Dynamics of Salivary Gland AQP5 under Normal and Pathologic Conditions.

AQP5 plays an important role in the salivary gland function. The mRNA and protein for aquaporin 5 (AQP5) are expressed in the acini from embryonic days E13-16 and E17-18, respectively and for entire postnatal days. Ligation-reopening of main excretory duct induces changes in the AQP5 level which would give an insight for mechanism of regeneration/self-duplication of acinar cells. The AQP5 level in the submandibular gland (SMG) decreases by chorda tympani denervation (CTD) via activation autophagosome, suggesting that its level in the SMG under normal condition is maintained by parasympathetic nerve. Isoproterenol (IPR), a ß-adrenergic agonist, raised the levels of membrane AQP5 protein and its mRNA in the parotid gland (PG), suggesting coupling of the AQP5 dynamic and amylase secretion-restoration cycle. In the PG, lipopolysaccharide (LPS) is shown to activate mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signalings and potentially downregulate AQP5 expression via cross coupling of activator protein-1 (AP-1) and NF-κB. In most species, Ser-156 and Thr-259 of AQP5 are experimentally phosphorylated, which is enhanced by cAMP analogues and forskolin. cAMP-dependent phosphorylation of AQP5 does not seem to be markedly involved in regulation of its intracellular trafficking but seems to play a role in its constitutive expression and lateral diffusion in the cell membrane. Additionally, Ser-156 phosphorylation may be important for cancer development.

Effects of isoproterenol on aquaporin 5 levels in the parotid gland of mice in vivo.

In the membrane fraction of mouse parotid gland (PG), the protein level of aquaporin 5 (AQP5), a member of the water channel family, was increased by injection (ip) of isoproterenol (IPR), a ß-adrenergic agonist, at 1 h, and stayed at high levels until 6 h; this change occurred simultaneously as amylase secretion. The AQP5 level then decreased and returned toward the original level at 12-48 h. After IPR injection, the AQP5 mRNA gradually increased and reached a maximum at 24 h. The facts suggest a rapid appearance of AQP5 at plasma membrane by IPR and subsequent degradation/metabolism by activation of proteolytic systems. Pretreatment of animals with two calpain inhibitors, N-Ac-Leu-Leu-methininal (ALLM) and calpeptin, as well as a protein synthesis inhibitor, cycloheximide (CHX), significantly suppressed the IPR-induced AQP5 degradation in the PG membrane fraction; such suppression was not observed by two proteasome inhibitors, MG132 and lactacystin, or the lysosome denaturant chloroquine, although most of these inhibitors increased AQP5 protein levels in unstimulated mice. The AQP5 protein was also degraded by µ-calpain in vitro. Furthermore, we demonstrated that µ-calpain was colocalized with AQP5 in the acinar cells by immunohistochemistry, and its activity in the PG was increased at 6 h after IPR injection. These results suggest that the calpain system was responsible for IPR-induced AQP5 degradation in the parotid gland and that such a system was coupled to the secretory-restoration cycle of amylase in the PG.

Role of aquaporin 5 and glandular blood flow in the acetylcholine-induced secretion of saliva in rats.

To clarify the role of the aquaporin 5 (AQP5) in salivary secretion, we evaluated acetylcholine (ACh)-induced secretion in Sprague-Dawley (SD) rats, rats expressing a low level of AQP5 protein (AQP5/low SD) which developed from SD rats, and Wistar/ST rats. The salivary secretion in AQP5/low SD rats in response to infusions of low-dose ACh (60-120 nmol/min) was 27-42% of that in SD rats. By contrast, Wistar/ST rats exhibited comparable secretion to that of SD rats in response to low-doses ACh, despite their low-level expression of AQP5. Experiments using spectrofluorometry and RT-PCR demonstrated no differences in the ACh-induced Ca2+ responses or the mRNA expression of muscarinic receptor, Cl- channel, or cotransporter between these strains. These findings imply that factors other than the function of salivary acinar cells regulates the secretion in response to weak stimuli. Monitoring of the hemodynamics in the submandibular gland revealed that low-doses ACh induced different patterns of the fluctuations in the blood flow in these strains. The blood flow decreased below the resting level in AQP5/low SD rats, but remained mostly above the resting level in Wistar/ST rats. The present study reveals that the contribution of AQP5-dependent transport of water is altered by stimulus intensity and blood flow.

Relationships between feeding behaviors and emotions: an electroencephalogram (EEG) frequency analysis study.

Feeding behaviors may be easily affected by emotions, both being based on brain activity; however, the relationships between them have not been explicitly defined. In this study, we investigated how emotional environments modulate subjective feelings, brain activity, and feeding behaviors. Electroencephalogram (EEG) recordings were obtained from healthy participants in conditions of virtual comfortable space (CS) and uncomfortable space (UCS) while eating chocolate, and the times required for eating it were measured. We found that the more participants tended to feel comfortable under the CS, the more it took time to eat in the UCS. However, the EEG emergence patterns in the two virtual spaces varied across the individuals. Upon focusing on the theta and low-beta bands, the strength of the mental condition and eating times were found to be guided by these frequency bands. The results determined that the theta and low-beta bands are likely important and relevant waves for feeding behaviors under emotional circumstances, following alterations in mental conditions.

Effects of naturally occurring G103D point mutation of AQP5 on its water permeability, trafficking and cellular localization in the submandibular gland of rats.

BACKGROUND INFORMATION: AQPs (aquaporins) are water channel proteins that are expressed in almost all living things. In mammalians, 13 members of AQPs (AQP0-12) have been identified so far. AQP5 is known to be expressed mostly in the exocrine cells, including the salivary gland acinar cells. A naturally occurring point mutation (G308A, Gly103 > Asp103) was earlier found in the rat AQP5 gene [Murdiastuti, Purwanti, Karabasil, Li, Yao, Akamatsu, Kanamori and Hosoi (2006) Am. J. Physiol. 291, G1081-G1088]; in this mutant, the rate of initial saliva secretion under stimulated and unstimulated conditions is less than that for the wt (wild-type) animals. RESULTS: Here the mutant molecule was characterized in detail. Using the Xenopus oocyte system, we demonstrated the mutant AQP5 to have water permeability almost the same as that of the wt molecule. Mutant and wt AQP5s, tagged with GFP (green fluorescent protein; GFP-AQP5s) and expressed in polarized MDCK-II (Madin-Darby canine kidney II) cells, first appeared in the vesicular structure(s) in the cytoplasm, and were translocated to the upper plasma membrane or apical membrane during cultivation, with the mutant GFP-AQP5 being translocated less efficiently. Thapsigargin and H-89 both induced translocation in vitro of either molecule, whereas colchicine inhibited this activity; the fraction of cells showing apical localization of mutant GFP-AQP5 was less than that showing that of the wt molecule under any of the experimental conditions used. In the mutant SMG (submandibular gland) tissue, localization of AQP5 in the apical membrane of acinar cells was extremely reduced. Vesicular structures positive for AQP5 and present in the cytoplasm of the acinar cells were co-localized with LAMP2 (lysosome-associated membrane protein 2) or cathepsin D in the mutant gland, whereas such co-localizations were very rare in the wt gland, suggesting that the mutant molecules largely entered lysosomes for degradation. CONCLUSION: Replacement of highly conserved hydrophobic Gly103 with strongly hydrophilic Asp103 in rat AQP5, though it did not affect water permeability, may possibly have resulted in less efficient membrane trafficking and increased lysosomal degradation, leading to its lower expression in the apical membrane of the acinar cells in the SMG.

Novel phosphorylation of aquaporin-5 at its threonine 259 through cAMP signaling in salivary gland cells.

Aquaporin-5 (AQP5), a water channel, plays key roles in salivary secretion. The novel phosphorylation of AQP5 was investigated by using human salivary gland (HSG) cells and mouse salivary glands. In the HSG cells stably transfected with a wild-type mouse AQP5 construct, a protein band immunoreactive with antibody against phosphorylated PKA substrate was detected in the AQP5 immunoprecipitated sample, and its intensity was enhanced by short-term treatment of the cells with 8-bromo-cAMP, forskolin, or phorbol 12-myristate 13-acetate, but not by that with A23187 calcium ionophore. Such enhancement was inhibited in the presence of H-89, a PKA inhibitor. An AQP5 mutant (AQP5-T259A) expressed by transfection of HSG cells was not recognized by anti-phosphorylated PKA substrate antibody, even when the cells were stimulated with the protein kinase activators. Immunoblotting and immunofluorescence studies using a specific antibody detecting AQP5 phosphorylated at its Thr259 demonstrated that AQP5 was rapidly and transiently phosphorylated at the apical membrane of acinar cells in the submandibular and parotid glands after administration of isoproterenol, but not pilocarpine. Furthermore, both AQP5 and AQP5-T259A were constitutively localized at the plasma membrane in HSG cells under the resting and forskolin-stimulated conditions. These results suggest that AQP5 is phosphorylated at its Thr259 by PKA through cAMP, but not Ca(2+), signaling pathways, and that this phosphorylation does not contribute to AQP5 trafficking in the salivary gland cells.

Induction of Sca-1 via activation of STAT3 system in the duct cells of the mouse submandibular gland by ligation of the main excretory duct.

To examine the very initial step that takes place immediately after tissue injury and is linked to tissue regeneration, we employed the submandibular gland (SMG), which was injured by ligation of its main excretory duct (MED). Ligation of the MED of the SMG in mice induced the expression of Sca-1, a protein marker of hematopoietic stem cells. In the normal gland, a low level of Sca-1 was expressed, which was localized predominantly in the excretory duct cells. At 1 day after ligation, Sca-1 expression increased prominently in almost all of cells in the duct system, but not in the acinar cells. The level of Sca-1 mRNA had begun to increase at 6 h after ligation and continuously rose thereafter until it reached a plateau, which occurred ∼12 h after ligation. STAT3 phosphorylated at its tyrosine-705 (p-STAT3) in the ligated gland increased immediately after ligation, and it was localized in the nuclei of all duct cells. The results of an EMSA revealed the specific binding of a nuclear extract to the sequence of the γ-interferon activation site (GAS) present in the Sca-1 promoter and confirmed that such binding increased after ligation. Thus the present study suggests that STAT3, having been phosphorylated following MED ligation, was transferred to the nucleus, where it bound to the GAS element in the promoter of Sca-1 gene, resulting in promotion of Sca-1 gene expression. Actual prevention of STAT3 phosphorylation reduced the ligation-induced Sca-1 elevation.

Potential down-regulation of salivary gland AQP5 by LPS via cross-coupling of NF-kappaB and p-c-Jun/c-Fos.

The mRNA and protein levels of aquaporin (AQP)5 in the parotid gland were found to be potentially decreased by lipopolysaccharide (LPS) in vivo in C3H/HeN mice, but only weakly in C3H/HeJ, a TLR4 mutant mouse strain. In the LPS-injected mice, pilocarpine-stimulated saliva production was reduced by more than 50%. In a tissue culture system, the LPS-induced decrease in the AQP5 mRNA level was blocked completely by pyrrolidine dithiocarbamate, MG132, tyrphostin AG126, SP600125, and partially by SB203580, which are inhibitors for IkappaB kinase, 26S proteasome, ERK1/2, JNK, and p38 MAPK, respectively. In contrast, the expression of AQP1 mRNA was down-regulated by LPS and such down-regulation was blocked only by SP600125. The transcription factors NF-kappaB (p65 subunit), p-c-Jun, and c-Fos were increased by LPS given in vivo, whereas the protein-binding activities of the parotid gland extract toward the sequences for NF-kappaB but not AP-1-responsive elements present at the promoter region of the AQP5 gene were increased by LPS injection. Co-immunoprecipitation by using antibody columns suggested the physical association of the three transcription factors. These results suggest that LPS-induced potential down-regulation of expression of AQP5 mRNA in the parotid gland is mediated via a complex(es) of these two classes of transcription factors, NF-kappaB and p-c-Jun/c-Fos.

Induction of Sca-1 in the duct cells of the mouse submandibular gland by obstruction of the main excretory duct.

The effect of ligation of the main excretory duct (MED) of the mouse submandibular gland (SMG) on the expression of Sca-1, a stem cell antigen, was examined by Western blotting and immunohistochemistry. By Western blotting, the expression of Sca-1 with a molecular weight of 18 kDa was identified in the normal gland. At 1 day post-ligation, the expression level of Sca-1 was strongly increased in the experimental gland and weakly in the contralateral gland, and such expression in both glands decreased at 6 days. By immunohistochemistry, Sca-1 was detected weakly in the apical membrane of excretory duct (ED) cells of the SMG under the normal condition. By duct ligation, Sca-1 became expressed strongly in most cells of the two major duct systems, i.e., the striated duct (SD) and granular convoluted tubules (GCT), but was not detected in the acinar (Ac) cells. By fluorescence-activated cell sorter (FACS) analysis, the number of side population (SP) cells in this gland was found to be increased by ligation. These results imply that Sca-1-positive cells may have a role in the duct cell proliferation in the regeneration step elicited by MED ligation-induced injury.

[Perioperative management for a case of carotid artery stenting].

A 70-year-old male patient with severe cardiac dysfunction underwent carotid artery stenting for severe left carotid artery stenosis under monitored anesthetic care. He was sedated with propofol and fentanyl, and was monitored with ECG, pulse-oximeter and direct blood pressure measurement. He breathed spontaneously without severe hypoxia during the procedure. Followed by insertion of transient ventricular pacing wire against expected severe bradycardia, a guidewire was introduced into left internal carotid artery lesion via the right femoral artery. Soon after dilating the stenotic portion with a ballon catheter, sudden hypotension and bradycardia were recognized, which were successfully managed with bolus injections of vasoconstrictors and atropine sulphate. Even after stenting, hypotension continued for two days in spite of continuous administration of dopamine. Postoperative examination showed that the blood flow of the left carotid artery was doubled. Two weeks after the operation, he was discharged uneventfully.

Amniotic membrane matrix effects on calcineurin-NFAT-related gene expressions of SHED treated with VEGF for endothelial differentiation.

The nuclear factor of activated T-cell (NFAT) signaling pathway is involved in angiogenesis following initiation by vascular endothelial growth factor (VEGF). A number of angiogenic genes have been associated with calcineurin in the NFAT pathway, forming a calcineurin-NFAT pathway. This study aims to investigate the involvement of four angiogenic genes within the calcineurin-NFAT pathway in the endothelial-like differentiation of stem cells from human exfoliated deciduous teeth (SHED) cultured on a human amniotic membrane (HAM) induced by VEGF. SHED were induced with VEGF for 24 h, then cultured on the stromal side of HAM. The cells were then further induced with VEGF until days 1 and 14. To understand the role of calcineurin, its potent inhibitor, cyclosporin A (CsA), was added into the culture. Results from SEM and H&E analyses showed SHED grew on HAM surface. Gene expression study of Cox-2 showed a drastically reduced expression with CsA treatment indicating Cox-2 involvement in the calcineurin-NFAT pathway. Meanwhile, IL-8 was probably controlled by another pathway as it showed no CsA inhibition. In contrast, high expression of ICAM-1 and RCAN1.4 by VEGF and CsA implied that these genes were not controlled by the calcineurin-NFAT-dependent pathway. In conclusion, the results of this study suggest the involvement of Cox-2 in the calcineurin-NFAT-dependent pathway while RCAN1.4 was controlled by NFAT molecule in endothelial-like differentiation of SHED cultured on HAM with VEGF induction.

Inhibition and transcriptional silencing of a subtilisin-like proprotein convertase, PACE4/SPC4, reduces the branching morphogenesis of and AQP5 expression in rat embryonic submandibular gland.

The submandibular gland (SMG) develops through the epithelial-mesenchymal interaction mediated by many growth/differentiation factors including activin and BMPs, which are synthesized as inactive precursors and activated by subtilisin-like proprotein convertases (SPC) following cleavage at their R-X-K/R-R site. Here, we found that Dec-RVKR-CMK, a potent inhibitor of SPC, inhibited the branching morphogenesis of the rat embryonic SMG, and caused low expression of a water channel AQP5, in an organ culture system. Dec-RVKR-CMK also decreased the expression of PACE4, a SPC member, but not furin, another SPC member, suggesting the involvement of PACE4 in the SMG development. Heparin, which is known to translocate PACE4 in the extracellular matrix into the medium, and an antibody specific for the catalytic domain of PACE4, both reduced the branching morphogenesis and AQP5 expression in the SMG. The inhibitory effects of Dec-RVKR-CMK were partially rescued by the addition of recombinant BMP2, whose precursor is one of the candidate substrates for PACE4 in vivo. Further, the suppression of PACE4 expression by siRNAs resulted in decreased expression of AQP5 and inhibition of the branching morphogenesis in the present organ culture system. These observations suggest that PACE4 regulates the SMG development via the activation of some growth/differentiation factors.

Roles of lysosomal proteolytic systems in AQP5 degradation in the submandibular gland of rats following chorda tympani parasympathetic denervation.

Chorda tympani denervation (CTD) of rats was earlier shown to result in loss of submandibular gland (SMG) weight (at only 1 wk) and in continued reduction in aquaporin 5 (AQP5) protein expression (until 4 wk), without affecting its mRNA synthesis (Li X, Azlina A, Karabasil MR, Purwanti N, Hasegawa T, Yao C, Akamatsu T, Hosoi K. Am J Physiol Gastrointest Liver Physiol 295: G112-G123, 2008). The present study indicated that despite elevation of bax, a proapoptosis protein, by CTD, the operation also increased the level of bcl-2, an antiapoptosis protein, in the SMG. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay) showed no increase in the number of apoptotic cells in the SMG. CTD, however, induced strongly and transiently (at 1-3 days) the protein expression of LC3B-II, a marker protein of autophagosomes, suggesting that the reduction in the gland weight was due to onset of autophagy by CTD. Upon CTD, Lamp2, a lysosomal marker, gradually increased in amount, reaching a peak at the 14th day. Immunohistochemical analysis revealed an increase in the number of lysosome-like structures positive for both AQP5 and Lamp2 in the acinar cells of the SMG after CTD; similar changes were observed also for AQP5 and LC3Bs. These data suggest that AQP5 in the SMG entered autophagosomes and/or lysosomes for degradation upon CTD. In vitro AQP5-degrading activity was found in the SMG extracts, and such activity was shown to be increased by CTD. Inhibitor experiments implied cathepsins B and L to be candidate enzymes for this degradation under normal and CTD conditions, respectively.

[A case of the complications following glycerin enema which suggested malignant hyperthermia].

We experienced a case of the complications following glycerin enema which suggested malignant hyperthermia. A 73-year-old man with knee osteoarthritis was scheduled for total knee arthroplasty under general and epidural anesthesia. The patient received glycerin enema before surgery. After epidural catheterization, anesthesia was induced with thiopental, fentanyl, vecuronium and sevoflurane. The trachea was intubated and the patient was ventilated with sevoflurane-air-oxygen. Then, cola-like urine was drained and he became febrile up to 37.9 degrees C. Although there were no other symptoms suggesting malignant hyperthermia, the surgery was cancelled. We suspected not only hemolysis by the color of the serum and the blood chemistry, but also rhabdomyolysis by increased levels of serum creatine phosphokinase and myoglobin as well as urine myoglobin. He recovered uneventfully. On the third day, perirectal abscess and anal fissure were diagnosed, which were considered to be the cause of the fever. It is well-known that glycerin enema could cause hemolysis, but rabdomyolysis as a complication of glycerin enema has rarely been reported. We speculate that injection of hypertonic glycerin into the perirectal tissue could have caused rhabdomyolysis as well as hemolysis, which led to cola-like urine. The complications following glycerin enema can be incorporated to a differential diagnosis of malignant hyperthermia.

Bioactivity of alginetin, a caramelization product of pectin: Cytometric analysis of rat thymic lymphocytes using fluorescent probes.

Alginetin is the major product formed from pentoses and hexurionic acids. Alginetin is producted by cooking process of food including pection, a naturally-occurring polysacharride found in many plants. However, the biological interaction and toxicity of alginetin are not known at all. The aim of the present study was to investigate the cellular actions of alginetin on rat thymic lymphocytes. The effects of alginetin on the cell were examined using flow cytometry with fluorescent probes. Alginetin increased cellular content of non-protein thiols ([NPT]i) and elevated intracellular Zn2+ levels ([Zn2+]i). Chelation of intracellular Zn2+ reduced the effect of alginetin on [NPT]i, and chelation of external Zn2+ almost completely diminished alginetin-induced elevation of [Zn2+]i, indicating that alginetin treatment increased Zn2+ influx. Increased [NPT]i and [Zn2+]i levels in response to alginetin were positively correlated. Alginetin protected cells against oxidative stress induced by hydrogen peroxide and Ca2+ overload by calcium ionophore. It is considered that the increases in [NPT]i and [Zn2+]i are responsible for the cytoprotective activity of alginetin because NPT attenuates oxidative stress and Zn2+ competes with Ca2+. Alginetin may be produced during manufacturing of jam, which may provide additional health benefits of jam.

Citrus sudachi Peel Extract Suppresses Cell Proliferation and Promotes the Differentiation of Keratinocytes through Inhibition of the EGFR-ERK Signaling Pathway.

Citrus sudachi is a well-known fruit in Tokushima Prefecture, Japan, and its peels are rich in phytochemicals, including phenolic compounds. Although it is expected that the extract of the C. sudachi peel elicits various beneficial physiological activities, the effect on the skin has not been investigated. In this study, we report that the aqueous extract from the peel of C. sudachi suppresses cell proliferation of the immortalized human keratinocyte cell line, HaCaT, and primary normal human epidermal keratinocytes. The extract of C. sudachi peel suppressed epidermal growth factor (EGF)-induced EGF receptor activation and tumor necrosis factor (TNF)-α-induced extracellular regulated kinase (ERK) 1/2 activation, which suggests that the extract exerts its inhibitory effect through inhibition of both the EGF receptor (EGFR) and its downstream molecules. Additionally, the extract of C. sudachi peel potentiated calcium-induced keratinocyte differentiation. These results suggest that the extract of C. sudachi peel may have beneficial effects against skin diseases that are characterized by hyperproliferation of epidermal keratinocytes, such as those seen in psoriasis and in cutaneous squamous cell carcinoma.

Protein kinase A-regulated membrane trafficking of a green fluorescent protein-aquaporin 5 chimera in MDCK cells.

The green fluorescent protein (GFP) of the jellyfish, Aeqorea victoria, was used as an autofluorescent tag to track the trafficking of aquaporin 5 (AQP5), an exocrine gland-type water channel. Two groups of chimeric proteins were constructed; one in which GFP was fused to the amino-terminus of AQP5 (GFP-AQP5) and the other, in which it was fused to the carboxyl terminus of it (AQP5-GFP). In each group, 2 chimeras were produced, a wild-type AQP5 with its normal sequence and a mutant AQP5 having a mutated amino acid at 259, i.e., GFP-AQP5-T259A and AQP5-GFP-T259A. They were used to transfect Madin-Darby canine kidney (MDCK) cells. The GFP-AQP5 chimera was localized in the intracellular vesicles, which trafficked to the plasma membrane in response to N(6), 2'-O-dibutyryladenosine 3', 5'-cyclic monophosphate (dbcAMP). Membrane trafficking was inhibited by N-[2-(p-bromocinnamylamino)ethyl]-5-isoquimolinesulfonamide (H-89) but not by palmitoyl-dl-carnitine chloride (PCC). In contrast, the AQP5-GFP chimera expressed in MDCK cells was localized constitutively on the plasma membrane. The cellular localization of the latter chimera was not affected by stimulation with dbcAMP in the presence or absence of H-89 or PCC. Replacement of Thr-259 with Ala-259 did not affect the dbcAMP-induced translocation of the chimeric protein, suggesting that phosphorylation of Thr-259 was not necessary for AQP5 trafficking under the present experimental conditions. Thus, the GFP-AQP5 chimera will be a useful tool to study AQP5 trafficking in vitro, whereas the constitutive membrane localization of the AQP5-GFP chimera suggests the importance of the carboxyl terminus of the AQP5 protein for its sorting, whether it is translocated to intracellular vesicles or to the plasma membrane.

[Study of analgestic efficacy of ropivacaine-fentanyl patient-controlled epidural analgesia after upper abdominal gynecological surgery].

BACKGROUND: Most of the patients who undergo radical or subradical hysterectomy with paraaortic lymphadenectomy suffer from postoperative pain for upper abdominal incision. They also complain of postoperative nausea and vomiting (PONV) frequently, which are increased by opioids. METHODS: Reducing total fentanyl dose to 0.6 mg, frequency of moving pain complaints increased gradually. Therefore, we introduced patient-controlled epidural analgesia (PCEA) for suppressing pain on moving. We investigated analgestic efficacy of 0.2% ropivacaine-fentanyl PCEA in twelve patients undergoing upper abdominal gynecological surgery. Postoperative analgesic effects were evaluated by visual analogue scale (VAS) at rest and on moving, times of bolus infusion, side effects, and degrees of satisfication by patient's self-assessments. Continuous epidural infusion of 0.6 mg fentanyl in 288 ml 0.2% ropivacaine was started at a rate of 4 ml x hr(-1) with a bolus dose of 2 ml. RESULTS: VAS was maintained below 20 mm at rest but was elevated to the maximum of 45 mm on moving with few bolus requests. Ninty-two percents of the patients answered satisfied but fifty percents of them had PONV. CONCLUSIONS: We conclude that ropivacaine-fentanyl PCEA is effective after upper abdominal gynecological surgery, and we can decrease the dose of fentanyl by explaining PCEA system more effectively to the patients for suppressing the pain on moving and PONV.

Interplay between non-NMDA and NMDA receptor activation during oscillatory wave propagation: Analyses of caffeine-induced oscillations in the visual cortex of rats.

Generation and propagation of oscillatory activities in cortical networks are important features of the brain. However, many issues related to oscillatory phenomena are unclear. We previously reported neocortical oscillation following caffeine treatment of rat brain slices. Input to the primary visual cortex (Oc1) generates N-methyl-d-aspartate (NMDA) receptor-dependent oscillations, and we proposed that the oscillatory signals originate in the secondary visual cortex (Oc2). Because non-NMDA and NMDA receptors cooperate in synaptic transmission, non-NMDA receptors may also play an important role in oscillatory activities. Here we investigated how non-NMDA receptor activities contribute to NMDA receptor-dependent oscillations by using optical recording methods. After induction of stable oscillations with caffeine application, blockade of NMDA receptors abolished the late stable oscillatory phase, but elicited 'hidden' non-NMDA receptor-dependent oscillation during the early depolarizing phase. An interesting finding is that the origin of the non-NMDA receptor-dependent oscillation moved from the Oc1, during the early phase, toward the origin of the NMDA receptor-dependent oscillation that is fixed in the Oc2. In addition, the frequency of the non-NMDA receptor-dependent oscillation was higher than that of the NMDA receptor-dependent oscillation. Thus, in one course of spatiotemporal oscillatory activities, the relative balance in receptor activities between non-NMDA and NMDA receptors gradually changes, and this may be due to the different kinetics of the two receptor types. These results suggest that interplay between the two receptor types in the areas of Oc1 and Oc2 may play an important role in oscillatory signal communication.

Expression and localization of AQP5 in the stomach and duodenum of the rat.

The expression, localization, and regulation of aquaporin 5 (AQP5), a member of the water channel family of proteins, was investigated in tissues of the rat gastrointestinal tract. Reverse transcriptase--polymerase chain reaction (RT--PCR) detected AQP5 mRNA in the lower stomach and duodenum. DNA sequencing confirmed that the cDNA fragment amplified had the complete sequence of the AQP5 cDNA fragment. Western blot analysis indicated the expression of a 27 kDa molecular mass AQP5 protein in the lower stomach and duodenum, which size was the same as that found for the protein in the submandibular gland and lungs. By immunohistochemistry using the IgG affinity-purified AQP5 antibody, the pyloric gland and Brunner's gland were primarily stained in the lower stomach and duodenum, respectively; a strong staining appeared in the apical and lateral membranes in both glands. These results indicate that AQP5 is present in the rat lower stomach and duodenum where it may be involved in a water transport mechanism. These results also support the idea that AQP5, and probably other aquaporins, are involved in water secretion in the stomach and duodenum although the volume of water transported via AQPs is unclear.