c-jun调节hCG诱导仔猪睾丸间质细胞睾酮分泌的作用机制

为了研究c-jun调节h CG诱导仔猪睾丸间质细胞睾酮分泌的作用机制,采用离体仔猪睾丸间质细胞体外孵育法,c-jun ASODNs拮抗c-jun,加用c AMP,通过酶联免疫方法检测睾酮水平来观察c-jun在调节h CG诱导仔猪睾丸间质细胞分泌睾酮的影响。结果是h CG可刺激仔猪睾丸间质细胞的睾酮分泌,c-jun ASODNs(0.125~2μmol/L)呈剂量依赖性抑制h CG诱导离体睾丸间质细胞的分泌(r=-0.787,P0.01)。加用c AMP后睾酮分泌增加,可逆转c-jun ASODNs抑制h CG诱导离体睾丸间质细胞的睾酮分泌。结论是c-jun可促进h CG诱导离体仔猪睾酮间质细胞睾酮的分泌,此过程可能以c AMP作为第二信使,进行信息传递。     

c-jun对体外培养仔猪睾丸间质细胞睾酮分泌的影响

本试验用c-junASODNs诱导c-jun基因发生转录后沉默,探讨原癌基因c-jun对仔猪睾酮分泌的作用及可能机制。以2~3周龄长白仔猪为研究对象,采用体外培养体系,研究c-jun对基础状态下和hCG诱导下间质细胞(Leydig cell,LC)睾酮分泌及基础状态下LC增殖及凋亡的影响。结果显示,c-junASODNs以剂量依赖性方式抑制基础状态下和hCG诱导下睾酮分泌(P0.01)及基础状态下LC增殖(P0.01),当1μmol/Lc-junASODNs时,显著抑制LC的凋亡(P0.05)。结果表明,c-jun在基础状态下还是hCG诱导下均可促进仔猪LC睾酮的分泌,这种作用与c-jun促进LC增殖和凋亡有关。     

c-Fos调节hCG诱导的仔猪睾丸间质细胞睾酮分泌的信号转导途径

睾酮是一种重要的类固醇激素,动物体内约95%的睾酮都由睾丸间质细胞合成并分泌。研究显示,原癌基因参与性腺功能调控,c-Fos作为原癌基因的1种,在生精细胞发育过程和睾丸内分泌功能中起着重要调控作用。本试验以荣昌仔猪为试验对象,探究c-Fos调节hCG诱导仔猪睾丸间质细胞睾酮分泌的信号转导途径,为进一步研究仔猪睾酮分泌的机理奠定基础。结果显示:(1)间质细胞cAMP在hCG诱导后显著增高,当二丁酰cAMP与hCG共同作用时,睾酮分泌达到最大,且当二丁酰cAMP与c-Fos ASONDs作用时,可明显逆转c-Fos ASONDs对hCG诱导仔猪间质细胞睾酮分泌的抑制作用。(2)维拉帕米(10-5 mol/L)对hCG诱导的间质细胞睾酮分泌未见明显作用,当维拉帕米和c-Fos ASONDs共同作用时也没有加强c-Fos ASONDs对hCG诱导的睾酮分泌的抑制作用。     

X射线照射对体外培养仔猪睾丸间质细胞增殖和睾酮分泌的影响

通过X射线照射体外培养仔猪睾丸间质细胞(Leydig Cells,LC),检测睾酮分泌及LC增殖情况,了解X射线对雄性睾酮分泌的影响.以3周龄仔猪为研究对象,采用体外培养体系,在hCG诱导下,X射线辐射,测定24 h后LC睾酮分泌量及LC增殖的影响.结果显示,试验常用X射线曝光剂量(43.12～84.86 μGy)曝光一次以及在63.16μGy剂量下照射5 min、15min、30 min对体外培养仔猪睾丸间质增殖有抑制作用,但在曝光剂量43.12～84.86 μGy下LC睾酮分泌量与对照组相比差异不显著,在63.16μGy剂量下照射15 min、30 min睾酮分泌量与对照组相比差异显著(P＜0.05).表明常用X射线剂量曝光一次对睾丸间质细胞增殖有抑制作用,但睾酮分泌量影响不大,但随着照射时间的延长,间质细胞增殖和睾酮分泌显著下降,故在临床使用X射线时应该缩短照射时间,并做好防护.     

成年小鼠睾丸间质细胞的分离、鉴定及功能检测

为建立成年小鼠睾丸间质细胞分离纯化方法,并对分离纯化的睾丸间质细胞进行睾酮分泌功能检测,对成年小鼠睾丸组织进行Ⅰ型胶原酶消化、Percoll分离液密度梯度离心,分离成年小鼠睾丸间质细胞.细胞纯度用3β-羟类固醇脱氢酶(3β-hydroxy-steroid-dehydrogenase,3β-HSD)染色鉴定.将分离纯化的睾丸间质细胞进行体外培养,在基础睾酮和人绒毛膜促性腺激素(hCG)刺激培养条件下,用放射免疫分析法对培养上清中的睾酮含量进行检测.结果显示,通过该方法能获得高纯度成年小鼠睾丸间质细胞(＞95％),培养的睾丸间质细胞具有分泌基础睾酮以及对hCG刺激反应的能力.提示采用该方法对成年小鼠睾丸间质细胞进行分离纯化具有高效性、可用性,通过该方法获得的睾丸间质细胞是体外研究药物对睾酮分泌功能影响的良好模型.     

白细胞介素-1α对仔猪睾丸间质细胞睾酮分泌的影响

用体外培养的仔猪睾丸间质细胞，研究了白细胞介素－１α（ＩＬ－１α）对间质细胞睾酮分泌的影响。结果，ＩＬ－１α能抑制ｈＣＧ诱导的间质细胞分泌睾酮，其睾酮产生量随ＩＬ－１α剂量的增加及作用时间的延长而下降；用２０Ｕ／ｍＬ和５０Ｕ／ｍＬ的ＩＬ－１α作用４８ｈ，可分别抑制６０％及６５％的睾酮分泌量；但无ｈＣＧ诱导时，５０Ｕ／ｍＬ的ＩＬ－１α可使间质细胞基础睾酮的生成量增加１倍。提示睾丸内ＩＬ－１α可能通过多种途径调节间质细胞睾酮的产生。     

牛磺酸对大鼠睾丸间质细胞分泌睾酮的影响及作用机理初探

将雄性Wistar大鼠（220～250g）的睾丸间质细胞混悬液用不连续梯度（5％、30％、58％、70％）Percoll分离液分离，在细胞培养液中分别加入牛磺酸及促性腺激素（HCG）、雄烯二酮、孕酮、cAMP进行培养，用放射免疫分析方法测定作用24h后培养液中睾酮含量。结果表明，牛磺酸可使睾丸间质细胞分泌睾酮的能力显著增加；能增加HCG和cAMP诱导的睾酮分泌；能促进雄烯二酮和孕酮向睾酮的转化。牛磺酸能增加睾丸间质细胞睾酮的分泌，并可能在类固醇合成的多个环节中都起到了一定的促进作用。     

白纤维介素—1α调节仔猪睾丸间质细胞睾酮分泌的机制

本实验利用体外培养的２－３周龄仔猪睾丸间质细胞，研究了ＩＬ－１α调节间质细胞睾酮分泌的机制。结果表明，ＩＬ－１α能抑制ｈＣＧ刺激间质细胞分泌睾酮，其睾酮产生量随ＩＬ－１α剂量增大（０－１０μ／ｍｌ）及刺激时间延长（０－４８ｈ）而下降。     

白细胞介素-1α调节仔猪睾丸间质细胞睾酮分泌的机制

本实验利用体外培养的２～３周龄仔猪睾丸间质细胞，研究了ＩＬ１α调节间质细胞睾酮分泌的机制。结果表明，ＩＬ１α能抑制ｈＣＧ刺激间质细胞分泌睾酮，其睾酮产生量随ＩＬ１α剂量增大（０～１００μ／ｍｌ）及刺激时间延长（０～４８ｈ）而下降。用２０μ／ｍｌ和５０μ／ｍｌ的ＩＬ１α刺激４８ｈ，可分别抑制６０％和６５％的睾酮产生。ＩＬ１α同样抑制ｃＡＭＰ（３μｍｏｌ／ｍｌ）诱导的间质细胞睾酮的分泌，但不影响ｈＣＧ与间质细胞膜受体的结合量及ｈＣＧ诱导的第二信使ｃＡＭＰ的增加。说明ＩＬ１α抑制ｈＣＧ促睾酮分泌的作用，其抑制点不在ｈＣＧ与受体的结合及第二信使ｃＡＭＰ的聚集上，而在ｃＡＭＰ产生之后的某个环节。     

神经肽W对猪睾丸间质细胞增殖和睾酮分泌的影响

为了明确神经肽W(NPW)对猪睾丸间质细胞功能的影响,本试验采用RT-PCR和免疫荧光(IFA)技术研究了NPW受体NPBWR1(GPR7)、NPBWR2(GPR8)基因和蛋白在睾丸间质细胞的表达与分布,用MTT法和放射免疫分析(RIA)技术研究了不同浓度的NPW(NPW-30)对睾丸间质细胞增殖和睾酮分泌的影响。结果表明,NPBWR1和NPBWR2 mRNA在猪睾丸间质细胞中表达,NPBWR1在睾丸间质细胞上分布;10-6和10-8mol/L NPW处理睾丸间质细胞24 h可分别极限著或显著促进睾酮的分泌(P0.01,P0.05),10-10mol/L NPW可极显著促进睾丸间质细胞的增殖P0.01)。研究结果提示,NPW可促进猪睾丸间质细胞的增殖和睾酮的分泌,进而参与生殖的调控。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.