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131.
Insulin sensitising action of chromium picolinate in various experimental models of diabetes mellitus. 总被引:2,自引:0,他引:2
Urmila A Shindea Geeta Sharma Yan J Xu Naranjan S Dhalla Ramesh K Goyal 《Journal of trace elements in medicine and biology》2004,18(1):23-32
Although chromium is an essential element for carbohydrate and lipid metabolism, its effects in diabetic patients are still debated. We have studied the effect of 6 week treatment with chromium picolinate (8 microg/ml in drinking water) in streptozotocin (STZ)-induced type 1 and type 2 diabetic rat models. The mechanism of anti-diabetic action of chromium picolinate was studied using C2C12 myoblasts and 3T3-L1 adipocytes. Chromium picolinate significantly decreased the area under the curve over 120 min for glucose of both STZ-induced type 1 (40mg/kg, i.v. in adult rats) and type 2 (90 mg/kg, i.p. in 2 day old rat neonates) diabetic rats without any significant change in area under the curve over 120 min for insulin as compared to controls. The composite insulin sensitivity index and insulin sensitivity index (KITT) values of both type 1 and type 2 diabetic rats were increased significantly by chromium picolinate. Treatment with chromium picolinate produced a significant decrease in elevated cholesterol and triglyceride levels in both types of diabetic rats. In 3T3-L1 adipocytes, chromium picolinate (0-10 micromol) per se did not produce any effect, however, when co-incubated with insulin it significantly increased the intracellular triglyceride synthesis (EC50 = 363.7nmol/1). Similarly in C2C12 myoblasts, chromium picolinate alone did not produce any effect, however, it significantly increased insulin-induced transport of 14C-glucose. In conclusion, chromium picolinate significantly improves deranged carbohydrate and lipid metabolism of experimental chemically induced diabetes in rats. The mechanism of in vivo anti-diabetic action appears to be peripheral (skeletal muscle and adipose tissue) insulin enhancing action of chromium. 相似文献
132.
Randeep Singh Qamar Qureshi Kalyanasundaram Sankar Paul R. Krausman Surendra Prakash Goyal Kerry L. Nicholson 《Acta theriologica》2014,59(4):521-527
We used camera trapping in conjunction with a spatial explicit capture–recapture model to estimate striped hyena (Hyaena hyaena) density and occupancy models to investigate factors affecting striped hyena detection probabilities in Ranthambhore Tiger Reserve (RTR), Rajasthan, India. A sampling effort of 4,450 trap days/nights over 75 days yield 68 photo captures of 21 unique striped hyenas (based on individual markings and visual identification); the estimated striped hyena density was 5.49?±?1.27 individuals/100 km2. Results of our occupancy model suggested that a rugged terrain is an important factor that influences striped hyena detection probability. Correlation with striped hyena detection with human settlement provides evidence of social tolerance of striped hyena towards humans, and more occurrence of resources allowed coexistence of hyena in a human-dominated landscape. This elasticity (inhabited areas close to humans) demonstrated by striped hyenas is an exception among carnivore communities living in this semi-arid habitat. 相似文献
133.
Vijay Kumar Shalini Gour Nidhi Verma Suman Kumar Kundlik Gadhave Pushpendra Mani Mishra Pankaj Goyal Janmejay Pandey Rajanish Giri Jay Kant Yadav 《Journal of peptide science》2019,25(4)
Seminal amyloids are well known for their role in enhancing HIV infection. Among all the amyloidogenic peptides identified in human semen, PAP248‐286 was found to be the most active and was termed as semen‐derived enhancer of viral infection (SEVI). Although amyloidogenic nature of the peptide is mainly linked with enhancement of the viral infection, the most active physiological conformation of the aggregated peptide remains inconclusive. Lipids are known to modulate aggregation pathway of a variety of proteins and peptides and constitute one of the most abundant biomolecules in human semen. PAP248‐286 significantly differs from the other known amyloidogenic peptides, including Aβ and IAPP, in terms of critical concentration, surface charge, fibril morphology, and structural transition during aggregation. Hence, in the present study, we aimed to assess the effect of a lipid, 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC), on PAP248‐286 aggregation and the consequent conformational outcomes. Our initial observation suggested that the presence of the lipid considerably influenced the aggregation of PAP248‐286. Further, ZDOCK and MD simulation studies of peptide multimerization have suggested that the hydrophobic residues at C‐terminus are crucial for PAP248‐286 aggregation and are anticipated to be major DOPC‐interacting partners. Therefore, we further assessed the aggregation behaviour of C‐terminal (PAP273‐286) fragment of PAP248‐286 and observed that DOPC possesses the ability to interfere with the aggregation behaviour of both the peptides used in the current study. Mechanistically, we propose that the presence of DOPC causes considerable inhibition of the peptide aggregation by interfering with the peptide's disordered state to β‐sheet transition. 相似文献
134.
Goyal Khushboo Kaur Kamaljit Kaur Gurjit 《Physiology and Molecular Biology of Plants》2020,26(5):899-906
Physiology and Molecular Biology of Plants - The effect of potassium nitrate on the status of fermentative and sucrose metabolizing pathways was studied in two maize (Zea mays L.) genotypes, viz.,... 相似文献
135.
Vasoactive intestinal peptide (VIP) caused a dose-dependent fall in lower esophageal sphincter (LES) pressure and dose-dependent contractions in the body of the esophagus. The response to VIP in the esophagus or LES was not modified by atropine, phentolamine, haloperidol, pyrilamine, methysergide, indomethacin and tetrodotoxin, showing that it exerts direct action at the esophageal smooth muscle. These studies suggest that VIP causes contraction in the esophageal body and relaxation of the LES by a direct action on the smooth muscle. It is possible that VIP may be the common mediator of noncholinergic, nonadrenergic neurons that cause relaxation of the lower esophageal sphincter and contraction in the esophageal body. 相似文献
136.
N. Bouchriti A. El Marrakchi A. Fahim S. M. Goyal 《World journal of microbiology & biotechnology》1992,8(5):546-549
A 3-year bacteriological survey of an oyster-growing area in Morocco, where the Japanese oyster (Crassostrea gigas) is grown, showed that the contamination of this lagunar ecosystem was not continuous but intermittent and that animal manure and human recreational activities were important sources of pollution. The major source of contamination was of animal origin, except during the summer, when human contamination prevailed. 相似文献
137.
S. Bharali R. K. Purama A. Majumder C. M. G. A. Fontes A. Goyal 《Indian journal of microbiology》2007,47(2):109-118
The non-catalytic, family 11 carbohydrate binding module (CtCBM11) belonging to a bifunctional cellulosomal cellulase from Clostridium thermocellum was hyper-expressed in E. coli and functionally characterized. Affinity electrophoresis of CtCBM11 on nondenaturing PAGE containing cellulosic polysaccharides showed binding with β-glucan, lichenan, hydroxyethyl cellulose
and carboxymethyl cellulose. In order to elucidate the involvement of conserved aromatic residues Tyr 22, Trp 65 and Tyr 129
in the polysaccharide binding, site-directed mutagenesis was carried out and the residues were changed to alanine. The results
of affinity electrophoresis and binding adsorption isotherms showed that of the three mutants Y22A, W65A and Y129A of CtCBM11, two mutants Y22A and Y129A showed no or reduced binding affinity with polysaccharides. These results showed that tyrosine
residue 22 and 129 are involved in the polysaccharide binding. These residues are present in the putative binding cleft and
play a critical role in the recognition of all the ligands recognized by the protein. 相似文献
138.
In present studies, the new optical sensing platform based on optical planar waveguide (OPWG) for sucrose estimation was reported. An evanescent-wave biosensor was designed by using novel agarose–guar gum (AG) biopolymer composite sol–gel with entrapped enzymes (acid invertase (INV) and glucose oxidase (GOD)). Partially purified watermelon invertase isolated from Citrullus vulgaris fruit (specific activity 832 units mg−1) in combination with GOD was physically entrapped in AG sol–gel and cladded on the surface of optical planar waveguide. Na+–K+ ion-exchanged glass optical waveguides were prepared and employed for the fabrication of sucrose biosensor. By addressing the enzyme modified waveguide structure with, the optogeometric properties of adsorbed enzyme layer (12 μm) at the sensor solid–liquid interface were studied. The OPWG sensor with short response time (110 s) was characterized using the 0.2 M acetate buffer, pH 5.5. The fabricated sucrose sensor showed concentration dependent linear response in the range 1 × 10−10 to 1 × 10−6 M of sucrose. Lower limit of detection of this novel AG–INV–GOD cladded OPWG sensor was found to be 2.5 × 10−11 M sucrose, which indicates that the developed biosensor has higher sensitivity towards sucrose as compared to earlier reported sensors using various transducer systems. Biochips when stored at room temperature, showed high stability for 81 days with 80% retention of original sensitivity. These sucrose sensing biochips showed good operational efficiency for 10 cycles. The proper confinement of acid invertase and glucose oxidase in hydrogel composite was confirmed by scanning electron microscopy (SEM) images. The constructed OPWG sensor is versatile, easy to fabricate and can be used for sucrose measurements with very high sensitivity. 相似文献
139.
Randeep Singh Paul R. Krausman Puneet Pandey Qamar Qureshi Kalyanasundaram Sankar Surendra Prakash Goyal Anshuman Tripathi 《European Journal of Wildlife Research》2014,60(2):383-386
Long-term data of large felids is important to understand their reproductive biology and behavior for effective conservation planning. We used camera trap data and direct sightings from 2005 to 2013 to estimate the age of the first parturition of Bengal tigers (Panthera tigris) in a semi-arid habitat in India. We monitored 11 females in the Ranthambhore Tiger Reserve (RTR) from when they were 2–6 months old. The mean age at first reproduction (impregnation leading to cubs) was 51.3?±?(SE) 4.5 months. The tiger population in RTR is an important source population and genetic pool in the western most distribution of tiger. Thus, continuous monitoring of tiger populations is important to develop an understanding of reproductive biology. 相似文献
140.
Differential modulation of voltage-dependent K+ currents in colonic smooth muscle by oxidants 总被引:1,自引:0,他引:1
The effect of oxidants on voltage-dependent K+ currents was examined in mouse colonic smooth muscle cells. Exposure to either chloramine-T (Ch-T), an agent known to oxidize both cysteine and methionine residues, or the colon-specific oxidant monochloramine (NH2Cl) completely suppressed the transient outward K+ current (Ito) while simultaneously enhancing the sustained delayed rectifier K+ current (Idr). In contrast, the cysteine-specific oxidants hydrogen peroxide (H2O2) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) exhibited partial and slow suppression of Ito by inducing a shift in channel availability of -18 mV without affecting Idr. After enhancement by NH2Cl or Ch-T, Idr was sensitive to 10 mM tetraethylammonium but not to other K+ channel blockers, suggesting that it represented activation of the resting Idr and not a separate K+ conductance. Extracellular dithiothreitol (DTT) partially reversed the effect of H2O2 and DTNB on Ito but not the actions of NH2Cl and Ch-T on either Idr or Ito. Dialysis of myocytes with GSH (5 mM) or DTT (5 mM) prevented suppression of Ito by H2O2 and DTNB but did not alter the effects of NH2Cl or Ch-T on either Idr or Ito. Ch-T and NH2Cl completely blocked Ito generated by murine Kv4.1, 4.2, and 4.3 in Xenopus oocytes, an effect not reversible by intracellular DTT. In contrast, intracellular DTT reversed the effect of H2O2 and DTNB on the cloned channels. These results suggest that Ito is suppressed via modification of both methionine and cysteine residues, whereas enhancement of Idr likely results from methionine oxidation alone. colon; colitis; redox; ion channel 相似文献