Metabolic enhancement and increase of alveolar macrophages induced by ozone.
Male Wistar rats were exposed to 0.2 ppm ozone (O3) for 14 days and at intervals alveolar macrophages were collected by bronchoalveolar lavage to examine the effects of O3. The specific activities of glucose-6-phosphate dehydrogenase and glutathione peroxidase of alveolar macrophages increased to 1.6-fold (on the 3rd day) and 1.5-fold (on the 5th day), respectively, those of the control values. Similarly, the specific activities of pyruvate kinase, lactate dehydrogenase, and hexokinase also increased to 1.6-fold, 1.4-fold, and 1.2-fold, respectively, those of the control values on the 3rd day. The activities of all enzymes tested were maintained at significantly higher levels until the 14th day. Furthermore, the incorporation of [14C]thymidine into alveolar macrophages increased twice the control values on the 1st and 3rd days and was almost completely inhibited by the addition of 1.23 x 10(-4) M aphidicolin, a competitive inhibitor of DNA polymerase alpha. The number of alveolar macrophages collected from exposed animals also increased to 1.5-fold that of the control value on the 3rd day and was maintained at significantly higher level until the 14th day. It was noted that alveolar macrophages of small size preferentially increased between the 5th and 14th days. These results show that exposures to 0.2 ppm O3 induced a metabolic enhancement of the peroxidative metabolism, glycolysis, and DNA synthesis in alveolar macrophages and increased the macrophages of small size.
Mochitate
K
K
Basic Medical Sciences Division, National Institute for Environmental Studies, Ibaraki, Japan.
Miura
T
T
D000818:Animals; D002452:Cell Count / Q000187:drug effects; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010126:Ozone / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors
D010126:Ozone; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D013936:Thymidine