DEPLETION OF NORADRENALINE STORES IN SYMPATHETIC NERVE TERMINALS

—The alpha blocking agents phenoxybenzamine and phentolamine were used to increase impulse evoked release of noradrenaline from sympathetic nerve terminals. Measurement of the resulting depletion suggests that most of the noradrenaline released from nerve terminals comes from the low density noradrenaline storage particles.     

RNA TRANSPORT FROM NUCLEUS TO CYTOPLASM IN CHIRONOMUS SALIVARY GLANDS

The fine structure and cytochemistry of the extremely large RNA puffs, or Balbiani rings, in salivary gland nuclei of midge, Chironomus thummi, larvae have been investigated. The Balbiani rings are composed of a diffuse mass of electron-opaque 400 to 500 A granules, short threads about 180 to 220 A in diameter and associated fine chromatin fibrils. These components appear to be organized into brushlike elements which form the ring. Electron microscope cytochemistry has shown that the granules and short threads contain RNA. After ribonuclease digestion, only 50 to 100 A chromatin fibrils were apparent in the Balbiani ring, and the granules were no longer demonstrable. Deoxyribonuclease digestion had no apparent effect on these structures. Observations indicate that the granules are formed from the short threads and released into the nucleoplasm in which they are evenly distributed. At the nuclear envelope, many granules have been observed partially or completely within the nuclear pores. These granules become elongated and are shown to penetrate the center of the pore in a rodlike form, about 200 A in diameter. The Balbiani ring granules are not normally visible within the cytoplasm adjacent to the nuclear envelope, but have been rarely found in this region. It is suggested that the granules represent the product of the Balbiani ring, possibly a messenger RNA bound to protein, and that they regularly pass into the cytoplasm through a narrow central channel in the pores of the nuclear envelope.     

MASS PREPARATION OF NUCLEI FROM THE LARVAL SALIVARY GLANDS OF DROSOPHILA HYDEI

A method has been developed for isolating gram quantities of salivary glands from late third instar larvae of Drosophila hydei. The isolated glands have a normal appearance and incorporate RNA and DNA precursors normally. Nuclei can be isolated from these glands in 90% yield with the use of detergents. These nuclei contain morphologically normal giant polytene chromosomes.     

CHANGES IN ADRENALS AND SYMPATHETIC NERVE TERMINALS FOLLOWING COLD EXPOSURE

Abstract— Rats kept at 3°C for 24 h show no significant change in the catecholamine content of the adrenals, although the protein content is raised. Whole heart ventricles show no change in noradrenaline content, but the vesicular pellet isolated from heart ventricles has a decreased noradrenaline concentration and DBH activity and an increased protein content.     

小鼠颌下腺内交感神经末梢变性时程的性差异

外源性神经生长因子(NGF)对周边交感系统的营养性影响已有广泛的研究(Black,1978;Purves等,1978)。但是,内源性NGF是否同样行使这种影响,至今还没有被人证实(Nja等,1978)。1979年,Carstairs等人利用丙酸睾酮慢性处理,提高小鼠颌下腺内NGF含量以后,观察到颈上神经节(SCG)中有部分神经元肥大,但其它交感神经节不受影响。作者认为SCG内肥大的神经元就是支配颌下腺的那部分交感神经元。由于雄性小鼠颌下腺内的NGF含量是雌性小鼠的92倍(Hirata等,1979),我们实验室直接检查了小鼠颌下腺和虹膜的交感神经支配,发现成年雄性小鼠颌下腺的荧光基丛索远较雌性小鼠的     

视前区儿茶酚胺神经末梢损毁对针刺镇痛的影响

本实验在家兔双侧视前区内注入6-羟基多巴胺(6-OH-DA,4μg/每侧),选择性损毁该区儿茶酚胺(CA)神经末梢后,观察对针刺镇痛的影响。实验结果表明,注药后第二、四天,针刺镇痛效应较针前或对照组均有明显提高。注药后第十天,针刺镇痛效应基本恢复到对照组水平。用甲醛诱发荧光组织化学法显示视前区 CA 末梢,可见6-羟基多巴胺组的 CA 末梢明显减少。结果提示,视前区 CA 含量减少有利于针刺镇痛作用。     

ON THE SITE OF ORIGIN OF TRANSMITTER AMINO ACIDS RELEASED BY DEPOLARIZATION OF NERVE TERMINALS IN VITRO

Abstract— —The site of origin of transmitter amino acids released by depolarizing agents from nerve endings was studied. The model used was the incubated and depolarized synaptosome preparation from which the component soluble, synaptic vesicle, membrane and mitochondrial sub-fractions were obtained. Synaptosomal amino acids were radioactively labelled from D-[U-¹⁴C]glucose in vivo by intraventricular injection and in vitro during subsequent incubation. The specific radioactivities of amino acids released in response to K⁺ (56 mM) or veratrine (75 μM) were found to closely resemble those of the soluble cytoplasmic fraction, in most cases differing significantly from those of the other fractions. The specific radioactivity of the GABA and aspartate released by K⁺ stimulation and the GABA and glutamate released by veratrine were significantly different from that of the vesicles in each case. The specific radioactivities of glutamate released by both agents, and also GABA with K⁺ stimulation, were approximately double that of the amino acid released in control conditions. Depletion of the soluble cytoplasmic pools of glutamate, GABA and aspartate occurred following stimulation, corresponding to the induced-release of these compounds. Turnover of the amino acids in the other subfractions was too low to account for their participation in the release process in addition to the soluble cytoplasmic pool. A cytoplasmic origin of release of neurotransmitter amino acids from nerve endings is proposed.     

CYTOPLASMIC FINE STRUCTURE OF SCIARA SALIVARY GLANDS : I. Secretion

Cells from the anterior segment of the salivary glands of Sciara coprophila were found to synthesize and secrete into the gland lumen three morphologically distinct types of granule: 1) A large, electron-lucid granule, up to 1 µ in diameter, staining only faintly with pH 2 fast green and the PAS reaction; 2) an ellipsoid granule of moderate density, strongly fast green and PAS positive; and 3) a small spherical granule of high electron density. The cells contained numerous Golgi areas, up to an estimated 8,000 per cell. Evidence is presented for the transfer of material from the endoplasmic reticulum to the Golgi areas via small vesicles. Three types of Golgi areas were distinguishable, each containing intercisternal material resembling one of the three types of secretion granule. Patterns of secretion granule synthesis varied with the developmental stage of the larva as determined by counts of eye spots in the eye anlage. Lucid granules were most abundant in the youngest larvae, and decreased in abundance as larvae grew older, becoming virtually absent in prepupae. The small, dense granules were present in all gland cells, but became more prevalent in older larvae and prepupae. Ellipsoid granules were only occasionally present, and were independent of larval stage. It is suggested that lucid granules are digestive in function, since their abundance correlates with feeding patterns. Other granules may produce the external slime coating of the larvae, and also the mucoprotein component of the pupal cocoon.     

现代人头骨面部几项非测量性状的观察

用人类学观察法比较了中国云南、华北和欧洲现代人头骨的犬齿窝、颧骨缘突和梨状孔上外侧部膨隆的出现情况,以探讨其在人种、群体区分上是否有意义。结果：（1）在云南头骨,犬齿窝、颧骨缘突的出现率无性别差异,梨状孔上外侧部骨表面膨隆的出现率男性明显高于女性,而在欧洲头骨,这3项非测量必状的出现率男女间无差异。（2）上述3项性状,在中国云南和华北头骨（男性）的出现率无差异。（3）犬齿窝、梨状孔上外侧部骨表面膨隆的出现率,在现代欧洲人头骨明显高于现代中国人头骨。颧骨缘突的出现率在欧洲与中国现代人头骨上无差异。     

DEVELOPMENT OF THE ACINOUS AND ACCESSORY SALIVARY GLANDS IN NUCELLA LAPILLUS: (NEOGASTROPODA: MURICOIDEA)

The acinous and accessory salivary glands in Nucella lapillusare derived from two distinctly separate sites; the acinoussalivary glands evaginate from the walls of the buccal cavity,whilst the accessory salivary glands arise as paired invaginationsof the epithelium of the ventral lip of the mouth. During thedevelopment of the oesophagus, the acinous salivary glands growposteriorly and come to lie behind the nerve ring, but are pulledanteriorly through it when the proboscis elongates during development.The ducts of the accessory salivary glands fuse to form a singleduct with paired tubular glands during proboscis formation.The secretory cells in both pairs of salivary glands differentiateprior to the crawlaway's emergence from the egg capsule. Theontogeny of the salivary glands in Nucella shows that the accessorysalivary glands cannot be homologdus with the acinous salivaryglands or venom apparatus of the Conoidea. (Received 13 September 1996; accepted 25 November 1996)     

乙酰胆碱对蛇运动神经末梢离子通道活动的反馈调节

由研究乙酰胆碱受体激动剂和阻断剂的作用提出,在脊椎动物运动神经末梢存在着对乙酰胆碱（ＡＣｈ）释放的反馈调节。神经末梢的离了通道在递质释放中有重要作用。本文是利用周膜下记录技术。研究ＡＣｈ对蛇运动神经末梢离子通道调节作用的报告。（１）２ｍｍｏｌ／ＬＡＣｈ明显抑制依钙Ｋ流（ＩＫ,Ｃａ）此效应与３ｍｍｏｌ／ＬＴＥＡ的相似。由于ｎＡＣｈＲ激动剂尼古丁（２ｍｍｏｌ／Ｌ） 不影响Ｉｋ,ｆ和ＩＫ,Ｃdisplay stat     

STRUCTURAL AND FUNCTIONAL PROPERTIES OF POLYTENE NUCLEI ISOLATED FROM SALIVARY GLANDS OF DROSOPHILA HYDEI

Salivary gland nuclei of Drosophila hydei, isolated by a modification of the procedure described by Boyd et al. (9), retain their normal morphology during the isolation and subsequent incubation procedure. RNA synthesis was studied in isolated nuclei by biochemical and cytological techniques. In radioautographs 70% of the nuclei displayed a distribution of labeled RNA over the nuclear constituents similar to the distribution obtained after in vivo incorporation of radioactive precursor. Chromosome puffs and the nucleoli were specifically labeled. The remaining 30% of the nuclei showed a weak to very weak incorporation of radioactive precursor. In these nuclei most of the radioautographic grains were concentrated over the nucleolus, and a few grains were randomly distributed over the chromosomes. Actinomycin D and the absence of ATP, GTP, and CTP in the medium inhibited incorporation of radioactive precursor. The radioactive product was sensitive to combined pronase and RNase digestion. Addition of E. coli RNA polymerase to the incubation medium enhanced the specific labeling over the puffed regions. The sedimentation behavior of the RNA synthesized in isolated nuclei was different from that of RNA synthesized during a 20 min pulse of radioactive precursor administered to whole glands in vivo and in vitro. Neither the steroid ecdysterone nor a temperature treatment was effective in inducing new puffs in isolated nuclei.     

人小肠粘膜内神经元的组织化学与免疫组织化学观察

使用ＮＡＤＨ黄递酶组化法,我们观察到小肠的固有层和粘膜肌层内的神经元和小神经节。粘膜内神经元经ＮＡＤＨ黄递酶组化与ＮＳＥ免疫组化法联合染色,由蓝色转变为黑色;在同一切片内粘膜下丛和肌间神经丛的神经元具有相同的染色性。粘膜内一些ＡＣｈＥ阳性反应神经元,胞体呈校形,两端伸出较长的突起;另一些神经元胞体呈卵圆形或不规则形,可见突起伸入肠膝下部,参与腺周丛。粘膜内神经元的类型和性质有待进一步研究。     

SELECTIVE LOCALIZATION OF A HIGH AFFINITY CHOLINE UPTAKE SYSTEM AND ITS ROLE IN ACh FORMATTON IN CHOLINERGIC NERVE TERMINALS

The avian iris-ciliary nerve preparation exhibits two distinct choline uptake systems. One component, a sodium dependent, high affinity system Km-2 am and Vmax - 0.5 pmolpin per preparation is confined to nerve terminals. The other component is localized in muscle cells. It is sodium independent and low affinity system (Km - 200 am and Vmax - 16 pmol/min per muscle). The high affinity uptake of choline and the synthesis of ACh in the nerve terminals are coupled. Vmax Ach formation -0.5 pmol/min. is the same as Vmax for choline transport; however. with the external choline concentration equal to that of avian plasma only -50% of choline taken up is converted to ACh. In contrast to the nerve terminals, the cell bodies of the same neurons are deficient in the high affinity uptake-ACh synthesis coupled system. This indicates a nerve terminal membrane specialization related to neuro-transmitter synthesis.     

OBSERVATIONS ON A TRANSIENT PHASE OF FOCAL SWELLING IN DEGENERATING UNMYELINATED NERVE FIBERS

This study describes the nature and time-course of a swelling phase during the degeneration of unmyelinated nerve fibers, as observed in highly organized cultures of rodent sensory ganglia. Observations were made on nerve fascicles after they were cut and during nutritional deprivation. About 12 hr after nerve transection, large, clear vacuoles appear throughout fascicles distal to the cut. These vacuoles are most numerous at 24 hr and then gradually subside; after 48 hr, only small granules mark the severed fascicles. Electron microscopy shows that the vacuoles are, in fact, massive focal dilations of unmyelinated axons. Similar focal dilations in unmyelinated axons are observed if cultures are not refed for 5–7 days; under these conditions glucose concentrations fall below 20 mg/100 ml and degenerative changes begin to appear in neuronal somas. If the gas-tight assembly is opened and the culture refed, there is rapid disappearance of axonal dilations (usually within 1 hr) and recovery of many of the damaged neurons. Cooling (4°C) prevents this reversal, suggesting that an active process is involved. It is postulated that the swellings result from the failure of active axolemmal ion-pumping mechanisms prior to loss of selective permeability in the axon membrane. The reasons for the focal nature of the swellings is unknown. A literature review indicates that a phase of focal swelling has frequently been observed during the degeneration of unmyelinated nerve fibers in vivo.     

CELLULAR AND SECRETORY PROTEINS OF THE SALIVARY GLANDS OF SCIARA COPROPHILA DURING THE LARVAL-PUPAL TRANSFORMATION

The cellular and secretory proteins of the salivary gland of Sciara coprophila during the stages of the larval-pupal transformation were examined by electrophoresis in 0.6 mm sheets of polyacrylamide gel with both SDS-continuous and discontinuous buffer systems. After SDS-electrophoresis, all electrophoretograms of both reduced and nonreduced proteins from single glands stained with Coomassie brilliant blue revealed a pattern containing the same 25 bands during the stages of the larval-pupal transformation. With the staining procedures used in this study, qualitative increases and decreases were detected in existing proteins and enzymes. There was no evidence, however, for the appearance of new protein species that could be correlated with the onset of either pupation or gland histolysis. Electrophoretograms of reduced samples of anterior versus posterior gland parts indicated that no protein in the basic pattern of 25 bands was unique to either the anterior or posterior gland part. Electrophoretograms of reduced samples of secretion collected from either actively feeding or "cocoon"-building animals showed an electrophoretic pattern containing up to six of the 25 protein fractions detected in salivary gland samples, with varied amounts of these same six proteins in electrophoretograms of secretion samples from a given stage. Zymograms of non-specific esterases in salivary gland samples revealed a progressive increase in the amount of esterase reaction produce in one major band and some decrease in the second major band during later stages of the larval-pupal transformation.