WATER DEPRIVATION AND CIRCADIAN CHANGES IN PLASMA ARGININE VASOTOCIN AND MESOTOCIN IN THE DOMESTIC HEN (GALLUS DOMESTICUS)

Possible circadian variations in plasma levels of arginine vasotocin (AVT) and mesotocin (MT) were assessed in domestic hens (Gallus domesticus) under a 12h:12h light-dark (LD) schedule. Blood samples were taken at 4h intervals, and neurohypophyseal hormone levels were determined by radioimmunoassay. Marked circadian changes in both AVT and MT were observed in hens provided free access to water. Minimal and maximal AVT levels occurred at 08:00 and 20:00, respectively. Minimal MT levels occurred at 20:00, whereas maximal MT levels occurred over a broad time period of 04:00 to 12:00. In water-deprived hens, plasma AVT levels were elevated at each time point, and the circadian variations in plasma AVT and MT levels were attenuated. These results demonstrate that rhythmicity in neurohypophyseal function in a lower vertebrate species, like that in mammals, is disrupted by osmotic stress. (Chronobiology International, 18(6), 947–956, 2001)     

WATER DEPRIVATION AND CIRCADIAN CHANGES IN PLASMA ARGININE VASOTOCIN AND MESOTOCIN IN THE DOMESTIC HEN (GALLUS DOMESTICUS)

Possible circadian variations in plasma levels of arginine vasotocin (AVT) and mesotocin (MT) were assessed in domestic hens (Gallus domesticus) under a 12h:12h light-dark (LD) schedule. Blood samples were taken at 4h intervals, and neurohypophyseal hormone levels were determined by radioimmunoassay. Marked circadian changes in both AVT and MT were observed in hens provided free access to water. Minimal and maximal AVT levels occurred at 08:00 and 20:00, respectively. Minimal MT levels occurred at 20:00, whereas maximal MT levels occurred over a broad time period of 04:00 to 12:00. In water-deprived hens, plasma AVT levels were elevated at each time point, and the circadian variations in plasma AVT and MT levels were attenuated. These results demonstrate that rhythmicity in neurohypophyseal function in a lower vertebrate species, like that in mammals, is disrupted by osmotic stress. (Chronobiology International, 18(6), 947-956, 2001)     

泰和鸡肾小球旁器的观察

本文用光镜和透射电镜对泰和鸡(乌骨鸡)的肾小球旁器进行了观察。结果表明,泰和鸡的肾小球旁器由球旁细胞、过渡型致密斑、球外间膜细胞和极周细胞所组成。极周细胞在鸟类还属首次报道,它位于肾小囊脏层与壁层上皮移行处,环绕着肾小体的血管极,其结构与哺乳动物的相似。本文还就泰和鸡肾小球旁器的结构与功能的关系作了讨论。     

家鸡联会复合体的亚显微结构分析

本文以表面铺展——硝酸银染色技术,对家鸡的联会复合体(Syneptonemal Complex,SC)作亚显微结构分析。根据对10个精母细胞和10个卵母细胞SC的测量结果,绘制组型图。发现雌雄家鸡的常染色体的SC组型相同。在精母细胞中,性染色体(ZZ)的行为与常染色体相似。在卵母细胞中,性染色体ZW的长度不同,长轴为Z,短轴为W,两者之间只有部分配对,形成SC。从早粗线期到晚粗线期,由同源配对调整为非同源配对。另外,在一只雌鸡中,第一次观察到,有些细胞的常染色体能正常配对,而性染色体完全不配对的现象。     

鸡鸭异种间嵌合体的制备

本研究采集孵化14期鸡胚血液中的原始生殖细胞,在液氮中冷冻保存三个月后,解冻成活率达80％以上。以Ficoll密度梯度离心将其从血液中分离纯化,分离获得纯度为27.5%,平均每枚胚胎可获得近50个PGCs。将分离的PGCs 100-200个以微注射法转移至15期早期麻鸭胚胎中制备了鸡鸭种间嵌合体,孵出8（6♂,2♀）只雏鸭,总孵化率为7.3%（8／110）。以鸡W染色体特异性DNA探针原位杂交法在早期鸭胚性腺中检测鸡PGCs。在被检测的21个鸭胚的性腺中,16个有不同程度的阳性信号,嵌合率达76.2%(16/21)。实验结果表明鸡原始生殖细胞能够迁移并定居到鸭胚性腺中,并有可能在鸭性腺中增殖分化成有功能的配子。     

DNA AND THE FINE STRUCTURE OF SYNAPTIC CHROMOSOMES IN THE DOMESTIC ROOSTER (GALLUS DOMESTICUS)

The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium staining in the electron microscope to Feulgen staining and ultraviolet absorption in thicker sections seen with the light microscope. Following staining by indium, DNA was found mainly in the microfibril component of the synaptinemal complex. When DNA was known to have been removed from aldehyde-fixed material by digestion with DNase, indium stainability was also lost. However, staining of the digested material with non-selective heavy metal techniques demonstrated the presence of material other than DNA in the microfibrils and showed that little alteration in appearance of the chromosome resulted from DNA removal. The two dense lateral axial elements of the synaptinemal complex, but not the central one to any extent, also contained DNA, together with non-DNA material.     

黑水鸡与家鸡染色体带型同源性比较研究

从二倍体细胞大染色体组(Macrochromosomes)的G带特征比较分析,鹤形目的黑水鸡与鸡形目的家鸡带型相似程度很大,标志着这两种鸟类的亲缘关系较近,同时也充分说明了不同目鸟类在进化上染色体变异的保守性。其带型差异仅在于两次臂间倒位、两次臂内倒位和一次着丝点融合。此外,我们采用QM荧光——银染的相继染色法发现黑水鸡的W染色体上有NOR存在,这种核仁组织者区域与性染色质发生连锁的现象在鸟类是首次发现。     

QUANTITATIVE LYSOSOMAL ENZYME ACTIVITY CHANGES IN THE NEURAL LOBE OF THE RAT FOLLOWING WATER DEPRIVATION AND LACTATION

—The activities of five lysosomal enzymes, acid phosphatase, β-glucosidase, β-glucuronidase, β-galactosidase and N-arylamidase (classified according to Marks (1970)) were measured by means of sensitive microchemical techniques in frozen-dried rat neural lobe tissue after experimental and physiological stimulation of hormone release from the hypothalamo–neurohypophysial system i.e. water deprivation (3 and 6 days), delivery and lactation (10 days). During all conditions of stimulation increases of 29 to 106 per cent were measured for lysosomal enzyme activity, expressed as mmol/ng DNA/h. With histochemical staining methods the acid phosphatase activity appears to be mainly localized in the pituicytes, but it was impossible to visualize the microchemically measured acid phosphatase activity increase within the two main compartments of the neurohypophysis, i.e. axonal endings and the neurohypophysial glial cells, the pituicytes.     

家兔发热时脑脊液和血浆中精氨酸加压素含量的变化及禁水的抗热作用

本实验观察了发热家兔脑脊液(CSF)和血浆中精氨酸加压素(AVP)含量的变化及禁水对家兔内毒素(ET)发热效应的影响。实验结果表明:1.隔区注射AVP可明显抑制家兔ET性发热效应;2.发热组家兔CSF和血浆中AVP含量较正常组明显降低;3.禁水可明显对抗家兔ET性发热效应,其抗热作用与CSF和血浆中AVP含量升高有关;4.禁水也可使正常家兔体温水平下移。上述实验结果提示,AVP可能是家兔体内一种内源性退热物质,同时在正常体温调节中也可能发挥一定的作用。