副交感神經性作用이 肺胞表面 活性物質의 生成 및 分泌에 미치는 影響 = Effects of Parasympathetic Activity on the Production and Secretion of Pulmonary Surfactant of Rabbits

국문 초록 (Abstract)

Type Ⅱ 肺胞細胞에서 分泌되는 것으로 알려진 肺胞表面活性物質의 生成 및 分泌機轉이 neurohumoral effect에 依한 것인지를 究明코저 副交感神經性 作用을 亢進시키거나 遮斷시킨 操作을 施行한 家兎肺洗滌液의 表面活性度 및 type Ⅱ 肺胞細胞의 形態的 變化를 檢討하였으며 아울러 肺洗滌液의 蛋白質含量을 測定한 結果는 다음과 같다.
1. 正常家兎 肺洗滌液의 平均 最大 및 最小表面張力 및 stability index는 各各55.9 dyne/cm, 5.3 dyne/cm 및 1.7이었으며 蛋白質含量은 平均 165.5 μg/ml이었다.
2. 兩側頸部迷走神經을 電氣的으로 刺戟하거나 acetylcholine을 投與한 家兎肺洗滌液의 最小表面張力은 增加하여 stability index는 減少하였다.
蛋白質含量은 增加하였으며 특히 電氣的으로 刺戟한 群에서 增加의 程度가 甚하였다.
3. 兩側頸部 迷走神經을 切斷한 家兎肺洗滌液의 最小表面張力 및 蛋白質含量은 현저히 增加하였으며 atropine投與에 依해도 最小表面張力은 增加하였으나 肺胞洗滌液의 蛋白質含量은 正常이거나 若干 減少하였다.
4. 兩側頸部迷走神經을 電氣的으로 刺戟한 群의 type Ⅱ 肺胞細胞의 電子顯微鏡學的 所見은 osmiophilic inclusion body의 electron density가 正常 家兎의 그것에 比해서 增加되었다. 또 甚한 endoplasmic reticulum의 擴張을 보였으며 擴張된 endoplasmic reticulum內에는 osmiophilic material로 思料되는 物質을 볼 수 있었다. 그外 mitochondria 및 Golgi vesicle等 微細構造는 別變化를 나타내지 않았다.
5. 兩側頸部迷走神經切斷 및 atropine을 投與한 家兎의 type Ⅱ 肺胞細胞의 電子顯微鏡 所見은 osmiophilic inclusion body의 空胞現象, 構造 및 electron density의 不規則 等을 볼 수 있었으며 endoplasmic reticulum, mitochondria 및 Golgi vesicle等 微細構造에는 別變化를 볼 수 없었다.
6. 上記의 結果로 미루어 보아 type Ⅱ 肺胞細胞는 刺戟에 對해서 대단히 銳敏한 細胞로 思料되며 副交感神經性作用에 對한 type Ⅱ 肺胞細胞의 微細構造의 變化와 肺洗滌液의 表面活性度와는 반드시 比例的인 相關關係가 없었으나 微細構造物의 反應으로 미루어 볼 때 neurohumoral effect에 依해서 肺胞表面活性物質의 生成 및 分泌가 調節된다고 思料된다.
(本硏究中 電子顯微鏡的 觀察을 함에 있어서 始終 指導해 주신 本校 病理學敎室 孫泰重 敎授님께 깊이 感謝드립니다.)

다국어 초록 (Multilingual Abstract)

Conflicting results have been reported on the effects of the parasympathetic activity in the production and secretion of the lung surfactant. In the present stduy, an attempt was made to clarify the possible neurohumoral mechanism in the production and secretion of the lung surfactant, and two types of the parasympathetic activity were elecited on the rabbits, namely; exacerbtion in which acetylcholine and bilateral cervical electrical vagal stimulation were employed, and blockade in which atropine and bilateral cervical vagotomy were employed. The activities of the surfactant of the lung washings with the modified Langmuir-wilhelmy balance were studied as well as the electron microscopic observations of the type Ⅱ alveolar cells were made from the rabit so treated, and a comparison was made with the normal. The total protein content of lung washings was also measured.
Study of the surface tension:
The maximal and miniaml surface tension, stability index and the total protein content of the normal rabbit lung washing were 55.9dyne/cm, 5.3dyne/cm, 1.7 and 165.5μg/ml, respectively. The minimal surface tension of the lung washings was increased in all the groups studied with the most significant increase in the vagotomized group.
Measurement of protein:
The total protein content of the lung washings was sinificantly increased in the vagotomized and electrical vagal stimulated rabbits. But in the acetylcholine treated and atropinized rabbits it was slightly increased or within the normal limit.
Electron microscopic study:
In the normal rabbit, the type Ⅱ alveolar cell displayed abundant inclusions with the caracteristic deeply osmiophilic lamellae, and inclusion could be found throughout the cytoplasm. The endoplasmic reticulum was abundant, but the cisternae remained inconspicuous. However, mitochondria and Golgi vesicles were regularly distributed In electrical vagal stimulated rabbits, the type Ⅱ alveolar cell displayed conspicuous osmiophilic inclusions. Endoplasmic reticulum cisternae were massively dilated and contained abundant osmiophilic materials. In the vagotomized and atropinized rabbits, a moderate alteration of the osmiophilic inclusion bodies of type Ⅱ alveoler cell was produced, consisting of attenuationc of the typical lamellae and formation of vaculoes. Endoplasmic reticulum, mitochondria and Golgi vesicle were regularly distributed.
Both the exacerbation and blockade of the parasympathetic activity decreased the activity of pulmonary surfactant, but morphologically the enhancement of the secretory processes by parasympathetic effect, and degenerative changes of microstructures of type Ⅱ alveolar cell by anticholinergic effect were produced. The above results indicate that the production and secretion of the surfactant by the type Ⅱ alveolar cell may be governed by neurohumoral mechanism