Ruminal flora studies in the sheep. IX. The effect of pH on the ciliate population of the rumen in vivo

1959 ◽  
Vol 10 (4) ◽  
pp. 555 ◽  
Author(s):  
DB Purser ◽  
RJ Moir

Daily infusion of 7, 35, and 70 g of glucose m solution (1, 5, and 10 per cent. of the ration) into the rumen of Merino sheep maintained on an adequate diet resulted in the ruminal pH falling 2–4 hr after feeding, from a mean of 5.66 without added glucose to 5.40 at the higher glucose levels. The concentration of ammonia also decreased, whereas that of volatile fatty acids increased. At the 10 per cent. glucose level, food intake was depressed and the ruminal pH in this treatment did not fall below that at the 5 per cent. glucose level. A significant daily fall in the ruminal pH minima was found during the 3-day sampling period. No consistently significant differences in the concentration of ciliate Protozoa were found at four different sites in the rumen, either before or 1 hr after feeding, although there were significant differences between sheep. Samples taken from the bottom of the rumen immediately inferior to the ruminal cannula, before feeding and 1, 2, 4, 6, 8, 12, and 16 hr after feeding, showed: (a) Only oligotrichs in the ciliate population; (b) Marked diurnal fluctuation in the ciliate population, the concentration after feeding falling to as low as one-third of the prefeeding levels; (c) A diurnal cycle for dividing Protozoa which indicated that their capacity to multiply was strongly inhibited by the low pH experienced 2–4 hr after feeding. A depression of the average ciliate concentration daily during the 3-day sampling period was also demonstrated. This was related to a consistent but inexplicable fall in the daily ruminal pH minima over this period. It was concluded that the minimum pH within the rumen is an important factor controlling rumen protozoal concentrations in the sheep, and the need for cognizance of this phenomenon in studies of rumen Protozoa is stressed.

2014 ◽  
Vol 6 (3) ◽  
pp. 581-588
Author(s):  
M. A. Islam ◽  
A. Islam ◽  
M. R. I. Khan ◽  
R. Sharmin ◽  
M. I. I. Wahed ◽  
...  

Six marketed oral antidiabetic metformin tablets in Bangladesh have been studied for their drug content, release profile and glucose lowering capacities. This sort of study is a good indicator for in vivo evaluation of the quality of an oral antidiabetic preparation. Marketed preparations of metformin-HCl from different manufacturers were randomly chosen for this study. The drug content was within the United State Pharmacopoeia (USP) specified limit (95-105%) in all cases. The blood glucose levels were investigated in streptozotocin-induced diabetic rats (SIDRs) after 5 hours of single dose (110 mg/kg body weight) treatment of the products; significantly (p<0.05) reduced blood glucose level by 58.1, 53.2, 50.8, 77.0, 72.9 and 49.1%, respectively; which were consistent with antihyperglycemic effects of standard metformin-HCl (71.3%). All the products were found to be qualified in lowering blood glucose level. It may be inferred that the metformin-HCl tablets of Bangladeshi manufacturers complies with the standard specifications for drug contents, dissolution and antihyperglycemic properties.© 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.19290 J. Sci. Res. 6 (3), 581-588 (2014)


1995 ◽  
Vol 75 (3) ◽  
pp. 379-385 ◽  
Author(s):  
D. Ali Haïmoud ◽  
M. Vernay ◽  
C. Bayourthe ◽  
R. Moncoulon

An in vivo study was carried out to evaluate the effect of avoparcin on fiber, starch and nitrogen (N) digestion compared with monensin. Three dairy lactating cows with ruminal, duodenal and ileal cannulas were used in a 3 × 3 Latin square design. Cows were fed three diets; the control diet had no additive, and the others contained 33 ppm of either avoparcin or monensin-sodium. There were no treatment effects on ruminal pH and total volatile fatty acid levels; molar proportion of propionate tended to be higher (27.9–29.9 vs. 23.7%) and of butyrate tended to be lower (9.9–12.9 vs. 15.4%) for the antibiotic-supplemented diets. Also, both additives decreased ruminal ammonia N concentration (77.2–105.6 vs. 164.1 mg L−1). The supply of avoparcin or monensin reduced the ruminal breakdown of fiber (36.1 and 37.1 vs. 45.9%) starch (57.4 and 54.7 vs. 63.6%), and dietary N (59.5 and 53.6 vs. 67.3%); efficiency of bacterial protein synthesis was unchanged. Passage of bacterial N to the small intestine was not modified; flows of fiber, starch, nonammonia N and dietary N were improved by the both additives. In comparison with the control, monensin caused a greater quantity of glucose (2100 vs. 1500 g d−1) and total amino acids (AA) (1381 vs. 1047 g d−1) to be digested in the small intestine; avoparcin had a less pronounced effect on the intestinal absorption of glucose (1700 g d−1) and AA (1152 g d−1). Only monensin increased the plasma glucose levels (3.6 vs. 3.1 mM). Both additives did not affect total tract digestibilities of organic matter, fiber, starch, and N. Postruminal digestion of fiber was greater (16.0 vs. 7.3%) for antibiotic-supplemented diets, compensating for the lower forestomach digestion. In comparison with monensin dietary avoparcin had a less pronounced effect on the alteration of nutrient digestion. Key words: Avoparcin, monensin, rumen, intestines, amino acids, digestion, cattle


Author(s):  
Adel M. Aly ◽  
Ahmed S. Ali

: Glipizide (GZ) is an oral blood-glucose-lowering drug of the sulfonylurea class characterized by its poor aqueous solubility. Aiming for the production of GZ tablets with rapid onset of action followed by prolonged effect; GZ-Polyethylene glycol (PEG 4000 and 6000) solid dispersions with different ratios, (using melting and solvent evaporation method), as well as, coprecipitate containing GZ with polymethyl-methacrylate (PMMA) were prepared. Four tablet formulations were prepared containing; a) GZ alone, b) GZ: PEG6000, 1:10, c) GZ:PMMA 1:3, and, d)both GZ:PEG6000 1:10 and GZ:PMMA 1:3. The solvent evaporation method showed more enhancement of GZ solubility than the melting one, and this solubilizing effect increased with PEG increment. Generally, PEG6000 showed more enhancement of dissolution than PEG4000 especially at 1:10 drug: polymer ratio (the most enhancing formula). Also, the prepared tablet formulations showed acceptable physical properties according to USP/NF requirements. The dissolution results revealed that tablets containing PEG6000 (1:10) have the most rapid release rate, followed by the formula containing both PEG6000 and PMMA, while that including PMMA alone showed the slowest dissolution rate. Moreover, In-vivo studies for each of the above four formulations, were performed using four mice groups. The most effective formula in decreasing the blood glucose level, through the first 6 hours, was that containing GZ and PEG6000, 1:10. However, formula containing the combination of enhanced and sustained GZ was the most effective in decreasing the blood glucose level through 16 hours. Successful in-vitro in-vivo correlations could be detected between the percent released and the percent decreasing of blood glucose level after 0.5 hours.


2019 ◽  
Vol 9 (3) ◽  
pp. 248-263 ◽  
Author(s):  
Ashish K. Parashar ◽  
Preeti Patel ◽  
Arun K. Gupta ◽  
Neetesh K. Jain ◽  
Balak Das Kurmi

Background: The present study was aimed at developing and exploring the use of PEGylated Poly (propyleneimine) dendrimers for the delivery of an anti-diabetic drug, insulin. Methods: For this study, 4.0G PPI dendrimer was synthesized by successive Michael addition and exhaustive amidation reactions, using ethylenediamine as the core and acrylonitrile as the propagating agent. Two different activated PEG moieties were employed for PEGylation of PPI dendrimers. Various physicochemical and physiological parameters UV, IR, NMR, TEM, DSC, drug entrapment, drug release, hemolytic toxicity and blood glucose level studies of both PEGylated and non- PEGylated dendritic systems were determined and compared. Results: PEGylation of PPI dendrimers caused increased solubilization of insulin in the dendritic framework as well as in PEG layers, reduced drug release and hemolytic toxicity as well as increased therapeutic efficacy with reduced side effects of insulin. These systems were found to be suitable for sustained delivery of insulin by in vitro and blood glucose-level studies in albino rats, without producing any significant hematological disturbances. Conclusion: Thus, surface modification of PPI dendrimers with PEG molecules has been found to be a suitable approach to utilize it as a safe and effective nano-carrier for drug delivery.


2014 ◽  
Vol 222 (2) ◽  
pp. 201-215 ◽  
Author(s):  
Jillian L Rourke ◽  
Shanmugam Muruganandan ◽  
Helen J Dranse ◽  
Nichole M McMullen ◽  
Christopher J Sinal

Chemerin is an adipose-derived signaling protein (adipokine) that regulates adipocyte differentiation and function, immune function, metabolism, and glucose homeostasis through activation of chemokine-like receptor 1 (CMKLR1). A second chemerin receptor, G protein-coupled receptor 1 (GPR1) in mammals, binds chemerin with an affinity similar to CMKLR1; however, the function of GPR1 in mammals is essentially unknown. Herein, we report that expression of murineGpr1mRNA is high in brown adipose tissue and white adipose tissue (WAT) and skeletal muscle. In contrast to chemerin (Rarres2) andCmklr1,Gpr1expression predominates in the non-adipocyte stromal vascular fraction of WAT. Heterozygous and homozygousGpr1-knockout mice fed on a high-fat diet developed more severe glucose intolerance than WT mice despite having no difference in body weight, adiposity, or energy expenditure. Moreover, mice lackingGpr1exhibited reduced glucose-stimulated insulin levels and elevated glucose levels in a pyruvate tolerance test. This study is the first, to our knowledge, to report the effects ofGpr1deficiency on adiposity, energy balance, and glucose homeostasisin vivo. Moreover, these novel results demonstrate that GPR1 is an active chemerin receptor that contributes to the regulation of glucose homeostasis during obesity.


Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Margaret K Shirra ◽  
Karen M Arndt

AbstractBinding of the TATA-binding protein (TBP) to the promoter is a pivotal step in RNA polymerase II transcription. To identify factors that regulate TBP, we selected for suppressors of a TBP mutant that exhibits promoter-specific defects in activated transcription in vivo and severely reduced affinity for TATA boxes in vitro. Dominant mutations in SNF4 and recessive mutations in REG1, OPI1, and RTF2 were isolated that specifically suppress the inositol auxotrophy of the TBP mutant strains. OPI1 encodes a repressor of INO1 transcription. REG1 and SNF4 encode regulators of the Glc7 phosphatase and Snf1 kinase, respectively, and have well-studied roles in glucose repression. In two-hybrid assays, one SNF4 mutation enhances the interaction between Snf4 and Snf1. Suppression of the TBP mutant by our reg1 and SNF4 mutations appears unrelated to glucose repression, since these mutations do not alleviate repression of SUC2, and glucose levels have little effect on INO1 transcription. Moreover, mutations in TUP1, SSN6, and GLC7, but not HXK2 and MIG1, can cause suppression. Our data suggest that association of TBP with the TATA box may be regulated, directly or indirectly, by a substrate of Snf1. Analysis of INO1 transcription in various mutant strains suggests that this substrate is distinct from Opi1.


2013 ◽  
Vol 218 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Yusuke Seino ◽  
Takashi Miki ◽  
Wakako Fujimoto ◽  
Eun Young Lee ◽  
Yoshihisa Takahashi ◽  
...  

Glucose-induced insulin secretion from pancreatic β-cells critically depends on the activity of ATP-sensitive K+channels (KATPchannel). We previously generated mice lackingKir6.2, the pore subunit of the β-cell KATPchannel (Kir6.2−/−), that show almost no insulin secretion in response to glucosein vitro. In this study, we compared insulin secretion by voluntary feeding (self-motivated, oral nutrient ingestion) and by forced feeding (intra-gastric nutrient injection via gavage) in wild-type (Kir6.2+/+) andKir6.2−/−mice. Underad libitumfeeding or during voluntary feeding of standard chow, blood glucose levels and plasma insulin levels were similar inKir6.2+/+andKir6.2−/−mice. By voluntary feeding of carbohydrate alone, insulin secretion was induced significantly inKir6.2−/−mice but was markedly attenuated compared with that inKir6.2+/+mice. On forced feeding of standard chow or carbohydrate alone, the insulin secretory response was markedly impaired or completely absent inKir6.2−/−mice. Pretreatment with a muscarine receptor antagonist, atropine methyl nitrate, which does not cross the blood–brain barrier, almost completely blocked insulin secretion induced by voluntary feeding of standard chow or carbohydrate inKir6.2−/−mice. Substantial glucose-induced insulin secretion was induced in the pancreas perfusion study ofKir6.2−/−mice only in the presence of carbamylcholine. These results suggest that a KATPchannel-independent mechanism mediated by the vagal nerve plays a critical role in insulin secretion in response to nutrientsin vivo.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Varsha Ghadyale ◽  
Shrihari Takalikar ◽  
Vivek Haldavnekar ◽  
Akalpita Arvindekar

Inhibition of intestinal alpha glucosidase plays a major role in preventing rise in postprandial glucose level in diabetics.Cymbopogon martinii(CM) (family Poaceae) is used in traditional Indian medicine in treatment of diabetes mellitus. The alpha glucosidase inhibitory action of the plant is studied. The active component was separated using hot water extraction of the whole plant powder, differential solvent extraction, and silica gel column chromatography. The 30 : 70 toluene : ethyl acetate fraction showed optimum activity. The silica gel chromatography fraction demonstrated 98, 98, and 68% inhibition for starch, maltose, and sucrose, respectively, at 5 mg/kg body weight of rats. Intestinal absorption studies using noneverted intestinal sacs, as well as in vivo studies in streptozotocin-induced diabetic rats using oral glucose tolerance with maltose and sucrose load, revealed better inhibition of alpha glucosidase as compared to acarbose. Kinetic studies using Lineweaver Burk plot showed mixed to noncompetitive type of inhibition by CM. In vivo studies with maltose load of 2 mg and 3 mg/gm body weight showed a noncompetitive pattern of inhibition at 5 mg/kg body weight of CM as against 60 mg/kg body weight of acarbose. Thus CM is more effective alpha glucosidase inhibitor and at lower concentration than acarbose.


1997 ◽  
Vol 77 (3) ◽  
pp. 475-490 ◽  
Author(s):  
Klaus Schumann ◽  
Annette Lebeau ◽  
Ursula Gresser ◽  
Theodor Gunther ◽  
Jürgen Vormann

To investigate the mechanism of tissue Fe accumulation in graded Mg deficiency rats were fed on diets of different Mg contents (70, 110, 208, 330, and 850 mg Mg/kg) for 10, 20, and 30 d during rapid growth. There was no significant impact of Mg deficiency or high luminal Mg concentrations on intestinal59Fe transferin vitroorin vivo. Plasma Mg concentrations and body weight started to decrease after 10 d. Significant haemolytic anaemia was observed after 20 d with siderosis in liver and spleen developing in parallel. Anaemia showed no features of Fe deficiency or infiammation. Comparison between the 70 mg Mg/kg group and animals that received the same quantity of a Mg-adequate diet (850 mg Mg/kg) permitted estimation of quantities of Fe liberated by haemolysis and the increased Fe content in liver and spleen. Both variables showed a high degree of correlation, indicating that the excess of liberated haemoglobin Fe was stored in the tissue. The erythropoietic activity was high during rapid growth, i.e. at days 10 and 20 and decreased significantly after 30 d in all except the most Mg-deficient groups. However, haemolytic anaemia developed because even the high erythropoietic activity in the 70 and 110 mg Mg/kg groups was not sutlicient to recycle all haemoglobin Fe liberated by haemolysis. After 30 d of Mg-deficient feeding the erythrocyte Mg content had decreased to 40% of control values. According to the literature Mg-deficient erythrocytes have a decreased survival time which is likely to be the cause of the observed haemolysis.


2004 ◽  
Vol 286 (4) ◽  
pp. G627-G634 ◽  
Author(s):  
Chang An Chu ◽  
Yuka Fujimoto ◽  
Kayano Igawa ◽  
Joseph Grimsby ◽  
Joseph F. Grippo ◽  
...  

The rate of liver glucokinase (GK) translocation from the nucleus to the cytoplasm in response to intraduodenal glucose infusion and the effect of physiological rises of plasma glucose and/or insulin on GK translocation were examined in 6-h-fasted conscious rats. Intraduodenal glucose infusion (28 mg·kg-1·min-1 after a priming dose at 500 mg/kg) elevated blood glucose levels (mg/dl) in the artery and portal vein from 90 ± 3 and 87 ± 3 to 154 ± 4 and 185 ± 4, respectively, at 10 min. At 120 min, the levels had decreased to 133 ± 6 and 156 ± 5, respectively. Plasma insulin levels (ng/ml) in the artery and the portal vein rose from 0.7 ± 0.1 and 1.8 ± 0.3 to 11.8 ± 1.5 and 20.2 ± 2.0 at 10 min, respectively, and 12.4 ± 3.1 and 18.0 ± 4.8 at 30 min, respectively. GK was rapidly exported from the nucleus as determined by measuring the ratio of the nuclear to the cytoplasmic immunofluorescence (N/C) of GK (2.9 ± 0.3 at 0 min to 1.7 ± 0.2 at 10 min, 1.5 ± 0.1 at 20 min, 1.3 ± 0.1 at 30 min, and 1.3 ± 0.1 at 120 min). When plasma glucose (arterial; mg/dl) and insulin (arterial; ng/ml) levels were clamped for 30 min at 93 ± 7 and 0.7 ± 0.1, 81 ± 5 and 8.9 ± 1.3, 175 ± 5 and 0.7 ± 0.1, or 162 ± 5 and 9.2 ± 1.5, the N/C of GK was 3.0 ± 0.5, 1.8 ± 0.1, 1.5 ± 0.1, and 1.2 ± 0.1, respectively. The N/C of GK regulatory protein (GKRP) did not change in response to the intraduodenal glucose infusion or the rise in plasma glucose and/or insulin levels. The results suggest that GK but not GKRP translocates rapidly in a manner that corresponds with changes in the hepatic glucose balance in response to glucose ingestion in vivo. Additionally, the translocation of GK is induced by the postprandial rise in plasma glucose and insulin.


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