Enhancement by streptozotocin of O− 2 radical generation by the xanthine oxidase system of pancreatic β-cells
M Nukatsuka, H Sakurai, Y Yoshimura, M Nishida… - FEBS letters, 1988 - Elsevier
M Nukatsuka, H Sakurai, Y Yoshimura, M Nishida, J Kawada
FEBS letters, 1988•ElsevierSpin-trapping techniques and electron spin resonance (ESR) spectroscopy were used to
study the relationship between the effect of streptozotocin (STZ) on pancreatic β-cells and
free radical formation by these cells. Results showed that STZ enhanced generation of the
DMPO-OH radical adduct, which is a degradation product of the superoxide anion (O− 2) in
the presence of cellular components, in a hypoxanthine-xanthine oxidase (XOD) system with
a homogenate of β-cells. This enhancing effect was also observed in a system without …
study the relationship between the effect of streptozotocin (STZ) on pancreatic β-cells and
free radical formation by these cells. Results showed that STZ enhanced generation of the
DMPO-OH radical adduct, which is a degradation product of the superoxide anion (O− 2) in
the presence of cellular components, in a hypoxanthine-xanthine oxidase (XOD) system with
a homogenate of β-cells. This enhancing effect was also observed in a system without …
Abstract
Spin-trapping techniques and electron spin resonance (ESR) spectroscopy were used to study the relationship between the effect of streptozotocin (STZ) on pancreatic β-cells and free radical formation by these cells. Results showed that STZ enhanced generation of the DMPO-OH radical adduct, which is a degradation product of the superoxide anion (O−2) in the presence of cellular components, in a hypoxanthine-xanthine oxidase (XOD) system with a homogenate of β-cells. This enhancing effect was also observed in a system without cellular components; STZ increased the signal height due to the O−2 radical in a concentration-dependent manner and caused a maximum of 150% enhancement at a concentration of 1.5 mM. Thus, STZ seemed to enhance the generation of the O−2 radical in the XOD system, probably by some mechanism of its interaction with XOD. Pancreatic β-cells exhibited a high XOD activity and a very low superoxide dismutase activity. Therefore, the present result supports the possibility that the cytotoxic effect of STZ is closely related to free radical generation in pancreatic β-cells.
Elsevier