Kainic acid (KA)를 투여하여 경련을 유발한 후 대뇌겉질에 분포하는 혈류조절물질인 eNOS와 VIP 및 NPY 면역양성반응세포의 변화에 대하여 면역조직화학과 RT-PCR을 시행하여 다음과 같은 결과를 얻었다. 경련 후 1일과 3일군에서 eNOS 면역양성반응세포들이 대뇌겉질의 여러부위에서 관찰되었다. 특히 이차운동겉질, 일차 몸통감각겉질, 청각겉질 및 시각겉질에서 많은 수의 eNOS 면역양성반응세포들이 발현되었다. 그러나 띠겉질, 팽대뒤겉질 및 후각뇌주위겉질에서는 eNOS 면역양성반응세포가 거의 관찰되지 않았다. 경련 후 1일, 3일 및 6일군의 대뇌겉질에서 eNOS가 모세혈관과 작은 혈관들에서 발현이 증가되었다. 경련에 의한 다른 면역양성반응세포들의 변화를 알아보기 위해 VIP와 NPY 면역양성반응세포에 대한 면역조직화학을 시행한 결과 새로 발현되는 VIP와 NPY 면역양성반응세포들이 관찰되지 않았다. 별아교세포의 표지물질인 GFAP도 경련 후 1일군에서 증가된 발현을 볼 수 없었다. eNOS와 VIP 및 NPY mRNA의 변화를 RT-PCR을 이용해 관찰한 결과 eNOS의 변화가 1일과 3일 군에서 현저하게 증가되는 것을 관찰할 수 있었다. 따라서 본 실험결과 경련후에 eNOS가 신경세포들에서 특이적으로 발현되며 신경펩타이드 함유 신경세포들과 별아교세포는 발현변화가 적은 것을 알 수 있었다.
Administration of kainic acid (KA) results in induction of epileptiform activity and motor seizures. Nitric oxide (NO) mediates the increase in cerebral blood flow during seizure activity. However, the production site of NO has not been clearly defined. Recent studies showed that constitutive nitric oxide synthase may be induced under certain conditions. Therefore, this study was aimed to investigate the change in endothelial nitric oxide synthase (eNOS), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) since these are involved in cerebral blood flow. Rats were treated with KA and killed at 6 hours, 1, 3, 6 and 12 days after seizure. Expressional changes were assessed by immunohistochemistry and RT-PCR. eNOS was detected in the blood vessels of the cerebral cortex of the control group, but was not detected in neurons. eNOS-positive neurons were induced in the cerebral cortex at 1 and 3 days after seizure and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, insular cortex, ectorhinal cortex, parietal association cortex, temporal association cortex, auditory cortex and visual cortex. The levels of eNOS mRNA increased at 1 and 3 days after seizure compared to controls. The staining intensity of eNOS-positive microvessels was elevated in samples obtained 1, 3, and 6 days after seizure compared to the control group. However, NPY- and VIP-positive neurons, and glial fibrillary acidic protein-positive astrocytes were not induced in the cerebral cortex after seizure. Therefore, specific neuroactive substances may be induced in the cerebral cortex after seizure. Nitric oxide, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced eNOS-positivity and upregulated eNOS-positive microvessels may affect the cerebral blood flow and neuronal activity in the cerebral cortex after seizure.