Ganglioside GD1a enhances osteogenesis by activating ERK1/2 in mesenchymal stem cells of Lmna mutant mice.

Mutations in Lmna usually cause a series of human disorders, such as premature aging syndrome (progeria) involving the skeletal system. Gangliosides are known to be involved in cell surface differentiation and proliferation of stem cells. However, the role of gangliosides in Lmna dysfunctional mesenchymal stem cells (MSCs) is unclear. Therefore, Ganglioside's role in osteogenesis of Lmna dysfunctional MSCs analyzed. As a result of the analysis, it was confirmed that the expression of ganglioside GD1a was significantly reduced in MSCs derived from LmnaDhe/+ mice and in MSCs subjected to Lamin A/C knockdown using siRNA. Osteogenesis-related bone morphogenetic protein-2 and Osteocalcin protein, and gene expression were significantly decreased due to Lmna dysfunction. A result of treating MSCs with Lmna dysfunction with ganglioside GD1a (3 µg/ml), significantly increased bone differentiation in ganglioside GD1a treatment to Lmna-mutated MSCs. In addition, the level of pERK1/2, related to bone differentiation mechanisms was significantly increased. Ganglioside GD1a was treated to Congenital progeria LmnaDhe/+ mice. As a result, femur bone volume in ganglioside GD1a-treated LmnaDhe/+ mice was more significantly increased than in the LmnaDhe/+ mice. Therefore, it was confirmed that the ganglioside GD1a plays an important role in enhancing osteogenic differentiation in MSC was a dysfunction of Lmna.

Skin accumulation of advanced glycation end products and cardiovascular risk in Korean patients with type 2 diabetes mellitus.

Background: The formation of advanced glycation end products (AGEs) takes place during normal aging; however, their production is faster in people having diabetes. The accumulated AGEs reportedly play a role in the occurrence of various age-related disorders. Furthermore, the skin autofluorescence (SAF) technique can be used to detect accumulated AGEs levels. There are few reports on the association between skin accumulation of AGEs and risk of complications in type 2 diabetes mellitus. Methods: In this study, we aimed to describe the association between the skin accumulation of AGEs and cardiovascular risk factors in Korean patients with type 2 diabetes. A total of 310 Korean patients with diabetes were enrolled, and the levels of AGEs were measured using SAP. Levels of fasting blood glucose (FBS), triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol, proteinuria, arterial pulse wave velocity (PWV), and blood vessel age were measured using an automatic waveform analyzer. General linear models were used to identify the independent effect of AGEs after adjusting for covariates (age, weight, and duration of diabetes). Results: The skin levels of AGEs were strongly correlated with the diabetes duration. Significant independent associations were observed for AGEs with FBS (P < 0.01), proteinuria (P < 0.001), and PWV (P < 0.001). The advanced glycated product was independently associated to the arterial pulse wave conduction velocity that is used as a representative method for measuring arteriosclerosis by analysis early cardiovascular risk factors. Conclusion: Our results show that an increase in SAF levels in Korean patients with type 2 diabetes is associated with PWV and vein age, and thereby with arterial stiffness. Therefore, our results suggest that AGEs are associated with cardiovascular risk factors. The level of AGEs can thus be used as an indicator of cardiovascular diseases in the clinical diagnosis of patients with type 2 diabetes.

Early-life stress induces EAAC1 expression reduction and attention-deficit and depressive behaviors in adolescent rats.

Neonatal maternal separation (NMS), as an early-life stress (ELS), is a risk factor to develop emotional disorders. However, the exact mechanisms remain to be defined. In the present study, we investigated the mechanisms involved in developing emotional disorders caused by NMS. First, we confirmed that NMS provoked impulsive behavior, orienting and nonselective attention-deficit, abnormal grooming, and depressive-like behaviors in adolescence. Excitatory amino acid carrier 1 (EAAC1) is an excitatory amino acid transporter expressed specifically by neurons and is the route for the neuronal uptake of glutamate/aspartate/cysteine. Compared with that in the normal control group, EAAC1 expression was remarkably reduced in the ventral hippocampus and cerebral cortex in the NMS group. Additionally, EAAC1 expression was reduced in parvalbumin-positive hippocampal GABAergic neurons in the NMS group. We also found that EAAC1-knockout (EAAC1-/-) mice exhibited impulsive-like, nonselective attention-deficit, and depressive-like behaviors compared with WT mice in adolescence, characteristics similar to those of the NMS behavior phenotype. Taken together, our results revealed that ELS induced a reduction in EAAC1 expression, suggesting that reduced EAAC1 expression is involved in the pathophysiology of attention-deficit and depressive behaviors in adolescence caused by NMS.

Endoplasmic Reticulum Stress Increases DUSP5 Expression via PERK-CHOP Pathway, Leading to Hepatocyte Death.

Hepatocyte death is critical for the pathogenesis of liver disease progression, which is closely associated with endoplasmic reticulum (ER) stress responses. However, the molecular basis for ER stress-mediated hepatocyte injury remains largely unknown. This study investigated the effect of ER stress on dual-specificity phosphatase 5 (DUSP5) expression and its role in hepatocyte death. Analysis of Gene Expression Omnibus (GEO) database showed that hepatic DUSP5 levels increased in the patients with liver fibrosis, which was verified in mouse models of liver diseases with ER stress. DUSP5 expression was elevated in both fibrotic and acutely injured liver of mice treated with liver toxicants. Treatment of ER stress inducers enhanced DUSP5 expression in hepatocytes, which was validated in vivo condition. The induction of DUSP5 by ER stress was blocked by either treatment with a chemical inhibitor of the protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathway, or knockdown of C/EBP homologous protein (CHOP), whereas it was not affected by the silencing of IRE1 or ATF6. In addition, DUSP5 overexpression decreased extracellular-signal-regulated kinase (ERK) phosphorylation, but increased cleaved caspase-3 levels. Moreover, the reduction of cell viability under ER stress condition was attenuated by DUSP5 knockdown. In conclusion, DUSP5 expression is elevated in hepatocytes by ER stress through the PERK-CHOP pathway, contributing to hepatocyte death possibly through ERK inhibition.

Aristolochic Acid I Causes Testis Toxicity by Inhibiting Akt and ERK1/2 Phosphorylation.

Aristolochic acid (AA) is a natural bioactive substance found in Chinese herbs that induce toxicity during ovarian maturation of animals and humans. Apoptosis is induced by various types of damage and governs the progression of biological cell removal that controls the equilibrium between cell growth and death. However, the AA toxicity mechanism during testis maturation in mouse has not been elucidated and was thus the focus of the present study. This study used TM4 Sertoli cells and an ICR mouse model, both of which were injected with aristolochic acid I (AAI) for 4 weeks. Testis dimensions and weight were surveyed to define AAI cytotoxicity in the mice testis. The MTT assay was used to analyze the cytotoxicity of AAI in TM4 Sertoli cells. An apoptosis expression mediator was analyzed through Western blotting, while the measure of apoptosis-induced cell death of TM4 Sertoli cells and testis tissues was analyzed by the TUNEL assay. We found that AAI strongly inhibits survival in TM4 cells and that AAI significantly activated apoptosis-induced cell death in TM4 Sertoli cells and mice testis tissue. In addition, AAI suppressed the expression of B-cell lymphoma 2 (Bcl-2), a factor related to anti-apoptosis. It markedly improved pro-apoptotic protein expression, including Bcl-2-associated X protein, poly(ADP-ribose) polymerase, and caspase-3 and -9. Furthermore, we observed that AAI significantly reduced the size and weight of mouse testis. Moreover, germ cells and somatic cells in testis were markedly damaged by AAI. In addition, we found that AAI significantly inhibits ERK1/2 and Akt activation in TM4 Sertoli cells and testis tissue. The data obtained in this study indicate that AAI causes severe injury for the period of testis development by impeding apoptosis related to the Akt and ERK1/2 pathway.

Aristolochic Acid I induces ovarian toxicity by inhibition of akt phosphorylation.

Aristolochic acids are natural products found in Chinese herbs of the Aristolochiaceae family. Aristolochic acid I (AAI) is a potent carcinogen and was found to be toxic in animal and clinical studies. Apoptosis is a rapid, selective process of physiological cell deletion that regulates the balance between cell proliferation and cell death and is induced by various kinds of damage. However, the toxicity of AAI during ovarian maturation in the mouse is unclear and is the subject of the present investigation. We used Chinese hamster ovary-K1 (CHO-K1) cells and an AAI injection mouse model: MTT assay was used to assess AA toxicity to cells; ovary size and weight were measured to determine the toxicity of AA to mouse ovary; western blot was used to assess apoptosis; TUNEL assay was used to evaluate apoptotic cell death; and immunohistochemistry was used to examine the local expression of apoptotic proteins in ovary tissue. We found that AAI significantly inhibits the viability of CHO-K1 cells and strongly induces apoptotic cell death in CHO-K1 cells and in mouse ovary. In addition, we observed that AAI markedly increases the expression of pro-apoptotic proteins, including Bax, caspase-3, caspase-9, and poly(ADP) ribose polymerase (PARP). In contrast, anti-apoptotic proteins, such as Bcl-2 and survivin, were decreased by AAI treatment. Furthermore, we observed that ovary size and weight were significantly reduced and that the number of ovulated oocytes was markedly suppressed in AAI-treated mice. These results suggest that AAI strongly induces toxic damage during ovarian maturation by inhibiting Akt phosphorylation-mediated suppression of apoptosis.

The role of autophagy induced by pemetrexed in lung adenocarcinoma cells.

Autophagy is known as an important regulatory mediator for cell survival or death and its important role in cancer. Pemetrexed (PTX) has been used in chemotherapy for lung cancer. However, the underlying molecular mechanisms have not been fully clarified. To investigate the role of autophagy induced by PTX in A549 cells, we performed MTT assay, acridine orange staining, western blotting, Annexin V/PI by using the 3-MA autophagy inhibitor. PTX induced autophagy after 48 h treatment in A549 cells. Furthermore, PTX showed acidic vesicular organelles (AVOs) and expressed LC3-II in A549 cells. The induction of autophagy by PTX was inhibited by 3-MA which was confirmed by reduced AVOs. When the autophagy was inhibited, Annexin V was increased. In addition, PARP cleavage was increased as shown by western blotting. Taken together, PTX induced autophagy in A549 cells and these cellular events possibly cause the apoptotic and/or necrotic cell death of A549 cells.

The effect of continuous epidural electrical stimulation on neuronal proliferation in cerebral ischemic rats.

OBJECTIVE: To investigate the effect of electrical stimulation (ES) on the recovery of motor skill and neuronal cell proliferation. METHODS: The male Sprague-Dawley rats were implanted with an epidural electrode over the peri-ischemic area after photothrombotic stroke in the dominant sensorimotor cortex. All rats were randomly assigned into the ES group and control group. The behavioral test of a single pellet reaching task (SPRT) and neurological examinations including the Schabitz's photothrombotic neurological score and the Menzies test were conducted for 2 weeks. After 14 days, coronal sections were obtained and immunostained for neuronal cell differentiation markers including bromodeoxyuridine (BrdU), neuron-specific nuclear protein (NeuN), and doublecortin (DCX). RESULTS: On the SPRT, the motor function in paralytic forelimbs of the ES group was significantly improved. There were no significant differences in neurological examinations and neuronal cell differentiation markers except for the significantly increased number of DCX+ cells in the corpus callosum of the ES group (p<0.05). But in the ES group, the number of NeuN+ cells in the ischemic cortex and the number of NeuN+ cells and DCX+ cells in the ischemic striatum tended to increase. In the ES group, NeuN+ cells in the ischemic hemisphere and DCX+ cells and BrdU+ cells in the opposite hemisphere tended to increase compared to those in the contralateral. CONCLUSION: The continuous epidural ES of the ischemic sensorimotor cortex induced a significant improvement in the motor function and tended to increase neural cell proliferation in the ischemic hemisphere and the neural regeneration in the opposite hemisphere.

Fatty diets retarded the propulsive function of and attenuated motility in the gastrointestinal tract of rats.

Digestive functions are considered to be alterable by the ingestion of fatty diets. This study aimed to investigate the hypothesis that dietary fats may exert site-specific effects on the propulsive functions of the gastrointestinal (GI) tract. After male Wistar rats were fed either low-fat diet or high-fat diet (HFD) for 8 weeks, the propulsive function of the luminal contents of the entire GI tract was simultaneously examined in vivo. In comparison with a low-fat diet, an HFD significantly increased the body weight gains but significantly decreased the diet and caloric intakes, fecal weights, and fecal pellet numbers. Gastric emptying in the HFD-fed rats tended to be delayed, but this was not significant. High-fat diet feeding significantly slowed the small bowel transit times, and the luminal residuals emptied from the gastric antrum were largely accumulated in the proximal parts of the small intestine. An HFD also significantly prolonged the colonic transit times. In conclusion, fatty diets retarded the propulsive function of the entire GI tract, and the delayed gastroduodenal transit of fatty diets may act as a primary causal factor for producing the attenuated motile function of the GI tract in rats.

cAMP/PKA Agonist Restores the Fasting-Induced Down-Regulation of nNOS Expression in the Paraventricular Nucleus.

Gene expression of neuronal nitric oxide synthase (nNOS) changes in the hypothalamic paraventricular nucleus (PVN) depending on feeding conditions, which is decreased during food deprivation and restored by refeeding, and phosphorylated cAMP response element binding protein (pCREB) was suggested to play a role in its regulation. This study was conducted to examine if the fasting-induced down-regulation of the PVN-nNOS expression is restored by activation of cAMP-dependent protein kinase A (cAMP/PKA) pathway. Freely moving rats received intracerebroventricular (icv) injection of cAMP/PKA activator Sp-cAMP (40 nmol) or vehicle (sterilized saline) following 48 h of food deprivation. One hour after drug injections, rats were transcardially perfused with 4% paraformaldehyde, and the PVN tissues were processed for nNOS or pCREB immunohistochemistry. Sp-cAMP significantly increased not only nNOS but also pCREB immunoreactivities in the PVN of food deprived rats. Fasting-induced down-regulation of the PVN-nNOS was restored by 1 h after the icv Sp-cAMP. Results suggest that cAMP/PKA pathway may mediate the regulation of the PVN-nNOS expression depending on different feeding conditions.

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. After completion of the experiments, gastric emptying and small bowel transit were measured in vivo, and the contractile responses of colonic strips to excitatory and inhibitory neurotransmitters were estimated using isometric force transducers in vitro. RESULTS: In comparison with normal and sham-operated rats, rats which received unilateral TPX plus VAX showed a significant decrease in body weight and in fecal pellet number and weight throughout the entire week. Application of TPX plus VAX to rats markedly delayed gastric emptying and small bowel transit. In TPX plus VAX rats, the longitudinal muscles of the proximal colon showed a significant reduction in contractile responses to acetylcholine (5 × 10(-6) mol/L), and a dramatic attenuation of contractile responses was also observed in both the longitudinal and circular muscles of the distal colon. However, the spontaneous contractility of the colonic strips from TPX plus VAX rats was not significantly affected by treatment with N-nitro-L-arginine-methyl ester (0.1 mol/L). CONCLUSION: The results indicate that unilateral TPX plus VAX reduced the motor function of the GI tract in rats, and the reduced gut motility is likely mediated, at least in part, by inhibition of the excitatory neurotransmitter system.

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 1.71×10(-9) g/ml. Among GI tracts, a prominent contractile response to AJEA was observed only in the DCLM. The contractile patterns produced by AJEA remarkably differed from those caused by acetylcholine and 5-HT. 4-DAMP and methoctramine at 0.5 µM significantly blocked the AJEA (1.0 µg/ml)-induced contraction of DCLM, but ondansetron, GR113808 and methysergide at 1.0 µM in combination did not change the AJEA-induced DCLM contractions. Acetylethylcholine mustard (5.0 µM) significantly diminished the AJEA-induced DCLM contractions, whereas p-chlorophenyl alanine (1.0 µM) did not affect the stimulatory effects of AJEA on the DCLM contractions. CONCLUSION: The present results suggest that AJEA may specifically act on the DCLM among GI smooth muscles, and AJEA-induced DCLM contraction is likely mediated, at least, by activation of ChAT and acetylcholinergic muscarinic receptors.

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. RESULTS: ATD and DATD dose-dependently increased both tension and amplitude of distal colon longitudinal muscle (DCLM), but they stimulated only amplitude in the distal colon circular muscle. The ED(50) values of ATD and DATD to stimulate the amplitude of DCLM were revealed as 9.1×10(-9)M and 1.8×10(-8)M, respectively. l-NAME (0.1mM) significantly increased the ADT (1µM)-induced contraction of DCLM, whereas SNAP (0.1mM) markedly reduced the stimulatory effects of ATD on DCLM contractility. The combined effects of SNAP and atropine (0.5µM) on the ATD-induced contraction of DCLM were similar to the inhibitory effects of SNAP alone. Suramin (0.1mM) significantly enhanced the increase of ATD-induced DCLM contraction, whereas ADPßS (0.1mM) markedly abolished the stimulatory effects of ATD on the spontaneous contractility of DCLM. CONCLUSIONS: The present results demonstrate that acetylene compounds, ATD and DATD, are the effective phytochemical of Atractylodes japonica to stimulate the motility of distal colon in rats, and ATD possibly enhances the spontaneous contractility of distal colon through inhibiting the mechanism of nitrergic-purinergic relaxation.

Chronic Administration of Monosodium Glutamate under Chronic Variable Stress Impaired Hypothalamic-Pituitary-Adrenal Axis Function in Rats.

The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS+MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naïve mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS+MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS+MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS+MSG group as compared to all other groups, except the naïve group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.

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. This study investigated the regulatory effects of PT on the colonic motility. MATERIALS AND METHODS: Immature fruits of PT were sequentially partitioned with MeOH, n-hexane, CHCl(3), EtOAc, n-BuOH and H(2)O, and the effects of PT extracts on the contractility of colonic strips and colonic luminal transit in rats were measured in vitro and in vivo, respectively. RESULTS: Among six different extracts, only hexane extract of PT (PTHE) dose-dependently increased the low frequency contraction of longitudinal muscle in distal colonic strips, and the ED(50) value was revealed to be 0.71 microg/ml. The contractile patterns induced by PTHE were remarkably different from those caused by acetylcholine (ACh) and serotonin (5-HT). The stimulatory effects of PTHE on the whole distal colonic strips were more prominent than on the mucosa/submucosa-denuded segments. The M(2) receptor-preferring, methoctramine (0.5 microM), and M(3) receptor-preferring antagonist, 4-DAMP (0.5 microM) significantly blocked the PTHE (1 microg/ml)-induced contraction of distal colon longitudinal muscles, whereas the 5-HT receptor antagonists (1.0 microM, alone or in combination) selective for 5-HT(3) (ondansetron), 5-HT(4) (GR113808) and 5-HT(1, 2, 5-7) (methysergide) receptors did not change the PTHE (1 microg/ml)-induced contractility of distal colon longitudinal muscles. SNAP (0.1mM), a NO donor, enhanced the stimulatory effects of PTHE on the longitudinal muscle of distal colon, but l-NAME (0.1mM), a NO synthesis inhibitor, had no effects. PTHE (10-100mg/kg) caused a dose-dependent increase of colonic luminal transit. CONCLUSIONS: Collectively, these findings suggest that PTHE specifically acts on the longitudinal muscle of distal colon in rats, and these stimulatory effects are likely mediated, at least, by activation of acetylcholinergic M(2) and M(3) receptors.

Plasma and brain matrix metalloproteinase-9 after acute focal cerebral ischemia in rats.

BACKGROUND AND PURPOSE: Plasma levels of matrix metalloproteinase-9 (MMP-9) have been proposed to be a useful biomarker for assessing pathological events in brain. Here, we examined the temporal profiles of MMP-9 in blood and brain using a rat model of acute focal cerebral ischemia. METHODS: Plasma and brain levels of MMP-2 and MMP-9 were quantified at 3, 6, 12, and 24 hours after permanent middle cerebral artery occlusion in male Sprague-Dawley rats. Infarct volumes at 24 hours were confirmed with 2,3,5-triphenyl-tetrazolium-chloride staining. RESULTS: In plasma, zymographic bands were detected between 70 and 95 kDa corresponding to pro-MMP-2, pro-MMP-9, and activated MMP-9. A higher 135-kDa band was also seen that is likely to be NGAL-conjugated MMP-9. After ischemia, there were no significant changes in pro-MMP-2, but plasma levels of pro-MMP-9 steadily increased over the course of 24 hours. Activated MMP-9 levels in plasma were significantly elevated only at 24 hours. Plasma NGAL-MMP-9 complexes showed a transient elevation between 3 to 6 hours, after which levels decreased back down to pre-ischemic baselines. In brain homogenates, pro-MMP-2, pro-MMP-9, and activated MMP-9 were seen but no NGAL-MMP-9 bands were detected. Compared to the contralateral hemisphere, MMP-2 and MMP-9 levels in ischemic brain progressively increased over the course of 24 hours. Overall levels of MMP-9 in plasma and brain were significantly correlated, especially at 24 hours. Plasma levels of pro-MMP-9 at 24 hours were correlated with final infarct volumes. CONCLUSIONS: Elevated plasma levels of MMP-9 appear to be correlated with brain levels within 24 hours of acute cerebral ischemia in rats. Further investigation into clinical profiles of MMP-9 in acute stroke patients may be useful.

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. Magnolol at 3 microM significantly increased the contractions of jejunum longitudinal and colon circular muscles, but not the longitudinal muscle contractions in fundus, antrum and colon. Pretreatment of ileum strips with either atropine (0.5 microM) or 4-diphenyllacetoxy-N(2-chloriethyl)-piperidine (4-DAMP, 0.5 microM) dramatically inhibited the acetylcholine (ACh, 0.1 microM)- and magnolol (3 microM)-induced longitudinal muscle contractions, but they were not affected by methoctramine (0.5 microM) and hexamethonium (0.5 microM). Ondansetron (0.1 microM) and GR113808 (2 microM) significantly reduced the tone of ileum longitudinal muscle contractions stimulated by 5-HT (10 microM), but not the amplitude. Magnolol (3 microM)-induced ileum longitudinal muscle contractions, both tone and amplitude, were significantly blocked by GR113808, but not by ondansetron. Taken together, magnolol differently regulates the spontaneous GI motility according to the region of GI tracts and orientation of smooth muscles, and magnolol-induced regulation of smooth muscle contractions in rat GI strips is likely to be mediated, at least in part, by activation of ACh and 5-HT receptors, possibly the M(3) and/or 5-HT(4) receptors.

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 (0.5 microM) or 4-DAMP (0.5 microM) significantly inhibited the acetylcholine (ACh, 1 microM)- and MIGB (30 microM)-stimulated contraction, and methoctramine (0.5 microM) also obviously reduced the tone and amplitude increased by ACh and MIGB, respectively. In the presence of methysergide (1 microM), pretreatment of ileum longitudinal muscles with both ondansetron (0.1 microM) and GR113808 (0.1 microM) significantly inhibited the contraction stimulated by 5-HT (10 microM), but not by MIGB. Taken together, it is concluded that MIGB differently regulates the spontaneous contractility (tone and/or amplitude) of GI segments according to the region of gut and orientation of smooth muscles, and these contractile responses of GI tracts to MIGB are likely mediated, at least, by activation of acetylcholinergic M2 and M3 receptors.