Analysis of water content in young rats brain edema by Raman spectroscopy

Cerebral edema, classified into vasogenic edema and cytotoxic edema, has long been studied and recognized to be complicated. The authors studied the cerebral edema models of young rats suffered from cryo-injury and triethyl tin chloride (TET) injury by Raman spectroscopy which can physiologically evaluate the cerebral water content (%) of very restricted area. The cryo-injury model was conducted in the following manner. A cryo-probe (-196 degrees C) was contacted to the exposed cranium for 20 seconds in an anesthetized 4-5-week-old Sprague-Dawley young rat. A coronal section of the injured brain covered with a slide glass and wrapped by Parafilm was obtained 2, 4, 6, 8, 12, 24, 48, 72 hours after the cryo-injury in order to measure the water content by Raman spectroscopy employed by Tashibu and Huizinga. TET injury model was obtained by intraperitoneal administration of TET (4.5 mg/Kg). The water content was observed by the same manner as for the cryo-injury model. Subsequent to the cryo-injury, the water content of the white matter which seemed to be higher than in adult rats increased rapidly and persisted in the same condition within 72 hours. Subsequent to TET injury, the water content of the white matter increased more rapidly than that of the gray matter, however, in adult rats the water content of the gray matter showed more rapid increase than that of the white matter. Increased water content followed by TET injury was higher in adult rats than in young rats.(ABSTRACT TRUNCATED AT 250 WORDS)