Establishment of a novel hyperuricemiaanimal model using mice and assessment ofhyporuricemia action of PNP inhibitor Ulodesine / 中国药理学通报

Aim To establish a novel acute hyperuricemia mouse model and apply it to evaluate the hyporucicemia effects of Ulodesine, a purine nucleoside phosphorylase(PNP) inhibitor.Methods The mice were intraperitoneal injected inosine and subcutaneous injected Oteracil potassium to induce accumulation of uric acid, and the animal blood was collected from eyeball or vena angularis in different time points.The levels of serum uric acid were measured and determined to test whether the acute hyperuricemia mouse model were successful or not.In order to verify the hyperuricemia seen in the model was associated with the accumulation of inosine, which was converted to uric acid by action of PNP,hyporucicemia effects of Ulodesine, a PNP inhibitor, was assessed in an enzyme assay and confirmed by using the newly established model.Result Accumulation of uric acid in the blood of mouse models was observed by combined injections of intraperitoneal 200 mg·kg-1 inosine and subcutaneous 200 mg·kg-1 Oteracil potassium respectively after 1.5 h.The enzyme assay indicated that Ulodesine was a potently PNP inhibitor with IC50 of 2.293 nmol·L-1.IV injection of Ulodesine eliminated uric acid accumulations in blood of the mouse model, which was expected as the in vivo action of Ulodesine.Conclusions A novel acute hyperuricemia mouse model is established.This is a relatively easy and more effective protocol to generate the hyperuricemia in mice, which will be a useful platform to assess the anti-hyperuricemia activity of PNP-target drugs in vivo.

Effect of active fractions from modified Simiao Wan on hyperuricemia and its mechanism / 中国药理学与毒理学杂志

OBJECTIVE Tostudytheeffectofeffectivefractions(EFC)frommodifiedSimiaoWan (MSW)onthelevelofuricacidinhyperuricemicratsandinvestigatethemechanism.METHODS Two types of hyperurice mic models were established.A persistant hyperurice mic model was prepared by giving rats oxonic acid 200 mg·kg -1 and feeding the m with hypoxanthine.The models were ig given with modified Simiaowan (MSW)50 g·kg -1 or EFC 1 2.5,25 and 50 g·kg -1 consecutively for 5 d.The models were treated with MSW or EFC 50 g·kg -1 for 3 d.After the final treatment,the uric acid concen-trations in seru m and urine were determined by an auto matic bioche mistry analyzer.The activity of xan-thine oxidase (XOD )in the serum and liver was determined by enzymic colorimetric method.The activity of purine nucleoside phosphorylase (PNP)and uricase was detected by spectrophotometry. RESULTS Comparedwithnormalcontrolgroup,theserumlevelofuricacidinbothmodelgroupswas remarkably increased(P<0.01 ).Compared to model control group,MSW 50 g·kg -1 and EFC 12.5, 25 and 50 g·kg -1 significantly reduced the serum level of uric acid(P<0.05,P<0.01 ),but increased the activity of erythrocyte PNP(P<0.01 )in the oxonic acid potassium-induced hyperuricemia rats. MSW 50 g·kg -1 and EFC 50 g·kg -1 elevated the activity of liver uricase in the nicotinic acid-induced hyperuricemia rats(P<0.05).EFC 50 g·kg -1 also significantly decreased the serum XOD activity of hyperuricemicrats.CONCLUSION EFCsignificantlyinhibitstheserumlevelofuricacidinhyperurice-mic rats,which might involve down-regulation of protein levels of serum XOD to inhibit the production of uric acid and activation of uricase to pro mote the deco mposition of uric acid.

Effects of E. coli purine nucleoside phosphorylase suicide gene therapy on gastric cancer cells / 吉林大学学报(医学版)

Objective To study the effects E.coli purine nucleoside phosphorylase suicide gene on human gastric cancer MKN-45 cells as well as the bystander effect.Methods The ePNP gene was subcloned to pcDNA3.1 to construct recombinant eukaryotic expression vector pcDNA3.1-ePNP.The recombinant plasmid was transfected into MKN-45 cells by lipofectamin method and positive cell clones were screened with G418.Then MePdR was added to these gene-modified cells and the sensitivity of the cells to MePdR was studied as well as the bystander effect.Results MePdR treatment of MKN-45/ePNP cells induced cytotoxic and antiproliferative effects in a concentration-dependent manner with 100% cell death since 1 mg?L-1.Bystander effect was strong in vitro as 100% of tumor cells were killed by MePdR with only 10% MKN-45/ePNP cells.The gene-modified gastric cancer cells MKN-45/ePNP were sensitive to the treatment of MePdR compared with unmodified tumor cells,and also a remarkable bystander effect was observed.Conclusion The efficiency of ePNP/MePdR system and the potential feasibility of suicide gene strategy for clinical therapy of human gastric cancer are demonstrated.

Purine Nucleoside Phosphorylase Activities in Sera and Lymphocytes of Peripheral Blood from Patients with Allergic Contact Dermatitis and Drug Eruption / 대한피부과학회지

The present study was designed to measure the activity of purine nucleosiae phosphorylase(PNPase) in sera and lymphocytes af peripheral blood from patients with allergie contact dermstitis and drug eruption since PNPase activities are known to be decreased in cell-mediated immune deficieney diseases. The PNPase activities in sera and lymphocytes of normal subjects were (7.2 +1.05) * 105 unit/L of sera and (1.85+0.38) unit/102 lymphocytes, respectively. In allergic contact dermatitis, the PNPase activities in sera and lymphocytes of patients were (3.9+0.78) *105 unit/L of aera and (0.69+0.23) uoit/102 lymphocyteis, which were signifieantly lower than those of normal subjects. There were no differences in PNPase activities of sera and lymphocytes between drug eruption patients and normal subjects. From these results, it is suggested that the lowered PNPase aetivity in allergie contact dermatitis might be associated with abnormal lymphocytes differentiation or activation or some other unknown mechanism, since lowered PNPase activity in allergic contact dermatitis is in contrast to the generally accepted concept that enhanced status of CMI in ACD will lead to the increase in PWPase activity.

Purine Nucleoside Phosphorylase Activities in Sera , Erythrocytes and Lymphocytes of Blood from Patients with Various Dermatoses / 대한피부과학회지

The present study was designed to measure the activity of purine nucleoside phosphorylalse (PNPase) in sera, erythrocytes and lymphocytes of blood from patients with various dermatoses as it's activities are known to be decreased in cell-mediated immune deficiency diseases. The PNPase activities in sera, erythrocytes and lymphocytes of normal subjects were (3. 9+1. 03) x 104 unit/L, 5.04+1. 06 unit/107rbc, l. 74+0. 35 unit/103 lymphocytes respectively. In urticaria, leukocytoclastic vasculitis and purpura, there were no differences in PNPase antivities between patients groups and normal subjects. In atopic dermatitis, there were no differences in PNPase activities of sera and erythrocytes between patients group and normal subjects. But, lymphocyte PNPase activities of atopic patients were lowered than those of normal subjects(1.41 +0. 52 unit/10 lymphocytes). In tuberculoid leprosy, there were no differences in lymphocyte PNPase activities between patients group and normal subjects. But, the PNPase activities in sera and erythrocytes of patients group were lowered than those of normal subjects (3. 20. 76) x 104 unit/L, 3. 8n+1.96 unit/107rbc). The PNPase activities in sera((l. 87+/-0. 62) x 104 unit/L), erythrocytes(2. 08+0. 98 unit/107rbc) and lymphocytes (0.51+0. 26 unit/103 lymphocytes) of lepromatous leprosy patients were significantly lowered than those of normal subjects.