Mechanisms of Sodium Transport at the Blood-Brain Barrier Studied with In Situ Perfusion of Rat Brain

The mechanism of unidirectional transport of sodium from blood to brain in pentobarbital-anesthetized rats was examined using in situ perfusion. Sodium transport followed Michaelis-Menten saturation kinetics with a V max of 50.1 nmol/g/min and a K m of 17.7 m M in the left frontal cortex. The kinetic analysis indicated that, at a physiologic sodium concentration, ∼26% of sodium transport at the blood-brain barrier (BBB) was carrier mediated. Dimethylamiloride (25 µ M ), an inhibitor of Na + /H + exchange, reduced sodium transport by 28%, whereas phenamil (25 µ M ), a sodium channel inhibitor, reduced the transfer constant for sodium by 22%. Bumetanide (250 µ M ) and hydrochlorothiazide (1.5 m M ), inhibitors of Na + -K + -2Cl − /NaCl symport, were ineffective in reducing blood to brain sodium transport. Acetazolamide (0.25 m M ), an inhibitor of carbonic anhydrase, did not change sodium transport at the BBB. Finally, a perfusate pH of 7.0 or 7.8 or a perfusate Pco 2 of 86 mm Hg failed to change sodium transport. These results indicate that 50% of transcellular transport of sodium from blood to brain occurs through Na + /H + exchange and a sodium channel in the luminal membrane of the BBB. We propose that the sodium transport systems at the luminal membrane of the BBB, in conjunction with Cl − /HCO 3 − exchange, lead to net NaCl secretion and obligate water transport into the brain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65689/1/j.1471-4159.1996.66020756.x.pd

Anthocyanin attenuates oxygen-glucose deprivation/reperfusion-induced apoptosis of PC12 cells via inactivation of ASK1/JNK/p38 signaling pathway

Purpose: To investigate whether the cytoprotective effect of anthocyanin (Anc) on oxygen-glucose deprivation/reperfusion (OGD/R)-induced cell injury is related to apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK)/p38 signaling pathway. Methods: PC12 cells were pre-treated with various concentrations of Anc (10, 50, and 100 μg/mL) in OGD/R-induced cell injury model. The 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay was used to assess cell viability. Cell apoptosis was measured by lactic acid dehydrogenase (LDH) release assay and flow cytometry. Western blot was employed to determine the protein expressions of BCL-2, BAX, caspase-3, p-ASK1 (Thr845), p-JNK, and p-p38. Results: The results indicate that Anc increased the viability of PC12 cells after OGD/R exposure (p < 0.05), and also efficiently rescued OGD/R-induced apoptosis (p < 0.05). Mechanistic studies showed that these protective roles of Anc are related to the inhibition of ASK1/JNK/p38 signaling pathway. Conclusion: The results indicate Anc protects against OGD/R-induced cell injury by enhancing cell viability and inhibiting cell apoptosis. The underlying mechanism of action is partly via inactivation of ASK1/JNK/p38 signaling pathway. Thus, Anc has promise as a potential natural agent to prevent and treat cerebral ischemia-reperfusion injury

Glutamine Uptake at the Blood-Brain Barrier Is Mediated by N-System Transport

The mechanism of unidirectional transport of glutamine from blood to brain in pentobarbital-anesthetized rats was examined using in situ perfusion. Amino acid uptake into brain across the blood-brain barrier (BBB) is classically thought to be via the Na-independent large neutral (L-system), acidic and basic amino acid transporters. In the presence of physiological concentrations of amino acids in the perfusate, which should saturate the known amino acid transporters at the BBB, the cortical transfer constant ( K i ) for l-[ 14 C]glutamine was 11.6 ± 1.1 µl/g/min. The addition of either 10 m M 2-amino-2-norbornanecarboxylic acid or 10 m M 2-amino-2-norbornanecarboxylic acid and 5 m M cysteine had no effect on the cortical K i for l-[ 14 C]glutamine, indicating that glutamine transport under these conditions does not occur by the L-, A-, or ASC-systems. Decreasing perfusate Na from 140 to 2.4 m M by Tris substitution reduced the cortical K i for l-[ 14 C]glutamine by 62% ( p ≤ 0.001). The Na-dependent uptake has the characteristics of N-system transport. It was inhibited by l-histidine and l-glutamine, both N-system substrates, and it was pH sensitive and moderately tolerant of Li substitution for Na. This putative N-system transporter at the luminal membrane of the BBB plays an important role in mediating brain glutamine uptake.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65581/1/j.1471-4159.1998.71062565.x.pd

Anti-depressant effect of Paeonia lactiflora Pall extract in rats

Purpose: To explore the effect of Paeonia lactiflora Pall. extract on depression in rats.Methods: Various doses (150, 300 and 600 mg/kg) of Paeonia lactiflora Pall. extract (PLPE) were orally administered to three groups of rats of 10 each, respectively, suffering from depression for 14 days. Fluoxetine was used as positive control. Tail suspension, forced swimming and monoamine oxidase (MAO) tests were carried out on the rats.Results: A dose-dependent reduction in rat immobility was observed. The effect of PLPE at the highest dose (600 mg/kg) was more potent than that of the reference antidepressant, fluoxetine. PLPE, at a dose ≥ 150 mg/kg significantly inhibited MAO A activity in rat whole brain in a dose-dependent manner (p < 0.01); however, only oral administration of PLPE at a dose of 600 mg/kg produced observable MAO B inhibitory activity in rat brain (p < 0.01). Only fluoxetine showed a tendency to inhibit both MAO A and B activities in animal brain. Neither PLPE nor fluoxetine, at the doses tested, produced significant effects on locomotor activity.Conclusion: The results suggest that Paeonia lactiflora Pall is a potential agent for the treatment of depression in humans.Keywords: Paeonia lactiflora, Depression, Tail suspension test, Forced swimming tes

The Effect of Acupuncture to SP6 on Skin Temperature Changes of SP6 and SP10: An Observation of “Deqi”

Background. Deqi sensation is a complex but an important component for acupuncture effect. In this study, we tried to observe the relationship between Deqi and skin temperature changes and whether there was some relativity between Deqi and needle stimulations on cold congealing and dysmenorrhea rat model. Thirty-two female Sprague Dawley (SD) rats were randomly divided into four groups (Saline Control Group, Model Group, Group A with strong stimulation, and Group B with small stimulation). Group A and Group B were performed with different stimulations. We found that, compared with saline control group, model group, and Group B, Group A showed that the skin temperature changes on right acupoint SP6 and SP10 increased significantly at 5 min–10 min interval. The skin temperature changes on left SP6 decreased at instant–5 min interval. The skin temperature changes on right SP10 decreased significantly at instant–5 min interval and 10 min–20 min interval. Thermogenic action along Spleen Meridian of Foot Greater Yin was manifested as simultaneous skin temperature increase on right SP6 and SP10 at 5 min–10 min interval after needling SP6, which was helpful to illustrate the relationship between the characteristic of Deqi and needle stimulations

Transcription phase, protein characteristics of DEV UL45 and prokaryotic expression, antibody preparation of the UL45 des-transmembrane domain

<p>Abstract</p> <p>Background</p> <p>Some UL45 gene function of Herpesvirus was reported. While there was no any report of the duck enteritis virus (DEV) UL45 protein as yet.</p> <p>Results</p> <p>The UL45 gene and des-transmembrane domain of UL45 (named UL45Δ gene, 295-675bp of UL45) of DEV were amplified by PCR and subcloned into the prokaryotic expression vector pET-32a(+). The constructed recombinant plasmids were transformed into the host strain BL21(DE3) PLysS and induced by IPTG. SDS-PAGE analysis showed the UL45 gene couldn't express while UL45Δ gene was highly expressed. His Purify Kit or salting-out could purify the protein effectively. Using the purified protein to immunize New-Zealand rabbits and produce polyclonal antibody. The agar diffusion reaction showed the titer of antibody was 1:32. Western blot analysis indicated the purified rabbit anti-UL45Δ IgG had a high level of specificity and the UL45 gene was a part of DEV genome. The transcription phase study of UL45 gene showed that expression of UL45 mRNA was at a low level from 0 to 18 h post-infection (pi), then accumulated quickly at 24 h pi and peaked at 42 h pi. It can be detected till 72 h pi. Besides, western blot analysis of purified virion and different viral ingredients showed that the UL45 protein resided in the purified virion and the viral envelope.</p> <p>Conclusions</p> <p>The rabbit anti-UL45Δ IgG was produced successfully and it can serve as a good tool for penetrating studies of the function of DEV UL45 protein. The transcription phase and protein characteristics analysis indicated that DEV UL45 gene was a late gene and UL45 protein may be a viral envelope protein.</p

PROKINETIC AND LAXATIVE EFFECTS OF XIAO'ER QIXINGCHA, A HOUSEHOLD PEDIATRIC HERBAL FORMULA

Background: Xiao'er Qixingcha, a household Chinese Medicinal formula, has been extensively applied in pediatric clinic for dyspepsia and constipation for hundreds of years. The present study firstly inspected whether the extract of Xiao'er Qixingcha (EXQ) has in vivo and in vitro prokinetic and laxative effects, and evaluated its acute toxicity. Materials and methods: In the in vivo study, small intestinal transit rates and fecal output characters (number and fecal weight) were measured on normal and two models of constipated mice (induced by diphenoxylate and by water-fasting respectively). In the in vivo study, the contraction rates of ileum smooth muscle were examined with EXQ treatment. Moreover, in acute toxicity study, EXQ was administered orally for 14 days to juvenile SD rats, and clinical signs, viscera lesion and body weight were monitored daily. Results: EXQ at all doses significantly increased the small intestinal transit rates, and ameliorated the fecal output characters of normal mice. In diphenoxylate-induced constipated mice, EXQ dose-dependently improved the small intestinal transit rates and fecal output. In water-fasting-induced constipated mice, EXQ dose-dependently improved the small intestinal transit rates, and significantly ameliorated the fecal output characters at 2.92 and 6.75 g/kg. Furthermore, in the in vitro study, EXQ dose-dependently raised the contraction rates of the isolated rabbit ileum smooth muscle. Finally, the acute toxicity study indicated that no toxicological effect was observed in terms of clinical signs, viscera lesion or change of body weight. Conclusions: Taken together, EXQ exhibited prominent prokinetic and laxative activities, promising it as a safe and effective alternative pharmaceutical therapy for constipation

Essential oil from Chenopodium ambrosioides L. induces mitochondrial-mediated pathway and endoplasmic reticulum stress-related apoptosis in human liver cancer SMMC-7721 cells

Purpose: To evaluate the cytotoxic effect of essential oil derived from Chenopodium ambrosioides L. in Sichuan Province on human liver cancer SMMC-7721 cells, as well as its possible molecular mechanisms.Methods: Cytotoxicity was characterized by MTT assay and transmission electron microscopy (TEM) of SMMC-7721 cells ultrastructure. The apoptotic effect of the essential oil was evaluated by changes in mitochondrial membrane potential and Western blot assay.Results: MTT assay data indicate that the essential oil was cytotoxic to SMMC-7721 cells, while TEN revealed that there were vacuoles and nucleus fragmentation in the SMMC-7721 cell cytosol, cell swelling, and a large amount of leakage. Mitochondrial membrane potential assay and Western Blot data indicate that the essential oil induced cell apoptosis.Conclusion: The essential oil of Chenopodium ambrosioides L. in Sichuan Province seems to induce apoptosis of human liver cancer SMMC-7721 cells via the mitochondrial-mediated pathway and endoplasmic reticulum stress. Thus, this plant requires further investigation as a potential source of ananti-liver cancer drug. Keywords: Chenopodium ambrosioides Essential oil; Anti-tumor activity, Liver cancer Apoptosis, SMMC-7721 cell

Curcumin’s Metabolites, Tetrahydrocurcumin and Octahydrocurcumin, Possess Superior Anti-inflammatory Effects in vivo Through Suppression of TAK1-NF-κB Pathway

Curcumin (CUR), a promising naturally occurring dietary compound, is commonly recognized as the potential anti-inflammatory agent. While the application of CUR was hampered by its low stability and poor systemic bioavailability, it has been suggested that the biological activities of CUR are intimately related to its metabolites. In the current investigation, we aimed to comparatively explore the anti-inflammatory effects of tetrahydrocurcumin (THC), octahydrocurcumin (OHC), and CUR, and to elucidate the underlying action mechanisms on experimental mice models of acute inflammation, i.e., xylene-induced ear edema, acetic acid-induced vascular permeability, and carrageenan-induced paw edema. The results showed that THC and OHC exerted significant and dose-dependent inhibitions on the formation of ear edema induced by xylene and paw edema provoked by carrageenan and inhibited the Evans blue dye leakage in peritoneal cavity elicited by acetic acid. Moreover, THC and OHC treatments were more effective than CUR in selectively inhibiting the expression of cyclooxygenase 2 (COX-2) and suppressing nuclear factor-κB (NF-κB) pathways via transforming growth factor β activated kinase-1 (TAK1) inactivation in the carrageenan-induced mouse paw edema model