Abstract
Metabolism of PGF2α in lung was studied by two methods, namely, through pulmonary circulation using guinea pig lung perfusion on one hand and through the broncho-alveolar system using guinea pig and dog broncho-alveolar lavages on the other. Localization of prostaglandin dehydrogenase activity in the lung was also studied using histochemical techniques.
I. In guinea pig lung perfusion, amounts of up to 23.57±5.32ng/ml PGF2α-M were detected in perfusion fluids after infusion of 200ng/ml of PGF2α.
II. In guinea pig broncho-alveolar lavage, up to 71.4±6.1ng/ml PGF2α-M was detected in lavage fluids after instillation of 100ng/ml of PGF2α. In dog broncho-alveolar lavage, up to 2.92±0.59ng/ml PGF2α-M was detected in lavage fluids after instillation of 400ng/ml of PGF2α. The values of PGF2α-M in PGF2α broncho-alveolar lavage fluids were significantly higher than those in control saline broncho-alveolar lavage fluids.
III. The existence of PGDH activity in type II alveolar epithelial cells was confirmed by histochemical investigation.
The above results strongly suggest that not only capillary endothelial cells but also type II alveolar epithelial cells are greatly involved with the metabolism of PGF2α in the lung.
