scholarly journals Noninvasive Evaluation of Intestinal Lactase with 4-Galactosylxylose: Comparison with 3- and 2-Galactosylxylose and Optimization of the Method in Rats

2006 ◽  
Vol 52 (2) ◽  
pp. 270-277 ◽  
Author(s):  
Carmen Hermida ◽  
Guillermo Corrales ◽  
Oscar H Martínez-Costa ◽  
Alfonso Fernández-Mayoralas ◽  
Juan J Aragón
Keyword(s):  
Small Intestine ◽  
Low Cost ◽  
Noninvasive Evaluation ◽  
Kinetic Properties ◽  
Dependent Manner ◽  
Lactase Activity ◽  
Suckling Rats ◽  
In Vivo Measurement ◽  
Intestine Mucosa

Abstract Background: Urinary excretion of d-xylose by suckling rats after ingestion of a mixture of 4-, 3-, and 2-galactosylxyloses reflects lactase activity in vivo. We aimed to select the most convenient of these disaccharides for detecting changes of the enzyme activity in vivo and to optimize the method. Methods: 4-, 3-, and 2-Galactosylxyloses were synthesized and purified, then orally administered to suckling rats of different ages. d-Xylose was measured colorimetrically by the phloroglucinol reaction in urine and plasma. Lactase activity was determined in extracts of small intestine mucosa with lactose, galactosylxyloses, and phlorizin as substrates. Results: d-Xylose appeared in the urine in a dose-dependent manner after ingestion of any of the 3 galactosylxylose disaccharides. Correlation between d-xylose elimination and intestinal lactase activity was highest with 4-galactosylxylose (r = 0.97; n = 24), lower with 2-galactosylxylose (r = 0.89; n = 24), and lowest with 3-galactosylxylose (r = 0.34; n = 23). The kinetic properties of intestinal lactase accounted for these differences. d-Xylose concentration in plasma after administration of 4-galactosylxylose also correlated with lactase activity (r = 0.93; n = 33). Conclusions: 4-Galactosylxylose is the most suitable compound for the evaluation of lactase activity in vivo. Measurement of the derived d-xylose in either urine or blood gives an estimate of the total lactose digestive capacity of the small intestine. The optimized method holds promise for development of a simple, low-cost, and reliable new test for the noninvasive diagnosis of hypolactasia.

scholarly journals Design and construction of low-cost respiration chambers for ruminal methane measurements in ruminants

2017 ◽  
Vol 8 (2) ◽  
pp. 185 ◽  
Author(s):  
Jorge Rodolfo Canul Solis ◽  
Angel Trinidad Piñeiro Vázquez ◽  
Jeyderl Israe Arceo Castillo ◽  
José Alayón Alayón Gamboa ◽  
Armín Javier Ayala Burgos ◽  
...  
Keyword(s):  
Methane Production ◽  
Low Cost ◽  
Bos Indicus ◽  
Mass Action ◽  
Pennisetum Purpureum ◽  
Air Conditioner ◽  
Tropical Regions ◽  
In Vivo Measurement ◽  
Design Construction

ABSTRACTRuminant animals contribute significantly to methane emissions in tropical regions. Nonetheless, there are few facilities available in those regions of the world for in vivo measurement of methane production in cattle. The aim of the present work was to describe the design, construction and operation of respiration chambers for in vivo measurement of methane production in cattle in Mexico. Locally available materials were used in the construction. Walls, roof and doors were constructed of thermic panels with two windows of acrylic at the front so the animal can be observed at all times. Chambers have an air volume of 9.97 m3. Air is drawn from the chamber at a rate of 500 L/min by the effect of mass action flow generators. Methane was measured in air samples with an infrared analyzer. Chambers operate under a slight negative pressure of around -500 Pa. Air temperature inside the chambers is kept at 23 °C with an air conditioner, while relative humidity is maintained at 55 % with a dehumidifier. Functioning of the chambers was evaluated in Bos indicus, Nelore cattle fed Taiwan grass (Pennisetum purpureum) and a concentrate (18 % crude protein), and measurements were made during runs of 23 h duration. Methane production was on average 173.2 L per day, while the emission factor was 17.48 L methane per kilogram o dry matter consumed. It concludes that this respiration facility is capable of measuring methane production accurately in cattle fed tropical rations.

Effects of isovalerate supplementation on morphology and functional gene expression of small intestine mucosa in pre- and post-weaned dairy calves

2018 ◽  
Vol 156 (2) ◽  
pp. 272-281 ◽  
Author(s):  
Q. Liu ◽  
C. Wang ◽  
Y. L Zhang ◽  
C. X. Pei ◽  
S. L Zhang ◽  
...  
Keyword(s):  
Small Intestine ◽  
Dairy Calves ◽  
Peptide Transporter ◽  
Proximal Jejunum ◽  
Small Intestinal Mucosa ◽  
Adaptation Period ◽  
Dependent Manner ◽  
Villus Height ◽  
Crypt Depth ◽  
Intestine Mucosa

AbstractThe present study evaluated the effects of isovalerate supplementation on the development of the small intestinal mucosa in dairy calves. Forty-eight Chinese Holstein bull calves at 15 days of age and 45.1 ± 0.36 kg of body weight were assigned randomly to four groups. The treatments were control, low-isovalerate, moderate-isovalerate and high-isovalerate with 0, 3, 6 and 9 g isovalerate per calf per day, respectively. The study comprised 75 days with a 15-day adaptation period followed by a 60-day sampling period. Calves were weaned at 60 days of age. Six calves were chosen from each treatment at random and slaughtered at 30 and 90 days of age. The small intestine morphology and activities of amylase and trypsin improved significantly with increasing age. No interaction between treatments and age was observed. The small intestine length, mucosa layer thickness, villus height and crypt depth increased linearly with increasing isovalerate supplementation. However, the ratio of villus height to crypt depth was not affected by treatment. Activities of amylase and trypsin increased linearly. The lactase activity increased linearly during the 75-day period and for pre-weaned calves but was unaltered for post-weaned calves. The relative mRNA expressions of growth hormone receptor, insulin-like growth factor-1 receptor and sodium-glucose co-transporter-1 in the small intestine mucosa increased linearly, and a similar pattern was observed for the expression of peptide transporter-1 in the duodenum and proximal jejunum. The results suggested that small intestine development was promoted by isovalerate in a dose-dependent manner.

scholarly journals Thyroid hormone modulation of brain in vivo tyrosine hydroxylase activity and kinetics in the female catfish Heteropneustes fossilis

2003 ◽  
Vol 179 (2) ◽  
pp. 205-215 ◽  
Author(s):  
R Chaube ◽  
KP Joy
Keyword(s):  
Tyrosine Hydroxylase ◽  
Medulla Oblongata ◽  
Kinetic Studies ◽  
Brain Regions ◽  
Kinetic Properties ◽  
Dependent Manner ◽  
Apparent Velocity ◽  
Heteropneustes Fossilis ◽  
Hormone Modulation

In the female catfish Heteropneustes fossilis, administration of thyroxine (T(4))(,) 1 micro g/g body weight, i.p., in both gonadal resting and preparatory phases for 7, 14 and 21 days caused hyperthyroidism, as evidenced from a duration-dependent significant increase in serum triiodothyronine (T(3)), and of tyrosine hydroxylase (TH) activity in telencephalon, hypothalamus-pituitary and medulla oblongata (Newman-Keuls' test; P<0.05). Hypothyroidism induced by adding 0.03% thiourea to aquarium water holding the catfish for 7, 14 and 21 days decreased serum T(3) levels in a duration-dependent manner (Newman-Keuls' test; P<0.05) and inhibited TH activity in the brain regions. T(4) replacement in 21day thiourea-treated fish restored and even elevated significantly serum T(3) levels as well as brain TH activity in a duration-dependent manner. In general, the changes in enzyme activity were higher in the forebrain regions than medulla oblongata and in the resting phase than preparatory phase. Kinetic studies by Lineweaver-Burk plots showed that the stimulatory effect following T(4) administration and T(4) replacement on TH activity was due to increased affinity of the enzyme for its cofactor (6,7-dimethyl-2-amino-4-hydroxy-5,6,7,8-tetrahydropteridine), as evident from a significant decrease in apparent Michaelis-Menten constant (K(m)) and an increase in apparent velocity maximum (V(max)). The TH inhibition due to the thiourea treatment can be related to decreased affinity of the enzyme for its cofactor, as evident from a significant increase in apparent K(m) value and a significant decrease in V(max). These data clearly show that circulating levels of T(4)/T(3) modulate brain TH activity by altering the kinetic properties of the enzyme, which, in turn, influence catecholaminergic activity and dependent functions.

scholarly journals Effect of the microbial lactase (EC 3.2.1.23) activity in yoghurt on the intestinal absorption of lactose: An in vivo study in lactase-deficient humans

1990 ◽  
Vol 64 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Philippe Marteau ◽  
Bernard Flourie ◽  
Philippe Pochart ◽  
Claude Chastang ◽  
Jehan-François Desjeux ◽  
...  
Keyword(s):  
Small Intestine ◽  
Intestinal Absorption ◽  
Transit Time ◽  
Terminal Ileum ◽  
Area Under Curve ◽  
Starter Culture ◽  
Breath Hydrogen ◽  
Lactase Activity ◽  
Perfusion Technique

Breath hydrogen excretion was measured in eight lactase (EC 3.2.1. 108)-deficient volunteers ingesting 18 g lactose in the form of milk, yoghurt and heated yoghurt. Total excess hydrogen excretion (area under curve) was significantly lower after yoghurt and heated yoghurt, than after milk: 103 (SE 29), 191 (SE 32), and 439 (SE 69) respectively (P < 0.001). The oro-caecal transit time of fermentable components from yoghurt and heated yoghurt (mainly lactose) was longer than that from milk: 165 (SE 17), 206 (SE 19), v. 103 (SE 19) min (P < 0.01). An intestinal perfusion technique was used in the same subjects after ingestion on two consecutive days of 18 g lactose in yoghurt and heated yoghurt. Significantly less lactose was recovered from the terminal ileum after yoghurt than after heated yoghurt meals: 1740 (SE 260) v. 2825 (SE 461) mg (P < 0.05), and approximately one-fifth of the lactase activity contained in yoghurt reached the terminal ileum. These findings indicate that more than 90% of the lactose in yoghurt is digested in the small intestine of lactase-deficient subjects and suggest that both the lactase activity contained in the viable starter culture and a slow oro–caecal transit time are responsible for this excellent absorption.

scholarly journals Quercetin Inhibits Pacemaker Potentials via Nitric Oxide/cGMP-Dependent Activation and TRPM7/ANO1 Channels in Cultured Interstitial Cells of Cajal from Mouse Small Intestine

2015 ◽  
Vol 35 (6) ◽  
pp. 2422-2436 ◽  
Author(s):  
Huijin Gim ◽  
Joo Hyun Nam ◽  
Soojin Lee ◽  
Ji Hwan Shim ◽  
Hyun Jung Kim ◽  
...  
Keyword(s):  
Small Intestine ◽  
Opioid Receptor ◽  
Interstitial Cells Of Cajal ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Pacemaker Potentials ◽  
Cells Of Cajal ◽  
Gi Motility

Background: Quercetin regulates gastrointestinal (GI) motor activity but the molecular mechanism involved has not been determined. The authors investigated the effects of quercetin, a flavonoid present in various foods, on the pacemaker activities of interstitial cells of Cajal (ICCs) in murine small intestine in vitro and on GI motility in vivo. Materials and Methods: Enzymatic digestion was used to dissociate ICCs from mouse small intestines. The whole-cell patch-clamp configuration was used to record pacemaker potentials in cultured ICCs in the absence or presence of quercetin and to record membrane currents of transient receptor potential melastatin (TRPM) 7 or transmembrane protein 16A (Tmem16A, anoctamin1 (ANO1)) overexpressed in human embryonic kidney (HEK) 293 cells. The in vivo effects of quercetin on GI motility were investigated by measuring the intestinal transit rates (ITRs) of Evans blue in normal mice. Results: Quercetin (100-200 μM) decreased the amplitudes and frequencies of pacemaker activity in a concentration-dependent manner in current clamp mode, but this action was blocked by naloxone (a pan-opioid receptor antagonist) and by GDPβS (a GTP-binding protein inhibitor). However, potassium channels were not involved in these inhibitory effects of quercetin. To study the quercetin signaling pathway, we examined the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of guanylate cyclase, and of RP-8-CPT-cGMPS, an inhibitor of protein kinase G (PKG). These inhibitors blocked the inhibitory effects of quercetin on pacemaker activities. Also, L-NAME (100 μM), a non-selective NO synthase (NOS) inhibitor, blocked the effects of quercetin on pacemaker activity and quercetin stimulated cGMP production. Furthermore, quercetin inhibited both Ca2+-activated Cl- channels (TMEM16A, ANO1) and TRPM7 channels. In vivo, quercetin (10-100 mg/kg, p.o.) decreased ITRs in normal mice in a dose-dependent manner. Conclusions: Quercetin inhibited ICC pacemaker activities by inhibiting TRPM7 and ANO1 via opioid receptor signaling pathways in cultured murine ICCs. The study shows quercetin attenuates GI tract motility, and suggests quercetin be considered the basis for the development of novel spasmolytic agents for the prevention or alleviation of GI motility dysfunctions.

scholarly journals Chromatin Remodeling Complexes Interact Dynamically with a Glucocorticoid Receptor–regulated Promoter

2008 ◽  
Vol 19 (8) ◽  
pp. 3308-3322 ◽  
Author(s):  
Thomas A. Johnson ◽  
Cem Elbi ◽  
Bhavin S. Parekh ◽  
Gordon L. Hager ◽  
Sam John
Keyword(s):  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Tandem Repeats ◽  
Inducible Promoter ◽  
Kinetic Properties ◽  
Dependent Manner ◽  
Chromatin Remodeling Complexes ◽  
Mmtv Promoter

Brahma (BRM) and Brahma-related gene 1 (BRG1) are the ATP-dependent catalytic subunits of the SWI/SNF family of chromatin-remodeling complexes. These complexes are involved in essential processes such as cell cycle, growth, differentiation, and cancer. Using imaging approaches in a cell line that harbors tandem repeats of stably integrated copies of the steroid responsive MMTV-LTR (mouse mammary tumor virus–long terminal repeat), we show that BRG1 and BRM are recruited to the MMTV promoter in a hormone-dependent manner. The recruitment of BRG1 and BRM resulted in chromatin remodeling and decondensation of the MMTV repeat as demonstrated by an increase in the restriction enzyme accessibility and in the size of DNA fluorescence in situ hybridization (FISH) signals. This chromatin remodeling event was concomitant with an increased occupancy of RNA polymerase II and transcriptional activation at the MMTV promoter. The expression of ATPase-deficient forms of BRG1 (BRG1-K-R) or BRM (BRM-K-R) inhibited the remodeling of local and higher order MMTV chromatin structure and resulted in the attenuation of transcription. In vivo photobleaching experiments provided direct evidence that BRG1, BRG1-K-R, and BRM chromatin-remodeling complexes have distinct kinetic properties on the MMTV array, and they dynamically associate with and dissociate from MMTV chromatin in a manner dependent on hormone and a functional ATPase domain. Our data provide a kinetic and mechanistic basis for the BRG1 and BRM chromatin-remodeling complexes in regulating gene expression at a steroid hormone inducible promoter.

scholarly journals FGF-18, a Novel Member of the Fibroblast Growth Factor Family, Stimulates Hepatic and Intestinal Proliferation

1998 ◽  
Vol 18 (10) ◽  
pp. 6063-6074 ◽  
Author(s):  
Mickey C.-T. Hu ◽  
Wan R. Qiu ◽  
You-ping Wang ◽  
Dave Hill ◽  
Brian D. Ring ◽  
...  
Keyword(s):  
Small Intestine ◽  
Growth Factor ◽  
Transgenic Mice ◽  
Signal Sequence ◽  
Fibroblast Cell ◽  
Tissue Growth ◽  
Dependent Manner ◽  
Fibroblast Growth

ABSTRACT The fibroblast growth factors (FGFs) play key roles in controlling tissue growth, morphogenesis, and repair in animals. We have cloned a novel member of the FGF family, designated FGF-18, that is expressed primarily in the lungs and kidneys and at lower levels in the heart, testes, spleen, skeletal muscle, and brain. Sequence comparison indicates that FGF-18 is highly conserved between humans and mice and is most homologous to FGF-8 among the FGF family members. FGF-18 has a typical signal sequence and was glycosylated and secreted when it was transfected into 293-EBNA cells. Recombinant murine FGF-18 protein (rMuFGF-18) stimulated proliferation in the fibroblast cell line NIH 3T3 in vitro in a heparan sulfate-dependent manner. To examine its biological activity in vivo, rMuFGF-18 was injected into normal mice and ectopically overexpressed in transgenic mice by using a liver-specific promoter. Injection of rMuFGF-18 induced proliferation in a wide variety of tissues, including tissues of both epithelial and mesenchymal origin. The two tissues which appeared to be the primary targets of FGF-18 were the liver and small intestine, both of which exhibited histologic evidence of proliferation and showed significant gains in organ weight following 7 (sometimes 3) days of FGF-18 treatment. Transgenic mice that overexpressed FGF-18 in the liver also exhibited an increase in liver weight and hepatocellular proliferation. These results suggest that FGF-18 is a pleiotropic growth factor that stimulates proliferation in a number of tissues, most notably the liver and small intestine.

A technique for protecting delicate specimens during processing

1989 ◽  
Vol 47 ◽  
pp. 982-983
Author(s):  
R.J. Mount ◽  
R.V. Harrison
Keyword(s):  
Basilar Membrane ◽  
Low Cost ◽  
Organ Of Corti ◽  
Region Of Interest ◽  
Sensory Epithelium ◽  
Physical Damage ◽  
Air Drying ◽  
Specimen Handling ◽  
Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

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