·AIM:To determine the effects of protocatechuic acid(PCA)on streptozocin-induced diabetic retinopathy(DR)in rats.·METHODS:Wistar rats were given a 50 mg/kg intraperitoneal injection of streptozocin to induce...·AIM:To determine the effects of protocatechuic acid(PCA)on streptozocin-induced diabetic retinopathy(DR)in rats.·METHODS:Wistar rats were given a 50 mg/kg intraperitoneal injection of streptozocin to induce diabetes.Animals were assigned randomly one of four groups(8 rats per group):control,diabetic,diabetic plus PCA(25 mg/kg·d),and diabetic plus PCA(50 mg/kg·d).After inducing diabetes,treatments were started one week later and continued for eight weeks.After the experiment,the rats were sacrificed,and their retinas were taken for biochemical and molecular analysis.·RESULTS:PCA administration diminished the blood glucose and glycated haemoglobin levels relative to the diabetic group.In diabetic rats,PCA lowered elevated levels of advanced glycosylated end products(AGEs)and receptor for AGEs(RAGE).In the retina of diabetic rats,PCA effectively decreased inflammatory cytokine,nuclear factor-κB,tumour necrosis factor-α,interleukin-1β,and vascular endothelial growth factor,and increased antioxidant markers glutathione,superoxide dismutase,and catalase.·CONCLUSION:The protective benefits of PCA against DR may be attributable to its suppression of the AGEs and RAGE and its antioxidant and anti-inflammatory properties.展开更多
Aim:Sleep disorders are common in Alzheimer’s disease(AD)and assumed to directly influence cognitive function and progression of the disease.The present study evaluated sleep characteristics in a rat model of AD that...Aim:Sleep disorders are common in Alzheimer’s disease(AD)and assumed to directly influence cognitive function and progression of the disease.The present study evaluated sleep characteristics in a rat model of AD that was induced by intracerebroventricular administration of streptozocin,and we assessed the possible underlying mechanisms.Methods:The cognition ability of rats was assessed by Morris water maze(MWM)trails.Sleep parameters were analyzed by electroencephalographic(EEG)and electromyographic(EMG)recordings.The neuronal activity in sleep-wake regulating brain areas was evaluated by double-staining immunohistochemistry test.High performance liquid chromatograph-electrochemical detection(HPLC-ECD)was used for the detection of neurotransmitters.Results:On day 14 after STZ injection,the rats exhibited sleep disorders that are similar to those in AD patients as evidenced by significant increase in wakefulness and decrease in rapid-eye movement sleep(REMS)and non-REMS.The c-Fos expression analysis indicated that neuronal activity and the number of neurons in the dorsal raphe nucleus and locus coeruleus decreased in STZ rats.In the ventrolateral preoptic nucleus(VLPO),the activity ofγ-aminobutyric acid(GABA)neurons was suppressed.In the arousal-driving parabrachial nucleus(PBN),GABAergic activity was suppressed,whereas glutamatergic activity was promoted.The neurotransmitter analysis revealed a reduction of GABA in the VLPO and PBN and elevations of glutamate in the PBN.A direct injection of the GABAA receptor antagonist bicuculline in the PBN in normal rats induced a similar sleep disorder pattern as in STZ rats.Furthermore,a microinjection of GABA in the PBN improved sleep disorders induced by STZ.Conclusion:These results suggest that the reduction of GABAergic inhibition in the PBN and VLPO may be involved in sleep disorders induced by STZ.Our novel findings encourage further study aimed at investigating the new mechanisms of sleep regulation in sporadic AD.展开更多
基金Supported by Model Construction of Regional Prevention and Treatment of Diabetic Retinopathy,Sichuan Science and Technology Support Program (No.2016FZ0091)。
文摘·AIM:To determine the effects of protocatechuic acid(PCA)on streptozocin-induced diabetic retinopathy(DR)in rats.·METHODS:Wistar rats were given a 50 mg/kg intraperitoneal injection of streptozocin to induce diabetes.Animals were assigned randomly one of four groups(8 rats per group):control,diabetic,diabetic plus PCA(25 mg/kg·d),and diabetic plus PCA(50 mg/kg·d).After inducing diabetes,treatments were started one week later and continued for eight weeks.After the experiment,the rats were sacrificed,and their retinas were taken for biochemical and molecular analysis.·RESULTS:PCA administration diminished the blood glucose and glycated haemoglobin levels relative to the diabetic group.In diabetic rats,PCA lowered elevated levels of advanced glycosylated end products(AGEs)and receptor for AGEs(RAGE).In the retina of diabetic rats,PCA effectively decreased inflammatory cytokine,nuclear factor-κB,tumour necrosis factor-α,interleukin-1β,and vascular endothelial growth factor,and increased antioxidant markers glutathione,superoxide dismutase,and catalase.·CONCLUSION:The protective benefits of PCA against DR may be attributable to its suppression of the AGEs and RAGE and its antioxidant and anti-inflammatory properties.
文摘Aim:Sleep disorders are common in Alzheimer’s disease(AD)and assumed to directly influence cognitive function and progression of the disease.The present study evaluated sleep characteristics in a rat model of AD that was induced by intracerebroventricular administration of streptozocin,and we assessed the possible underlying mechanisms.Methods:The cognition ability of rats was assessed by Morris water maze(MWM)trails.Sleep parameters were analyzed by electroencephalographic(EEG)and electromyographic(EMG)recordings.The neuronal activity in sleep-wake regulating brain areas was evaluated by double-staining immunohistochemistry test.High performance liquid chromatograph-electrochemical detection(HPLC-ECD)was used for the detection of neurotransmitters.Results:On day 14 after STZ injection,the rats exhibited sleep disorders that are similar to those in AD patients as evidenced by significant increase in wakefulness and decrease in rapid-eye movement sleep(REMS)and non-REMS.The c-Fos expression analysis indicated that neuronal activity and the number of neurons in the dorsal raphe nucleus and locus coeruleus decreased in STZ rats.In the ventrolateral preoptic nucleus(VLPO),the activity ofγ-aminobutyric acid(GABA)neurons was suppressed.In the arousal-driving parabrachial nucleus(PBN),GABAergic activity was suppressed,whereas glutamatergic activity was promoted.The neurotransmitter analysis revealed a reduction of GABA in the VLPO and PBN and elevations of glutamate in the PBN.A direct injection of the GABAA receptor antagonist bicuculline in the PBN in normal rats induced a similar sleep disorder pattern as in STZ rats.Furthermore,a microinjection of GABA in the PBN improved sleep disorders induced by STZ.Conclusion:These results suggest that the reduction of GABAergic inhibition in the PBN and VLPO may be involved in sleep disorders induced by STZ.Our novel findings encourage further study aimed at investigating the new mechanisms of sleep regulation in sporadic AD.
