The bundle of schütz and its relation to the regulation of food intake

Résumé Les lésions provoquées chez des souris par une injection d'aurothioglucose dans la région ventromédiale de l'hypothalame sont suivies de la dégénérescence du fasciculus dorsalis longitudinalis (faisceau de Schütz). Cette observation indique que l'origine de cette structure efférente est glucoréceptive et fait partie du système glucorécepteur qui contrôle la satiété.

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Supported in part by a grant-in-aid from NINDB (No. NB-01941), and by the Fund for Research and Teaching, Department of Nutrition, Harvard University. We thank Dr.E. B. Hershberg of the Schering Corporation, Bloomfield, N.J. for goldthioglucose (6-SP-111).     

A possible role of guanine-deaminase inhibitor

Zusammenfassung Diskussion über die Frage der Ätiologic der Xanthinurie.     

Inhibition of food intake in the rat by cyproheptadine

Summary In a model of conditioned feeding behavior, oral administration of cyproheptadine (1–100 mg/kg), 30 min before presentation of food, produced a dose-dependent reduction of food intake in the rat (ED₅₀17 mg/kg during the 1st h of testing). This anorexic effect persisted for at least 24 h. These results provide further evidence that under certain conditions cyproheptadine, which is used as an orectic agent in man, can produce anorexia.     

A possible role for histamine in larval growth

Résumé Le rôle possible de l'histamine au cours de la croissance larvaire a été étudié. L'inhibition de l'oxydase des diamines au moyen de l'aminoguanidine, a fortement ralenti la croissance larvaire duTribolium confusum. Cette substance, cependant, ne s'est pas avérée toxique. D'autre part l'inhibition des décarboxylases par le semicarbazide ou le deoxypyridoxine ne modifie pas la croissance sans devenir toxique.     

A possible role of acid mucopolysaccharides in the urine concentrating process

Résumé Par l'adsorption de plus d'eau que de corps dissous, les acides mucopolysaccharides (MPS-s) de la medulla interne du rein peuvent participer à l'élaboration d'urine concentrée. Ce nouveau mécanisme hypothétique laisse supposer que le MPS est le produit d'une synthèse cellulaire et qu'il prend l'eau d'adsorption au moment de la secrétion. Ensuite, le MPS quitte le rein par les voies veineuses et lymphatiques et enfin se détruit dans un autre organe.

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Participant of the USPHS Career Award Program.     

A possible role of microtubules in the C cells secretory mechanism

Riassunto Le modalità di secrezione dei granuli contenenti Calcitonina da parte delle cellule C sono state studiate in tiroidi di cane in condizioni normali e in coltura organotipica con alto tenore di calcio. È stata notata la presenza di numerosi microtubuli alla periferia delle cellule e alcune immagini suggeriscono un attacco dei microtubuli ai granuli secretori. Viene prospettato che i microtubuli abbiano importanza nel meccanismo di secrezione delle cellule C e forse delle cellule della serie APUD in generale, e che questo possa essere del tipo «emiocitosi».     

A possible new role for the anti-ageing peptide carnosine

The naturally occurring dipeptide carnosine (β-alanyl-L-histidine) is found in surprisingly large amounts in long-lived tissues and can delay ageing in cultured human fibroblasts. Carnosine has been regarded largely as an anti-oxidant and free radical scavenger. More recently, an anti-glycating potential has been discovered whereby carnosine can react with low-molecular-weight compounds that bear carbonyl groups (aldehydes and ketones). Carbonyl groups, arising mostly from the attack of reactive oxygen species and ow-molecular-weight aldehydes and ketones, accumulate on proteins during ageing. Here we propose, with supporting evidence, that carnosine can react with protein carbonyl groups to produce protein-carbonyl-carnosine adducts (‘carnosinylated’ proteins). The various possible cellular fates of the carnosinylated proteins are discussed. These proposals may help explain anti-ageing actions of carnosine and its presence in non-mitotic cells of long-lived mammals. Received 29 November 1999; accepted 27 December 1999     

The effects of ethanol on embryonic actin: A possible role in teratogenesis

Summary When the neural crest is cultured in the long or short term presence of ethanol, monoclonal anti-actin reveals the development of a disorganized actin cytoskeleton. In the long term, many cells fail to differentiate morphologically, whereas in the short term already differentiated cells rapidly alter their shape and their cell-to-cell contacts.     

A possible metabolic role for o-diphenoloxidase in Mycobacterium leprae

Among mycobacteria, Mycobacterium leprae is unique in its ability to oxidize a variety of diphenols to quinones in vitro. What physiologic role o-diphenoloxidase has in the organism remained unknown. Reducing substrates like NADPH, NADH and ascorbic acid reacted with the quinone formed from dopa (3,4-dihydroxyphenylalanine); the substrates were oxidized and the quinone was reduced back to diphenol in the process. Since the quinone undergoes reversible oxidation-reduction, diphenoloxidase might serve as an alternative respiratory mechanism in M. leprae for the utilization of other substrates, as has been reported in plants.     

Effect of selenium on food and water intake in the rat

Zusammenfassung Verabreichung von Selen verändert das Stoffwechselgleichgewicht bei 21-Tage alten Ratten, bei denen der Wasserverbrauch proportional zur Nahrungsaufnahme erfolgt, ebenso besonders die freiwillige Futter- und Wasseraufnahme. Diese Befunde sind bei der Untersuchung der Wirkung von Selen auf die Zahnkaries im Rattenversuch zu berücksichtigen.     

A possible physiochemical explanation for the psychotherapeutic role of lithium]

Manic-depressive psychosis could result from degradation of lipids in some neuronic membranes. This degradation could lead to fatty acids, which when ionized in the external medium would definitely disappear. If this medium contains Li+, a poorly soluble precipitate would be formed with the fatty anions. This precipitate, impermeable to its formative ions would slow down the dissipation of the fatty acids and thus facilitate the resynthesis of the original lipids. Ca++ cations being divalent could not play the same role.     

Induction of obesity in obese-hyperglycaemic mice on normal food intake

Zusammenfassung Nachweis, dass bei einem Mäusestamm, welcher eine genetisch bedingte Fettsucht aufweist, die Fettsucht auch bei Nahrungseinschränkung auftritt, wenn diese Tiere homozygot sind, dies im Gegensatz zu heterozygoten Tieren. Daraus wird der Schluss gezogen, dass diese Fettsucht nicht primär alimentär, sondern durch einen genetischen, metabolischen Defekt bedingt ist.     

Effect on food intake in the pig of heating and cooling the spinal cord

Résumé Le réchaufement ou le refroidissement du cordon médullaire du porc par perfusion des thermodes intravertébrales avec un fluide tiède ou froid ne change pas la quantité de nourriture consommée; ceci élimine le rôle des enregistreurs vertébraux de température en tant que médiateurs de la consommation de nourriture chez cette espèce.

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Supported by Special Research Fellowship No. MH-51485 from USPHS.