Patterns of Brain Activation and Meal Reduction Induced by Abdominal Surgery in Mice and Modulation by Rikkunshito

Abdominal surgery inhibits food intake and induces c-Fos expression in the hypothalamic and medullary nuclei in rats. Rikkunshito (RKT), a Kampo medicine improves anorexia. We assessed the alterations in meal microstructure and c-Fos expression in brain nuclei induced by abdominal surgery and the modulation by RKT in mice. RKT or vehicle was gavaged daily for 1 week. On day 8 mice had no access to food for 6–7 h and were treated twice with RKT or vehicle. Abdominal surgery (laparotomy-cecum palpation) was performed 1–2 h before the dark phase. The food intake and meal structures were monitored using an automated monitoring system for mice. Brain sections were processed for c-Fos immunoreactivity (ir) 2-h after abdominal surgery. Abdominal surgery significantly reduced bouts, meal frequency, size and duration, and time spent on meals, and increased inter-meal interval and satiety ratio resulting in 92–86% suppression of food intake at 2–24 h post-surgery compared with control group (no surgery). RKT significantly increased bouts, meal duration and the cumulative 12-h food intake by 11%. Abdominal surgery increased c-Fos in the prelimbic, cingulate and insular cortexes, and autonomic nuclei, such as the bed nucleus of the stria terminalis, central amygdala, hypothalamic supraoptic (SON), paraventricular and arcuate nuclei, Edinger-Westphal nucleus (E-W), lateral periaqueduct gray (PAG), lateral parabrachial nucleus, locus coeruleus, ventrolateral medulla and nucleus tractus solitarius (NTS). RKT induced a small increase in c-Fos-ir neurons in the SON and E-W of control mice, and in mice with surgery there was an increase in the lateral PAG and a decrease in the NTS. These findings indicate that abdominal surgery inhibits food intake by increasing both satiation (meal duration) and satiety (meal interval) and activates brain circuits involved in pain, feeding behavior and stress that may underlie the alterations of meal pattern and food intake inhibition. RKT improves food consumption post-surgically that may involve modulation of pain pathway.

Serotonin 2C receptor contributes to gender differences in stress-induced hypophagia in aged mice

The combination of depression and anorexia may influence morbidity and progressive physical disability in the elderly. Gender differences exist in hypothalamic-pituitary-adrenal axis activation following stress exposure. The objective of this study was to investigate gender differences in feeding behavior under novelty stress in aged mice. Food intake measurement, immunohistochemical assessment, and mRNA expression analysis were conducted to investigate the role of serotonin 2C receptor (5-HT(2C)R) and its relationship with ghrelin in stress-induced suppression of feeding behavior in aged mice. After exposure to novelty stress, a 21-fold increase in plasma corticosterone and remarkable suppression of food intake were observed in aged male mice. Furthermore, a 5-HT(2C)R agonist suppressed food intake in aged male mice. Novelty stress induced a 7-fold increase in 5-HT(2C)R and c-Fos co-expressing cells in the paraventricular nucleus of the hypothalamus in aged male mice but caused no change in aged female mice. Plasma acylated ghrelin levels decreased in stressed aged male mice and administration of the 5-HT(2C)R antagonist inhibited this decrease. The 5-HT(2C)R antagonist also reversed the suppression of food intake in estrogen receptor α agonist-treated aged male mice. Therefore, conspicuously suppressed feeding behavior in novelty stress-exposed aged male mice may be mediated by 5-HT(2C)R hypersensitivity, leading to hypoghrelinemia. The hypersensitivity may partly be due to estrogen receptor activation in aged male mice.

Expression of marA is remarkably increased from the early stage of development of fluoroquinolone-resistance in uropathogenic Escherichia coli

BACKGROUND

Analyses of efflux pumps overexpression and mutations in quinolone resistance determining region (QRDR) in early stage of development of resistance to fluoroquinolones (FQs) are valuable to discuss countermeasures against them. We induced levofloxacin (LVFX)-resistant strains from susceptible uropathogenic Escherichia coli in vitro to analyze the mechanisms of development of FQs-resistance.

METHODS

89 strains were exposed to discontinuous elevation of LVFX dose, and mRNA level of efflux pumps and their regulators as well as mutations developed in QRDR of LVFX-resistant strains were analyzed.

RESULTS

In 5 strains, a stepwise increase in MIC to LVFX (up to >128 μg/ml)was observed. Compared to the parent strains, additional mutations in QRDR were observed in the strains developing high MIC. Remarkable increase of marA expression was observed even in the early stage of LVFX-resistance development, and it lasted until high-level resistance was developed. On the other hand, moderate increase in acrB expression but only low increase in yhiU, yhiV, mdfA, tolC and sdiA were observed.

CONCLUSIONS

These results suggested that marA expression is a sensitive marker for early detection of development of LVFX-resistance.

Administration of exogenous acylated ghrelin or rikkunshito, an endogenous ghrelin enhancer, improves the decrease in postprandial gastric motility in an acute restraint stress mouse model

BACKGROUND

Physical or psychological stress causes functional disorders in the upper gastrointestinal tract. This study aims to elucidate the ameliorating effect of exogenous acylated ghrelin or rikkunshito, a Kampo medicine which acts as a ghrelin enhancer, on gastric dysfunction during acute restraint stress in mice.

METHODS

Fasted and postprandial motor function of the gastric antrum was wirelessly measured using a strain gauge force transducer and solid gastric emptying was detected in mice exposed to restraint stress. Plasma corticosterone and ghrelin levels were also measured. To clarify the role of ghrelin on gastrointestinal dysfunction in mice exposed to stress, exogenous acylated ghrelin or rikkunshito was administered, then the mice were subjected to restraint stress.

KEY RESULTS

Mice exposed to restraint stress for 60 min exhibited delayed gastric emptying and increased plasma corticosterone levels. Gastric motility was decreased in mice exposed to restraint stress in both fasting and postprandial states. Restraint stress did not cause any change in plasma acylated ghrelin levels, but it significantly increased the plasma des-acyl ghrelin levels. Administration of acylated ghrelin or rikkunshito improved the restraint stress-induced delayed gastric emptying and decreased antral motility. Ameliorating effects of rikkunshito on stress-induced gastric dysfunction were abolished by simultaneous administration of a ghrelin receptor antagonist.

CONCLUSIONS & INFERENCES

Plasma acylated/des-acyl ghrelin imbalance was observed in acute restraint stress. Supplementation of exogenous acylated ghrelin or enhancement of endogenous ghrelin signaling may be useful in the treatment of decreased gastric function caused by stress.

Preventive effect of rikkunshito on gastric motor function inhibited by L-dopa in rats

We previously reported that ghrelin prevented l-dopa (LD)-induced inhibition of gastric emptying (GE) of a non-nutrient solution in rats. Parkinson's disease treatment involves the combined administration of l-dopa with the enzyme l-amino acid decarboxylase inhibitor, carbidopa (CD) to reduce peripheral formation of dopamine. We investigated the effect LD/CD given orogastrically (og) on GE of a non-nutrient or nutrient meal and whether og pretreatment with rikkunshito, a kampo medicine clinically used to treat gastroparesis, influenced LD/CD effect on GE and postprandial antral and duodenal motility in conscious rats. LD/CD (20/2 mgkg(-1)) decreased significantly GE to 26.3 ± 6.0% compared to 61.2 ± 3.2% in og vehicle monitored 20-min after a non-nutrient meal and to 41.9 ± 5.8% compared to 72.9 ± 5.2% in og vehicle monitored 60 min after a nutrient meal. Rikkunshito (0.5 or 1.0 g kg(-1)) reduced the LD/CD (20/2 mg kg(-1)) inhibition of GE of non-nutrient meal (36.9 ± 7.4% and 46.6 ± 4.8% respectively vs. 12.1 ± 7.4% in og vehicle plus LD/CD) while having no effect alone (56.6 ± 8.5%). The ghrelin antagonist, [d-Lys(3)]-GHRP-6 (1 mg kg(-1)) injected intraperitoneally partially reversed rikkunshito preventive effect on LD/CD-inhibited GE. Rikkunshito (1.0 g kg(-1)) blocked LD/CD (20/2 mg kg(-1))-induced delayed GE of a nutrient meal and the reduction of postprandial antral motility. In 6-hydroxydopamine-induced Parkinson's disease rat model, rikkunshito (1.0 g kg(-1), og) also prevented LD/CD-inhibited gastric emptying of a nutrient meal and enhanced fasting plasma levels of acylated ghrelin. These data indicate that oral rikkunshito alleviates the delayed GE induced by LD/CD in naïve and PD rat model in part through ghrelin-related mechanisms.

Rikkunshito ameliorates bleomycin-induced acute lung injury in a ghrelin-independent manner

Acute lung injury (ALI) is a critical syndrome consisting of acute respiratory failure associated with extensive pulmonary infiltrates. The pathological characterization of ALI includes injuries of alveolar epithelial cells (AECs), alveolar neutrophilic infiltration, and increases in proinflammatory cytokines, which cause destruction of the alveolar capillary barrier and subsequent devastating lung fibrosis. Rikkunshito (RKT), a traditional Japanese herbal medicine, is widely used for the treatment of patients with gastrointestinal symptoms and is known to stimulate ghrelin secretion. The therapeutic effects of RKT on organ inflammation and fibrosis remain unknown. We investigated the pharmacological potential of RKT in the treatment of ALI by using a bleomycin-induced ALI model in mice. RKT or distilled water (DW) was given to mice daily starting 12 h after bleomycin administration. The RKT-treated mice showed a definitively higher survival rate than the DW-treated mice after injury. They also had smaller reductions in body weight and food intake. The amelioration of neutrophil alveolar infiltration, pulmonary vascular permeability, induction of proinflammatory cytokines, activation of the NF-κB pathway, apoptosis of AECs, and subsequent lung fibrosis were notable in the RKT-treated mice. RKT administration increased the plasma ghrelin levels in wild-type mice, and it also mitigated the ALI response in both ghrelin-deficient mice and growth hormone secretagogue receptor-deficient mice after lung injury. Our results indicate that RKT administration exerts protective effects against ALI by protecting the AECs and regulating lung inflammation independently of the ghrelin system, and they highlight RKT as a promising therapeutic agent for the management of this intractable disease.

Molecular cloning and sequence analysis of the cyanobacterial gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase

Ribulose-1,5-bisphosphate carboxylase/oxygenase consists of large subunits (LS) and small subunits. In plants, the LS is encoded in chloroplast DNA and the small subunit, in nuclear DNA. In cyanobacteria, both subunits are thought to be encoded in chromosomal DNA because of prokaryotes. The gene for the LS of ribulose-1,5-bisphosphate carboxylase/oxygenase from a cyanobacterium, Anacystis nidulans 6301, has been cloned in pBR322 and subjected to sequence analysis. The coding region contains 1,416 base pairs (472 codons). The deduced amino acid sequence of A. nidulans LS protein shows 80% homology with sequences of maize, spinach, and tobacco LS proteins; the nucleotide sequence of A. nidulans LS gene shows 70% homology with sequences of the plant genes. Between A. nidulans LS and the plant LS proteins there is exact sequence homology around the lysine residue to which the activator CO(2) binds and around the two lysine residues to which ribulose 1,5-bisphosphate binds. The amino acid sequence where the LS binds to the small subunit is also highly conserved. From comparison of the LS proteins of A. nidulans and the three plants, the rate of amino acid substitution is estimated to be 0.25-0.5 x 10(-9) per year per site, which is far below the median value of various types of proteins (1.2 x 10(-9) for hemoglobin alpha). The LS protein is thus a conserved protein.

Left ventricular free wall rupture associated with a combination of acute myocardial infarction and stress-provoked cardiomyopathy: An autopsy case

A 74-year-old female was admitted to our hospital due to prolonged chest pain that had lasted about 2 h. An electrocardiogram revealed ST-elevation in leads I, aVL, and V3-6, with an increase in myocardial necrosis markers. Emergency coronary angiography was performed, and left ventriculography showed the typical features of apical ballooning, and so a diagnosis of Takotsubo cardiomyopathy (TC) was made. On the 10th day after admission, the patient suddenly went into cardiopulmonary arrest because of a blow-out type left ventricular (LV) free wall rupture. Despite extensive cardiopulmonary resuscitation, the patient died. The autopsy revealed hemopericardium and a perforating wound located in the anterior wall of the LV. It was revealed that the diagonal branch of the coronary artery was occluded, and so a diagnosis of TC coexisting with acute myocardial infarction (AMI) was made. No previous case of TC accompanied by AMI has been reported. We present its clinical course during hospitalization and the result of a histopathologic examination.

Exendin-4 protects pancreatic beta cells from the cytotoxic effect of rapamycin by inhibiting JNK and p38 phosphorylation

It has been reported that the immunosuppressant rapamycin decreases the viability of pancreatic beta cells. In contrast, exendin-4, an analogue of glucagon-like peptide-1, has been found to inhibit beta cell death and to increase beta cell mass. We investigated the effects of exendin-4 on the cytotoxic effect of rapamycin in beta cells. Incubation with 10 nM rapamycin induced cell death in 12 h in murine beta cell line MIN6 cells and Wistar rat islets, but not when coincubated with 10 nM exendin-4. Rapamycin was found to increase phosphorylation of c-Jun amino-terminal kinase (JNK) and p38 in 30 minutes in MIN6 cells and Wistar rat islets while exendin-4 decreased their phosphorylation. Akt and extracellular signal-regulated kinase (ERK) were not involved in the cytoprotective effect of exendin-4. These results indicate that exendin-4 may exert its protective effect against rapamycin-induced cell death in pancreatic beta cells by inhibiting JNK and p38 signaling.

Gamma-glutamyl compounds and their enzymatic production using bacterial gamma-glutamyltranspeptidase

Some amino acids and peptides, which have low solubility in water, become much more soluble following gamma-glutamylation. Compounds become more stable in the blood stream with gamma-glutamylation. Several gamma-glutamyl compounds are known to have favorable physiological effects on mammals. Gamma-glutamylation can improve taste and can stabilize glutamine in aqueous solution. Because of such favorable features, gamma-glutamyl compounds are very attractive. However, only a small number of gamma-glutamyl amino acids have been studied although many other gamma-glutamyl compounds may have characteristics that will benefit humans. This is mainly because gamma-glutamyl compounds have not been readily available. An efficient and simple method of producing various gamma-glutamyl compounds, especially gamma-glutamyl amino acids, using bacterial gamma-glutamyltranspeptidase has been developed. With this method, modifications of reactive groups of the substrate and energy source such as ATP are not required, and a wide-range of gamma-glutamyl compounds can be synthesized. Moreover, bacterial gamma-glutamyltranspeptidase, a catalyst for this method, is readily available from the strain over-producing this enzyme. The superiority of producing gamma-glutamyl compounds with bacterial gamma-glutamyltranspeptidase over other methods of production is discussed.

116 EFFECTS OF l-GLUTAMINE ON CRYOPRESERVATION OF IMMATURE BOVINE OOCYTES

The cryopreservation of bovine oocytes remains a challenge despite significant reported progress. Immature bovine oocytes have a complex structure and the conventional cryoprotectants (penetrating cryoprotectants, sugars, and macromolecules) appear to be not sufficient to preserve them efficiently during freezing. Studies on semen and fibroblast cryopreservation indicate that amino acids, particularly l-glutamine, protect enzymes during freezing and increase the post-thaw viability. Therefore, the amino acids may optimize oocyte cryopreservation when associated with conventional cryoprotectants. This work evaluated the effect of l-glutamine on cryopreservation of immature bovine oocytes after in vitro maturation. Oocytes with homogeneous cytoplasm and several cumulus cell layers from slaughterhouse ovaries were distributed randomly in three groups: non-vitrified control, vitrified control, and vitrified with l-glutamine. Oocytes from vitrified groups were exposed for 10 min to PBS + 10% FCS + 10% ethylene glycol (EG) + 0.25 m trehalose (T), and for 30 s to PBS + 10% FCS + 25% EG + 25% dimethylsulfoxide + 0.5 m T at room temperature, adding 80 mm l-glutamine for the third group. Oocytes were loaded into OPS and plunged in liquid nitrogen. For thawing, OPS were immersed in PBS + 10% FCS + 10% EG + 1 m T for three min. Oocytes werethen placed in PBS + 10% FCS + 0.5 m T and in PBS + 10% FCS, remaining three min in each solution. For in vitro maturation, oocytes were washed three times on holding medium (TCM-HEPES + FCS + pyruvate + gentamycin), washed three times in maturation medium (TCM-bicarbonate + FCS + pyruvate + gentamycin + hCG + FSH + estradiol), and cultured in microdrops (90 μL) of maturation medium covered with mineral oil at 38.5°C under 5% CO2 in air and high humidity for 24 h. Oocytes were denuded, fixed in paraformaldehyde and triton, stained with Hoechst 33342, and evaluated under epifluorescence microscopy. Oocytes at metaphase II were considered matured. The group vitrified with l-glutamine had a significantly higher maturation rate than the group vitrified without l-glutamine; however, both had significantly lower maturation rates than the non-vitrified control group. In conclusion, l-glutamine improved the viability of vitrified oocytes. Table 1. Oocyte maturation rates of non-vitrified control, vitrified control, and vitrified with glutamine groups This work was supported by FAPESP 03/08543-1.

228 COLLECTION AND EVALUATION OF SEMEN OF SLOTH (BRADYPUS TRIDACTYLUS)

Sloths are animals that suffer with the destruction and fragmentation of forests. They experience a low population growth rate and need to be studied further for the preservation of the species. The objective of this study was to contribute data relevant to the reproductive physiology of this species, selecting a semen collection method and evaluating seminal characteristics that have never before been described in the literature. Fifteen Bradypus tridactylus males were captured in Manaus, Brazil. Nine of them were captured during the first half of 2004 (Group 1) and the others during the second half (Group 2). The animals were anesthetized with an i.m. injection of a combination of ketamine (10 mg/kg) and xylasine (1 mg/kg). Semen was collected by electroejaculaton using a rectal probe designed for domestic cats. Electrostimulations were given with a 0-100 mA/0-12 V variable electrostimulator in sequences of three progressive intensities, with ten repetitions at each intensity and variation of 10 mA between them. They started with 20 mA and peaked at 60 mA. Each stimulus lasted about 3 s. It was not possible to define the best intensity of stimulus to use and ejaculation could take place at any time of the stimulation (Fisher's exact test). Sperm motility and vigor were immediately analyzed. Sperm count was determined in a Neubauer chamber at a 1:50 (v:v) dilution in formol-saline. Morphology was examined at the same dilution. Fresh semen smears were made and stained using Spermac Stain� (Minit�b, Tiefenbach, Germany) protocol for a better evaluation of the spermatozoa acrosome and midpiece. In both methods 200 cells were counted for morphological evaluation. All animals ejaculated approximately 30 �L to 90 �L of semen. In some ejaculates the semen was too thin and flowed down the penis, so that the volume effectively collected was not sufficient for a complete spermiogram. Spermatozoa presented a wide variety of defects, and some physical characteristics differed (not significantly) between samples collected during the first and second halves of the year. Motility and vigor were very low, the sperm did not show forward progression, only oscillatory movement. However, a high percentage (80%) of spermatozoa were moving. The concentration in Group 1 ranged from 5000 spermatozoa/mm3 to 685 500 spermatozoa/mm3 (mean � 218 571.4 � 242 499.4). Sperm concentation was not assessed in Group 2. The morphology of the head could be elongated or squared, or the head could have a base narrower than the apex. The tail showed a unique feature: the midpiece narrowed abruptly, forming a nip in its transition to the tail. This was similar in appearance to the segmental aplasia of the mitochondrial sheath, but it was considered normal because it was observed in all spermatozoa. Although further studies are necessary to standardize the semen evaluation of sloths and to define the best protocol for electroejaculation, this pioneering study has shown the characteristics of sloth spermatozoa and the possibility of collecting semen throughout the electroejaculation process in this species. This work was supported by Fapesp 03/07457-4.

298 SPERM CAPACITATED WITH CALCIUM IONOPHORE AS A VECTOR FOR IN VITRO PRODUCTION OF BOVINE TRANSGENIC EMBRYOS

Production of transgenic mouse embryos by microinjection is a well established and successful technique. However, when microinjection protocols were used for bovine, the amount of the oocyte lipid content did not allow the production of bovine transgenic embryos. Sperm-mediated gene transfer (SMGT) is an alternative for this species because it has lower cost and does not require microinjection handling. One of the procedures to introduce exogen DNA into oocytes is by means of sperm capacitated with calcium ionophore (CaI). The aim of this work was to evaluate different CaI concentrations ([CaI]), sperm incubation times with CaI (tCa), and incubation times of sperm capacitated with DNA (tDNA) (EYFP; Clontech, Palo Alta, CA, USA) to establish a satisfactory method for IVP of bovine transgenic embryos. Slaughterhouse oocytes with compact cumulus and uniform ooplasm were in vitro maturated in TCM-199 medium + 10% FCS + FSH + hCG + estradiol (E2) + piruvate + gentamicin under 5% CO2 in air, at 39�C and high humidified atmosphere for 24 h. Semen was thawed in a water bath at 37�C for 30 s and separated by Percoll gradient (45/90%) at 600g for 30 min. After this procedure, sperm cells were washed in TALP-semen medium by centrifugation at 200g for 5 min at room temperature. Supernatant was removed and capacitation (5 � 106 spermatozoa/group) was induced with CaI (250 nM or 500 nM for 1 or 5 min). Capacitated sperm cells were incubated with 500 ng/mL DNA for 1 or 2 h. Nontreated spermatozoa were used as control group. Sperm cells (1 � 105) were used to inseminate 20 oocytes/90 mL microdroplets for 18 h. The presumptive zygotes were co-cultured in SOFaa medium with a granulosa cell monolayer under high humidified atmosphere, at 39�C and 5% CO2 in air. Blastocyst rates were analyzed by ANOVA. Independent variables were replicate, [CaI], tCa, tDNA, and the double and triple interactions among the last three variables; when appropriate, means were compared by orthogonal contrasts. There was [CaI] � tCa � tDNA interaction for blastocyst rate (P < 0.02). Treatments with 250 nM ([CaI]), 5 min (tCaI), and 1 h (tDNA) or 500 nM ([CaI]), 1 min (tCaI), and 1 h (tDNA) resulted in 36.1% and 37.4% blastocyst rates, respectively, similar to the control group (30.5%; P > 0.4). These results demonstrated that it is possible to capacitate spermatozoa with CaI to produce transgenic embryos, without alteration of blastocyst rate. This work was supported by FAPESP 03/08542-5 and 03/07456-8.

327 CHARACTERIZATION OF FETAL AND ADULT FIBROBLASTS FROM NELORE BOVINE FOR NUCLEAR TRANSFER

Cloning by nuclear transfer is a technology that has provided major advances in reproductive sciences. It is an efficient method: (1) to produce transgenic embryos, fetuses, and animals; (2) to multiply genetically superior adult animals; and (3) to generate proteins, tissues, and organs for xenotransplants of human interest. Basic studies on nuclear transfer have contributed to understanding how genomic activation and cell cycle synchrony affect nuclear reprogramming and cloning efficiencies. The aim of this study was to establish a stable lineage of Nelore adult and fetal fibroblasts for embryo reconstruction. Cultures were characterized by morphological aspects, and by immunocytochemical and ultrastructural analysis. Cultures of fetal and adult fibroblasts at passage 2 stained positively for cytokeratin, a typical protein from the intermediate filament of epithelial cells, in some cells but staining was not found in subsequent passages. A dense and organized network occurred in adult and fetal fibroblast cultures presenting positive immunostainig for vimentin in pass 5, 10, and 15 subcultures, but did not stain for cytokeratin (negative control). The results demonstrated that fibroblasts continued expressing vimentin and maintained their morphological aspects in culture. The ultrastructural analysis showed the presence of organelles involved in protein synthesis including dilated rough endoplasmatic reticulum, Golgi cisternae, and polyribosomes. Elongate mitochondria were distributed around the Golgi complex, suggesting high metabolic activity. These results demonstrated that adult and fetal fibroblasts continued to develop biological activities and maintained specific characteristics under these culture conditions. In conclusion, adults and fetal fibroblasts can be successfully used as donor cells for nuclear transfer. This work was supported by FAPESP 01/11931-8 and 01/13944-0.