Dermal tuberculous lesions were produced in rabbits by the injection of BCG, the vaccine strain of the tubercle Bacillus. The lesions showed a remarkable increase of focal fibrinolytic activity throughout a 4- to 53-day period of growth and regression. The fibrinolytic activity was caused by a plasminogen activator. At 11 to 18 days, when hypersensitivity to the BCG vaccine became pronounced and caseous centers developed, fibrinolytic activity was particularly high. It was mainly related to dilated small blood vessels and to new capillaries in the granulation tissue. In the deep dermis near the lesion, dilated larger blood vessels showed increased fibrinolytic activity during the late stages of the healing process. Dilated larger blood vessels in the deep dermis between the lesion area and the normal skin frequently showed increased activity independent of the age of the lesion.
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Molecular Biology
- Clinical Biochemistry