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[摘要]:In rats, an injection of streptozotocin (STZ) elevated blood levels of glucose 4 weeks later (STZ-induced diabetes) and an over-production of microvessels of retinal and choroidal capillaries of eyes developed. A previous study has shown that administration of Stephania tetrandra S. Moore (STSM) in culture prevented the over-production of microvessels of those capillaries of STZ-induced diabetes in vitro. Therefore, the study investigated whether or not orally administered STSM could inhibit over-production of microvessels of those capillaries of STZ injected rats in vivo. When STSM was given at the same time as the STZ injection and continued daily for 7 weeks, STSM prevented the elevation of blood glucose level and over-production of microvessels of those capillaries. When STSM was given after elevation of blood glucose level of glucose (4 weeks after STZ injection) and continued daily for 4 weeks, STSM lowered the elevated blood glucose level but had no effect on the over-production of microvessels of those capillaries. It was inferred that deposition of N-epsilon(carboxymethyl) lysine in retinal and choroidal tissues, which is induced by STZ-induced diabetes may deteriorate the blood-retinal barrier and the blood-choroidal barrier. One might, therefore, speculate that advanced STZ-induced diabetes may deteriorate the blood-retinal barrier and blood-choroidal barrier. Therefore, STSM may not reach the retinal and choroidal tissues in the posterior ocular region in vivo. Copyright (C) 2008 John Wiley & Sons, Ltd. |
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