Ecdysteroid receptors located in the central nervous system of an insect

Summary Using thaw-mount autoradiography for steroid hormones, we obtained direct evidence for a nuclear localization of ecdysteroid binding sites in target organs of blowfly (Calliphora vicina) larvae. The binding sites revealed properties of ecdysteroid receptors. Endocrine cells of the ring gland were found to be target tissues of ecydysteroids. This observation provides morphological evidence for a network of complex interendocrine regulation. In the central nervous system receptorcontaining neurons were identified which include many, if not all, neurosecretory cells of the brain. A map of ecdysteroid sensitive cells of the larval brain is presented.     

DNA synthesis in the nuclei of differentiating muscle fibers of the silkworm,Bombyx mori L.

Summary Incorporation of³H-thymidine (³HTdr) into the nuclei of myofibril-containing myofibers of larvae of the silkworm,Bombyx mori, was shown by means of light microscope (LM) and electron-microscope (EM) autoradiography. The number of DNA-synthesizing myonuclei attains 42% 12–18 h after each molt. Thus in the developing silkworm DNA replication and myofibrillogenesis are coexisting and not mutually exclusive processes as is the rule in vertebrate somatic myogenesis.     

皮肤中儿茶酚胺类体液物质及毛囊与针刺效应的关系

通过对针刺穴位两端经络线上施加各种因素，观察了运动对针刺效尖的影响，进一步对其影响国素进行化分析和形态定位，结果表明，拔除经经毛囊和切断经线皮肤都可以明显地阻断针刺效应，而向皮肤经线切口滴加液体则能明显的改变再针刺效应，用高压液相色谱法检测到针刺可以使经线皮肤循经释放去甲肾上腺素，肾上腺素等儿茶酚胺类物质，其含量明显高于没有针刺的经线，用放射自显影技术观察到儿茶酚胺类物质的分布有明显的纵形线性特征     

Presynaptic effects of spider toxins: Increase of high affinity uptake in the arthropod peripheral glutamatergic system

In contrast to the reported effects of polyamines on the high affinity neurotransmitter uptake, two polyamine-like spider toxins significantly increase the high affinity uptake of glutamate as demonstrated with high resolution autoradiography. The effects of both spider toxins were compared to those of a polyamine toxin from the waspPhilanthus triangulum, which is known to inhibit the high affinity glutamate uptake.     

Vitamin D receptors in heart: Effects on atrial natiuretic factor

We report that receptors for vitamin D exist in distinct regions of the heart in female and male mice, predominantly in the right atrium where most of the cardial atrial natriuretic peptide (ANF) is produced. Tritiated 1,25-dihydroxyvitamin D₃ (1,25-D₃, vitamin D, soltriol) and ANF are colocalized in nuclei and cytoplasm respectively in identical cardiomyocytes. Changes of ANF tissue and blood levels under dietary deficiency and treatment with 1,25-D₃ suggest direct genomic actions of vitamin D on myoendocrine cells of the atrium for the regulation of ANF manufacture and secretion. These results were obtained by combining thaw-mount autoradiography with immunocytochemistry using tritiated 1,25-D₃ and an antibody against rat ANF. This antibody was also used in a radioimmunoassay to determine atrial natriuretic factor in plasma, atria and ventricles of normal or vitamin D-deficient mice.     

Presence of specific binding sites for [3H]sarcophytol-A in cultured human skin fibroblasts

Summary The presence of specific binding sites for [³H]sarcophytol-A in human skin fibroblasts was examined using biochemical and morphological methods. The displacement studies clearly revealed that high (K_D=31.0 nM) and low (K_D=6.05 M) affinity sites were present in the intact cells. Moreover, autoradiographic studies using light microscopy revealed that the specific binding sites may exist in boththe cytoplasm and the nuclei.     

中华大蟾蜍(Bufo bufo gargarizans Contor)早期胚胎发育中RNA的合成

以~3H-尿嘧啶核苷作为RNA合成的标记前身物,用放射自显术研究了中华大蟾蜍早期胚胎发育中RNA合成的速率及其与发育之间的关系。结果表明:从受精卵开始至原肠胚期,RNA的合成活性逐渐增强,神经胚期略有下降;RNA合成速率有明显的动—植物极梯度;在诱导与被诱导部位,RNA合成速率明显高于其它部位.     

花背蟾蜍角膜早期形态发生中透明质酸的合成变化及其与角膜分化的关系

本文以花背蟾蜍的胚胎(19～25期)为材料,采用放射自显影技术,以~3H—氨基葡糖标记氨基多糖,并用链霉菌透明质酸酶和睾丸透明质酸酶处理作对照,在光镜水平上研究了透明质酸在角膜早期形态发生中合成变化。结果表明:透时质酸的产生及消除与角膜的形成及分化有相应的关系,在内角膜基质原基开始形成的第20期,即间充质细胞向预定角膜上皮与晶状体之间迁移之际,透明质酸的合成量达到最高水平,此后透明质酸的合成量逐渐减少到最低水平,这相应于角膜上皮开始变薄、透明及分化。本文就透明质酸在角膜早期形态发生中的作用机制进行了初步讨论。     

成年小白鼠新生神经元的观察

将 3[H]标记的胸腺嘧啶核苷 (3[H]-thymidine)注入成年小白鼠腹腔 ,大脑中的神经细胞有丝分裂 ,可通过放射自显影在新生神经细胞中以银粒方式显现 3[H]标记 ,在光镜下观察脑切片中的银粒细胞即为新生神经元 .本实验利用放射自显影的方法 ,在成年小白鼠的海马和嗅球区域观察到新生神经元 .     

Bovine pituitary intraglandular colloid fraction F5 localized in the rat endocrine pancreas

Summary Bovine pituitary intraglandular colloid thought to be a waste product, is the holocrine secretion of intermediate lobe cells. It is housed in the intraglandular lumen (residual lumen) and is extruded into the venous circulation of the cavernous sinuses via clefts in the capsule of the gland aligned with the intraglandular lumen. Intraglandular colloid, fraction F₅ (mol.wt 34,000), radiolabeled with (¹²⁵I)Na and injected (0.15 ml) into the right internal jugular vein of male Wistar rats, accumulated in the endocrine pancreas. Autoradiographs showed that the material had specifically localized in the capillary network of the endocrine pancreas. Since the intermediate lobe is poorly vascularized, intraglandular colloid is considered to be the transport medium for intermediate lobe materials.This study was supported by a grant from the Natural Sciences and Engineering Research Council of Canada.I would like to thank S. Choles and J. Bennett for their technical expertise with the help of P. Galvin and W. Halina. I thank members of the Central Animal Facilities, McMaster University Medical Centre, Hamilton, Ontario, for labeling the intraglandular colloid and for counting the decay rate of the tissue. I would also like to thank Drs. A. deBold and J. Kraicer, Faculty of Medicine, Queen's University, Kingston, Ontario, for their interest in this study.