Fibrinolytic effects of transparietal ultrasound associated with intravenous infusion of an ultrasound contrast agent: study of a rat model of acute cerebral stroke.
The aim of this study was to evaluate the thrombolytic effect of focused transparietal ultrasound in combination with a specific contrast agent (microbubbles) in acute cerebral ischemia. Acute cerebral ischemia was induced in 10 rats by intra-arterial clots injection. Five rats (group 1) were treated with a combination of transparietal ultrasound (probe 2 MHz, acoustic power 500 mW/cm(2)) and intravenous injection of 0.6 mL of the ultrasound contrast agent (UCA) sulfur hexafluoride. Five rats (group 2) were treated by fibrinolytic intravenous infusion (recombinant tissue plasminogen activator). Cerebral cellular energy production was determined by measuring the cellular phosphorylation using phosphorus magnetic spectroscopy before and during ischemia induction and after treatment. Measures were performed on a dedicated 2.35T magnet. The ratio phosphocreatine (P(Cr)) on inorganic phosphate (P(i)), P(Cr)/P(i), estimation of the oxidative phosphorylation metabolism and the intracellular pH (pHi) were measured in the two groups. Compared with the ischemia induction period, both treatments were associated with an increase of P(Cr)/P(i) and pHi values, respectively, +80% and +100% in group 1 (p=0.07) and +100% and +80% in group 2 (p=0.04). There was no significant difference between the two groups for the response treatment. To conclude, treatment with intravenous fibrinolytic infusion and treatment with focused ultrasound in combination with UCA seems to be equally effective in treating acute cerebral ischemia in rats. (E-mail: j.p.tasu@chu-poitiers.fr).
Moumouh
Ahmed
A
Department of Imaging, CHU of Poitiers, Poitiers; Inserm, Tours cedex, France.
Barentin
Laurent
L
Tranquart
François
F
Serrierre
Sophie
S
Bonnaud
Isabelle
I
Tasu
Jean Pierre
JP
D000208:Acute Disease; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000628:therapy*; D003131:Combined Modality Therapy / Q000379:methods; D003287:Contrast Media / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D007275:Injections, Intravenous; D009682:Magnetic Resonance Spectroscopy; D045423:Microbubbles; D010785:Photophosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013459:Sulfur Hexafluoride / Q000627:therapeutic use; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D014464:Ultrasonic Therapy; D014463:Ultrasonography
D003287:Contrast Media; D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator; D013459:Sulfur Hexafluoride