朱鹮粪样睾酮和雌二醇水平的初步测定

本试验通过粪样睾酮（T）和雌二醇（17B-B）水平的测定，建立了一种简单易行的朱鹩粪样激素测定方法。结果表明，雌鸟粪中雌二醇水平显著高于雄鸟，分别为672．65±97．39ng/g和68．28±32．03ng/g；雄乌粪中睾酮水平显著高于雌乌，分别为2527．95±1100．51ng/g和327．77±132．62ng/g。以粪样代替血样，作为一种非损伤性的采样方法，在自然状态下监测朱鹩体内激素水平的变化，为进一步开展朱鹩的生殖内分泌研究提供了新的思路。     

Serum levels of reproductive steroid hormones in captive sand tiger sharks, <Emphasis Type="Italic">Carcharias</Emphasis><Emphasis Type="Italic">taurus</Emphasis> (Rafinesque), and comments on their relation to sexual conflicts

Levels of reproductively-related steroids were determined in captive male sand tiger sharks, Carcharias taurus, maintained at two institutions: SeaWorld Adventure Park Orlando and the National Aquarium in Baltimore. Sexual conflicts were absent at the former, but were documented at the latter. Serum titers of 17β-estradiol, progesterone, testosterone, and 5α-dihydrotestosterone were determined via radioimmunoassay in adult male sharks from 1988 to 2000. Sampling overlap between the two institutions occurred for 3 months of the year, but steroid concentrations were compared only for April due to the occurrence of sexual conflicts in the sharks at the National Aquarium in Baltimore in that month. For April, testosterone and dihydrotestosterone were significantly higher in the SeaWorld males, and progesterone was significantly higher in the National Aquarium in Baltimore males, while estradiol was not significantly different. Steroid levels were also determined from serial samples taken monthly over 17 months from three male sharks and one female shark at the National Aquarium in Baltimore in 2001–2002 and were compared with corresponding observed sexual conflicts. The steroid levels obtained showed distinct annual hormonal cycles in the male sharks and corroborated a biennial cycle for the single serially-sampled female shark. Furthermore, the steroid levels for individual males correlated with sexual conflicts as well as their position within the male dominance hierarchy. As this species is depleted in some regions globally, insight into the steroid profile of mature sand tiger sharks is important for a greater understanding of the relationship between their reproductive physiology and behavior, and may aid in captive management and reproduction. L. E. L. Rasmussen—Deceased.     

Anti-Müllerian Hormone as a Diagnostic Marker for Equine Cryptorchidism in Three Cases with Equivocal Testosterone Concentrations

Cryptorchidism is a developmental disorder which can be diagnosed by a variety of different tests. Still, equine field veterinarians often rely on endocrine markers to detect retained testicular tissue. This report describes the value of anti-Müllerian hormone (AMH) as a diagnostic marker for cryptorchidism in three stallions suspected of cryptorchidism, with equivalent serum testosterone concentrations. A single measurement of AMH identified cryptorchidism, with inconclusive testosterone concentrations as either gelding or stallion. Furthermore, a human chorionic gonadotropin (hCG) stimulation test or surgery was performed to support the diagnostic value of AMH. To conclude, the endocrine panel for cryptorchidism should be expanded to include determination of serum AMH, as this determination can increase the diagnostic accuracy of a single blood sample.     

单色光对肉鸡生长发育的影响

 【目的】采用LED（Light-emitting diodes）灯作为光源，比较单光色对AA肉鸡生长发育及其生产性能的影响，并对其内在机理进行初步探讨。【方法】将264羽刚出壳的雄性AA肉鸡分为4个处理组，对照组为白光组（400～760 nm），试验组为红光组（660 nm）、绿光组（560 nm）和蓝光组（480 nm），每个处理设3个重复，每个重复22羽，自由采食。光照强度15 lx，光照制度23h﹕1h（L﹕D）。【结果】试验前期（0～26 d），蓝绿光组体重始终高于红白光组（6.86%～10.75%，P＜0.05），绿光组料肉比最低为1.8；试验后期（27～49 d），蓝光组体重最高，且在49日龄蓝光组体重比其它处理组体重高17.87%（P＜0.05），胴体重、胸肌重、大腿重、小腿重和净膛重均高于其它处理组（14.39%～19.86%，P＜0.05），而料肉比最低，为2.12。利用放射免疫法检测血清中睾酮的含量，发现试验前期睾酮水平随日龄的增长而增加，21日龄时各处理组睾酮水平达到高峰；试验后期各组睾酮水平缓慢降低。但在试验前期，蓝绿光组的睾酮水平比红白光组高35.37%～37.13%（P<0.05）；而试验后期，蓝光组的睾酮水平比其它光组高14.36%～28.77%（P＜0.05）。【结论】在15 lx光照强度下，肉鸡生长前期采用绿光或蓝光照射，生长后期采用蓝光照射，能显著促进肉鸡的生长发育和提高其生产性能，这可能与蓝绿光能更有效地刺激睾酮分泌有关。     

Exogenous testosterone modulates tumor necrosis factor-alpha and acute phase protein responses to repeated endotoxin challenge in steers

Clinical responses to some disease agents differ between sexes and this dimorphism has been attributed to the immunomodulating effects of steroid hormones. Our objective was to determine in steers the effect of testosterone on circulating concentrations of immune response mediators (tumor necrosis factor-alpha, TNF-alpha; serum amyloid-A, SAA; haptoglobin, HG; xanthine oxidase, XO; nitric oxide, NO) after two consecutive endotoxin challenges (LPS1 and LPS2, 5 days apart; 0.25 microg/kg BW). Sixteen crossbred steers (328+/-6 kg) were assigned to control (CON, n=8) or testosterone cypionate treatment (TES, n=8; 100 mg/m2 body surface; i.m. injection 12 and 2 days before LPS1). The response to LPS was calculated as area under the timexconcentration curve (AUC) for the parameter measured. After LPS1, TNF-alpha AUC was greater in TES than CON (P<0.05). Plasma HG and SAA concentrations increased (P<0.01) after LPS1 and LPS2. In all steers SAA AUC was greater after LPS1 than LPS2 (P<0.01) but the response was augmented over CON with testosterone treatment (P<0.05). HG response to LPS1 within 24 h was not affected by testosterone. However, 5 days after LPS1 mean plasma HG concentration remained higher in TES than CON (P<0.01). HG response to LPS2 was greater in TES than CON (P<0.01). Plasma nitrate+nitrite concentration (NO production marker) and XO activity increased after each LPS challenge but responses were not affected by testosterone treatment. Results indicate that the presence of circulating testosterone increases the magnitude of the TNF-alpha response to LPS challenge as well as the subsequent increases in acute phase proteins (APP). Effects of testosterone on increases in TNF-alpha and APP may underlie a differential presentation of disease symptoms between sexes or between steers and bulls. The data also suggest a role for testosterone in the development of tolerance to repeated immune challenge through its effect on the increased magnitude and duration of HG response.     

雄激素通过Fas途径诱导小鼠骨髓巨噬细胞凋亡

通过雄激素诱导小鼠骨髓巨噬细胞凋亡以及对Fas信号传导通路的研究来探讨雄激素对免疫系统抑制作用的机制。采用不同浓度（1～10 nmol／L）的雄激素处理小鼠骨髓巨噬细胞24h后,先用DNA片段电泳法和Annexin—V／PI双染后流式细胞仪检测不同处理组的细胞凋亡的情况;再用RT—PCR半定量法观察雄激素对Fas途径中一些基因表达的影响。发现10nmol／L雄激素处理的巨噬细胞凋亡率31．7％比对照组7．4％显著升高,并伴随Fas途径中相关基因（Fas,FasL,FADD,caspase-8和caspase．3）转录水平的升高。雄激素可能是通过Fas途径来诱导小鼠骨髓巨噬细胞发生凋亡,从而发挥其免疫抑制作用。     

Effects of ghrelin and its analogues on chicken ovarian granulosa cells

The aim of these in vitro experiments was (1) to examine the effects of ghrelin on the basic functions of ovarian cells (proliferation, apoptosis, secretory activity); (2) to determine the possible involvement of the GHS-R1a receptor and PKA- and MAPK-dependent post-receptor intracellular signalling cascades; (3) to identify the active part of the 28-amino acid molecule responsible for the effects of ghrelin on ovarian cells. We compared the effect of full-length ghrelin 1-28, a synthetic activator of GHS-R1a, GHRP6, and ghrelin molecular fragments 1-18 and 1-5 on cultured chicken ovarian cells. Indices of cell apoptosis (expression of the apoptotic peptide bax and the anti-apoptotic peptide bcl-2), proliferation (expression of proliferation-associated peptide PCNA), and expression of protein kinases (PKA and MAPK) within ovarian granulosa cells were analysed by immunocytochemistry. The secretion of progesterone (P(4)), testosterone (T), estradiol (E(2)) and arginine-vasotocin (AVT) by isolated ovarian follicular fragments was evaluated by RIA/EIA. It was observed that accumulation of bax was increased by ghrelin 1-28, GHRP6 and ghrelin 1-18, but not by ghrelin 1-5. Expression of bcl-2 was suppressed by addition of ghrelin 1-28, GHRP6 and ghrelin 1-5, but promoted by ghrelin 1-18. The occurrence of PCNA was reduced by ghrelin 1-28, GHRP6, ghrelin 1-18 and ghrelin 1-5. An increase in the expression of MAPK/ERK1, 2 was observed after addition of ghrelin 1-28, GHRP6 and ghrelin 1-18, but not ghrelin 1-5. The accumulation of PKA decreased after treatment with ghrelin 1-28 and increased after treatment with GHRP6 and ghrelin 1-18 but not ghrelin 1-5. Secretion of P(4) by ovarian follicular fragments was decreased after addition of ghrelin 1-28 or ghrelin 1-5 but stimulated by GHRP6 and ghrelin 1-18. Testosterone secretion was inhibited by ghrelins 1-28 and 1-18, but not by GHRP6 or ghrelin 1-5. Estradiol secretion was reduced after treatment with ghrelin 1-28 but stimulated by ghrelins 1-18 and 1-5; GHRP6 had no effect. AVT secretion was stimulated by ghrelin 1-28, GHRP6 and ghrelin 1-18, but inhibited by ghrelin 1-5. The comparison of the effects of the four ghrelin analogues on nine parameters of ovarian cells suggest (1) a direct effect of ghrelin on basic ovarian functions-apoptosis, proliferation, steroid and peptide hormone secretion; (2) that the majority of these effects can be mediated through GHS-R1a receptors; (3) an effect of ghrelin on MAPK- and PKA-dependent intracellular mechanisms, which can potentially mediate the action of ghrelin at the post-receptor level; (4) that ghrelin residues 5-18 may be responsible for the major effects of ghrelin on the avian ovary.     

Testosterone profiles and their correlation with sexual libido in male camels

The study was conducted on 4 male Jaisalmeri camels (Camelus dromedarius) on their circulating testosterone (T) profiles and correlation with sexual libido. The average T concentration was low during hot months of April to September, started increasing in the months of October and November, continued to increase steadily in the months of December, January and February followed by decline in the ensuing months. Individual variations in onset and cessation of T surge were observed. Sexual libido as indicated by copulation time (CT) and volume of semen ejaculated (V) was high during January to April months, declined slowly over May month followed by complete cessation in later half of June. Sexual libido was almost negligible during July to November months. The sexual libido was also low during December month. Like circulating T profiles, individual variations were also observed in sexual libido. Data indicated that onset as well as cessation of T surge preceded the onset and cessation of sexual libido in all the animals. A positive correlation was found among circulating T (concentration), CT and V of semen. It is concluded that seasonal changes in circulating testosterone governs sexual libido in male camels.     

不同光照周期对鸡睾酮合成的影响

为研究不同光照周期对公鸡睾酮合成的影响,试验选择120只20周龄体重相近的AA(爱拔益加)公鸡,随机分配到3个不同光照处理组,SD、CTR、LD组分别采用8L:16D、12.5L:11.5D、16L:8D光照周期,4周后采集血清和睾丸;用ELISA技术检测睾酮含量,用实时荧光定量PCR和Westernblot技术检测睾酮合成的3个关键酶(StAR、Cyp11a1、3β-HSD)表达量,HE染色观察睾丸中曲细精管横截面积。结果表明:睾酮含量随光照周期延长极显著增加(P<0.01),并伴随睾酮分泌关键酶StAR、Cyp11a1、和3β-HSD表达量极显著升高(P<0.01),曲细精管横截面积极显著增大(P<0.01)。综上,不同光照周期可通过影响睾酮合成3个关键酶表达而影响睾酮合成,随着光照时间延长,睾酮合成增加,睾丸生精功能增强。