Reduction of gastrointestinal motility by unilateral thyroparathyroidectomy plus subdiaphragmatic vagotomy in rats.

Aim: To investigate whether the combined methods of unilateral thyroparathyroidectomy (TPX) and subdiaphragmatic vagotomy (VAX) can be adapted for rats and used as a reliable method to produce a rat model of long-term reduction of gastrointestinal (GI) motor function.

Methods: Male Sprague-Dawley rats were randomly divided into 3 groups, normal, sham-operated and unilateral TPX plus VAX. The TPX plus VAX rats received VAX 7 d after application of TPX, and dietary intake and fecal output were then measured daily for 1 wk.

Regulatory roles of ganglioside GQ1b in neuronal cell differentiation of mouse embryonic stem cells.

Gangliosides play an important role in neuronal differentiation processes. The regulation of ganglioside levels is related to the induction of neuronal cell differentiation. In this study, the ST8Sia5 gene was transfected into mESCs and then differentiated into neuronal cells.

Inhibition of ganglioside GD1a synthesis suppresses the differentiation of human mesenchymal stem cells into osteoblasts.

In this study, we investigated the regulatory role of ganglioside GD1a in the differentiation of osteoblasts from human mesenchymal stem cells (hMSCs) by using lentivirus-containing short hairpin (sh)RNA to knockdown ST3 β-galactoside α-2, 3-sialyltransferase 2 (ST3Gal II) mRNA expression. After hMSCs were infected for 72 h with the lentivirus constructed with ST3Gal II shRNAs, the puromycin-resistant cells were selected and subcultured to produce hMSCs with ST3Gal II mRNA knockdown. The hMSCs established from human dental papilla abundantly expressed CD44 and CD105, but not CD45 and CD117.

Signalling pathways responsible for the methylisogermabullone-induced contraction of ileal longitudinal muscles.

Objectives: We have previously reported that methylisogermabullone (MIGB) stimulates small bowel motility through activation of acetylcholinergic receptors. This study investigated the cellular signalling pathways implicated in the regulation of ileal contractility by MIGB.

Methods: The ileal longitudinal muscles prepared from rats were treated with MIGB isolated from radish roots, and muscle contractility and protein expression were measured by force transducer and Western blot, respectively.

Acetylene compound isolated from Atractylodes japonica stimulates the contractility of rat distal colon via inhibiting the nitrergic-purinergic relaxation.

Aim Of The Study: Our previous research has showed that rhizome of Atractylodes japonica Koidz (Compositae) exhibits an increase in the spontaneous contractility of distal colon in rats. The aims of this study are to identify the phytochemical(s), which stimulate(s) the colonic contractility, contained in Atractylodes japonica and to evaluate the pharmacological mechanism responsible for the colonic muscle contraction.

Materials And Methods: Based on the stimulatory activity-guided fractionation on the isometric contraction of rat distal colonic strips, atractylodiol (ATD) and diacetyl-atractylodiol (DATD) were isolated from the CHCl(3) fractions of Atractylodes japonica.

Pharmacological mechanism responsible for the Atractylodes japonica-induced distal colonic contraction in rats.

Background And Aim: Atractylodes japonica Koidz (Compositae) has been commonly used to treat the gastrointestinal (GI) disorders in Korean traditional medicine, but its pharmacological roles in the regulation of GI motility have not been clarified yet.

Methods: Atractylodes japonica was sequentially partitioned with MeOH, n-hexane, CHCl(3), EtOAc and n-BuOH saturated with H(2)O, and the effects of Atractylodes japonica extracts on the spontaneous contractility of GI muscle strips prepared from rats were measured.

Results: Among five different fractionations, EtOAc extracts of Atractylodes japonica (AJEA) dose-dependently increased the low frequency contraction of distal colon longitudinal muscles (DCLM), and the ED(50) values were revealed to be 1.

Skin lesions associated with Demodex sp. in a llama (Lama glama). [corrected].

A 2.5-yr-old female llama (Lama glama) [corrected] with skin lesions was presented to the Animal Health Center in Seoul Grand Park Zoo, Korea. Mites of the genus Demodex in the absence of other mites or fungi were identified from the lesions by skin scrapings.

Estrogenic activity produced by aqueous extracts of silkworm (Bombyx mori) pupae in ovariectomized rats.

This study examined the estrogenic activity produced by aqueous extracts of silkworm (Bombyx mori) pupae in ovariectomized (OVX) rats. The components of silkworm pupae were extracted in distilled water at room temperature for 6 hours. The ovaries of six-week old female rats were then bilaterally removed.

Different stimulatory effects of methylisogermabullone on the spontaneous contractility of rat gastrointestinal segments.

Using rat gastrointestinal (GI) strips, this study investigated the stimulatory effects of methylisogermabullone (MIGB) purified from radish on the spontaneous contractility of GI smooth muscles and pharmacological mechanisms involved in the MIGB-induced GI contraction. MIGB at 30 microM differently regulated the tone and amplitude of spontaneous GI contractility according to the region (fundus through distal colon) and orientation (longitudinal and circular) of smooth muscles: a significant increase in both tone and amplitude of spontaneous contraction in the ileum longitudinal and distal colon circular muscles and in amplitude only in the fundus, jejunum and distal colon longitudinal muscles. Pretreatment of ileum longitudinal muscles with atropine (0.

Hexane extract of Poncirus trifoliata (L.) Raf. stimulates the motility of rat distal colon.

Aim Of The Study: Poncirus trifoliata (L.) Raf. (Rutaceae, PT) has been commonly used for treating gastrointestinal (GI) disorders in Korean traditional medicine, but its pharmacological roles in the regulation of colonic motility have not been clarified.

5-hydroxytryptophan acts on the mitogen-activated protein kinase extracellular-signal regulated protein kinase pathway to modulate cyclooxygenase-2 and inducible nitric oxide synthase expression in RAW 264.7 cells.

In this study, we evaluated the effect of 5-hydroxytryptophan on anti-inflammatory and analgesic activity in RAW 264.7 cells. Cells were treated with different concentrations of 5-hydroxytryptophan for either 1 h or for 24 h.

Regulation of contractile activity by magnolol in the rat isolated gastrointestinal tracts.

This study examined the pharmacological property of magnolol, a phenolic compound purified from Magnolia officinalis, on the GI motility using the rat isolated gastrointestinal (GI) strips. Magnolol (0.3-30 microM) dose-dependently stimulated the tone and amplitude of spontaneous contractions in ileum longitudinal muscles.

Effects of gangliosides on the differentiation of human mesenchymal stem cells into osteoblasts by modulating epidermal growth factor receptors.

Gangliosides are sialic acid-conjugated glycosphingolipids that are believed to regulate cell differentiation as well as the signals of several signal molecules, including epidermal growth factor receptors (EGFR). These compounds are localized in a glycosphingolipid-enriched microdomain on the cell surface and regulated by the glycosphingolipid composition. However, the role that gangliosides play in osteoblastogenesis is not yet clearly understood, therefore, in this study, the relationship between gangliosides and EGFR activation was investigated during osteoblast differentiation in human mesenchymal stem cells (hMSCs).

TGF-beta1-induced PINCH-1-ILK-alpha-parvin complex formation regulates mesangial cell proliferation and hypertrophy.

TGF-beta1-induced glomerular mesangial cell (GMC) injury is a prominent characteristic of renal pathology in several kidney diseases, and a ternary protein complex consisting of PINCH-1, integrin-linked kinase (ILK) and alpha-parvin plays a pivotal role in the regulation of cell behavior such as cell proliferation and hypertrophy. We report here that PINCH-1-ILK-alpha-parvin (PIP) complex regulates the TGF-beta1-induced cell proliferation and hypertrophy in cultured rat GMCs. When GMCs were treated with TGF-beta1 for 1, 2 and 3 days, the PIP complex formation was up-regulated after 1 day, but it was down-regulated on day 2.

Effects of daunorubicin on ganglioside expression and neuronal differentiation of mouse embryonic stem cells.

Gangliosides are implicated in neuronal development processes. The regulation of ganglioside levels is closely related to the induction of neuronal cell differentiation. In this study, the relationship between ganglioside expression and neuronal cell development was investigated using an in vitro model of neural differentiation from mouse embryonic stem (mES) cells.

Dynamic changes of gangliosides expression during the differentiation of embryonic and mesenchymal stem cells into neural cells.

Stem cells are used for the investigation of developmental processes at both cellular and organism levels and offer tremendous potentials for clinical applications as an unlimited source for transplantation. Gangliosides, sialic acid-conjugated glycosphingolipids, play important regulatory roles in cell proliferation and differentiation. However, their expression patterns in stem cells and during neuronal differentiation are not known.

TGF-beta1 regulates the PINCH-1-integrin-linked kinase-alpha-parvin complex in glomerular cells.

Glomerular damage is a major cause of renal failure. Recent studies suggest that a ternary protein complex that consists of PINCH-1, integrin-linked kinase, and alpha-parvin, cytoplasmic components of cell-extracellular matrix adhesions, plays pivotal roles in regulation of glomerular cell behavior. It is reported here that TGF-beta1, a key factor in the progression of glomerular failure, regulates the PINCH-1-integrin-linked kinase-alpha-parvin (PIP) complex formation in glomerular podocytes and mesangial cells.

Differential expression of gangliosides in the ovary and uterus of streptozotocin-induced and db/db diabetic mice.

Gangliosides are widely distributed in mammalian cells and play important roles in various functions such as cell differentiation and growth control. In addition, diabetes and obesity cause abnormal development of reproductive processes in a variety of species. However, the mechanisms underlying these effects, and how they are related, are not fully understood.

Differential expression patterns of gangliosides in the ischemic cerebral cortex produced by middle cerebral artery occlusion.

Neuronal damage subsequent to transient cerebral ischemia is a multifactorial process involving several overlapping mechanisms. Gangliosides, sialic acid-conjugated glycosphingolipids, reduce the severity of acute brain damage in vitro. However their in vivo effects on the cerebral cortex damaged by ischemic infarct are unknown.

Methylisogermabullone isolated from radish roots stimulates small bowel motility via activation of acetylcholinergic receptors.

We have previously reported that extract of radish roots exhibits an increase in gastrointestinal motility through the activation of muscarinic acetylcholine (ACh) receptors. Based on the stimulatory activity-guided fractionation on rat ileal segments, this study isolated methylisogermabullone (MIGB, C23H31O5NS, MW 433) from methanol extracts of radish roots. MIGB caused a significant increase of the isolated rat ileal contraction in a concentration-dependent manner (23-693 microM), and the pattern of MIGB-induced ileal contraction was different in the time course to that produced by ACh.

Pathophysiological implication of ganglioside GM3 in early mouse embryonic development through apoptosis.

Apoptosis may occur in early embryos where the execution of essential developmental events has failed, and gangliosides, sialic acid-conjugated glycosphingolipids, are proposed to regulate cell differentiation and growth. To evaluate the regulatory roles of ganglioside GM3 in early embryonic development, this study examined its expressional patterns in apoptotic cells during early embryonic development in mice. Pre-implanted embryos were obtained by in vitro fertilization, which were treated at the 4-cell stage with three the apoptosis inducers, actinomycin D, camptothecin and cycloheximide, for 15 h.

Modulation of cell proliferation and hypertrophy by gangliosides in cultured human glomerular mesangial cells.

Glomerular mesangial cells (GMCs) in diverse renal diseases undergo cell proliferation and/or hypertrophy, and gangliosides have been reported to play an important role in modulating cell structure and function. This study compared the effects of transforming growth factor-beta1 (TGF-beta1) and the effects of the application of exogenous gangliosides on GMCs and investigated whether the application of exogenous gangliosides regulated cellular proliferation and hypertrophy. Human GMCs were cultured with exogenous gangliosides and TGF-beta1 in a media containing 10% fetal bovine serum and in a media without the fetal bovine serum.

Ganglioside GM3 inhibits the high glucose- and TGF-beta1-induced proliferation of rat glomerular mesangial cells.

Abrupt proliferation of glomerular mesangial cells (GMCs) is a common feature in the early stage of diabetic glomerulopathy, and ganglioside GM3 (NeuAcalpha3Galbeta4Glcbeta1Cer) is thought to regulate the proliferation of many cell types. Recently, we have reported ganglioside GM3 as a modulator of glomerular hypertrophy in streptozotocin-induced diabetic rats []. This study examined whether modulation of cellular ganglioside GM3 could regulate the high glucose- and transforming growth factor-beta1 (TGF-beta1)-induced proliferation of GMCs.

Reabsorption of neutral amino acids mediated by amino acid transporter LAT2 and TAT1 in the basolateral membrane of proximal tubule.

In order to understand the renal reabsorption mechanism of neutral amino acids via amino acid transporters, we have isolated human L-type amino acid transporter 2 (hLAT2) and human T-type amino acid transporter 1 (hTAT1) in human, then, we have examined and compared the gene structures, the functional characterizations and the localization in human kidney. Northern blot analysis showed that hLAT2 mRNA was expressed at high levels in the heart, brain, placenta, kidney, spleen, prostate, testis, ovary, lymph node and the fetal liver. The hTAT1 mRNA was detected at high levels in the heart, placenta, liver, skeletal muscle, kidney, pancreas, spleen, thymus and prostate.

Amino acid transport system L is differently expressed in human normal oral keratinocytes and human oral cancer cells.

Previously, we reported the expression and function of system L amino acid transporter in KB human oral epidermoid carcinoma cells. In the present study, therefore, we investigated the expression and function of system L amino acid transporter in human normal oral keratinocytes (HNOK) and compared the expressions and functions of system L amino acid transporters in HNOK and KB cells. The HNOK expressed L-type amino acid transporter 1 (LAT1) and L-type amino acid transporter 2 (LAT2) with their subunit 4F2hc in the plasma membrane but the expression of LAT1 was very weak, which is in contrast to the KB cells expressing LAT1 but not LAT2 with the 4F2hc in the plasma membrane.