Bleomycin and its analogues are widely used as antineoplastic drugs. Upon adminstration some adverse effects such as pulmonary fibrosis, stomatitis and dermatosis are often observed.There have been many reports that these adverse effects were induced by inhibition of vascularization.Some studies suggested that the disturbance of the vascularity due to Bleomycin was related to its antineoplastic effect.
Pepleomycin an analogue of Bleomycin has been shown to be equal to or more effective than Bleomycin.It has also been shown that administration of Pepleomycin results in less incidence of pulmonary fibrosis, but that stomatitis and dermatosis are frequently observed. These observations suggest that Pepleomycin has more effects on homeostasis of the circulatory system.
The present study used male rats (Sprague Dawley) that had been treated with both Bleomycin and Pepleomycin by interperitoneal injection at specified intervals.The tongue submucosa was resected.Then, changes in capillary and pericapillary tissues were observed by electron microscopy or light microscopy.
In the group treated with Bleomycin, hypertrophy was observed in the capillary endotherium. While, pericapillary tissue seemed to consistently remain unchanged.They seemed to disturbance of permeability in the capillary.In the Pepleomycin treatment group, reduction in the size of the capillary endotherium and in some cases, fenestration of the endotherium were induced.Many changes in pericapillary tissue were also observed.They seemed to accelerate permeability in the capillary.
The results of this study suggested that Bleomycin and Pepleomycin influences the local circulatory system and is related to antineoplastic effects.