ABSTRACT
The effect of three doses of prednisolone and ACTH respectively on the weight of the body, the lungs and the hilar lymph nodes was studied on rats killed one month after the intratracheal (i.t.) injection of 50 mg of fine-particulate quartz. The prednisolone was administered via the drinking water, and the ACTH was injected intraperitoneally during the period between the i.t. injection of quartz dust and the killing of the animals.
Prednisolone causes the rats to become cachectic and reduces the weight of the hilar lymph nodes. It also retards the transport of quartz dust from the lungs via the lymphatics. All these effects increase with increasing doses of prednisolone. However, its effect on the lung weight is insignificant.
ACTH does not affect the body weight, but retards the weight increase of the lungs and the hilar lymph nodes. These effects increase with increasing doses of ACTH, and seem to be connected with an ability of ACTH to promote the clearance of quartz dust from the lungs and hilar lymph nodes. The method used, however, does not make it possible to differentiate quantitatively between any ACTH effects on the bronchogenie and lymphatic lung-clearance mechanisms. Available data, however, indicate that the stimulation of the dust transport from the lungs and hilar lymph nodes is, at least to some extent, related to the lymphatic system.
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