The Effect And Mechanism Of Acupuncture On The Role Of Astrocytes In Regulating Neural-vascular Function In MCAO Rats

Objective: To investigate the effect of acupuncture at Neiguan and Quchi on the re-covery of the cerebral function, the activation of astrocytes, the increase of cerebral mi-crocirculatory blood flow, and the promotion of brain glucose metabolism in MCAO ratsand to explore the mechanism of acupuncture on the role of astrocytes in regulating thecerebral microcirculatory blood flow and glucose metabolism in MCAO rats, in order toprovide theoretical basis for the research of the mechanism of acupuncture upon ischemicstroke.Methods: MCAO in rats was induced using suture-occluded method, given continu-ously acupuncture at Neiguan and Quchi for7days. The effect of acupuncture on the re-covery of cerebral function, the increase of cerebral microcirculatory blood flow, the con-tent of brain glutamate, and the expression of GFAP mRNA, mGluR5mRNA andCYP2C11mRNA was observed using neurological behavior score, immunohistochemistry,real-time quantitative PCR and Western Blot analysis to study the effect and the mecha-nism of acupuncture on the astrocyte activation of MCAO rats in regulating the cerebralmicrocirculatory blood flow quantity. The effect of acupuncture on the content of lactateand pyruvic acid, the expression of GFAP, GLUT1, MCT1, GLUT3, and MCT2was ob-served to study the effect and the mechanism of acupuncture on the astrocytes of MCAOrats in regulating brain glucose metabolism.Results: Continuously acupuncture at Neiguan and Quchi for7days significantlyimproved the recovery of the cerebral function. The therapeutic effect of the acupunctureat Neiguan or Quchi had no significant differences.The acupuncture at Neiguan and Quchi can facilitates proliferation of astrocytes, and the expression of GFAP and GFAP mRNA, shows that acupuncture can facilitates the ac-tivation and proliferation of astrocytes.The acupuncture at Neiguan and Quchi significantly raised the cerebral microcircu-latory blood flow, and the expression of mGluR5mRNA, CYP2C11mRNA in MCAO rats.Improvements in the expression of mGluR5mRNA showed superior for Neiguan thanQuchi. The acupuncture at Neiguan and Quchi drastically reduced the excessive brainglutamate content in MCAO rats, and the improvement of this index showed superior forNeiguan than Quchi.The acupuncture at Neiguan and Quchi significantly raised brain pyruvic acid contentand the expression of GLUT1, GLUT3, MCT1while drastically reduced brain lactate con-tent in MCAO rats.Conclusions: Acupuncture at Neiguan and Quchi can activate the astrocytes, whichbenefits the brain in two aspects. In the first place, the activation of the astrocytes pro-motes the expression of mGluR5mRNA and CYP2C11mRNA, thus leading to the re-laxation of micro-vascular smooth muscle and the increase of the cerebral microcircula-tory blood flow. On the second place, the activation of the astrocytes promotes the use ofthe lactate to meet the energy requirement for nerve cells when the brain is short of blood.This may be one of the important mechanisms that the acupuncture can improve ischemicstroke.In addition, the acupuncture at Neiguan and Quchi can drastically reduce the exces-sive brain glutamate, and hence the toxic effect upon nerve cells. The acupuncture can alsoraise the expression of glucose transporter protein in micro-vascular endothelial cells andnerve cells so as to promote the transport and use of glucose, thus contributing to the re-covery of the damage of the brain nerve function.