Localization of plasminogen activators in XXXX @entity694 by immunoperoxidase staining.

@entity1 @entity5 @entity1456 @entity3 @entity652 @entity694 @entity420 @entity320
The immunoperoxidase technique, using antibodies against @entity1 urinary urokinase (Mr 55,000), was used for the localization of this enzyme in histological preparations of @entity1 @entity694 and normal colon tissue. The localization of tissue (vascular) activator was also investigated using antibodies against enzyme purified from @entity1 @entity320 . Both the "indirect method" and the peroxidase-antiperoxidase technique were found to be useful. Urokinase-reactive material was found in all tissues examined (33 primary @entity5 , 11 @entity3 , and 8 @entity652 ). In the normal colon, urokinase was found only in some of the goblet cells of the mucosal epithelium. In @entity694 , diffuse specific staining was observed in the cytoplasm, but the most intense staining was localized at the edge of the @entity5 cells bordering the lumen of the glands. In some cases, intense supranuclear staining could be observed in a location corresponding to the Golgi apparatus. In a few instances, urokinase could be seen associated with fibroblasts near the advancing front of an invading @entity5 . @entity652 , a @entity5 but often a precursor of @entity5 , also showed the presence of urokinase. Most significant were the observations showing that, in regions of the mucosal glands where normal epithelial cells were abruptly replaced by @entity5 cells, the appearance of cytoplasmic urokinase showed strict and exclusive association with the malignant cells, and the same was the case in transitions from normal epithelium to @entity652 . In contrast to urokinase, @entity1456 was not associated with @entity5 cells, but was consistently present in the stroma which separates the @entity5 glands and was localized in the endothelium of the blood vessels. This visual evidence was supported by results of extraction of plasminogen activators from @entity5 , and from the separated mucosal and submucosal layers of the normal colon of the same @entity1 , which showed that urokinase is most abundant in the @entity5 tissue and least abundant in the submucosa, while tissue activator is most prevalent in the well-vascularized mucosa and submucosa and scarce in the usually poorly vascularized @entity420 .
