Experientia最新文献_第7页

Plasma and hepatic antioxidant control and vitamin A nutritional status. 血浆和肝脏抗氧化控制及维生素A营养状况。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925575

I Subirade, Y Fernandez, B Périquet, S Mitjavila, F Anglade, A Périquet

引用次数: 1

Vitamin B12 amplifies circadian phase shifts induced by a light pulse in rats. 维生素B12可以放大光脉冲在大鼠体内引起的昼夜节律相移。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925576

M Ikeda, K Honda, S Inoué

{"title":"Vitamin B12 amplifies circadian phase shifts induced by a light pulse in rats.","authors":"M Ikeda, K Honda, S Inoué","doi":"10.1007/BF01925576","DOIUrl":"https://doi.org/10.1007/BF01925576","url":null,"abstract":"Vitamin B12 (VB12) is a putative modulator of the human circadian clock, improving entrainability to the 24 h light-dark cycle. The present study was intended to elucidate the mechanism of VB12 action in an animal model. In male rats free-running under constant dim illumination, a single light pulse of 50-1000 lux for 20 min given at circadian time (CT) 20 induced a 0.28 to 1.08 h phase advance and at CT 14 induced a 0.54 to 2.10 h phase delay. A 3 h intracerebroventricular (icv) infusion of 30 nmol VB12 starting 2 h prior to a 20 min 200 lux light pulse significantly amplified phase shifts in comparison with saline-treated or untreated controls. The mean phase advance (1.13 h) was 1.8-fold greater than that of saline-infused controls, whereas the mean phase delay (2.28 h) was 2.9-fold greater. These values were comparable to the maximal phase shifts caused by 1000 lux light pulses in untreated rats. Since the same VB12 treatment alone had failed to induce a phase shift in a previous experiment, these results indicate that VB12 strongly enhanced light pulse-induced phase shifts and thus augmented the entrainability of the circadian clock to light.","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 7","pages":"691-4"},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01925576","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Relationship of phosphatidylcholine to hydrophobic surfactant on rat intestinal chylomicron secretion. 磷脂酰胆碱与疏水表面活性剂对大鼠肠乳糜微粒分泌的关系。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925571

J B Rodgers, D A Beeler, P Tso

{"title":"Relationship of phosphatidylcholine to hydrophobic surfactant on rat intestinal chylomicron secretion.","authors":"J B Rodgers, D A Beeler, P Tso","doi":"10.1007/BF01925571","DOIUrl":"https://doi.org/10.1007/BF01925571","url":null,"abstract":"Hydrophobic surfactants such as Poloxalene inhibit triglyceride secretion into lymph by enterocytes. The inhibitory effect of these agents on triglyceride secretion is reversed when lipid presented for absorption is exclusively in the form of phosphatidylcholine (PC) and not triglyceride. The present investigation performed in conscious mesenteric lymph fistula rats was designed to determine whether various mixtures of triglyceride and PC given intraduodenally with Poloxalene would also reverse the inhibitory effect of Poloxalene on triglyceride secretion into lymph. A 50-50 mixture of triolein (TO) and PC resulted in normal triglyceride secretion into lymph. However, when the mixture of lipids was 75-25, TO to PC, results for triglyceride recovery in lymph were considerably reduced. The transport rate for triglyceride into lymph was not as depressed, however, as observed for Poloxalene treated rats given lipid for absorption basically in the triglyceride form. Substitution of phosphatidylethanolamine for PC had no beneficial effect on triglyceride secretion in Poloxalene treated rats. It is concluded that PC can reverse the inhibitory effect of Poloxalene on triglyceride secretion into lymph even when considerable amounts of triglyceride along with PC are presented for absorption.","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 7","pages":"671-6"},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01925571","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19671961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Na/K pump, resting potential and selective permeability in canine Purkinje fibres at physiologic and room temperatures. 生理和室温下犬浦肯野纤维的Na/K泵、静息电位和选择性通透性。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925568

J H Lee

{"title":"The Na/K pump, resting potential and selective permeability in canine Purkinje fibres at physiologic and room temperatures.","authors":"J H Lee","doi":"10.1007/BF01925568","DOIUrl":"https://doi.org/10.1007/BF01925568","url":null,"abstract":"All mammalian cells maintain a resting potential generated by ions moving down concentration gradients. In excitable cells, the inside potential is negative relative to outside. In order to maintain this electrochemical gradient, the sodium potassium (Na/K) pump actively transports out three sodium ions for every two potassium ions it brings in. This process generates a net outward current and thus hyperpolarizes the resting potential. I employed dihydroouabain (DHO) to inhibit the Na/K pump and thus measure its contribution to the resting potential. It contributed 9.0 mV at 34 degrees C and 3.8 mV at 25 degrees C. The PK/PNa ratios were calculated at both temperatures before and after subtracting the Na/K pump contribution. These ratios also suggested a decreased contribution of the Na/K pump under hypothermia. Taken together, these results suggest that the pump contribution to the resting potential is more significant at physiologic temperatures (34 degrees C) than at room temperature (25 degrees C), and that estimates of selective permeability can only be accurately obtained after assessing and eliminating the Na/K pump contribution to the resting potential.","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 7","pages":"657-60"},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01925568","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19671958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Two classes of metabolites from Theonella swinhoei are localized in distinct populations of bacterial symbionts. 两类来自猪单胞菌的代谢物被定位在不同的细菌共生体群体中。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925581

C A Bewley, N D Holland, D J Faulkner

引用次数: 237

Resuscitation of cadaveric livers from non-heart-beating donors after warm ischemic insult: a novel technique tested in the rat. 热缺血损伤后非心脏供体尸体肝脏的复苏:一种在大鼠中测试的新技术。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925569

T Minor, H Klauke, W Isselhard

引用次数: 17

Apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pig ovaries. 猪卵巢闭锁腔卵泡中颗粒细胞发生凋亡，而积云细胞不发生凋亡。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925566

N Manabe, Y Imai, H Ohno, Y Takahagi, M Sugimoto, H Miyamoto

引用次数: 45

Insect hormones in vertebrates: anabolic effects of 20-hydroxyecdysone in Japanese quail. 脊椎动物体内的昆虫激素:20-羟基蜕皮素在日本鹌鹑体内的合成代谢作用。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925578

K Sláma, K Koudela, J Tenora, A Mathová

{"title":"Insect hormones in vertebrates: anabolic effects of 20-hydroxyecdysone in Japanese quail.","authors":"K Sláma, K Koudela, J Tenora, A Mathová","doi":"10.1007/BF01925578","DOIUrl":"https://doi.org/10.1007/BF01925578","url":null,"abstract":"Ecdysteroids are hormones controlling cell proliferation, growth and the developmental cycles of insects and other invertebrates. They are occasionally present in various unrelated plants for no apparent reason; no phytohormonal function has yet been identified. In certain cases, ecdysteroids are accumulated to high levels in leaves, roots or seeds. Some ecdysteroid-containing plants have been known as medicinal plants for centuries. One of them, Leuzea carthamoides Iljin (Asteraceae), growing in Central Asia, contains 0.4% ecdysteroid in dry roots and 2% in seeds. A pharmacological preparation from this plant, \"Ecdisten', is already available as a commercial preparation for its anabolic, tonic and other effects, for medical use (review). It remained problematic, however, whether ecdysteroids were truly responsible for these effects, because Leuzea contains a number of other biologically active compounds in addition to ecdysteroids. We extracted and purified ecdysteroids from the seeds of Leuzea. With 6 g of 96% 20-hydroxyecdysone (20E), we made a large-scale feeding assay with Japanese quail to find out whether ecdysteroid alone could duplicate the anabolic effects of the seeds. We found that the 96% ecdysteroid increased the mass of the developing quails in a dose-dependent manner, with the rate of increase proportional to the ecdysteroid content in the seeds; there was a 115% increase in living mass with 100 mg kg-1 of pure 20E compared with 109.5% increase with 100-180 mg kg-1 20E equivalents in the seeds. We conclude that the plethora of growth-promoting, vitamin-like effects induced in vertebrates by Leuzea is mediated by ecdysteroids.","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 7","pages":"702-6"},"PeriodicalIF":0.0,"publicationDate":"1996-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01925578","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 61

Rapid development and a long life: an association expected under a stress theory of aging. 快速发展和长寿:衰老压力理论下的一种关联。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925565

P A Parsons

引用次数: 9

Amylin given by central or peripheral routes decreases gastric emptying and intestinal transit in the rat. 中央或外周给药胰淀素可减少大鼠胃排空和肠转运。

Experientia Pub Date : 1996-07-15 DOI: 10.1007/BF01925572

G Clementi, A Caruso, V M Cutuli, E de Bernardis, A Prato, M Amico-Roxas

引用次数: 42