This study was undertaken to investigate the ultrastructural changes of the lung with
special references to the alveolar lining cells of rats after inhalation anesthesia with
ether, halothane and methoxyflurane respectively.
The results were summarized as follow:
1) Light microscopically, the findings of lung tissue were very similar in the all groups.
Immediately after anesthsia, mild congestion arid interstitial edema were noted. Four and
12 hours after anesthesia, the alveolar linings cells were increased in number with mild
thickening of the alveolar septae. Increase of bronchiolar secretory activities were not
prominent.
2) Electron microscopically, no significant change was noted in type Ⅰ alveolar cell in
the all groups. Most prominent changes were occurred in the type Ⅱ alveolar cells in
the all groups. with the ether anesthesia, marked changes of osmiophilic inclusion
bodies, such as increased number, pleomorphism, decreased density and vacuolization
were noted immediately after anesthesia. These changes were considerably recovered at
4 hours and completely returned to the normal pattern at 12 hours. Halothane and
methoxyflurane anesthesis also induced similar changes in the type Ⅱ ceIls, but they
were milder than ether anesthesized animals. Osmiophilic inclusion bodies were increased
in number, with pleomorphism of the shape, decreased density, vacuolization and
extrusion of their contents. After 4 and 12 hours, the number of type Ⅱ cells was also
increased.
The endothelial cells of alveolar capillaries showed nearly normal pictures in the ether
anesthesized groups, but showed mild swelling, increase of pinocytotic vesicles, dilatation
of rough ER and vacuolar formation in the both halothane and methoxyflurane
anesthesized groups immediately after anesthesias. These changes were markedly
recovered at 4 hours an completely returned to normal at 12 hours.
The number of alveolar phagocytes were slightly increased in all experimental groups
at 4 and 12 hours, with increase of autophagic vacuoles.
3) These findings suggest that ether anesthesia induces marked degenerative and
adaptive changes in the alveolar type Ⅱ cells, particularly in their osmiophilic inclusion
body, but does not effect alveolar capillary endothelial cells. On the other hand,
halothane and methoxyflurane induce relatively milder degenerative and adaptive changes
on the alveolar type Ⅱ cells, while mild degenerative changes are induced in the
alveolar capillary endothetial cells. All these changes, occurred on the type Ⅱ epithelial
cells and alveolar capillary endothelial cells, are reversible changes and times required
for their recovery are retatively short.
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