On the Cation Exchanger Properties of Rat Mast Cell Granules and their Storage of Histamine

Mast cell granules free of a surrounding membrane were isolated from water-lysed rat peritoneal and thoracic mast cells by differential centrifugation. The granules were depleted of their histamine by suspension in 10 mM sodium phosphate buffer and the sodium-charged granules then converted into the “hydrogen form” by repeated washing in slightly acid deionized water. The cation exchanger properties of the mast cell granules were investigated by testing the applicability of the Rothmund-Kornfeld equation for cation exchangers to the binding of Na⁺ and Hi⁺ ions to granule sites. The results lend further support to the view that the mast cell granule acts as a cation exchanger with the exchanger function localized to protein carboxyls in the protein-heparin complex of the granule matrix.     

Role of the α-Receptor in the Control of Noradrenaline Release from Sympathetic Nerves

Phenoxybenzamine, hydergin and phentolamine, all markedly increased the overflow of ³H-nor-adrenaline in response to transmural stimulation of the guinea pig vas deferens. After phannacological blockade of neuronal and extraneuronal uptake of noradrenaline, and after inhibition of local prostaglandin formation, the three compounds were still effective and caused increased overflow of ³H-noradrenaline. This effect was abolished by prostaglandin E₂. Using the same pharmacological blockade, noradrenaline and methoxamine inhibited stimulated overflow of ^“H-noradrenaline in a dose-dependent manner. It is concluded that the activity of α-receptors Per se can feed back regulate the release of noradrenaline from sympathetic nerves. The possibility that the receptors are presynaptically located and that they act on Ca⁺⁺ influx into the neuron is discussed.     

Affinity of Noradrenaline and Dopamine for Neural α-Receptors Mediating Negative Feedback Control of Noradrenaline Secretion in Human Vasoconstrictor Nerves

Isolated superfused field stimulated biopsy specimens of human peripheral arteries and veins, preincubated with ³H-(-)-noradrenaline (NA) to label the neural stores of NA, were used to study the potency of dopamine (DA) and of NA as triggers of α-adrenoceptor mediated negative feedback control of sympathetic neurotransmitter secretion, evoked by stimulation with trains of 300 shocks at 1 Hz. In this preparation DA was found to be only slightly less potent than NA in depressing both the secretion of ³H-NA, and the contractile response, evoked by nerve stimulation. DA depressed the contraction evoked by exogenous NA as well, but to a very much smaller extent. On the other hand, DA was a very weak agonist on the α-receptors of the smooth muscle; nearly 1 000 times higher concentrations of DA were required to mimick contractions evoked by exogenous NA. The results show that the neural α-receptor function involved in control of NA secretion differs considerably from the α-receptors of e.g. smooth muscle, with respect to sensitivity to DA. It seems possible that the observed depressing effect of DA on NA secretion may be of pharmacological and clinical interest; it may at least in part explain the vasodilating effect of DA infusions in man.     

Ionic Requirements for Rapid Axonal Transport in vitro in Frog Sciatic Nerves

The effects of K⁺, Na+, hypo- and hypertonicity on the synthesis and fast axonal transport of ³H-leucine-labelled protein were studied in vitro in the frog sciatic system. The methodology used made it possible to discriminate between effects on synthesis and transport of protein. The preparation which consisted of the dorsal ganglia, the sciatic nerve and the gastrocnemius muscle was placed in an incubation chamber. The ganglia were incubated in standard Ringer containing ^SH-leucine and the nerve was prefused with modified Ringer. Perfusion of the nerve for 17 h with K⁺-free Ringer or Na⁺-free Ringer did not affect the rapid axonal transport of ³H-leucine-labelled material from the ganglia along the nerve towards a ligature in front of which it accumulated. Nor was the transport influenced by concentrations of K⁺ up to 68.8 mM. In contrast concentrations exceeding 100 mM K⁺ partially inhibited the transport. Inhibition by ouabain (0.1 mM) was not prevented by elevating K⁺ to 30 mM. Deviation from isotonicity, towards a hypo- or a hypertonic medium, partially inhibited axonal transport. The transport inhibitory effects showed reversibility. Experimental conditions, which arrested the transport, were tested in separate experiments for effects on uptake of ³H-leucine into TCA-soluble and insoluble ganglionic components. K⁺ substituted for Na⁺, ouabain (0.1 mM) and hypotonic Ringer partially inhibited the amino acid uptake hut also subsequent steps in the incorporation process, whereas only the latter was inhibited by hypertonic Ringer. The results are discussed in relation to possible changes in energy metabolism.     

不同波长的弱激光对大白鼠损伤坐骨神经再生的作用

本文在He-Ne激光对大白鼠损伤坐骨神经再生作用研究的基础上、用不同波长作进一步的究研,找出激光参数之一——波长的影响及作用。通过观察动作电位、雪旺氏细胞生长情况,从而找出它的规律。     

Differential Distribution of Renal Nerves in the Sympathetic Ganglia of the Rat

The renal nerve plexus comprises efferent and afferent fibers. It controls urine production and bodily fluid homeostasis. Efferent fibers to the kidney include sympathetic nerve fibers from their main ganglia, the prevertebral suprarenal ganglia (SrG), and the paravertebral sympathetic chain ganglia (ChG). In the present study, we examined topological innervation from these ganglia to the renal parenchymal segments of the left kidney of the rat. Fluoro‐Gold was injected into the rostral or caudal poles of the left kidney. Approximately 50% of the cells in the SrG of rats injected in the rostral pole were labeled, while 60% of the cells in the ChG T13 of rats injected in the caudal pole were labeled. In addition, we performed dual‐probe retrograde tracing of the nerves using two kinds of fluorescent‐conjugated cholera toxins (f‐CTbs) injected into the rostral and caudal poles of the left kidney. The cells labeled with each f‐CTb were distributed differently in the left SrG and the lower ChGs; no dual‐labeled cells were found in these ganglia. Anterograde tracing with pCAGGS‐tdTomato vector transfected into the left SrG showed that tdTomato‐labeled nerve varicosities extended to the cortical arterioles and urinary tubules. Immunohistochemistry revealed that they were positive to tyrosine hydroxylase and synaptophysin, suggesting that they possessed sympathetic nerve endings. Our results show that renal efferent nerves in the SrG may control the rostral part of the kidney and innervate the multiple effectors in the cortex. Anat Rec, 300:2263–2272, 2017. © 2017 Wiley Periodicals, Inc.     

Rapid Transport of Noradrenaline in Adrenergic Axons of Rat Sciatic Nerve Distal to a Crush1

The transport of NA in the rat sciatic nerve distal to a crush was studied in 5 mm segments. The disappearance of a NA fraction in consecutive segments with time after crushing (0–12 h) was interpreted to indicate a proximo-distal migration of a NA fraction into further distal parts of the nerve. This transportable NA fraction was found to be about 45% of the NA in normal sciatic nerves and migrated at a rate of approximately 8 mm/h. The apparently non-mobile fraction (55%) was probably mainly located in vaso-constrictor nerve terminals of the blood vessels supplying the nerve. This non-mobile NA fraction does not contribute to the NA accumulations proximal to a crush. Thus, when calculating the rate of transport of any substance from accumulation experiments, corrections for a non-mobile fraction must always be considered.     

Control of the Neurotoxicity of 6-Hydroxydopamine by Intraneuronal Noradrenaline in Rat Iris

In vitro studies with the neurotoxic compounds 6-hydroxydopamine (6-OH-DA) and 6-aminodopamine (6-A-DA) showed that noradrenaline (NA) markedly inhibited the autooxidation of 6-OH-DA, but not of 6-A-DA. In vivo studies of the adrenergic nerves in rat iris showed that the neurotoxic potency of 6-OH-DA, but not 6-A-DA, was increased after NA depletion by α-methyl-p-tyrosine methylester(H44/68). Neurotoxicity was evaluated by measuring the associated decrease in ³H-NA uptake. lntraocular injection of NA counteracted the degenerative action of 6-OH-DA in both untreated and H44168 pretreated rats. Intraocular NA did not interfere with the neurotoxicity of 6-A-DA. Additionally, octopamine did not affect the rate of autooxidation nor the neurotoxic potency of 6-OH-DA or 6-A-DA. Control experiments with ³H-6-OH-DA showed that the intraneuronal NA levels did not significantly affect the intraneuronal accumulation of 6-OH-DA. The parallelism between the in vitro results on autooxidation and in vivo data on neurotoxicity makes it appear that the neurotoxic potency of 6-OH-DA and 6-A-DA is closely associated with their rates of autooxidation. The control of the degenerative action of 6-OH-DA by intraneuronal NA may be mediated via reaction of NA with radicals formed from oxygen during autooxidation of 6-OH-DA.     

Effects of Colchicine and Vinblastine on Axonal Transport of Choline Acetyltransferase in Rat Sciatic Nerve1

The effects of colchicine (0.5–10^-2 M) and vinblastine (10^-2-10^-5 M) upon axonal transport of choline acetyltransferase (CAT) and on nerve impulse conduction have been investigated in the rat sciatic nerve. High concentrations of colchicine (0.5 M) and vinblastine (10^-2 M) blocked completely both axonal transport of CAT and impulse conduction. 10^-3 M vinblastine did not affect impulse conduction until 20–22 h after injection, but this concentration of vinblastine did block CAT transport; 5 × 10^-5 and 10^-4 M vinblastine blocked CAT transport but not impulse conduction. 10^-2 M and 10^-1 M colchicine were without effect on impulse conduction, but did produce substantial, although incomplete, block of CAT transport. The results are discussed in relation to the possible involvement of microtubules in transport of CAT.     

Effect of Nerve Stimulation In Vitro on the Noradrenaline Content of the Rat Vas Deferens in the Presence of Inhibitors of Noradrenaline Uptake and Synthesis

Isolated rat vas deferens preparations were intermittently field stimulated (30 s every min) for 2 or 4 h at 7 or 25 imp/s. At the low stimulation frequency only a very small reduction (7 %) of the endogenous noradrenaline (NA) stores was seen during 4 h stimulation while it was about 15 % after 2 h and 37 % after 4 h at 25 imp/s. Addition of drugs known to inhibit NA synthesis (a-methyl-p-tyrosine, a-MPT, 4times10^-4M) or uptake (cocaine, 10^-5M) did not apparently influence neither the spontaneous nor *the nerve-induced reduction of the endogenous NA stores. The present results seem to support the hypothesis that the functional transmitter pool of the short adrenergic neurons of the vas deferens is very small, and that the residual NA reuptake and synthesis after pharmacological blockade, together with minute refilling from the large storage pools, are able to maintain transmitter homeostasis without significant changes of the total endogenous NA content of the vas deferens.     

Motor and Secretory Effects of Nerves on the Parotid Gland of the Rat

The influence of parasympathetic and sympathetic nerves on the parotid gland of the rat was investigated. It was found that both divisions of the autonomic nerves evoke secretion and probably also motor effects in this gland. Secretion elicited on sympathetic stimulation was mediated both via α- and β-adrenoceptors, while motor effects were mediated via α-adrenoceptors. On stimulation of the autonomic nerves a lower duct pressure was reached in the parotid than in the submaxillary gland, and on sympathetic nerve stimulation the flow of saliva always started later from the parotid than from the submaxillary gland. These findings are discussed in the view of the different arrangement of the myoepithelial cells in the 2 glands.     

Sequential Exocytosis of Storage Granules during Antigen-Induced Histamine Release from Sensitized Rat Mast Cells in vitro An electron microscopic study

The morphological changes appearing in sensitized rat mast cells incubated with antigen at 25° C for times ranging from 30 s to 10 min were studied using light and electron microscopy. Histamine release was assayed in parallel. After a latent period of 30 s, during which no histamine release or morphological changes occurred, degranulation and histamine release commenced and increased progressively with time. The first changes were seen in the most peripherally-located granules, and consisted of a fusion of the cell membrane with the perigranular membrane and a swelling and a reduction of the electron-density of the granules. With increasing time these changes were seen to spread deeper into the cells, resulting in the formation of labyrinthic cavities contatining changed granules; such granules were also seen outside the cells. Using the extracellular tracer lanthanum these apparently intracellular cavities were demonstrated to be in unbroken communication with the extracellular milieu. Thus when sensitized rat mast cells are incubated with antigen sequential exocytosis of histamine-storing granules take place. The results agree with the hypothesis that histamine release takes place by ion exchange between histamine and extracellular cations both in granules expelled from the cells and in those retained in cavities open to the exterior.     

半活体和离体大白鼠坐骨神经轴向力学性质的差异

成年Ｗｉｓｔａｒ大鼠坐骨神经（ＳＣＮ）１４侧，随机分为２组，分别在半活体和离体两种不同状态下进行单轴拉伸试验，结果表明：当轴向应力在０￣３６ｋＰａ范围时，半活体和离体的ＳＣＮ应力应变关系为指数函数关系，但材料常数Ｘ，间有显著性差异。     

The Effect of Reserpine and Tetrabenazine on the Accumulation of Noradrenaline in the Rat Sciatic Nerve after Ligation

The accumulation of noradrenaline (NA) in the rat sciatic nerve after ligation was studied at different intervals after the administration of reserpine and tetrabenazine. The histochemical fluorescence method of Hillarp and coworkers was used. It was found that the two drugs were both able to abolish the NA fluorescence above and below both single and double ligations. Pretreatment with nialamide prevented the disappearance of NA occurring after reserpine. The reappearance of NA above a 1 hr ligation of the sciatic nerve occurred 15–18 hrs after an intraperitoneal injection of reserpine. The first signs of the reappearance was observed above a high ligation about 3 hrs before it could be seen above a ligation performed about 2 cm lower. The same pattern of recovery of NA in the sciatic nerve was observed in animals treated locally with reserpine on the ganglia, from which the adrenergic nerves in the sciatic nerve take their origin. However, the fluorescence of NA in these animals usually reappeared about 3 hrs earlier than in systemically treated animals. The restituted NA could be abolished by a second dose of reserpine. In double ligated rats recovery of NA after reserpine could be observed only above the upper ligation. After tetrabenazine, however, double ligated nerves regained the NA content almost completely above both lesions within 12–15 hrs. The results give strong support to the view that the amine storage granules are manufactured in the cell body and transported down the axons to the terminals.     

On the Methylation of Ethanol Amine,Dimethyl Ethanol Amine,Guanidine Acetic Acid and Homocysteine

By means of the colorimetric method of MCCARTHY and SULLI-VAN for the determination of methionine in biological mixtures, an investigation is made of the methylation of ethanol arnine, dimethyl ethanol amine, glycocyamine and homocysteine. The results extend and corroborate those of previous investigations.