Effect of photoperiod manipulation on the daily rhythms of melatonin and reproductive hormones in caged European sea bass (Dicentrarchus labrax)

Reproduction in fish is cyclical and timed to guarantee the survival of the offspring. Seasonal variations in reproductive hormones of fish have been deeply investigated in fish over the last years. However, there are few studies regarding the daily changes in reproductive hormone profiles in teleosts. The aim of the present research was to investigate the effects of photoperiod manipulation on melatonin and reproductive hormones (pituitary sbGnRH, pituitary LH and plasma LH, testosterone [T], and 11-ketotestosterone [11KT]) daily rhythms in male sea bass, kept in net cages under farming conditions in winter (9L:15D). Fish were distributed in two groups, one under constant long photoperiod (18L:6D) and the other under natural photoperiod. The photoperiod strongly influenced the daily melatonin profile, so that the duration of the nocturnal melatonin rise was longer in the control group than in the group exposed to the artificial photoperiod (18L:6D). A daily rhythm was observed in the pituitary sbGnRH profile in both groups, showing the lowest levels during the dark period. A daily rhythm of pituitary LH was detected in the control group, which was suppressed in the group under long photoperiod. Daily variations in plasma LH were observed, the highest levels being found in the dark phase in both groups, although this profile was significantly altered by artificial light, maintaining a fixed relationship between the first nocturnal rise of melatonin and the nocturnal peaks of plasma LH in both groups. Plasma T levels showed significant fluctuations in their daily cycle following a sinusoidal pattern with an acrophase around sunrise in both groups, without any influence of light regime. No significant daily variations in plasma levels of 11-KT were observed in none of the groups. Our results provide the first evidence of the presence of daily variations in pituitary sbGnRH content, pituitary and plasma LH, and plasma T in sea bass. Artificial lights suppressed the circulating melatonin and significantly affected the daily rhythm of LH storage and release.     

A review on the effect of the photoperiod and melatonin on interactions between ghrelin and serotonin

Ghrelin and serotonin, which exhibit rhythmic secretion profiles under feeding/fasting conditions, are sensitive to increases and decreases in the day length and form a close web of interrelationships in the regulation of energy homeostasis. Ghrelin and serotonin are biochemically and functionally linked to the suprachiasmatic nucleus, which is a circadian pacemaker, and melatonin, which is an internal transducer of photic environmental changes. Ghrelin and serotonin might be candidates for integrating photic and nonphotic signals, such as light and food availability in the central nervous system. The mechanisms that convert a light signal into a variety of physiological and behavioral rhythms remain unknown. However, we know that the conversion of light signals is necessary to maximize an animal’s chances of survival and reproduction.     

Yes相关蛋白在结直肠癌组织中的表达及其临床意义

目的:研究结直肠癌变组织中Yes相关蛋白及mRNA的表达,探讨其临床意义.方法:收集2010-03/2011-03福建省南安市医院普外科及福建医科大学附属第一医院普外科80例结直肠癌患者术中切除的癌组织,同时收集20例癌旁组织和正常结直肠组织,应用免疫组织化学S-P法和原位杂交方法检测结直肠癌组织、癌旁组织和正常组织中Yes相关蛋白及mRNA的表达.原位杂交法和免疫组织化学S-P法均严格按照试剂盒说明操作.结果:结直肠癌组织中Yes相关蛋白及mRNA的阳性表达率分别为66.25%和68.75%,癌旁组织中Yes相关蛋白及mRNA的阳性表达率分别为20.0%和25.0%和正常结直肠黏膜组织Yes相关蛋白及mRNA的阳性表达率分别为10.0%和15.0%.结直肠癌组织中Yes相关蛋白及mRNA的阳性表达率明显高于癌旁组织和正常结直肠黏膜组织(P<0.01),癌旁组织与正常结直肠黏膜组织中Yes相关蛋白及mRNA阳性表达率比较差别无统计学意义.Yes相关蛋白及mRNA阳性表达率与年龄、性别、肿瘤部位之间比较差异无统计学意义,但与肿瘤分化程度和肿瘤分期等之间比较差异有统计学意义(P<0.05或0.01).结论:Yes...     

黄芪多糖对2型糖尿病大鼠GLUT4mRNA表达的影响

目的 探讨黄芪多糖对2型糖尿病(T2DM)大鼠脂肪组织葡萄糖转运蛋白4(GLUT4)基因表达的影响.方法 将Wistar大鼠随机分为正常对照组、模型组、黄芪多糖高、中、低剂量治疗组.用药12w后,RT-PCR检测GLUT4 mRNA基因表达水平.结果 黄芪多糖高、中剂量治疗组GLUT4 mRNA表达高于模型组.结论 黄芪多糖可上调T2DM大鼠GLUT4 mRNA表达,从而实现其降血糖作用.     

MACC-1 mRNA和c-Met mRNA在胃癌组织中的表达及其临床意义

目的检测胃癌组织中结肠癌转移相关因子-1（MACC-1）mRNA和肝细胞生长因子受体原癌基因c-Met mRNA的分子表达水平,并探讨其与胃癌临床病理生物学行为的关系以及它们之间的相关性。方法采用实时荧光定量PCR（QT-PCR）技术检测45例胃癌及其癌旁组织标本中MACC-1 mRNA和c-Met mRNA的表达水平。结果 MACC-1 mRNA和c-Met mRNA的表达与组织学分级、浸润深度、临床分期、淋巴结转移显著相关（P〈0.05）,与年龄、肿瘤大小无关（P〉0.05）。且两者表达呈正相关（r=0.366,P〈0.05）。结论 QT-PCR技术可对胃癌组织中的MACC-1 mRNA和c-Met mRNA表达进行定量检测;MACC-1 mRNA和c-Met mRNA的高表达与胃癌的侵袭转移有关,可作为胃癌腹膜转移的预后评估因子。     

氯胺酮鞘内注射对慢性坐骨神经损伤大鼠脊髓 NMDA-2B mRNA表达的影响

目的：探讨氯胺酮连续鞘内注射对慢性坐骨神经损伤大鼠脊髓背角N-甲基-D天冬氨酸亚基（NR2B）mRNA表达的影响。方法：雄性SD大鼠18只，随机分为假手术组、CCI组和氯胺酮组。按Bennett等法制作CCI模型，测von-Frey丝触痛及冷水阈值，采用原位杂交技术检测各组脊髓背角NR2B mRNA表达的变化。结果：CCI组痛阈显著下降，冷水阈显著升高，脊髓背角有大量NR2B mRNA阳性表达（P＜0．01）；氯胺酮组仅出现轻度痛敏症状，NR2B mRNA表达受到明显抑制（P＜0．01）。结论：NR2B mRNA表达上调可能是神经损伤后慢性疼痛的发病机制之一，氯胺酮可抑制其表达从而发挥一定程度的镇痛作用。     

羊水脱落细胞中c—myc基因检测在诊断葡萄胎中的意义

目的 研究羊水脱落细胞中c-myc mRNA的检测在葡萄胎的诊断意义.方法 以53例健康妊娠女性为对照,采用RT-PCR检测50例良性葡萄胎患者和48例恶性葡萄胎患者羊水脱落细胞中c-myc mRNA的表达.结果 健康组女性阳性率为5.7%(3/53),良性葡萄胎患者阳性率为26%(13/50),恶性葡萄胎患者阳性率为75%(36/48),三者之间差异有统计学显著性意义(P＜0.05或P＜0.01).结论 检测羊水脱落细胞中c-myc mRNA的表达有助于恶性葡萄胎的诊断,对良性葡萄胎的诊断也有一定的参考意义.     

脂多糖对增生性瘢痕患者正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原及胶原酶信使核糖核酸表达的调控及意义

目的:研究细菌脂多糖对增生性瘢痕患者正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原及胶原酶信使核糖核酸表达的影响,了解细菌脂多糖在增生性瘢痕形成中的生物学作用。方法:体外培养增生性瘢痕患者瘢痕组织及正常皮肤成纤维细胞,应用不同浓度(0.005~1.0μg/mL)的大肠杆菌细菌脂多糖(E.coli055:B5)对正常皮肤成纤维细胞进行刺激,并对刺激后细胞传代至表型稳定(第8代),采用逆转录-聚合酶链反应法检测细菌脂多糖对正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原及胶原酶信使核糖核酸表达的调控作用,观察剂量-效应关系。分别以同个体相同代数的瘢痕组织成纤维细胞和未经细菌脂多糖刺激的正常皮肤成纤维细胞做对照。结果:细菌脂多糖刺激浓度0.005~0.5μg/mL范围内促进正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原信使核糖核酸表达,抑制胶原酶信使核糖核酸表达(P<0.01),均在0.1μg/mL浓度点作用达高峰;当细菌脂多糖刺激浓度到达1.0μg/mL时,抑制正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原信使核糖核酸表达,促进胶原酶信使核糖核酸表达,且均显著低于阴性对照组(P<0.01);当浓度为0.1μg/mL时,正常皮肤成纤维细胞Ⅰ,Ⅲ型前胶原信使核糖核酸和胶原酶...