[Protective effects of scopolamine on rabbits with acute brain injury].
OBJECTIVE
To study the protective effects of scopolamine (Sco) (a muscarinic receptor antagonist) on rabbits with acute brain injury, and preliminarily explore the roles of acetylcholine (ACh) in the early pathologic changes of traumatic brain injury(TBI).


METHODS
The model of acute brain injury was established by a free-falling device, and the rabbits received Sco intraperitoneally at 5 minutes and 2 hours after brain injury respectively. Transcranial Doppler (TCD) was used to monitor cerebral blood flow velocity (CBV) and pulsatility index (PI) of middle cerebral artery (MCA). The levels of Ca2+, the activities of superoxide dismutase (SOD), the contents of malondiadehyde (MDA) and Evans blue (EB) were measured, and the pathological changes were observed in brain tissue.


RESULTS
This model consisted with the pathologic changes of accelerated brain injury. Sco reduced the levels of Ca2+, EB and MDA, increased the activities of SOD, and improved cerebral blood flow following brain injury.


CONCLUSIONS
In the early stage of brain injury, ACh can cause neuron calcium overload, oxide free radical reaction, cerebral vasospasm, and increase blood-brain barry(BBB) permeability. Scopolamine, a muscarinic receptor antagonist, can improve these pathologic changes. As a result, Sco has protective effects on brain tissue injury.
Shi
B Z
BZ
Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha 410078.
Zhang
Z Q
ZQ
Feng
Z Y
ZY
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001783:Blood Flow Velocity; D001930:Brain Injuries / Q000378:metabolism* / Q000503:physiopathology; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011817:Rabbits; D011897:Random Allocation; D012601:Scopolamine / Q000494:pharmacology*
D018727:Muscarinic Antagonists; D018696:Neuroprotective Agents; D012601:Scopolamine; D000109:Acetylcholine