Effect of bombesin on glucose transport system in biomembranes

Summary Bombesin is able to stimulate the glucose transport system supported by a contractile glucose binding protein (GBP) in biomembranes. The increase of glucose transport indicates that bombesin affects GBP.     

Pancreatic islet β-cell deficit and glucose intolerance in rats with uninephrectomy

This study was performed to examine the effect of chronic renal impairment and renin-angiotensin system (RAS) activation induced by unilateral nephrectomy (UNX) on the development of pancreatic islet β-cell deficit and glucose intolerance. Sprague-Dawley rats were randomized into three groups: untreated UNX (n = 10), UNX treated with the angiotensin-converting enzyme inhibitor lisinopril (n = 8) and sham operation (n = 10). Blood glucose, serum insulin, renal function and histological changes of kidney and pancreas were examined 8 months postoperation. Compared with the sham rats, UNX rats developed renal impairment, insulin deficiency and glucose intolerance. Histological staining revealed an islet β-cell deficit associated with increased immunoreactivity for angiotensin and angiotensin type 1 receptor in UNX rats. Treatment with lisinopril significantly improved renal dysfunction, hyperglycemia, insulin secretion and islet RAS expression. These data suggest that chronic renal impairment and RAS activation may contribute to islet β-cell loss and glucose intolerance. RAS blockade may therefore prevent these disorders. Received 29 August 2007; received after revision 25 September 2007; accepted 27 September 2007     

Location of dopamie stores in rat kidney

Summary In normotensive and genetically hypertensive Wistar rats, chronic renal denervation reduces renal cortical levels of noradrenaline and dopamine by more than 90%. Non-neural stores of renal dopamine are therefore small or absent.This work was supported by the National Heart Foundation of Australia, the National Health and Medical Research Council of Australia and the University of Melbourne. I wish to thank K. Mather and T. Harris for able technical assistance.     

Frequency gradient in the autorhythmicity of the pyeloureteral pacemaker system

Summary The pacemaker properties of the various regions of isolated segments of the rabbit renal pelvis were examined. The results show that pacemaker frequency and waveform of contraction change significantly within the renal pelvis. The highest frequency was encountered at the fornix, while the ureteropelvic junction is lowest.This work was supported by NIH Grant No AM19366.     

The glucose dependence of pancreatic endocrine responses to 2-deoxyglucose in the calf

Summary The initial plasma glucose concentration of unanesthetized calves with cut splanchnic nerves, given 2-deoxyglucose (1.2 mmoles/kg, i.v.), was either lowered by prior starvation, or raised by a continuous infusion of exogenous glucose. Raising the initial plasma glucose concentration completely suppressed the release of pancreatic glucagon and pancreatic polypeptide but substantially enhanced the release of insulin in response to 2-deoxyglucose.This work has been supported by the Medical Research Council and the Leverhulme Trust. We are also indebted to Mr P.M.M. Bircham and Mr G.P. Macgregor for their skilled technical assistance.     

Tissue catecholamines following renal denervation in spontaneously hypertensive rats

Summary The delay in blood pressure increase observed in spontaneously hypertensive rats following bilateral renal denervation appeared to be due to a temporary reduction of the renal catecholamines content.This work was supported by grants from the Institut National de la Santé et de la Recherche Médicale (ATP 32-76-64, and AU 79-35) and from the Fonds National Suisse de la Recherche Scientifique (3.033.76)     

Mechanical simulation of renal pelvic wall peristalsis in the rat

Summary A urinary concentrating defect was induced in Munich-Wistar rats by removing the renal pelvis from 1 kidney. This defect was partially corrected by crudely simulating the actions of pelvic wall peristalsis with a mechanical system that cyclically compressed the exposed renal papilla.A portion of this work was conducted at The Mount Desert Island Biological Laboratory, Salsbury Cove, Maine and was supported by NIH grant 2 RO1-AM15972-10 awarded to Dr B. Schmidt-Nielsen. Additional support came from the Maine and Pennsylvania Affiliates of the American Heart Association.     

Elevated kidney glucosyltransferase activity in genetic prediabetic mice

Summary Glucosyltransferase activity in the renal cortex of genetic diabetic KK mice was significantly increased at 40 days of age when compared to that of Swiss albino and F₁ hybrid mice. This increase in enzyme activity in the absence of glucose intolerance can be regarded as an earlier genetic marker for the diagnosis of diabetic microangiopathy.Acknowledgments. This research was supported in part by the General Research Support Grant No. RR-05398 from the General Research Support Branch, Division of Research Resources, National Institutes of Health, National Institutes of Health Training Grant No. 5-T01-AM-05617-06, Hope for Diabetics Foundation, Inc., and Pfizer Research Laboratories. Dr.R. A. Camerini-Davalos was a Career Scientist of the Health Research Council of the City of New York, and Drs.A. S. Reddi andC.A. Velasco were N. I. H. Trainees in Diabetes Mellitus during part of this study.     

解聚复肾宁对糖尿病肾病大鼠TNF—OL、MCP-1的影响

目的观察解聚复肾宁（Jiejufushenning,JJFSN）对糖尿病（Diabetes mellitus,DM）大鼠肾组织肿瘤坏死因子-α（Tumorneerosisfactor-alpha,TNF-α）、单核细胞趋化蛋白-1（Monocyte chemoattractant protein-1,MCP-1）和血清TNF-α的影响,探讨其肾保护作用机制。方法腹腔注射链脲佐菌素（Streptozotocin,STZ）建立SD大鼠DM模型,将成模DM大鼠随机分为3组：DM模型组（B组）、JJFSN组（C组）、厄贝沙坦（Irbesartan）组（D组）,另设正常对照组（A组）。采用相应干预措施处理12周。常规方法测定12周末各组大鼠空腹血糖（FBG）、血尿素氮（BUN）、血肌酐（Scr）、肾重／体重（KW／BW）、24h尿蛋白（24huFro）;放免法测血清TNF-α含量：免疫组织化学方法测肾组织TNF—Ot、MCP-1的表达;PAS染色评估细胞外基质;电镜观察肾组织超微结构改变。结果与A组相比．B组大鼠FBG、BUN、Scr、KW／BW、24huPro及血清TNF-α升高（P〈0．05）,肾组织TNF—Ot、MCP-1表达明显增高（P〈0．05）;肾组织超微结构明显异常;C组和D组上述指标显著改善（P〈0．05）,肾组织超微结构异常改善。结论竹FSN能延缓DM大鼠肾损害进程,其机制可能与抑制TNF-α、MCP-1上调有关。     

Presence of natural killer cells in Peyer's patches of the mouse

Summary Natural cell-mediated cytotoxicity of normal murine Peyer's patch cells against Ehrlich ascites carcinoma was found in a short-term⁵¹Cr release assay. Peyer's patch and lymph node cells showed natural cytotoxicity at approximately the same level.Acknowledgments. This work was supported by grant No. 10.5 from the Polish Academy of Sciences.     

The pH-dependence of glucose transport inhibition by local anesthetics in human erythrocytes

Summary Local anesthetics vary in inhibition of glucose transport in human erythrocytes at different pH-values in the incubation media.The authors thank Dr G. Zimmer for valuable discussions. The work was supported by the Deutsche Forschungsgemeinschaft.     

Effect of epinephrine upon irreversible disposal and recycling of glucose in dogs

Summary Irreversible utilization and recycling of glucose during epinephrine-induced hyperglycemia were studied in adrenal-demedullated dogs exposed to neutral or cold ambient temperature. Whatever the ambient temperature, most of the extra glucose mobilized by epinephrine is recycled rather than irreversibly utilized by the peripheral tissues.This work was supported by a grant from Université Claude Bernard (U.E.R. Lyon Nord and U.E.R. Biologie Humaine).J. Schellhorn was on leave from the University of Chile. The authors thank D. Rougier and G. Dallevet for their excellent technical assistance.     

The influence of the steroid hormones on the physical state of human erythrocyte membranes

Summary Steroids alter the physical state of the regions in the human erythrocyte membrane, where glucose transport is occurring.The work was supported by the Deutsche Forschungsgemeinschaft. We thank Dipl. Phys. P. Geck for the aid in statistical evaluation.     

Effect of steviol and its structural analogues on glucose production and oxygen uptake in rat renal tubules

The effect of several natural products of Stevia rebaudiana on glucose production and oxygen uptake in rat renal cortical tubules was investigated. Steviol, isosteviol and glucosilsteviol decreased glucose production and inhibited oxygen uptake. The sweet principle stevioside, and steviolbioside, however, were without effect on gluconeogenesis and oxygen uptake.     

RNA-synthesis in rat kidneys after fluorinated anesthetics or inorganic fluoride administration

Summary RNA-synthesis in rat kidneys is affected by the administration of 0.5% methoxyflurane and 1% enflurane; also fluoride, a product of fluorinated anesthetics metabolism, hinders renal RNA-synthesis in rats.Acknowledgments. This work was supported by a grant from C.N.R., Roma.     

Effects of 2-deoxy-D-glucose,glucose and insulin on efferent activity in gastric vagus nerve

Summary Intracarotid injection of 2-deoxy-D-glucose and insulin increased the efferent activity in the gastric vagus nerve of anesthetized rats, while glucose injection transiently decreased vagus activity.This work was supported by research grant No. 212105 from The Ministry of Education, Science and Culture of Japan.     

Effect of steviol and its structural analogues on glucose production and oxygen uptake in rat renal tubules

Summary The effect of several natural products ofStevia rebaudiana on glucose production and oxygen uptake in rat renal cortical tubules was investigated. Steviol, isosteviol and glucosilsteviol decreased glucose production and inhibited oxygen uptake. The sweet principle stevioside, and steviolbioside, however, were without effect on gluconeogenesis and oxygen uptake.     

Formation of ethanol by bacteria. A pledge for the use of extreme thermophilic anaerobic bacteria in industrial ethanol fermentation processes

Summary Many anaerobic, facultatively anaerobic and even some strictly aerobic microorganisms form various amounts of ethanol from glucose. Only few mesophilic and extreme thermophilic bacteria ferment glucose stoichiometrically to 2 ethanol and 2 carbondioxid. Biotechnological processes at elevated temperatures seem advantageous in many respects. Hence, thermophiles and extreme thermophiles can potentially substitute for yeast in ethanol production on an industrial scale. Advantages and disadvantages of thermophilic mixed cultures and of potentially useful organisms are discussed.Acknowledgment. This work was partly supported by Energy and Research Development Administration contract number EY-76-509-0888-M003 and by the Deutsche Forschungsgemeinschaft.     

Uterine glucose metabolism in the prepubertal rat treated neonatally with androgen,estrogen, and antihormones

Summary Estrogen secretion during infancy may selectively enhance the phosphogluconate oxidative pathway in the rat uterus, for altered estrogen-stimulated glucose oxidation prepubertally is correlated (+0.91) with impaired ovarian development and not uterine estrogen receptor content.This work was supported in part by NSF Research Grant PCM-8409586.     

Preliminary observations concerning the effect of dopamine on uranyl nitrate induced renal failure

Summary Dopamine infusion, when commenced 24 h after the insult, was ineffective in modifying the course of uranyl nitrate induced renal failure in rabbits.Acknowledgments. This study was supported in part by the Lillian and Charles Duncan Research Grant for the Investigation of Factors Affecting Atherogenesis. The dopamine was provided by Arnar-Stone Laboratories, Inc.