The role of astrocytes during repair of cerebral infarction in mdx mice

様々な大きさのジストロフィンアイソフォーム(427kDa, 260kDa, 140kDa, 116kDa, 71-75kDa)が広く体内に存在していることはよく知られている.中枢神経系においては71-75kDaのDp71が著明に多く,毛細血管の内皮の基底膜に接しているアストロサイトの細胞質に局在することが報告されている.しかしながらDp71の機能についてはよくわかっていないことが多い.そこで今回,脳組織におけるDp71の役割を調べるために,コントロールマウス(wild-typeマウス)およびデュシャンヌ型筋ジストロフィーモデル動物であるmdxマウスを用いて実験的脳梗塞を作成し,その治癒過程を形態学的に観察した.また,GFAPおよびDp71に関して生化学的に分析をおこなった.HE染色およびGFAP免疫組織学的染色の結果から,形態学的にはmdxマウスとコントロールマウスの脳に違いは認められなかった.しかしながら,mdxマウスの脳において,Dp71の発現量がコントロールマウスよりも少ないことがわかった.またmdxマウスにおいて,脳梗塞の修復過程におけるアストロサイトの反応がコントロールマウスよりも弱いことがわかった.これらの結果から,mdxマウスの脳において,アストロサイトの機能,アストロサイトの血管新生に関わる機能の障害されていることが示唆された.It is now well known that dystrophin isoforms (427kDa, 260kDa, 140kDa, 116kDa, 71-75kDa) are widely distributed throughout our body. In the central nervous system a considerable amount of Dp71 (71-75kDa) is found in the perivascular cytoplasm of the astrocytes. However, the function of this dystrophin is still unknown. To investigate the role of Dp71 in the brain tissue, cerebral infarction was induced in the control (wide-type) mouse and mdx mouse which is known as an animal model of human muscle dystrophy (Duchenne type), and morphological changes of the infarcted area were observed during repair of the infarction. In addition, biochemical analysis of GFAP and Dp71 was carried out in the brain of the control and mdx mouse. In our present study, there were no differences in brain morphology between mdx and control mouse as revealed in H-E stain and GFAP immunohistochemistry. However, the Dp71 were smaller in quantity in the brain of the mdx mouse than that of the control mouse. The reaction of astrocytes during repair of serebral infarction was distinctly delayed in the mdx mouse compared with that of the control mouse. These findings suggest that the astrocytes in the brain of the mdx mouse are functionally impaired including perivascular cytoplasmic processes with relation to neo-vascularization

Distribution and Elimination of Insulin and C-peptide in a Benign Insulinoma Patient

The distribution and elimination of insulin and C-peptide was evaluated in a case of benign insulinoma, using the method of gel chromatography. The significant differences between total Immunoreactive insulin (IRI) level and the level of Peak I plus Peak II of IRI was noticed in splenic vein. This fact suggested that intermediate and/or abnormal IRI could be released from the tumor. In order to diagnose a hypoglycemic patient with completely normal IRI and CPR level in peripheral blood, the gel chromatographic separation of IRI from splenic and/or portal blood could be useful