Decrease in cerebral free magnesium concentration following closed head injury and effects of VA-045 in rats

Abstract 1. 1. We examined the alterations in cerebral free Mg 2+ concentration in closed head injury (CHI) in rats and the effects of VA-045, a novel apovincaminic acid derivative, on them with in vivo 31 P-NMR. 2. 2. Free Mg 2+ decreased by about 30% within 20 min after head impact and, afterward, it gradually decreased further to reach about 60% of the control level after 3 hr. VA-045 inhibited the decrease. 3. 3. In nonimpacted rats, VA-045 did not alter the free Mg 2+ level. 4. 4. The decrease in cerebral free Mg 2+ following CHI may be a critical factor in the development of irreversible tissue injury, and VA-045 may prevent it.