Ảnh hưởng của peroxit đến enzyme nitric oxide synthase ở nội mô trong các động mạch vành

Molecular and Cellular Biochemistry - Tập 183 - Trang 147-152 - 1998
K.A. Shah1, S.E. Samson1, A.K. Grover1
1Department of Biomedical Sciences, McMaster University, Hamilton, Canada

Tóm tắt

Các loài oxy phản ứng (ROS) được sản xuất trong tình trạng thiếu máu và tái tưới máu. Vì enzyme nitric oxide synthase nội mô (eNOS) đóng vai trò quan trọng trong sự giãn mạch phụ thuộc vào nội mô, chúng tôi đã nghiên cứu tác động của peroxit lên enzyme này. Chúng tôi đã điều trị các tế bào nuôi cấy từ nội mô động mạch vành lợn bằng các nồng độ khác nhau của hydro peroxide, rửa chúng, hòa tan và đo hoạt tính NOS bằng cách chuyển đổi arginine thành citrulline. Hydro peroxide đã ức chế hoạt tính eNOS với giá trị IC50 là 0,85 ± 0,39 mM. Trong một thí nghiệm khác, chúng tôi đã tưới các động mạch bằng dung dịch chứa 0 hoặc 1 mM hydro peroxide, rửa chúng, loại bỏ nội mô bằng bông gòn, ly tâm và hòa tan nội mô, sau đó theo dõi hoạt tính NOS của nó. Hydro peroxide (1 mM) không ảnh hưởng đáng kể đến hoạt tính NOS trong thí nghiệm này (p > 0,05). Chúng tôi kết luận rằng sự bất hoạt của eNOS do hydro peroxide không đóng vai trò chính trong tổn thương do thiếu máu-tái tưới máu, vì nồng độ peroxit đạt được trong tình trạng thiếu máu-tưới máu thấp hơn nhiều so với nồng độ ảnh hưởng đến hoạt tính eNOS.

Từ khóa

#oxy phản ứng #eNOS #enzym nitric oxide synthase #thiếu máu #tái tưới máu

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