Effects of disuse and nerve stump length on the development of fibrillation in denervated soleus muscle

Summary Both in normal (control) and in cordotomized (disused) rats, the soleus muscle was denervated either by cutting the sciatic nerve near the trochanter (proximal denervation) or by cutting the soleus nerve near the insertion into the muscle (distal denervation). In the control muscles, the development of fibrillation was not dependent on the level of nerve section. In disused muscles, the development of fibrillation was greater following distal denervation than following the proximal one.     

A histochemical study of denervated marsupial hemidiaphragm.

The marsupial (quokka) hemidiaphragm showed postdenervation hypertrophy and subsequent atrophy. The type II muscle fibres hypertrophied up to 20 days postoperation and then regressed. However, the type I fibres hypertrophied throughout the experimental period (100 days) studied. Unlike denervated eutherian hemidiaphragm, fibre-splitting was absent in the denervated marsupial muscle. An enhancement of the ATPase reaction in the denervated type I fibres may be due to dedifferentiation. Presumably innervation exerts a 'negative control' and prevents increase of type I fibre size in the normal hemidiaphragm.     

Satellite cells in denervated muscles.

It is known that, in a denervated striated muscle, the satellite cells multiply by mitotic division. A liaison between these satellite cells and the Schwann cell in front of the post-synaptic membrane in denervated frog muscle has been observed. It is probable that such cell connections help in the subsistence of the Schwann cell in a denervated muscle.     

Satellite cells in denervated muscles

Summary It is known that, in a denervated striated muscle, the satellite cells multiply by mitotic division. A liaison between these satellite cells and the Schwann cell in front of the post-synaptic membrane in denervated frog muscle has been observed. It is probable that such cell connections help in the subsistence of the Schwann cell in a denervated muscle.     

拟南芥基因组中注释为小檗碱桥环酶基因的分子克隆及异源表达

小檗碱桥环酶(BBE)催化(S)-牛心果碱((S)-reticuline)中N-CH3与分子内苄基部分中羟基的邻位芳香碳之间C-C键的形成,该酶属于双共价黄素蛋白家族,是苄基异喹啉类生物碱向小檗碱类生物碱转化的关键酶.迄今,在拟南芥(Arabidopsis thaliana)中尚未发现复杂生物碱,但其基因组测序结果表明拟南芥含有众多可能与复杂生物碱生物合成相关的基因,其中与BBE类似的基因有12个.基于与已知功能的BBE及拟南芥中BBE序列的分析,选定拟南芥中4个注释为BBE的编码基因为目的基因,设计特异引物,从拟南芥cDNA中扩增并克隆到pGM-T载体中,筛选重组子,测序并分析,获得了4个BBE目的基因,分别为AT2G34810、AT5G44400、AT5G44410和AT5G44440.将上述基因克隆至表达载体pET-28a或pET-30a中,分别转入大肠杆菌Rosetta(DE3)中,IPTG诱导实现了上述基因的异源表达.     

Freisetzung von Kalium aus denerviertem und innerviertem Skelettmuskel durch Acetylcholin

Summary Both hind limbs of cats (one being normally innervated, the other 8–12 days after denervation) were perfused and the quantities of potassium liberated from the two limbs in response to intraarterial injections of varying amounts of acetylcholine were compared by collecting the venous outflow from both sides separately; considerably larger quantities of potassium were found to be liberated from the denervated than from the innervated muscle after equal doses of ACH; the threshold dose of ACH for eliciting a measurable liberation of potassium being much lower on the denervated side. The dose response relation between injected ACH and potassium-liberation is of a different nature for innervated and denervated muscle. The results obtained are compatible with expectations derived from the short circuit theory of the transmitter action on the neuromuscular endplate (Fatt andKatz). The reasons of the difference in the dose relations for the innervated and denervated muscle are discussed.     

Über den Einfluss von Desoxycorticosteron auf Kontraktur und Kaliumfreisetzung durch Acetylcholin an der innervierten und denervierten Skelettmuskulatur

Summary The release of potassium ions from striated muscle, and the changes in mechanical tension developed by the gastrocnemius muscle on intraarterial injection of ACh, were investigated by isolated perfusion of the hind limbs in cats. The reaction of the normal innervated and chronically denervated muscle in the same animal were compared before and during perfusion with 2·10^–4 M/l desoxycorticosterone glucoside (DCG). The following results were obtained: after perfusion with DCG no change in the spontaneous release of potassium ions occurred neither on the innervated nor on the denervated muscle. The potassium release following intra-arterial injections of various doses of ACh was significantly reduced on innervated and denervated muscle. On the denervated muscle there was also a considerable reduction of the height of contractures caused by ACh administration. The results make it probable that DCG acts by an inhibition of depolarisation in the same way asd-tubocurarine.     

Alkaline phosphatase activity in normal and denervated skeletal muscle

Summary Changes in the specific activity of alkaline phosphatase in the normal and denervated skeletal muscle have been studied both histochemically as well as biochemically for a maximum period of 8 weeks of its postnatal development. In the normal muscle, a heterogenous population of fibres with respect to the enzyme distribution is observed. Relatively higher levels of enzyme in the denervated muscle and also the proliferation of extrafibrillar connective tissue in the diseased muscle show its specific association with the lytic processes.     

A histochemical study of denervated marsupial hemidiaphragm

Summary The marsupial (quokka) hemidiaphragm showed postdenervation hypertrophy and subsequent atrophy. The type II muscle fibres hypertrophied up to 20 days postoperation and then regressed. However, the type I fibres hypertrophied throughout the experimental period (100 days) studied. Unlike denervated eutherian hemidiaphragm, fibre-splitting was absent in the denervated marsupial muscle. An enhancement of the ATPase reaction in the denervated type I fibres may be due to dedifferentiation. Presumably innervation exerts a negative control and prevents increase of type I fibre size in the normal hemidiaphragm.I am grateful to Dr O.M. Sola and Professor B.A. Kakulas for their help and encouragement.     

What’s new in the renin-angiotensin system?

The type 1 angiotensin receptor (AT(1)) activates an array of intracellular signalling pathways that control cell and tissue responses to the peptide hormone angiotensin II (AngII). The capacity of AT(1) receptors to initiate and maintain such signals has typically been explained on the basis of conventional heterotrimeric guanine nucleotide binding protein (G protein) activation, specifically G(q/11). Accumulating evidence from studies utilising a variety of AT(1) receptor mutants and AngII analogues indicates that some important downstream effects of AT(1) receptors are independent of classical G protein coupling. Importantly, AT(1) receptor-mediated endocytosis, tyrosine phosphorylation signalling and mitogen-activated protein kinase activation as well as transactivation of the epidermal growth factor receptor can occur in G(q/11)-uncoupled receptor mutants. These observations point to a functional partitioning of AT(1) receptor signals that permits separation of short-term AngII actions (e.g., vasoconstriction) from more extended events, such as pathological cell growth in heart and blood vessels, and may open up new avenues for selective antagonism.     

Influence of halogenated deoxyuridines on the radiation sensitivity ofEscherichia coli

Zusammenfassung Halogenierte Deoxyuridine IUDR, BUDR und FUDR wurden im Medium als bakterielle Sensibilisatoren für Röntgenstrahlen untersucht. Es wird gezeigt, dass nur IUDR als Sensibilisator funktionieren kann, scheinbar sowohl durch die Bildung des langlebigen giftigen molekularen Jods als auch durch die Bildung des kurzlebigen giftigen Jod-Atoms.

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This work was supported in part by an institutional grant from the U.S. National Cancer Institute, No. CA-08748 and by a grant from the U.S.Atomic Energy Commission, No. AT(30-1)910.     

Der Einfluss von Acetylcholin auf die42Kalium-Abgabe postnataler,denervierter und reinnervierter Skeletmuskulatur

Summary The loss of⁴²K from the isolated rat diaphragm into the bathing solution is increased by acetylcholine, (a) 3 to 4 days after birth, (b) 7 to 14 days after sectioning of the phrenic nerve. The⁴²K loss is not altered by acetylcholine in the diaphragm of adult rats and after the denervated diaphragm has become reinnervated.     

Impaired proximal tubular transport functions in anaesthetized splanchnicotomized dogs

Summary The maximal tubular transport of inorganic phosphate,d-glucose and para-aminohippuric acid, respectively, was depressed on the denervated side in unilaterally splanchnicotomized, anaesthetized dogs. It is concluded that renal sympathetic activity might in general regulate proximal tubular transport functions.The authors are indebted to Mrs V. Vajda, Mr A. Karai, Mrs K. Kéry, Mrs B. Asztalos, Mr S. Szécsi and Mr J. Vártok for their valuable technical assistance.     

Photoreactivable sectors and the systematics of the genusPichia

Zusammenfassung Es wird der Beweis erbracht, dass photoreaktivierungsfähige Sektoren von Zellen einen zusätzlichen Affinitätsparameter zwischer Hefen der GattungenHansenula undPichia bilden und vielleicht wertvolle Daten für die endgültige Erschliessung der intragenerischen Phylogenie derPichia liefern.

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These studies were aided in part by a contract No. AT (11-1)-1772 with the U.S. Atomic Energy Commission.     

Variation of the fine structure in granulocytes of great apes

Zusammenfassung Elektronenmikroskopische Untersuchungen der Granulocyten anthropoider Affen ergaben Unterschiede in der Struktur der eosinophilen Granula und eine bisher unbekannte fibrilläre Granulationsform in Orangutan Neutrophilen.

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These studies were supported by U.S. Public Health Service Grant No. FR 00165 from the National Institutes of Health and Atomic Energy Commission grant No. AT (30-1) 3808.     

Analysis of nucleic acid derivatives at the subnanomolar level. II. Quantitative analysis of ribose derivatives by tritium labeling

Zusammenfassung Es wird eine Methode zur quantitativen Analyse von Ribosederivaten beschrieben, welche etwa fünftausendmal empfindlicher ist als die spektrophotometrischen Standardverfahren.

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This work was supported by grants-in-aid from the U.S. Atomic Energy Commission (No. AT(30-1)2643), the U.S. Public Health Service (No. CA 05018), and the American Cancer Society (No. E-51-J). This is publication No. 1325 of the Cancer Commission of Harvard University.

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The first paper of this series³ described a procedure for detecting subnanomolar quantities of mono- and oligonucleotides on PEI-cellulose thin layers.     

Untersuchungen über das Verhalten des denervierten Rattenzwerchfellstreifens in verschieden konzentrierten [Ca++]- und [K+]-Lösungen

Summary The denervated diaphragm of the rat possesses a lower calcium concentration and dry weight than the non-denervated muscle. Decrease of [Ca]_e causes a faster rise and fall of the K-contracture in the non-denervated diaphragm of the rat. Increase of [Ca]_e has the reverse effect. The behaviour of the denervated muscle is different. TEA and carbachol influence the potassium contracture in almost the opposite way.     

Tannin und Adrenalin

Summary Tannic acid in concentrations which of themselves have no action potentiates and prolongs the action of adrenaline on the isolated rabbit intestine (inhibitory effect) and on the isolated non-pregnant rabbit uterus (excitatory effect). The adrenaline-pressor effect in the decapitated cat and, in the same species, its stimulant action on the nictitating membrane (either denervated or normal) may also be potentiated by tannic acid. Since the oxidation of adrenalinein vitro is inhibited by tannic acid, it seems that this—in addition to a possible increase of permeability—is mainly responsible for the potentiation of adrenaline.     

What’s new in the renin-angiotensin system?

The angiotensin AT(4) receptor was originally defined as the specific, high-affinity binding site for the hexapeptide angiotensin IV (Ang IV). Subsequently, the peptide LVV-hemorphin 7 was also demonstrated to be a bioactive ligand of the AT(4) receptor. Central administration of Ang IV, its analogues or LVV-hemorphin 7 markedly enhance learning and memory in normal rodents and reverse memory deficits observed in animal models of amnesia. The AT(4) receptor has a broad distribution and is found in a range of tissues, including the adrenal gland, kidney, lung and heart. In the kidney Ang IV increases renal cortical blood flow and decreases Na(+) transport in isolated renal proximal tubules. The AT(4) receptor has recently been identified as the transmembrane enzyme, insulin-regulated membrane aminopeptidase (IRAP). IRAP is a type II integral membrane spanning protein belonging to the M1 family of aminopeptidases and is predominantly found in GLUT4 vesicles in insulin-responsive cells. Three hypotheses for the memory-potentiating effects of the AT(4) receptor/IRAP ligands, Ang IV and LVV-hemorphin 7, are proposed: (i) acting as potent inhibitors of IRAP, they may prolong the action of endogenous promnestic peptides; (ii) they may modulate glucose uptake by modulating trafficking of GLUT4; (iii) IRAP may act as a receptor, transducing the signal initiated by ligand binding to its C-terminal domain to the intracellular domain that interacts with several cytoplasmic proteins.     

Cell cycle changes after denervation of the newt limb regenerate,studied in vitro

Summary The proliferation of the mesenchyme of medium bud stage blastemas ofPleurodeles, measured by³H-thymidine incorporation and mitotic index, decreases about 40–50% under denervated conditions when cultivated in vitro for 4 days; epidermis is not affected in this case. Autoradiography of blastemas after³H-thymidine long term labeling shows that 3/4 of the mesenchymal cells and 1/4 of the epidermal cells are cycling when the blastema is innervated; there is no significant change of these percentages when the blastema is denervated. The results show, contrary to in vivo experiments, that denervation does not provoke an exiting from the cell-cycle but only lengthening of the cycle of the mesenchymal cells (probably of the G₁ phase).