Abstract
An examination was made of the role of component substances of the cerebrospinal fluid (CSF) such as platelet-derived growth factor (PDGF) in the development of proliferative angiopathy, one of the characteristic organic changes of cerebral vessels caused by subarachnoid hemorrhage (SAH). Experimental SAH was induced by a transorbital tear of the right middle cerebral artery (MCA) in 16 cats. Significant luminal narrowing and wall thickening due to proliferative organic changes were observed in the right MCA in 10 case with SAH. Such changes were minimal in 6 cats in which tissue plasminogen activator was administered intrathecally at 24 hours after SAH. PDGF (either the A or B dimer; 1 jig) was injected into the cisterna magna in 20 other cats. Organic changes equivalent to those noted in the cats with SAH were observed especially in cats receiving intrathecal PDGF B dimer. Immunohistochemically, PDGF was detected on the outer side of the MCA within 2 days after SAH. These findings suggest that bioactive substances capable of eliciting organic changes are released into the CSF in SAH. Furthermore, in particular PDGF (possibly the B chain) may play an important role in the development of organic changes in the vessel wall following SAH. From the clinical standpoint, intrathecal fibrinolysis may be effective for preventing the organic changes.
