Research On The Effects Of Low Intensity Microwave Radiation On The Reproductive Endocrine System Of Male Mice

Part I Effects of low intensity microwave radiation on reproductive function in male mice【Objective】To investigate the effects of low intensity microwave radiation on reproductive function in male mice.【Methods】45 male mice of 4 weeks age were randomized into 4 groups and exposed to electromagnetic fields with frequency of 900MHz and power density of 0μW/cm2(sham-exposed controls),50μW/cm2,150μW/cm2,250μW/cm2 respectively 12 hours per day for 60 days using experimental exposure device.On the day of last treatment, immediately after the termination of exposure sham-exposure and exposure mice were sacrificed. The testes and epididymis of every mouse were viscerated and weighted,and the sperm count,sperm motility and morphology of sperm in epididymis were analysed, and Serum testosterone(T) and luteinizing hormone(LH) were measured.【Results】(1) The organ indexThe testes weight and testes index of radiation groups decreased in some degree:The testes weight and testes index of 50μW/cm2 groupe were (84.96±20.58)mg,(0.174±0.039)% respectively,and those of 150μW/cm2 groupe were (76.29±21.66)mg,(0.161±0.046)% respectively.They all lower than those[(138.45±30.34mg,(0.287±0.056)%] of sham-exposed controls statistically significantly . The epididymis weight of each group showed no notable change.(2) Effects of microwave radiation on sperm counting,sperm motility and abnormal sperm rate of male miceThe average sperm motility rates of 50μW/cm2 group,150μW/cm2 group,250μW/cm2 group were 59.625%,44.917%,53.545% respectively,and they all lower than tha(t78.750%)of sham-exposed controls statistically significantly (P<0.01 for all).The average abnormal sperm rates of 50μW/cm2 group,150μW/cm2 group,250μW/cm2 group were 4.52%,7.192%,4.673% respectively,and they all lower than tha(t2.840%)of sham-exposed controls statistically significantly (P<0.01 for all).The average sperm counting of 50μW/cm2 group,150μW/cm2 group were (5.35±0.75)×106/ml and (5.43±1.00)×106/ml respectively,and they were both lower than that[(6.51±0.74)×106/ml] of sham-exposed controls statistically significantly (P<0.05 and P<0.01 respectively). In 250μW/cm2 group, the average sperm counting was (5.95±0.94)×106/ml and was not different from that of sham-exposed group.(3)Histology of testes:In testis pathological section of exposed groups mice,there existed various degrees of confused cell layers of seminiferous tubule and broadened intercellular space.The mount of sperms in seminiferous tubule decreased or even vanished showing a weaken capacity of spermatogenesis. The density of Leydig cell showed some degrees of decrease. The mice in 150μW/cm2 group showed the most significant change, followed by 250μW/cm2 group and 50μW/cm2 group.(4) The level of hormone in serum:The average serum T level of 50μW/cm2 group,150μW/cm2 group mice were (2.546±0.535) ng/ml and ( 2.093±0.732) ng/ml espectively,and they were both lower than that [(3.466±0.808)ng/ml]of sham-exposed controls statistically significantly (P<0.05 and P<0.01 respectively). The average serum T level of 150μW/cm2 group mice was (2.868±0.749) ng/ml, but the difference of it with that of sham-exposed controls was of no statistically significant though the number of the former was somehow lower. Though the serum T level showed difference, the average serum LH level had no distinction among groups.【Conclusions】Under this experimental condition,900MHz microwave radiation at power density range from 50mW/cm2 to 250mW/cm2 may cause testes injury, sperm counting decrease,sperm motility rates decline,and abnormal sperm rates elevating and change serum T level of male mice.This result hints that low intensity of.civilian use microwave band may affect male reproductive function negatively.Part II Effects of low intensity microwave radiation on reproductive endocrine function in male mice【Objective】To investigate the effects of low intensity microwave radiation on reproductive endocrine function in male mice.【Methods】48 male mice of 4 weeks age were randomized into 6 groups. They are sham-exposed control group,caponizing control group, pure radiating control group with microwave radiating of 150μW/cm2, caponizing group with microwave radiating of 50μW/cm2, caponizing group with microwave radiating of 150μW/cm2, and caponizing group with microwave radiating of 250μW/cm2. The radiating groups were whole-body exposure to 900MHz GSM-like microwave 12 hours per day for 60 days using experimental exposure device.On the day of termination, the mice were sacrificed with decapitate. The testes of the mice in sham-exposed controls and pure radiating controls were viscerated and weighted.The serum testosterone(T) level and luteinizing(LH) level were detected for every mouce and compared by group. The SDH and ATPase activities of hypothalamus tissue were measured for every mouce and compared by group. The ultrastructure especially the mitochondria ultrastructure of hypothalamus tissue was investigated electron microscopically.【Results】(1)The organ index:The testes weight and testes index of pure radiating controls were (0.123±0.014)g,(0.263±0.032)% respectively.They both lower than those[(0.147±(0.016)g,(0.303±0.042)%] of sham-exposed controls statistically significantly . But the epididymis weight of pure radiating controls showed no notable change.(2) The level of hormone in serum:The serum testosterone(T) concentrations of all caponizing groups were in very low level. The serum testosterone(T) concentrations of pure radiating controls was (3.026±0.367)ng/mL,and that of sham-exposed controls was (4.256±0.501)ng/mL.They had differance with statistically significance.The serum luteinizing(LH) concentrations of pure radiating controls was (5.480±2.276)mIU/ml,while The serum LH concentrations of sham-exposed controls was (6.493±1.872)mIU/ml.But the difference was not statistically significant.The serum LH concentrations [(8.614±2.843)mIU/ml] of caponizing controls had some elevate compared with that [(6.493±1.872)mIU/ml] of sham-exposed controls.though the difference was not statistically significant ,the phenomeno showed the influence of caponizing on LH level.About the serum LH of microwave radiating caponizing groups, it was (7.339±2.663)mIU/ml in 50μW/cm2group,(6.276±3.020)mIU/ml in 150μW/cm2 group,and (7.663±3.464)mIU/ml in 250μW/cm2 group.This result showed that under the radiation of microwave, the serum LH level of all caponizing groups'mice did not reach the level [(8.614±2.843)mIU/ml] of caponizing controls,and that of 150μW/cm2 group was only as high as that of sham-exposed controls.That indicated that microwave radiation may depress the secretory function of pituitary.(3) The SDH and ATPase activities of hypothalamus tissue:The SDH activities of hypothalamus tissue of sham-exposed controls and caponizing controls were (12.341±3.343)U/mgprot and (12.346±2.023)U/mgprot respectively, and showed no statistically significance.But all radiating exposure groups showed low activity level and had statistically significance compare with that of sham-exposed controls.They were (8.534±1.455)U/mgprot in pure radiating controls,(9.074±1.719)U/mgprot in 50μW/cm2 group,(7.453±1.240)U/mgprot in 150μW/cm2 group,and (8.120±1.663)U/mgprot in 250μW/cm2 group.The ATPase activities of hypothalamus tissue of sham-exposed controls and caponizing controls were (30.704±6.057)U/mgprot and (29.898±5.378)U/mgprot respectively, and their diffrence had no statistically significance. But all radiating exposuregroups showed low activity level and had statistically significance compare with that of sham-exposed controls.They were (18.651±3.486)U/mgprot in pure radiating controls, (24.240±4.365)U/mgprot in 50μW/cm2 group, (16.425±4.153)U/mgprot in 150μW/cm2 group, and (17.911±3.529)U/mgprot in 250μW/cm2 group respectively.The correlations of serum LH level with hypothalamus ATPase activity were 0.795 in 50μW/cm2 group and 0.717 in 150μW/cm2 group respectively with statistically significance, and this phenomenon indicates that there may be some association between serum LH level and hypothalamus function.(4)mitochondria ultrastructure of hypothalamus tissue:In radiation groups, the mitochondria ultrastructure of hypothalamus tissue displayed changes of various degrees,including mitochondria density decling, part mitochondria swelling,decrease or even disappearance of mitochondrial cristae ,and cavitation formation. The most obvious change happened in 150μW/cm2 group.【Conclusions】Under this experimental condition, 900MHz microwave radiation may impair cell mitochondria and energe metabolism of hypothalamus tissue cells and thus influence their physiologic function.These results contribute to the assessment of potential male fertility risks after continuous chronic exposure to RF radiation at low level.