| Background:Diabetes mellitus(DM) occurs as a clinical syndrome.57.9%of DM cases are associated with erection dysfunction(ED).ED has become one of important factors negatively influencing the patient's life.Apart from associated variables(e.g. age and sex),ED can be an independent contributor to life quality.Lagged-behind study on the mechanism of DM related ED has to some extend hindered the clinical treatment.The congtribute of age development to erection dysfunction has already been confirmed,As a complication of diabetes mellitus,erection dysfunction of paitents who got DM has been reserched too.But,The mechanism study of the synergistic effect of DM and Age increasing on erectile dysfunction need us to pay more attention to.Gap junction is a special membrane structure linking two neighboring cell.Gap junction intercellular communication(GJIC) facilitates the exchange of information, energy and substances,participates the metabolic couple in intercellular substantial exchange and electronic couple in electronic signal transferring,and plays a regulating role in the whole physiological process of cellular metabolism,homeostasis, and cell differentiation.Gap junction in the corpus spongiosum smooth muscle cell is mainly composed of connexin43(CX43),which through electronic couple and metabolic couple connects the numerous cells in the corpus spongisum smooth muscle as a functional entity to regulate the synchronic diastole among smooth muscle cells, induce the relaxation of smooth muscle of corpus spongiosum and maintain penile erection.The present study,therefore,attempts to observe the effect on rat's erectile function caused by diabetes mellitus and age development to explore the pathophysiology of DM related ED through measuring the expression connexin 43(CX43) in DM rat's corpus cavernous.It is hoped that the pathophysiological study can provide theoretical basis for clinical treatment on DM related ED.Part 1:The mechanism study of aging-related erectile dysfunctionObjective:Establish the age-development model of rats,the mechanism of aging-related erection dysfunction were investigated.Methods:1.3 months,9 months rats and 18 months rats were sliped into three groups.After 1 week breeding,they were injected with a low dose(80μg/kg.d) of apomorphine(APO) in order to measure correspondent penile erections.2.3 months,9 months rats and 18 months rats were killed and corpus cavernosum under albuginea of radix penis were made into ultramicrocuts(70nm),and were observed by TEM-1 200EX transmission electron microscope.3.Real time PCR and Western blot method were thereafter conducted to examine the expression of connexin 43(cx43) in the rat corpus cavemosum of both groups.Results:1.Penile erection times and ratio were declined as age developed.2.Endotheliocyte and smooth muscle cells appeared arrengement chaos,chorisis, as age developped.Besides,interstitial tissue increased,maldistribution.The number of mitochondria increased but their structure were disorder.The number of crista mitochondriales were decline.Mitochondrial Swelling and vacuole increasing were also been observed.3.Both Real time PCR and western blot showed that the expression of CX43 gene and protein has declined as age develepped. Conclusions:1.The decline of times and radio of penile erection confirmed the contribution of age development to ED.2.Expression of Cx43 gene and protein in old rats was declined compared with young age group.That means the decline of expression of Cx43 gene and protein is a reason of aging-related erectile dysfunction.The mechanism study of DM-related erectile dysfunctionObjective:Establish the DM model of rats,the mechanism of DM-related erection dysfunction were investigated.Methods:1.DM model of rats was established.40 rats were send to experimental group(20 for DM,20 for treatment.20 rats as contol group.Both the rats from defferent group and experimental group were injected with a low dose(80μg/kg.d) of apomorphine (APO) in order to measure correspondent penile erections.2.Rats from experimental group were killed after 12 weeks and corpus cavemosum under albuginea of radix penis were made into ultramicrocuts(70nm),and were observed by TEM-1 200EX transmission electron microscope.3.Real time PCR andWestern blot method were thereafter conducted to examine the expression of connexin 43(cx43) in the rat corpus cavernosum of three groups.Results:1.Penile erection times and ratio were declined in experimental group2.Endotheliocyte and smooth muscle cells appeared arrengement chaos,chorisis, in DM group and DM treatment group.Besides,interstitial tissue increased, maldistribution.The number of mitochondria increased but their structure were disorder.The number of crista mitochondriales were decline.Mitochondrial Swelling and vacuole increasing were also been observed.3.Both Real time PCR and western blot showed that the expression of CX43 gene has declined in DM group and DM treatment group.Conclusions:1.The decline of times and radio of penile erection confirmed the contribution of DM to ED.2.Expression of Cx43 gene and protein in DM rats was declined compared with NDM group.That means the decline of expression of Cx43 gene and protein is a reason of DM-related erectile dysfunction.Part 3:The mechanism study of the synergistic effect of DM and Age increasing on erectile dysfunctionObjective:To investigat the synergistic effect of DM and Age increasing on erectile dysfunction.Methods:1.3 month rats and 18 month rats were sliped into two groups.40 rats were send to experimental group(20 for DM,20 for treatment).20 rats as control group.All the rats from different group were injected with a low dose(80μg/kg.d) of apomorphine(APO) in order to measure correspondent penile erections.2.6 and 21 month rats were killed and corpus cavernosum under albuginea of radix penis were made into ultramicrocuts(70nm),and were observed by TEM-1 200EX transmission electron microscope.3.Real time PCR andWestern blot method were thereafter conducted to examine the expression of connexin 43(cx43) in the rat corpus cavernosum of both groups.Results:1.The effects of DM on different months rats(1) For the same month,penile erection times and ratio were declined in DM group and treatment group,comparing with the control group.(2) In 6 montth group,the ultrastructure of DM group and treatment group changed obviously comparing with the control group.Besides,there have been significant difference in ultrastructure between the DM group and treatment group.In 21 month group,the ultrastructure of DM group and treatment group were also changed obviously comparing with the control group.However,there have not been significant difference in ultrastructure between the DM group and treatment group.(3) Real time PCRIn 6 montth group,Ct was 22.5±2.3,25.9±1.3 and 28.1±2.7 for control group, treatment group and DM group,respectively.And there was significant difference between the 3 groups(P=0.001).Concerning the multiple comparison,the P value was 0.001 for DM group versus control group,0.01 for treatment group versus control group,and 0.018 for DM group versus treatment group.In 21 montth group,Ct was 23.6±3.5,24.6±2.6 and 25.1±3.2 for control group,treatment group and DM group,respectively.And there was significant difference between the 3 groups(P=0.001).Concerning the multiple comparison,the P value was 0.004 for DM group versus control group,0.012 for treatment group versus control group,and 0.316 for DM group versus treatment group.(4) Western blot showed the similar result with the real time PCR.In 6 month group,the expression of CX43 protein has declined in both the DM group and treatment group,compared with the control group.Furthermore,the expression level was higher in treatment group than DM group.In 21 month group,though the expression of CX43 protein has declined in both the DM group and treatment group compared with the control group,there was no significant difference between the treatment group and DM group.2.The effects of age on DM rats(1) The penile erection times and ratio were declined in 21 month group comparing with the 6 month group,with significant difference.(2) Real time PCRCX43 gene expression was declined in 21 month DM group compared with the 6 montth DM group.And the gene expression was also declined in 21 month treatment group compared with the 6 montth treatment group.(4) Western blot showed the similar result with the real time PCR.The expression of CX43 protein has declined in both the DM group and treatment group with the age increasing.Conclusions:1.The decline of times and radio of penile erection confirmed the contribution of synergistic effect of DM and Age increasing on erectile dysfunction to ED.2.With the age increasing,treatment effect of insulin for DM was decreasing. |
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