| BackgroundAlcohol dependence,as the neuropsychiatric disease,is not only the most common public health problem worldwide,but also causes many alcohol-related diseases and even death,yet the mechanism is still unclear.In recent years,the role of phosphodiesterases(PDEs),a superfamily of enzymes(PDE1-11)hydrolyzing c AMP and c GMP,in alcohol dependence has received increasing attention.However,due to the lack of highly selective inhibitors of individual PDE subtypes,it is difficult to identify the role of PDE subtypes in the regulation of drinking behavior.Based on the current studies and our previous work,here we hypothesized that PDEs expression in the brain of C57BL/6J(C57)and DBA/2J(DBA)mice,which exhibit high and low alcohol preference,respectively,is different.These PDE subtypes with different expression between the two mouse lines may be targets for treatment of alcohol dependence.AimsScreening of PDE subtypes in related brain areas of C57 and DBA mice,and exploring its possible mechanisms.Methods1.Healthy adult male and female C57 and DBA mice were randomly selected for the alcohol two-bottle choice test.Alcohol(7% and 10%)consumption and water consumption were measured daily,and alcohol intake and preference rate were calculated.Another batch of mice was used to detect the consumption and preference of sucrose and quinine also using the two-bottle choice test in mice.2.Healthy naive adult male and female C57 and DBA mice were sacrificed,followed by decapitation and removal of the brain.The striatum,hippocampus,cerebral cortex,and amygdala of the brain were dissected.Western blot analysis was used to detect the difference in PDE expression levels in each of the brain regions.The differential PDE subtypes screened by Western blot were used to further detect the difference in m RNA expression levels using real-time PCR.3.By comparing the PDEs expression levels in the brain of two strains of mice before and after alcohol drinking,the PDE subtypes with different changes were screened out.The protein expression levels of these PDE subtypes in various brain regions before and after drinking in C57 mice were examined.It was determined whether alcohol drinking caused the corresponding PDE subtype changes.4.Finally,the corresponding PDE inhibitors were administered to C57 mice to detect alcohol drinking behavior changes.Results1.Differences in drinking behavior between C57 and DBA mice.(1)Compared to DBA mice,there was no significant difference in body weights of C57 mice;(2)In the alcohol two-bottle choice test,alcohol intake and preference of C57 mice were significantly higher than DBA mice.(3)There were no significant changes in sucrose intake and preference between C57 and DBA mice in the sucrose two-bottle choice test.(4)No significant changes were observed in quinine intake and preference between C57 and DBA mice the quinine two-bottle choice test.2.Differences in the expression of PDE subtypes in drinking-related brain regions of C57 and DBA mice.This experiment was performed using naive mice.PDE expression in drinking-related brain regions of C57 and DBA mice showed that,compared to naive DBA mice,C57 mice showed significant higher in the expression of PDE4 B,7A,8B,and 9A in the striatum,hippocampus,cerebral cortex,and amygdala.3.PDE7 A,8B,and 9A in the drinking-related brain regions of naive and alcohol-drinking C57 mice.Expression of PDE4 B,7A,9A in the striatum,hippocampus,cortex,and amygdala was significantly increased relative to naive C57 mice,while PDE8 B was increased simply in the hippocampus.4.Effect of the PDE4 inhibitor rolipram and PDE7 inhibitor 5-Nitro-2,N,N-trimethylbenzenesulfonamide(NTMBS)on alcohol drinking behavior in C57 mice.Rolipram(0.5,1 mg/kg)and NTMBS(0.3,1 and 3 mg/kg)reduced alcohol intake and preference without altering the total fluid intake in C57 mice.Conclusion1.Alcohol intake and preference of C57 mice were significantly higher than DBA mice.2.There were significant increased in the expression of PDE4 B,7A,8B,and 9A in alcohol drinking-related brain regions of C57 mice compared to DBA mice.3.PDE4 B,7A,and 9A were significantly increased after alcohol drinking eight days in C57 mice.4.PDE4 and PDE7 inhibitors significantly reduced alcohol intake and preference in C57 mice,suggesting that increased PDE4 and PDE7 may be responsible for the regulation of alcohol drinking. |
