ABSTRACT
Objective: To observe the effects of different doses of human urinary Kallidinogenase (HUK) on the expression of bradykinin 1 receptor (B1R) and bradykinin 2 receptor (B2R) in SD rats with middle cerebral artery occlusion(MCAO). Methods: The right MCAO model of SD rats was established by modified Zea Longa thread thrombus method. The 25 successfully prepared SD rats were randomly divided into five groups (5 in each group):the Sham group,the I/R model group (I/R +saline group),the HUK low dose treatment group (I/R + LDP group),the HUK medium dose treatment group (I/R + MDP group) and the HUK high dose treatment group (I/R + HDP group). After 30 min,each group was given HUK (the I/R + LDP group:3. 50 × 10-3 PNAU/kg;the I/R + MDP group:8. 75 × 10-3 PNAU/kg;the I/R + HDP group: 17.50 × 10-3 PNAU/kg) or saline tail vein injection for continuous 7 days. The samples were taken after regular injection once a day. The relative expression of mRNA in the marginal area of infarction was detected by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR),and microvascular growth density (MVD) was measured by vWF factor inimuno -fluorescence (FITC). Results (1)B1R mRNA expression;Compared with I/R + saline group, the mRNA expression of B1R in I/R + LDP group,I/R + MDP group,I/R + HDP group was all up-regulated ([0. 34 ± 0. 05], [0. 35 ± 0. 04], [0. 47 ± 0. 03] vs. [0.23 ±0.05],all P <0.05);Compared with I/R + LDP group and I/R + MDP group,the mRNA expression of B1R in I/R +HDP group was was all up-regulated (all P<0.05). (2)B2R mRiNA expression:Compared with Sham group, the mRNA expression of B2R in I/R + saline group was up-regulated([0.33 ±0.01]vs. [0.23 ± 0. 02],P <0. 05);Compared with I/R + saline group, the mRNA expression of B2R in I/R + LDP group, I/R +MDP group, I/R + HDP group was all up-regulated ([0. 49 ± 0. 02], [0. 52 ±0. 04], [0. 71 ± 0. 03], respectively,all P < 0. 05); Compared with I/R + LDP group and I/R + MDP group, the mRNA expression of B2R in I/R + HDP group was was all up-regulated (all P <0. 05). (3) Compared with Sham group, the microvessel density(MVD)in I/R + saline group was increased ([169 ±6]vs. [74 ± 12],P < 0.01);Compared with I/R + saline group,the MVD in I/R + LDP group,I/R + MDP group, I/R + HDP group was all increased([240 ±9], [252 ±9], [349 ± 17].respectively,all P<0.01);Compared with I/R + LDP group and I/R + MDP group, the MVD in I/R + HDP group was increased (all P < 0. 01). Conclusion: A certain dose of HUK could upregulate the expression of Bl R and B2R in MCAO rats to promote vascular regeneration,and the effect of high dose HUK on neovascularization was more obvious.
ABSTRACT
Objective There is little research focusing on the expression and function of bradykinin 1 receptor ( B1R ) and bradykinin 2 receptor ( B2R) after cerebral ischemia/reperfusion on the basis of diabetes .The aim of this study was to compare the ex-pression difference and function change of B 1R and B2R in non-dia-betic and diabetic rats . Methods The cerebral ischemia/reperfu-sion model was established on 41 non-diabetic and type 2 diabetic rats, the weight and the biochemical index were measured on these two types of rats .8 non-diabetic rats and 8 diabetic rats were respec- tively assigned to two groups according to random number tables:control group and I/R 24 h group, 4 in each group.Real-time PCR was performed to observe the expressions of two receptors at 24 h after reperfusion .Then, 33 non-diabetic rats and 33 diabetic rats were randomly divided into 4 groups respectively, including sham group (n=6), saline group (n=9), B1R antagonist group (n=9) and B2R antagonist group (n=9).At 24 hours after cerebral I/R, neurological deficiency was evaluated by neurological severity scores ( NSS);infarct volume was observed by TTC staining;cell apoptosis was determined by TUNEL staining;neuron degeneration was de-tected by Fluoro-Jade C staining. Results Glucoses of diabetics at 3, 7, 14 d after model establishment [(23.45 ±5.01), (23.71 ±4.87), (22.72 ±4.11) mmol/L] were obviously elevated compared with non-diabetics [(5.77 ±0.75), (6.05 ±0.69), (7.15 ±1.09) mmol/L];blood cholesterin [(4.59 ±3.43) mmol/L] and insulin [(67.26 ±12.02) pmol/L] at 14 d after model establishment were evidently incresaed in comparison to those in non-diabetics [(1.58 ±0.37) mmol/L, (25.34 ±4.88) pmol/L] (P0.05).Compared with non-diabetics, diabetics suffered from more apparent up-regulation of B1R mRNA (P<0.01) but relatively less B2R mRNA (P<0.05) at 24 h after I/R.NSS score, infarction volume, damaged and apoptotic cells in B2R antagonis-treated non-diabetic rats at 24 h after I/R conspicuously decreased compared with saline-treated non-daibetic rats.Those indicators in B1R antagonis-treated diabeics were strikingly lessened compared with saline-treated daibetics . Conclusion I/R induced distinct up-regulation of B2R mRNA in non-diabetics and inhibiton of B 2R effectively ameliorated the infarct volume and cell injury after I/R in non-diabetics; I/R induced more notable up-regulation of B1R mRNA in diabetics and B1R antagonist exerted neuroprotective effects instead of B 2R antagonist af-ter I/R in diabetics.