CUMS-induced Depression Alter The Saxagliptin Pharmacokinetics And CYP450 Activity In GK Rats

ObjectiveThe comorbidity of diabetic patients with depression is becoming more and more epidemic.Our previous work found that chronic unpredicted mild stress(CUMS)induced-depression in SD rats changed hypoglycemic drug pharmacokinetics of mitiglinide.In order to better simulate the change situation of drug metabolism in diabetic patients complicated with depression,this study explored whether CUMS induced-spontaneous diabetic Goto–Kakizaki(GK)rats depression affect the hypoglycemic drug metabolism process in vivo,and provide theory evidence for the therapeutic regimen of clinical diabetic patients complicated with depression taking hypoglycemic drug.Methods1.Establishment of diabetic rat model: Male spontaneous diabetic GK rats,5 weeks old,purchased from Shanghai SLAC Laboratory Animal Co.,Ltd.,were kept in SPF-grade lab until the emergence of diabetes symptoms of polydipsia,polyphagia,polyuria,and then determine the postprandial 2 h blood glucose levels in rats.2.Establishment of depression rat model: The diabetic rats were randomly divided into two groups: control group and depression model group.The depression model group rat was fed alone in a cage,and gave different stress for 8 weeks.The stressors included restraint 1 h,hot water swimming(45°C,5min),cold water swimming(4°C,5 min),clip tail 1 min,cages tilting(45°,24 h),horizontal shaking 10 min,damp padding 24 h,noise interference 10 min,andday/night inversion 24 h.Rats were given a kind of stress each day,and avoided the same stress consecutively.The control group rats were bred without any stressor.3.Evaluation of depression model: Before and after the stress model establishment,the behavior scores(locomotion score and exploratory score)were determined by open-field test,and plasma 5-HT and DA levels were determined by enzyme-linked immunosorbent assay(ELISA)to confirm the successful establishment of the depression model induced by CUMS.4.Pharmacokinetics analysis of saxagliptin: After the depression model establishment,the depression group and the control group rats were given 0.5mg/kg saxagliptin orally and blood samples were collected at different time points.The plasma saxagliptin concentrations were assayed by high performance liquid chromatography–tandem mass spectrometry(HPLC-MS/MS)and calculated its parameters.5.Determination of CYP450 activity: All rats were sacrificed,excised the liver to prepare the liver microsomes suspension by differential centrifugation method and determined the liver microsomes total protein concentrations.The content of metabolites of the probe drugs by liver microsomes CYP1A/2C/2D/3A metabolism was determined by “Cocktails” probe drugs method to reflect the corresponding CYP450 subtype activity.Results1.Spontaneous diabetic GK rats emerged diabetes symptoms of polydipsia,polyphagia,polyuria at 12 weeks.The postprandial 2 h blood glucose levels of rats were 17.51 ± 5.52 mmol/L higher than the theoretical value of 11 mmol/L.Before and after the stress model,the behavior scores(locomotion score and exploratory score)of open-field test and plasma 5-HT and DA levels were significantly decreased(P<0.01).Compared with the control group,mental stateand response to stress of rats were sluggish,and physical activity and the weight were reduced in the depression group.2.The detection method of plasma saxagliptin by HPLC-MS/MS had good specificity,high sensitivity,and matrix effect,the lowest limit of quantitation,accuracy and precision were accorded with the requirements of biological samples.Compared with the control group,the pharmacokinetic parameters of saxagliptin were obviously changed in depression GK rats.The area under curve,peak time,peak concentration,mean residence time and clearance were statistically significant(P<0.05),but there was no significant difference in the half-time and apparent distribution volume3.The liver microsomes total protein concentrations had distinct difference between the depression and control group.The detection method of metabolites by HPLC-MS/MS was rapid,sensitive,easy to operate,and matrix effect,recovery,accuracy and precision were satisfied with the requirements of biological samples.There were significant differences in the concentrations of metabolites and the CYP450 activity between the two groups.The varying trend and regulating amplitude of different CYP450 subtypes activity were different.The liver microsomes CYP3 A activity was increased significantly in the depression group compared with the control group.Conclusions1.CUMS–induced depression altered the metabolic process of saxagliptin in vivo,liver microsomes total protein concentrations and CYP450 subtype activity in GK rats.2.The change of saxagliptin pharmacokinetics was caused by changing of liver drug metabolism enzyme CYP450 activity.3.CUMS–induced depression had different varying trend and regulating amplitude of different CYP450 subtypes activity in GK rats.