AIM: To investigate the remodeling of mesenteric arteryand the expression of TGF-β_1,c-Jun in mesenteric arteryand effects of imidapril and irbesartan on the remodelingin spontaneously hypertensive rats (SHR).METHODS: Thirty SHR (male/female,21/9),aged 13 wk,were randomly divided into 3 groups (7 male rats and 3female rats each group): SHR group,imidapril group(imidapril 3 mg/kg·d was given in drinking water for 14 wk),and irbesartan group (irbesartan 50 mg/kg·d was given indrinking water foe 14 wk).Ten homogenous Wistar Kyotorats,5 males and 5 females,weighing 206±49 g,wereselected as normal control group (WKY group).Systolicpressure was measured on d 1,2,4,6,8,10,12 and 14during the experiment and the rats were killed at the end ofthe experiment.Angiotensin Ⅱ (Ang Ⅱ) level in plasma andmesenteric arteries was measured by radioimmunoassay.The morphology of the secondary branches of mesentericartery were examined by light microscopy and electronmicroscopy.Reverse transcription polymerase chain reaction(RT-PCR) was used to detect the expression of transforminggrowth factor TGF-β_1 and c-Jun mRNA.RESULTS: Compared with imidapril group and irbesartangroup,the blood pressure was remarkably increased inSHR group.Ang Ⅱ level in plasma and mesenteric arteriesin SHR group was the same or lower than that in WKYgroup,and was higher in irbesartan group and lower inimidapril group.The remodeling of mesenteric arteries inSHR group was mostly obvious among the 4 groups.Theratio of TGF-β_1 absorbed light value to GAPDH absorbedlight value in the SHR group was 0.887±0.019,which wassignificantly higher than that in WKY group,imidapril group,and irbesartan group with the ratios of 0.780±0.018,0.803±0.005,and 0.847±0.017,respectively (P<0.01).Ang Ⅱ level in plasma and mesenteric arteries in imidaprilgroup was significantly lower than that in irbesartan group(P<0.05).The c-Jun absorbed light value/GAPDH absorbedlight value of mesenteric arteries in the SHR group was0.850±0.015,which was significantly higher than that inthe WKY,imidapril,and irbesartan groups (0.582±0.013, 0.743±0.012,and 0.789±0.013,respectively,P<0.01),andwas significantly lower in imidapril group than in irbesartangroup (P<0.05).CONCLUSION: Imidapril and irbesartan can not only controlblood pressure but also inhibit mesentedc arteries remodelingand mRNA expression of TGF-β_1,c-Jun in SHR.Imidapril ismore effective than irbesartan. AIM: To investigate the remodeling of mesenteric artery and the expression of TGF-β_1, c-Jun in mesenteric artery and effects of imidapril and irbesartan on the remodeling in spontaneously hypertensive rats (SHR). METHODS: Thirty SHR (male / female, 21/9) , aged 13 wk, were randomly divided into 3 groups (7 male rats and 3 female rats each group): SHR group, imidapril group (imidapril 3 mg / kg · d was given in drinking water for 14 wk), and irbesartan group (irbesartan 50 mg / kg · d was given indrinking water foe 14 wk) .Ten homogenous Wistar Kyotorats, 5 males and 5 females, weighing 206 ± 49 g, wereselected as normal control group (WKY group). Systolic pressure was measured on d 1,2 , 4,6,8,10,12 and 14during the experiment and the rats were killed at the end of the experiment. Angiotensin II (Ang II) level in plasma andmesenteric arteries was measured by radioimmunoassay. The morphology of the secondary branches of mesentericartery were examined by light microscopy and electronmicroscopy. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of transforming growth factor TGF-β_1 and c-Jun mRNA.RESULTS: Compared with imidapril group and irbesartangroup, the blood pressure was remarkably increased inSHR group. AngⅡ level in plasma and mesenteric arteriesin SHR group was the same or lower than that in WKYgroup, and was higher in irbesartan group and lower inimidapril group. The remodeling of mesenteric arteries inSHR group was mostly obvious among the 4 groups. Theratio of TGF- [beta] l absorbed light value to GAPDH absorbedlightvalues ​​in the SHR group was 0.887 ± 0.019, which wassignificantly higher than that in WKY group, imidapril group, and irbesartan group with the ratios of 0.780 ± 0.018, 0.803 ± 0.005, and 0.847 ± 0.017, respectively (P <0.01). Ang II level in plasma and mesenteric arteries in imidapril group was significantly lower than that in irbesartan group (P <0.05). The c-Jun absorbed light value / GAPDH absorbed light value of mesenteric arteries in the SHR group was0. 850 ± 0.015, which wAs significantly higher than that of inthe WICH, imidapril, and irbesartan groups (0.582 ± 0.013, 0.743 ± 0.012, and 0.789 ± 0.013, respectively, P <0.01), and was significantly lower in the imidapril group than in irbesartangroup : Imidapril and irbesartan can not only control blood pressure but also inhibit memorialc arteries remodeling and mRNA expression of TGF-β_1, c-Jun in SHR.Imidapril ismore effective than irbesartan.