Influence Of AngiotensinⅡ On The Sperm Function In Male Infertility

ObjectiveTo investigate the effect of angiotensinâ…¡(Angâ…¡)on the sperm motility and capacitation and intracellular calcium in male infertility in vitro and to explore its mechanism.Material and MethodsSperm were aseptically obtained by masturbation and prepared by swim-up technique from 32 infertile men.For the initial investigations,male infertility,all found to have normal semen parameters and negative antisperm antibody of blood serum.The present study is composed of the following three sub-article:Part one:Effect of Angiotensâ…¡on the capacitation in infertile men.Spermatozoa suspensions was incubated with the different concentrations of Angâ…¡at 37℃in vitro and acrosome reaction induced by progesterone were determined by means of a flow cytometer.The capacitation effect were assessed using FITC-PSA analysis,which can radiate green fluorescence at 510～550nm wavelength as excited by 488nm wavelength laser.Part two:Influence of angiotensinâ…¡on sperm motility in infertile men.Spermatozoa suspensions was incubated with the different concentrations of Angâ…¡at 37℃in vitro.Measurements were carried out at 20,40min for patients in all specimens and motive parameters were measured by computer-aided sperm analysis(CASA).Part three:Effect of Angiotensâ…¡on spermatozoa intracellular calcium in infertile men and to explore its mechanism.Spermatozoa suspensions was incubated with the different concentrations of Angâ…¡at 37℃in vitro.Fluorescence intensity of spermatozoa intracellular Ca²⁺were measured useing fluoreacent probe fura-2/AM by fluorospectrophotometer.Furthermore,the inhibiting effect of Losartana(a Angâ…¡blocker)and EGTA[ethyleneglycol bis(2-aminoethyl ether)tetraacetic acid] was also observed.Results1.In uncapacitated suspensions,Angâ…¡(10nmol/L or 100nmol/L)significantly increased the acrosome reaction induced by progesterone and accelerated capacitation in uncapacitated sperm of infertile men(p＜0.05).2.The results showed that Angâ…¡(10nmol/L or 100nmol/L)can significantly affect infertile men spermatozoa motility incubated(p＜0.05).3.In addition,same concentration of Angâ…¡stimulated increase in the intracellular Ca²⁺ concentration(p＜0.001).However,these effects of Angâ…¡were obviously inhibited by Losartan (a Angâ…¡blocker)and prevented by EGTA.ConclusionThese results indicat that Angâ…¡(10nmol/L or 100nmol/L)can significantly accelerate capacitation in uncapacitated sperm and increase the sperm mobility of infertile men. Mechanisms of action of Angâ…¡may be mediated by AT₁ receptor and accompanied by altering the intracellular Ca²⁺concentration.The responses obtained in vitro suggest that Angâ…¡could have significant effects on sperm function of infertile men in vivo,it could be used effectively in assisted reproductive technology and could also be served in infertility clinics and scientific research.