象に,換気機能,気道内細胞成分の頻度,白血球からの化学伝達物質遊離などの気道反応と関連した要素について,喘息の臨床病型との関連のもとに検討を加えた｡ 1. % MMF, % V(50), % V(25)などの換気パラメーターは老年症例において全般的に低く, % V(50)では若壮年症例に比べ有意の低値を示した｡臨床病型別では,II型喘息において,両年齢群とも他の病型に比べ% MMF, % V(50)及び% V(25)値は有意に低い傾向が見られた｡ 2. 気管支肺胞洗浄(BAL)液中のリンパ球頻度は,II型の老年症例において若壮年症例に比べ有意に低い値を示した｡BAL液中好中球頻度は,いずれの年齢群においても,他の病型に比べ有意に高い値を示した｡ 3. 白血球からのLTC(4)遊離は,II型の老年症例において若壮年症例に比べ,また他の臨床病型に比べ有意に低い値を示した｡ヒスタミンおよびLTB(4)遊離には両年歯群間に有意の差は見られなかった｡これらの結果は,換気機能,気道内細胞成分の頻度,白血球からの化学伝達物質遊離などが,加齢や臨床病態により影響を受けることをある程度示しているものと考えられた
