Increased matrix metalloproteinase-9 in blood in association with activation of interleukin-6 after traumatic brain injury: influence of hypothermic therapy.
Recent experimental data have shown that levels of matrix metalloproteinase-9 (MMP-9) increase after traumatic brain injury (TBI), degrading components of the basal lamina disrupting the blood-brain barrier. However, the post-traumatic secretion patterns of MMP-9 in humans are unknown. We measured the concentration of MMP-9 in plasma after TBI at the same time as the concentration of interleukin-6 (IL-6) in serum. Levels of MMP-9 and IL-6 in systemic arterial and jugular venous blood from seven patients with TBI were measured on days 0 and 1 post-injury. All patients underwent hypothermia at 32-35 degrees C as soon as possible after admission. Before induction of hypothermia, levels of MMP-9 in arterial and internal jugular venous blood exceeded the normal range. Higher MMP-9 levels were detected in internal jugular venous blood than in arterial blood. After hypothermia had been induced, MMP-9 levels in arterial blood and internal jugular venous blood decreased significantly, to within the normal range. In addition to these changes, a significant correlation was seen between levels of MMP-9 and IL-6 in internal jugular venous blood during the investigation period. These results indicate that MMP-9 is elevated in patients with acute TBI, and may play an important role in traumatic brain damage. The elevation of MMP-9 is associated with inflammatory events following TBI. Hypothermic intervention may suppress the elevation of MMP-9 with suppression of the inflammatory response, affording neuroprotection in TBI.
Suehiro
Eiichi
E
Department of Neurosurgery, Clinical Neuroscience, Yamaguchi University School of Medicine, Ube, Yamaguchi 755-8505, Japan. suehiro-nsu@umin.ac.jp
Fujisawa
Hirosuke
H
Akimura
Tatsuo
T
Ishihara
Hideyuki
H
Kajiwara
Koji
K
Kato
Shoichi
S
Fujii
Masami
M
Yamashita
Susumu
S
Maekawa
Tsuyoshi
T
Suzuki
Michiyasu
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001158:Arteries; D001930:Brain Injuries / Q000097:blood* / Q000628:therapy*; D005260:Female; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D006801:Humans; D007036:Hypothermia, Induced; D015850:Interleukin-6 / Q000097:blood*; D007601:Jugular Veins; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D013997:Time Factors
D015850:Interleukin-6; D020780:Matrix Metalloproteinase 9