An Experimental Model For Stricture Studies In The Anterior Urethra Of The Male Rabbit And The Study On Biological Activity Of Bradykinin-inhibiting Peptide

The thesis includes two parts:one is an experimental model for stricture studies in the anterior urethra of the male rabbit,the other is the effect of bradykinin-inhibiting peptide on guinea pig bladder relaxation induced by bradykinin.An experimental model for stricture studies in the anterior urethra of the male rabbitObjective:To establish a simple,economical and reliable experimental model of rabbit urethral stricture by using urinary catheter,and lay a foundation for the study of the treatment and mechanism of urethral stricture.Methods:Thirty male New Zealand rabbits were selected and routinely fed.The experiment was divided into 5 groups:In the anatomical group(n=6),we separated rabbits,urinary system to observe the effect of urethra when airbag became 4ml,10ml and 15ml;normal group(6 rabbits)only put the catheter into the urethra;in the 4ml group(6 rabbits),the catheter was placed in the bulbar urethra and 4ml 0.9%Nacl was injected for 2.5 hours;in the 10ml group(6 rabbits),the catheter was placed in the bulbar urethra and 10ml 0.9%Nacl was injected for 2.5 hours;in the 15ml group(6 rabbits),the catheter was placed in the bulbar urethra and 15ml 0.9%Nacl was injected for 2.5 hours.On the 30th day,we performed contrast examination for the rabbits,observed and measured the urethral stricture.Result:In the anatomical group,the catheter were accurately puted into the rabbit bulbar urethra,and when 4ml 0.9%Nacl was injected the bulbar urethra was inflated;when 10ml 0.9%Nacl was injected urethral mucosa was torn to form a 9.87±6.07mm2 wound;when 15ml 0.9%Nacl was injected urethral mucosa was torn to form a 27.94±3.24mm2 wound.After retrograde urethrography,0 rabbits were found to form urethral stricture in normal group,0 rabbits were found to form urethral stricture in 4ml group,3 rabbits were found to form urethral stricture in 10ml group,all rabbits were found to form urethral stricture in 15ml group.Conclusion:It is an economical,convenient and reliable method to establish the rabbit urethral stricture model by using catheter.Effect of bradykinin-inhibiting peptide on guinea pig bladder relaxation induced by bradykininObjective:To investigate the effect of bradykinin-inhibiting peptide on guinea pig bladder relaxation induced by bradykinin.Methods:Isolated bladder strips of guinea pigs were taken(lcm).The experiment was divided into 3 groups:normal group(add 10μmol/L ACH)control group(add 10μmol/L ACH+1μmol/L BK),BIP group(10μmol/L ACH+BIPat different concentrations+1μmol/L BK).RM6240 microbial signal acquisition and processing system,tension transducer were used to test the tension changes in bladder smooth muscle after acetylcholine,bradykinin,and bradykinin-inhibitory peptide were added.Result:The contractility of bladder smooth muscle in isolated guinea pigs was decreased in control group and BIP group.The differences were statistically significant(P<0.05).The contractility of bladder smooth muscle in the control group is significantly decreased when compared with the BIP group.The differences were statistically significant(P<0.05).Conclusion:Bradykinin-inhibition peptid can antagonize the effect of bradykinin-induced decreased bladder relaxation on guinea pigs.