Rabbit lung after combined exposure to soluble cobalt and trivalent chromium.
Eight rabbits were exposed to 0.7 +/- 0.4 mg/m3 Co2+ as CoCl2 and 1.2 +/- 0.7 mg/m3 Cr3+ as Cr(NO3)3 (group Co + Cr), eight to 0.6 +/- 0.5 mg/m3 Co2+ (group Co), and eight to filtered air (control group), for 4 months, 5 days/week, and 6 hr/day. All rabbits in group Co + Cr and group Co showed nodular aggregation of alveolar epithelial type II cells. Volume density of the type II cells was significantly higher in group Co + Cr than in group Co and the control group. There was intraalveolar macrophage accumulation in seven rabbits in group Co + Cr, one in group Co, and one in the control group. In lavage fluid the numbers of macrophages and the percentage of these cells with smooth surface and intracellular surfactant-like inclusions were more increased in group Co + Cr than in group Co as were oxidative metabolic and phagocytic activities of the macrophages. Total phospholipids, phosphatidylcholines, and especially 1,2-dipalmitoylphosphatidylcholine was markedly increased in group Co + Cr whereas only 1,2-dipalmitoylphosphatidylcholine was slightly increased in group Co. One mechanism behind the high amount of surfactant phospholipids in group Co + Cr seems to be an enhanced production of surfactant by the type II cells. Another mechanism is probably that Cr3+ reduces the capacity of alveolar macrophages to catabolize surfactant. The results imply that it is important to investigate effects of combinations of cobalt and chromium in the occupational environment.
Johansson
A
A
Section of Lung Medicine, Karolinska Institute, Stockholm, Sweden.
Curstedt
T
T
Rasool
O
O
Jarstrand
C
C
Camner
P
P
D000818:Animals; D002857:Chromium / Q000633:toxicity*; D017608:Chromium Compounds; D003035:Cobalt / Q000633:toxicity*; D004357:Drug Synergism; D008168:Lung / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D016676:Macrophages, Alveolar / Q000187:drug effects; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009566:Nitrates / Q000633:toxicity*; D010743:Phospholipids / Q000032:analysis; D011650:Pulmonary Alveoli / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure; D011817:Rabbits
D017608:Chromium Compounds; D009566:Nitrates; D010743:Phospholipids; D002857:Chromium; D003035:Cobalt; C041167:chromium nitrate; C018021:cobaltous chloride