Inhibition of RNA and DNA synthesis in Sertoli cells by co-culture with spermatogenic cells

Sertoli cell monolayers were prepared from 30-day-old rat testes and cultured for 7 days to eliminate contaminant germ cells. Some of these monolayers were co-cultured with a spermatogenic cell preparation enriched in pachytene spermatocytes and round spermatids (fraction 3 from a Percoll gradient), isolated from 30-day-old rat testes. After co-culture for 4 to 48 h, germ cells were removed. RNA synthetic activity in rat Sertoli cell cultures alone was 216,800 +/- 66,480 dpm [3H]uridine.2h-1 X 10(6) cells-1 (mean +/- SD) compared to 98,390 +/- 23,595 in rat Sertoli cells which had been co-cultured with germ cells of fraction 3 for 24 h (P less than 0.01). By contrast, RNA synthesis in Sertoli cell monolayers prepared from immature pigs were unaffected by co-culture with rat germ cells. A similar inhibitory effect of germ cells was observed in rat Sertoli cells stimulated with FSH or testosterone. Culture medium, conditioned by 20 h culture of a fresh preparation of rat spermatogenic cells of fraction 3, was active in inducing the inhibitory effect on RNA synthesis in rat Sertoli cells. Co-culture of rat Sertoli cells with germ cells of this fraction also decreased the incorporative of [3H]thymidine into DNA in rat Sertoli cells, from 9061 +/- 3339 to 4766 +/- 526 dpm.2h-1 X 10(6) cells-1 (P less than 0.01), but no such change was found in pig Sertoli cells. A different spermatogenic cell preparation, partially deprived of pachytene spermatocytes (fraction 5), stimulated rat Sertoli cell DNA synthesis (Sertoli alone 7833 +/- 2550, Sertoli cells which had been in co-culture with germ cells of fraction 5, 13,300 +/- 2279 dpm.2h-1 X 10(6) cells-1, P less than 0.05). These inhibitory actions of some germ cells on Sertoli cells were observed together with the previously reported simultaneous stimulatory effect of Sertoli cells on germ cells. These Sertoli cell-germ cell interactions of detected in culture may represent regulatory influences operating in vivo.     

Effects of luteinizing hormone, follicle-stimulating hormone, and epidermal growth factor on expression and kinase activity of cyclin-dependent kinase 5 in Leydig TM3 and Sertoli TM4 cell lines

We examined the effects of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and epidermal growth factor (EGF) on the expression and kinase activity of cyclin-dependent kinase 5 (Cdk5) in Leydig TM3 and Sertoli TM4 cell lines. Hormonal regulation of the expression and activity of Cdk5 by using normal and hypophysectomized rat testes was also investigated to elucidate its role. Cdk5 levels and kinase activity were significantly elevated in TM3 cells that were grown in the presence of 7.5% serum, EGF, or LH and were associated with an increase in testosterone production compared with controls. These increases were accompanied by an increase in proliferation of TM3 cells after treatment with serum or EGF but not with LH suggest that Cdk5 may be involved in cellular differentiation that is induced with LH treatment. In contrast, the presence of neither serum, EGF, nor FSH had a significant effect on Cdk5 activity levels in the Sertoli TM4 cell line, and there was no correlation with proliferative activity or transferrin levels. A significant decrease in Cdk5 expression and activity were noted in rat testis after hypophysectomy compared with normal rat testis and is associated with a simultaneous decrease in testosterone and transferrin levels. Immunohistochemical analysis revealed that Cdk5 was strongly expressed in the nuclei and cytoplasm of Leydig cells, Sertoli cells, spermatogonia, and peritubular cells of normal adult rat testis. After hypophysectomy, the pattern of Cdk5 staining differed markedly from that in normal rat testis and a profound reduction in staining of Cdk5 was observed in each tubule. Our results suggest that LH and EGF influence and modulate Cdk5 expression and activity in Leydig TM3 cells and may, conceivably, be involved in signal transduction cascades that are initiated by hormones or growth factors. Cdk5 in Sertoli TM4 cells is likely to possess some constitutive functions that are not affected by the cells' proliferation state. Moreover, Cdk5 is probably involved in the constitutive and hormonally stimulated activities of the rat testis, in addition to its involvement in cell proliferation.     

Hormonal regulation and germ cell-specific expression of heat shock protein 60 (hsp60) in the testis of macaque monkeys (Macaca mulatta and M. fascicularis)

Decrease of heat shock protein 60 (hsp60), a mitochondrial chaperonin, in germ cells of men has been shown to be associated with low spermatogenic efficiency. In the present study, we have investigated the hormonal regulation of hsp60 in a pre-clinical primate animal model. Hsp60 production in the testes of the intact cynomolgus monkey ( Macaca fascicularis ) and animals that had been treated with the GnRH antagonist Cetrorelix for 25 days was studied by immunohistochemistry. In addition, testes of untreated adult rhesus monkeys ( Macaca mulatta ) and immature animals either exposed to human chorionic gonadotrophin (hCG), human follicle stimulating hormone (FSH) or hCG and FSH in combination, as well as vehicle-treated controls were analysed. In adult monkeys, specific hsp60 staining was observed in Leydig cells, spermatogonia and early primary spermatocytes. The labelling in Sertoli cells was not stage dependent. The hsp60 staining pattern was unaffected by gonadotrophin releasing hormone (GnRH) antagonist treatment. Western blot analysis confirmed the presence of a single band of 60 kDa in␣testicular homogenates of the cynomolgus monkey. In the testis of immature rhesus monkeys, hsp60 immunoreactivity was visible in gonocytes, spermatogonia and in Sertoli cells, whereas interstitial cells were negative. In the experimental study, hCG alone or in combination with FSH caused a substantial and marked upregulation of the chaperonin in Leydig cells. Human FSH alone did not affect hsp60 expression. We conclude that hCG is an important regulator of Leydig cell hsp60 expression during development, whereas FSH in immature animals and GnRH in adult monkeys is of less importance.     

Germ cells and post-natal development of testicular function: in vitro studies]

Studies in recent years have clearly established that, in addition to the well known endocrine regulation by gonadotrophin hormones, spermatogenesis is under the modulatory control of a complex set of paracrine regulators. Whereas the role of Leydig cells (testosterone) and of Sertoli cells (nurce cells of germ cells) in spermatogenesis has focused most of the attention, until recently little was known about the contribution of germ cells in the spermatogenetic process. This was the aim of the present experiments. We have used, in vitro, 3 complementary approaches; 1) we measured the influence of the removal of germ cells contaminating Sertoli cell cultures by a hypotonic treatment; 2) in coculture, we examined to what extend isolated germ cells could affect Sertoli cell function; 3) we investigated the effects of germ cell conditioned media on Sertoli cell cultures. Our results indicate that germ cells are able to modulate Sertoli cell function in vitro. This germ cell influence varies according to: 1) the germ cell fraction tested (pachytene spermatocytes, early spermatids or cytoplast from elongated spermatids/residual bodies); 2) the parameter of Sertoli cell function studied (inhibition of oestradiol; stimulation of androgen-binding protein, transferrin...); 3) the age of the Sertoli cell donors; 4) the hormonal environment (+/- FSH). Furthermore we wave demonstrated that germ cell effects were partly at least mediated via proteinaceous factor(s) detected in germ cell spent media. Taking into account previous in vivo studies and these in vitro results, we have hypothesized that germ cells, in conjunction with hormones (LH, FSH, testosterone) play an important role in the ontogenesis of Sertoli cells and therefore in spermatogenesis.     

Follicle-stimulating hormone and testosterone stimulation of immature and mature Sertoli cells in vitro: inhibin and N-cadherin levels and round spermatid binding.

The in vitro response of Sertoli cells isolated from adult rat testes to testosterone (T) and follicle-stimulating hormone (FSH) treatment was investigated. Sertoli cells from >70-day-old Sprague-Dawley rats were isolated by a combined enzymatic treatment followed by the removal of the majority of contaminating germ cells with immobilized peanut agglutinin lectin. Sertoli cells were then cultured for 6-10 days, forming a confluent layer with a cell viability of >83% and 74-77% purity. The contaminating cells were peritubular cells (4-6%), pachytene spermatocytes (4-5%), round spermatids (<2%), elongated spermatids (<1%), and degenerating germ cells (14.8%). The proportion of degenerating germ cells decreased from 14.8% to 8.6% between days 6 and 10 in culture. After a prestimulation culture period of 4 days, FSH treatment over a 2-day period resulted in a dose-related increase of inhibin with a median effective dose (ED50) value of 36.7+/-20.4 ng/ml in comparison with an ED50 value of 4.4+/-0.9 ng/ml obtained with immature Sertoli cell cultures from 20-day-old rats. Mature Sertoli cells, in contrast to immature Sertoli cells, were unresponsive to combined FSH + T treatment for the production of the cell adhesion protein N-cadherin. FSH treatment promoted the in vitro binding of round spermatids isolated from adult testis to adult Sertoli cells in coculture. It is concluded that mature Sertoli cells in culture are responsive to FSH in terms of inhibin production and round-spermatid binding. The lack of an FSH + T-induced increase in N-cadherin or round spermatid binding is attributed to either a reduced sensitivity, or an alteration in the regulation of mature Sertoli cells by FSH + T.     

Effect of germ cells on vectorial secretion of androgen binding protein and transferrin by immature rat Sertoli cells in vitro

The influence of germ cells (greater than 85% pachytene spermatocytes) on vectorial secretion of androgen binding protein (ABP) and transferrin by immature rat Sertoli cells was investigated using two-compartment culture chambers. The ratio of ABP secreted into the outer and inner compartment in control cultures of Sertoli cells alone was 1.9, and was not influenced by either FSH or testosterone. Co-culture of Sertoli cells in direct contact with germ cells in the presence of FSH decreased this ratio, the decrease being most pronounced (0.7) after 2 days of co-culture. This effect was not observed if the germ cells were not in direct contact with Sertoli cell monolayers. The outer to inner compartment ratio of transferrin in Sertoli cell-alone cultures was 1.6 and, in contrast to ABP, was not significantly influenced by the addition of germ cells, even in the presence of FSH. It is concluded that in immature rat Sertoli cells the polarity of ABP secretion, but not that of transferrin, may be regulated by pachytene spermatocytes (and possibly other germ cells), and that this process is FSH-dependent.     

The correlation between serum epidermal growth factor/testicular epidermal growth factor receptor and spermatogenesis in rat

<正>Objective: To investigate the correlation between epidermal growth factor (EGF)/testicular epidermal growth factor receptor (EGF-R) and spermatogenesis in rat. Methods: Forty mature male Spraque-Dauley (SD) rats were randomly assigned to four groups, ten rats in each: sham operation group (SOG), sialoadenectomy group(SG), sialoade-nectomy group with injection of EGF (0. 25 μg·kg-1·d-1, SG-EGF Ⅰ) and sialoadenectomy group with injection of EGF (0. 50 μg·kg-1·d-1 , SG-EGF Ⅱ). The rats were routinely feed, and blood and testes were obtained on the 48th day after the operation. Serum EGF concentrations were determined by radioimmunoassay (RIA) , expression of EGF-R in testes was examined by the immunohistochemical method, and the spermatogenesis was pathologically checked. Results: Serum EGF levels in SG-EGFIand SG decreased significantly when compared with those of SOG (P<0. 05 and P< 0. 01, respectively). The testicular function of spermatogenesis showed a moderate to severe impairment in SG. The expression of EGF-R in Leydig cells decreased in SG(P<0. 05). The two dosage groups of EGF replacement had different effects. There were no significant differences of EGF-R expression in testicular germ cells, Sertoli cells and Leydig cells in SOG, SG-EGFⅠand SG-EGFⅡ(P>0. 05). Conclusion: EGF may play an important role in the regulation of spermatogenesis. Serum EGF concentration and high expression of EGF-R in Leydig cells have a positive correlation with spermatogenic function of the testes.     

Expression of nitric oxide synthase during germ cell apoptosis in testis of cynomolgus monkey after testosterone and heat treatment

This study investigates the possible involvement of nitric oxide synthase (NOS) in activating germ cell death in monkeys after mild testicular hyperthermia and/or hormonal deprivation. Groups of 8 adult male monkeys received 1 of the following treatments for 12 weeks: 1) 2 empty Silastic implants, 2) 2 testosterone (T) implants, 3) daily exposure of testes to heat (43 degrees C for 30 minutes) for 2 consecutive days, or 4) 2 T implants plus testicular heat exposure. Testicular biopsies were performed before and on days 3, 8, 28, and 84 of the treatment. In control monkey testes, endothelial NOS (eNOS) was observed mainly in Sertoli cells and spermatogonia. No obvious alteration in eNOS levels was detected in any of the treatment group as assessed by Western blotting. Induction of inducible NOS (iNOS) in testes of the 3 treated groups was detected by immunoblotting as early as day 3 after treatment compared with that of controls. Immunocytochemistry further revealed a small increase in iNOS expression in both germ cells and Sertoli cells after T treatment. However, treatment of heat or heat in combination with T markedly induced iNOS expression in germ cells. These data suggest that iNOS, but not eNOS, may be involved in monkey testicular germ cell death after heat and/or T treatment.     

FSH and bFGF stimulate the production of glutathione in cultured rat Sertoli cells

Migration of developing germ cells from the basal to the adluminal compartment of the seminiferous epithelium requires extensive tissue restructuring, resulting in the production of reactive oxygen species. Sertoli cells are involved in this process. Glutathione (GSH), produced by Sertoli cells, has an essential role in cell protection against oxidative stress. Intracellular GSH content is maintained by de novo synthesis, involving glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunits, and by recycling from oxidized GSH, catalysed by glutathione reductase (GR). To assess whether follicle-stimulating hormone (FSH) and basic fibroblast growth factor (bFGF) modulate GSH production in Sertoli cells by regulating the expression of GCLC, GCLM and/or GR, we performed in vitro studies using rat Sertoli cells in primary culture. FSH and bFGF stimulation increased Sertoli cell GSH levels after 24 h incubation. The simultaneous addition of FSH and bFGF did not produce any further effect. GCLM expression was upregulated by FSH and bFGF 6 h. At 24 h, only the FSH-mediated effect was still observed. FSH and bFGF also upregulated GR expression. In conclusion, our results show that FSH and bFGF increase GSH levels in Sertoli cells through stimulation of the de novo synthesis and recycling by upregulating GCLM and GR expression respectively. Therefore, protection of germ cells against oxidative stress seems to be regulated by hormones and germ cell-released growth factors capable of influencing the production of Sertoli cell GSH.     

Functional analysis of the cooled rat testis

Direct cooling of the testis results in the depletion of most germ cells in vivo. Germ cell-depleted testes are now commonly used to investigate spermatogenic regeneration and can serve as recipients for germ cell transplantation. The present study explored the effects of cooling rat testes on the depletion of endogenous germ cells, spermatogenic regeneration, and Sertoli cell function. Adult rat testes were cooled with iced Ringer's solution for 60 minutes, which results in the initiation of apoptotic germ cell loss within 8 hours. Pachytene spermatocytes at stages XII-I were the cells most sensitive to cooling. In 46%-67% of seminiferous tubule cross-sections, only Sertoli cells remained in the cooled testes 3-10 weeks after treatment. Germ cell loss was accompanied by a significant decrease in circulating inhibin B and an increase in follicle-stimulating hormone concentrations, which indicated a change in Sertoli cell function. Quantitative analysis of mRNA expression associated with apoptotic signals showed no significant uniform changes among the cooled testes, although some individuals had a distinct up-regulation of FAS mRNA at 24 hours. Attempts to use the cooled testes as recipient testes for mouse-to-rat germ cell transplantation were undertaken, but none of the mouse germ cells transplanted into the testes 15-34 days after cooling appeared to have undergone spermatogenesis 64-92 days after transplantation. These data suggest that modifications to Sertoli cell function resulting from testicular cooling create an environment that is unable to support spermatogenesis by donor germ cells.     

睾丸扭转后生精细胞凋亡与iBOS基因表达

本文研究了睾丸扭转复位后生精细胞凋亡与iBOS基因表达的关系。采用大鼠建立左侧睾丸扭转复位模型（720,2h)。用TUNEL法和免疫组化SP法分别检测扭转复位后第五天生精细胞凋亡和iBOS基因表达。研究发现凋亡主要见于染色质降解的生精细胞（初级精母细胞和圆形精子细胞）。间质细胞和支持细胞未见凋亡发生。iBOS表达见于各级生精细胞,在染色质降解的生精细胞（即凋亡细胞）强表达。本文研究表明睾丸扭转复位后生精细胞凋亡增加与iBOS基因表达密切相关。睾丸局部NO生成异常可能是生精细胞凋亡增加的原因之一。     

单侧隐睾对侧睾丸生精上皮保护作用的实验研究

目的探讨单侧隐睾鼠对侧睾丸生殖细胞和Sertoli细胞变化和还原型谷胱甘肽(GSH)对对侧睾丸的保护作用。方法30只SD雄性大鼠分为对照组(A组)、隐睾组(B组)、隐睾加GSH组(C组),每组各10只。采用化学比色法测定对侧睾丸GSH、丙二醛(MDA)含量;生物素-dUTP/酶标亲和素法检测睾丸生殖细胞的凋亡;透射电镜观察Sertoli细胞的超微结构。结果术后2周,与A组比较,B组对侧睾丸GSH明显降低,MDA和细胞凋亡明显增加(P<0.01),Ser-toli细胞线粒体和滑面内质网扩张。C组这种变化则明显减轻(P<0.01),与A组比较差异无统计学意义(P>0.05)。结论外源性GSH对单侧隐睾鼠对侧睾丸生殖细胞和Sertoli细胞有保护作用。     

一氧化氮合酶基因表达对实验性大鼠隐睾生殖细胞凋亡的影响

目的　研究诱生型一氧化氮合酶 (iNOS)及其mRNA表达与实验性大鼠隐睾生殖细胞发育、凋亡的关系。方法　 (1)采用SD雄性健康大鼠 16只 ,日龄 2 2天时复制单侧隐睾模型。 (2 )采用生物素 dUTP/酶标亲和素测定法检测睾丸生殖细胞凋亡。 (3)采用免疫组织化学方法检测大鼠睾丸生殖细胞中iNOS基因表达。 (4 )采用原位杂交法检测大鼠生殖细胞中iNOSmRNA的表达。结果　 (1)术后第 7天 ,与自身对侧正常睾丸相比 ,隐睾侧睾丸发生凋亡的生殖细胞数显著增加 (P <0 .0 1)。 (2 )单侧隐睾模型建立术后第 7天 ,在双侧睾丸的间质细胞、支持细胞和初级精母细胞中均可见iNOS蛋白及iNOSmRNA的弱阳性表达 ,在隐睾侧睾丸曲细精管中脱落的生殖细胞中可见iNOS蛋白及iNOSmRNA的强阳性表达。术后第 7天 ,与自身对侧正常睾丸相比 ,隐睾侧睾丸生殖细胞中iNOSmRNA表达显著增加 (P <0 .0 1)。结论　 (1)实验性大鼠隐睾可以导致睾丸生殖细胞凋亡增加。 (2 )iNOS蛋白及其mRNA的表达增加是隐睾生殖细胞凋亡增加的分子机制之一     

Specific localization of the basigin protein in human testes from normal adults, normal juveniles, and patients with azoospermia

Basigin is a transmembrane protein belonging to the immunoglobulin superfamily. Specific localization of the protein in normal human testes, from those of a 2-year-old boy to those of a 50-year-old man, and in testes with Sertoli cell only syndrome and germ cell arrest, is reported. Basigin localization was determined using an immunohistochemical technique with an antibody against human basigin. In the normal adult testes, basigin was detected at the periphery of both spermatocytes older than zygotene and round spermatids. In the juvenile testes, it was expressed in accordance with the appearance of pachytene spermatocytes. In this study, pachytene spermatocytes were detected in an 11-year-old boy. Basigin was not expressed in immature testes with germ cells younger than pachytene spermatocytes, namely in testes from boys aged 2-9 years. In testes from adult patients with Sertoli cell only syndrome, basigin was expressed at the periphery of Sertoli cells, but localization was confined to the adluminal compartment of the seminiferous tubule. In testes with germ cell arrest, the protein was expressed on germ cells from pachytene spermatocytes to step 2 spermatids, where present. The results show that in the normal human testes basigin is expressed with the onset of spermatocyte differentiation. Because human basigin is expressed in adult testes with Sertoli cell only syndrome, the protein seems to be synthesized in Sertoli cells and expression continues after these cells dedifferentiate in the seminiferous epithelium.     

Maturation, proliferation and apoptosis of seminal tubule cells at puberty after administration of estradiol, follicle stimulating hormone or both

AIM: To assess proliferative and apoptotic potential of the seminiferous epithelium cells in relation to Sertoli cell maturation in newborn rats under the influence of estradiol, follicle stimulating hormone (FSH) or both agents given together. METHODS: From postnatal day (PND) 5 to 15 male rats were daily injected with 12.5 microg of 17beta-estradiol benzoate (EB) or 7.5 IU of human purified FSH (hFSH) or EB + hFSH or solvents (control). On postnatal day 16, autopsy was performed. Sertoli cell maturation/function was assessed by morphometry. Proliferation of the seminiferous epithelium cells was quantitatively evaluated using immunohistochemical labeling against proliferating cell nuclear antigen and apoptosis using the TUNEL method. RESULTS: Although EB inhibited Sertoli cell maturation and hFSH was not effective, a pronounced acceleration of Sertoli cell maturation occurred after EB + hFSH. Whereas hFSH stimulated Sertoli cell proliferation, EB or EB + hFSH inhibited Sertoli cell proliferation. All treatments significantly stimulated germ cell proliferation. Apoptosis of Sertoli cells increased 9-fold and germ cells 2-fold after EB, and was not affected by hFSH but was inhibited after EB + hFSH. CONCLUSION: At puberty, estradiol inhibits Sertoli cell maturation, increases Sertoli and germ cell apoptosis but stimulates germ cell proliferation. Estradiol in synergism with FSH, but neither of the hormones alone, accelerates Sertoli cell maturation associated with an increase in germ cell survival. Estradiol and FSH cooperate to induce seminal tubule maturation and trigger first spermatogenesis.     

Evaluation of the ultrastructural changes in the human Sertoli cell in testicular disorders and the relationship of the changes to the levels of serum FSH

Sertoli cell ultrastructure was compared in men with testicular disorders (hypospermatogenesis; germ cell aplasia) and men with normal testes to determine if any specific cytological change could be correlated with diminished feedback from the testis resulting in elevated serum FSH levels. The normal Sertoli cell contained smooth endoplasmic reticulum, mitochondria and variable numbers of lipid inclusions, lipofuscin, crystals of Charcot-Böttcher and specialised inter-Sertoli cell junctional complexes. The principal abnormalities in Sertoli cells of men with testicular disorders were: 1) dilated vesicles of smooth endoplasmic reticulum and occasional expansions of the intercellular space; 2) increased numbers of cytoplasmic filaments; and 3) with germ cell aplasia inter-Sertoli cell junctions were complexly arranged due to interdigitation of Sertoli cell processes. Occasionally, increased lipid and lipofuscin aggregations were seen and in germ cell aplasia, aggregations of cytoplasmic glycogen were often present. Although these changes were seen more consistently with germ cell aplasia they were observed frequently with hypospermatogenesis where some tubules contained Sertoli cells with normal features. No correlation was found between abnormal Sertoli cell cytology and serum FSH levels.     

Evaluation of the ultrastructural changes in the human sertoli cell in testicular disorders and the relationship of the changes to the levels of serum FSH

Sertoli cell ultrastructure was compared in men with testicular disorders (hypospermatogenesis; germ cell aplasia) and men with normal testes to determine if any specific cytological change could be correlated with diminished feedback from the testis resulting in elevated serum FSH levels. The normal Sertoli cell contained smooth endoplasmic reticulum, mitochondria and variable numbers of lipid inclusions, lipofuscin, crystals of Charcot-B?ttcher and specialised inter-Sertoli cell junctional complexes. The principal abnormalities in Sertoli cells of men with testicular disorders were: 1) dilated vesicles of smooth endoplasmic reticulum and occasional expansions of the intercellular space; 2) increased numbers of cytoplasmic filaments; and 3) with germ cell aplasia inter-Sertoli cell junctions were complexly arranged due to interdigitation of Sertoli cell processes. Occasionally, increased lipid and lipofuscin aggregations were seen and in germ cell aplasia, aggregations of cytoplasmic glycogen were often present. Although these changes were seen more consistently with germ cell aplasia they were observed frequently with hypospermatogenesis where some tubules contained Sertoli cells with normal features. No correlation was found between abnormal Sertoli cell cytology and serum FSH levels.     

大鼠血清表皮生长因子和睾丸表皮生长因子受体与精子生成的相关性

目的　探讨血清表皮生长因子 ( EGF)和睾丸组织表皮生长因子受体 ( EGF-R)与大鼠精子生成的关系。　方法　 40只性成熟期雄性 SD大鼠 ,随机分为假手术组( SOG)、去颌下腺组 ( SG)、去颌下腺加腹腔注射 EGF I组 ( SG-EGF I)和 II组 ( SG-EGFII) ,每组 1 0只。SG-EGF I和 SG-EGF II分别腹腔内注射 EGF0 .2 5和 0 .50 μg·kg- 1·d- 1。大鼠常规喂养 48d,断头取血和睾丸。放射免疫法检测血清 EGF水平 ,病理检查睾丸生精功能和免疫组织化学检测睾丸组织 EGF-R的表达。　结果　大鼠血清 EGF水平SG-EGF I组明显下降 ( P<0 .0 5) ,SG组有非常显著下降 ( P<0 .0 1 ) ;睾丸生精功能中、重度障碍 ;间质细胞 EGF-R表达明显减少 ( P<0 .0 5)。补充不同剂量的 EGF对睾丸生精功能有不同影响。 SOG、SG-EGF I和 SG-EGF II大鼠睾丸生精细胞、支持细胞及间质细胞 EGF-R表达无显著性差异 ( P>0 .0 5)。　结论　EGF对精子发生具重要的调控作用 ,血清 EGF水平和睾丸间质细胞 EGF-R高表达与睾丸生精功能呈正相关