The paper reports the evaluation of the feasibility of using internal standard method for the determination of nicotine recovery in microdialysis in vitro. This in vitro experiment included two conditions. Nicotine and codeine phosphate were dissolved in Ringer's solution. Nicotine, codeine phosphate and the mixture of them were perfused through the CMA30 linear probe separately to calculate the proportion of the recovery (or delivery) of nicotine to that of codeine phosphate. And then codeine was perfused through the probe which was immersed in nicotine solution with different concentrations to calculate the proportion, too. In another condition nicotine was dissolved in rat plasma. The rat plasma protein binding rate was determined by using retrodialysis and internal standard method in vitro. The results are as follows: the proportion of the recovery (or delivery) of nicotine to that of codeine phosphate was fairly stable. The delivery of codeine was independent of nicotine concentration in the external medium. Protein binding rate determined by retrodialysis was almost the same as that determined by internal standard method. It suggests that the internal standard method is an effective way in the determination of nicotine recovery and codeine phosphate can be used as the internal standard.

Objective To detect the in-vitro microdialysis recovery of nicotine by decrement method(i.e.retrodialysis) and to investigate its influence factors,thus to supply experimental evidence for the in-vivo microdialysis of nicotine.Methods The in-vitro recovery of nicotine was detected by concentration difference method(increment method and decrement method).The stability of recovery was observed.The effects of the pretreatment with perfusate,and the flow rates and concentrations of the perfusate on nicotine recovery were studied.Results Filtering and stirring treatment increased the recovery,but the time of ultrasound degassing showed no effect on the recovery.The recovery detected by increment method was as the same as that detected by decrement method.Nicotine recovery was independent of nicotine concentration in the external medium,showing good stability.Conclusion It is necessary to filter and degas the perfusate before microdialysis.Retrodialysis can be used for the determination of in-vivo nicotine recovery.

Thyroid diseases are often accompanied with dyslipidemia.In me past,low level of myroid hormone(TH) was considered a main factor in causing elevated level of blood cholesterol in hypothyroid patients.However,some clinical features can not be explained by this traditional theory. For example,in subclinical hypothyroid cases,both levels of thyroid-stimulating hormone (TSH) and serum total cholesterol (TC) increase,while TH level remains normal.From this phenomenon,we speculate that in case with hypothyroidism,not only there is a relationship between serum TC and TH levels,but also serum TC level change is related to TSH in some way,which has not been noticed.The purpose of this paper is to review the new and most advanced progress in the research of TSH and cholesterol.

[Objective] To explore the in-vitro determination method for the recovery rate of sinomenine in microdialysis probe and to investigate the influencing factors. [Methods] The recovery rate of sinomenine was detected by concentration difference method (by gain and by loss) and zero-net flux method. [Results] The recovery rate detected by increment method was as the same as that by decrement method; the recovery rate had no correlation with the sinomenine concentration in the solvent. Sinomenine recovery assessed by concentration difference method had a good intra-day stability and intra-day reproducibility. Sinomenine concentration and recovery in the solvent could be determined accurately by zero-net flux method. [ Conclusion ] Microdialysis sampling can be used for the pharmacokinetic study of sinomenine and decrement method (ie. retrodialysis) can be used for the determination of recovery rate of sinomenine.

ObjectiveTo study the expression of adhesion mol ecules (CD 54 、CD 62p ) on diabetic neuropathy in the STZ induced rats and the effect of cilostazol treatment.MethodsSD rats were divided into four groups: normal control, diabetes control, insulin and cilostaz ol treated group. Sciatic nerve conductive velocity, the level of CD 54 /CD 62p on the surface of mononuclear cell/platelet were examined, and ultrast ructure of sciatic nerve was observed.ResultsCilostazol incr eased sciatic nerve conductive velocity significantly [DM=(20.3?2.2) m/s vs ci lostazol=(28.9?7.9)m/s,(P

Objective To observe the effects of palmitic acid (PA) and fenofibrate (FF) on rat islets. Methods Rat islets were isolated with collagenase digestion and divided into 6 groups: control group, PA0.2 group (with 0.2 mmol/L PA), PA0.4 group(with0.4mmol/LPA),FF group (with 5?10 -6 mol/L fenofibrate), PA0.2+FF group and PA0.4 +FF group. After being cultured 24 hours with PA in the presence or absence FF, baseline insulin secretion (BIS) and glucose stimulated insulin secretion (GSIS) were examined. The mRNA levels of insulin(INS), pancreas-duodenum homeobox-1 (PDX-1), glucose transport protein 2 (GLUT-2) and PPAR? were determined by RT-PCR or real-time PCR. Results (1)In both PA0.2 and PA0.4 groups, BIS was increased and GSIS increase was impaired as compared with control group (P0.05). Expressions of INS, PDX-1 ,GLUT2 and PPAR? mRNA were enhanced in PA0.2 +FF group and PA0.4 +FF group as compared with the two groups without FF respectively (all P

Objective To obtain more information concerning polymorphism of the thyrotropin (TSHR) in Graves diseases(GD). Methods (1)A family of GD was studied (including 3 patients and 9 healthy family members)to examine SNPs of TSHR through direct sequencing of all 10 exons and part of introns. (2)In the current case-control study, 30 patients with familiar GD, 48 sporadic patients and 96 healthy control individuals were used to assess whether SNP of TSHR was associated with GD. Genomic DNA was extracted from peripheral leukocytes isolated from ACD-anticoagulated blood. Ten exons were amplified by PCR, using primers designed by ourselves. After purifying, the products were sequenced. Results Eight polymorphisms were found. There was a novel polymorphism in exon 8. There were no significant differences between patients and controls. Conclusions These findings suggested that the novel and other polymorphisms of the TSHR gene may not be responsible for GD. There are racial differences in the distribution of polymorphisms of TSHR gene.

[Objective] To explore the feasibility and advantages of blood microdialysis technique for the pharmacokinetic study of sinomenine. [Methods] In this study, rats served as the experimental subjects and sinomenine was administered to the rats by intravenous injection. With microdialysis technique for blood sampling, the blood concentration of sinomenine was determined by high performance liquid chromatography (HPLC) and the associated pharmacokinetic parameters were analyzed by 3p97 program. [Results] The pharmacokinetics process of sinomenine in rats presented as the two-compartment model. The half-life of distribution phase was 10.98min and that of elimination phase was 44.71 min. [Conclusion] It is feasible to study pharmacokinetic parameters of sinomenine by using blood microdialysis technique. In comparison with the traditional technique, blood microdialysis technique is superior to the examination of drug blood concentration .

Objective To observe the effects of propylene glycol mannate sulfate(PGMS) on the expression of ICAM-1 and VCAM-1 in kidney of diabetic rats, and explore the protective effect of PGMS on kidney. Methods Diabetes was induced by injecting STZ. Then the rats were randomly divided into four groups: normal control group, diabetic modal group, treatment group with high-dose and low-dose of PGMS. 8 weeks later, the blood glucose concentrations, HbA1c, the ratio of kidney weight to body weight, urinary albumin excretion rate (UAE ) in 24 hours were examined. The ICAM-1 and VCAM-1 located were detected by immunohistochemistry, while the expression of ICAM-1 and VCAM-1 were detected by Western blot method and the levels of ICAM-1 and VCAM-1 mRNA by RT-PCR.Results PGMS could reduce kidney hypertrophy and lower urinary albumin excretion rate (UAE)of 24-hour significantly. Immunohistochemical study with light microscopy demonstrated that the levels, both ICAM-1 and VCAM-1 in the kidney of test groups decreased obviously. PGMS down-regulated the mRNA and protein levels of ICAM-1 and VCAM-1 significantly . A positive correlation between expression of ICAM-1,VCAM-1 and kidney lesion was observed. Conclusion: PGMS decreased the expression of ICAM-1 and VCAM-1 in diabetic rats.

The paper is to report the study of pharmacokinetics of transdermal administered nicotine in the brain of freely moving rat by using microdialysis with stable labeled isotope as internal standard. The pharmacokinetic behavior of nicotine in Sprague Dawley rat brain was investigated after intranasal administration (3.75 mg). Brain fluid samples were collected by intracerebral microdialysis with DL-nicotine as internal standard. Concentrations of nicotine and DL-nicotine in the sample were measured by HPLC-MS/MS. Main pharmacokinetic parameters were calculated and analyzed by Das 2.0 pharmacokinetic software. The recovery of nicotine and the delivery of DL-nicotine were the same. The fate of absorption and distribution was two compartment model and the values of t1/2alpha was 170.31 min, t1/2beta was 263.30 min and the AUC(0-infinity) was 2.75 x 10(5) microg x L(-1) min separately. DL-nicotine can be used to calibrate the recovery of nicotine, and the new method of stable isotope microdialysis can be used to study the pharmacokinetics of freely moving rat. It will make sense for the treatment of addiction of tobacco and provide a new thought for the research of pharmacokinetics-pharmacodynamic combination.