Nicotine Suppression of Gustatory Responses of Neurons in the Nucleus of the Solitary Tract

2006 ◽  
Vol 96 (4) ◽  
pp. 1877-1886 ◽  
Author(s):  
Christopher T. Simons ◽  
Yves Boucher ◽  
Mirela Iodi Carstens ◽  
E. Carstens
Keyword(s):  
Monosodium Glutamate ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Evoked Responses ◽  
Solitary Tract ◽  
Depressant Effect ◽  
Tongue Surface ◽  
Single Unit Recordings ◽  
Gustatory Neurons ◽  
Dose Dependent

This study investigated effects of nicotine applied to the tongue surface on responses of gustatory neurons in the nucleus of the solitary tract (NTS) in rats. In pentobarbital-anesthetized rats, single-unit recordings were made from NTS units responsive to one or more tastants (sucrose, NaCl, citric acid, monosodium glutamate, quinine). Application of nicotine (0.87, 8.7, or 600 mM) excited gustatory NTS units and significantly attenuated NTS unit responses to their preferred tastant in a dose-dependent manner. The depressant effect of nicotine was equivalent regardless of which tastant best excited the NTS unit. Nicotinic excitation of NTS units and depression of their tastant-evoked responses were both significantly attenuated by the nicotinic antagonist mecamylamine, which itself did not excite NTS units. In rats with bilateral trigeminal ganglionectomy, nicotine still excited nearly all NTS units but no longer depressed tastant-evoked responses. Nicotine did not elicit plasma extravasation when applied to the tongue. The results indicate that nicotine directly excites NTS units by gustatory nerves and inhibits their tastant-evoked responses by a nicotinic acetylcholine receptor-mediated excitation of trigeminal afferents that inhibit NTS units centrally.

scholarly journals Antioxidant and haematological potentials of fruit wastes from Terminalia catappa and observable trophic effect on weight of wistar rats after exposure to monosodium glutamate

2020 ◽  
Vol 9 (6) ◽  
pp. 392-398
Author(s):  
Philemon C Anuforo ◽  
◽  
Anthony Cemaluk C Egbuonu ◽  
Elizabeth U Egu ◽  
Ejike Chukwunyere ◽  
...  
Keyword(s):  
Normal Control ◽  
Wistar Rats ◽  
Monosodium Glutamate ◽  
Economic Benefits ◽  
Dependent Manner ◽  
Sod Activity ◽  
Trophic Effect ◽  
Terminalia Catappa ◽  
Fruit Wastes ◽  
Dose Dependent

This study investigated the antioxidant and haematological potentials of a fruit wastes from Terminalia catappa and observable trophic effect on weight of Wistar rats after acute exposure to monosodium glutamate. Twenty-four male albino Wistar rats with mean weight of 120.61±15.15 g were divided into six groups (n=4). Group 1, the normal control (received distilled water), group II, the negative control (received 8mg MSG/g b.wt), group III, the extract control (received 300 mg extract/kg b.wt), group IV (received 8 mg MSG/g b.wt. + 100 mg extract/kg b.wt.), group V (received 8 mg MSG/g b.wt. + 300 mg kg-1 b.wt. extract) and group VI (received 8 mg MSG/g b.wt. + 500 mg extract/kg b.wt). Treatment was administered daily by oral gavage for 14 days. Data were subjected to one-way ANOVA followed by Duncan post-hoc test at p<0.05 and means were estimated and significant differences noted. DPPH antioxidant assay for the fruit wastes ethanol extract of Terminalia catappa endocarp revealed the extract produced 92.8% inhibition which is comparable to 96.07% inhibition produced by ascorbic acid at the same concentration, as well as, possessed FRAP activity in a concentration dependent manner. In vivo antioxidant assays carried out revealed that the superoxide dismutase (SOD) activity was significantly (p<0.05) lowered in the MSG-treated group but the catalase (CAT) activity showed a non-significant decrease as compared to the normal control, confirming there was oxidative stress. However, treatment with the extract increased the activities of SOD and CAT perhaps due to the presence of phenolic and flavonoids components. There was a significant (p<0.05) increase in WBC and RBC and could be attributed to the potential of the extract to stimulate the immune system. Haemoglobin (Hb) and packed cell volume (PCV) in MSG-extract co-administered rats showed a positive ameliorative effect of the extract in a dose dependent manner when compared to MSG group. Weight gain following extract administration was not dose dependent. The results showed that the fruit wastes had antioxidant potency and haematological potential. This bio-approach is promising as it solves the problem of environmental burden, as well as, serves economic benefits and hence, may become increasingly attractive.

scholarly journals Remifentanil reduces auditory and somatosensory evoked responses during isoflurane anaesthesia in a dose-dependent manner

1996 ◽  
Vol 76 (6) ◽  
pp. 795-801 ◽  
Author(s):  
I Crabb ◽  
C Thornton ◽  
K M Konieczko ◽  
A Chan ◽  
R Aquilina ◽  
...  
Keyword(s):  
Dependent Manner ◽  
Evoked Responses ◽  
Isoflurane Anaesthesia ◽  
Dose Dependent

Evaluation of Dose and Route Effects of Platelet Activating Factor-Induced Extravasation in the Guinea Pig

1984 ◽  
Vol 52 (01) ◽  
pp. 034-036 ◽  
Author(s):  
Dean A Handley ◽  
Ronald G Van Valen ◽  
Mary Kay Melden ◽  
Robert N Saunders
Keyword(s):  
Guinea Pig ◽  
Platelet Activating Factor ◽  
The Other ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Naturally Occurring ◽  
Protein Rich ◽  
Dose Dependent

SummaryPlatelet-activating factor (PAF) is a naturally occurring lipid that is reported to induce vessel hyperpermeability leading to loss of protein-rich plasma (extravasation). We have quantitated the systemic extravasation effects of synthetic PAF in the guinea pig by monitoring increases in hematocrit. When given intravenously (10-170 ng/kg), PAF produced dose-dependent increases in hematocrit, with maximal hemoconcentration developing in 5-7 min. In leukopenic animals the expected hematocrit increase was reduced by 57%. PAF given intra-arterially produced the dose-dependent changes in hematocrit similar to the intravenous effects of PAF. However, PAF given intraperitoneally (10-2500 μg/kg) was 800-1100-fold less effective than the other routes and hemoconcentration continued for 30-45 min until a maximal hematocrit was observed. These results show that PAF may markedly influence extravasation of plasma in a dose and route-dependent manner.

scholarly journals Effect of monosodium glutamate on apoptosis and Bcl-2/Bax protein level in rat thymocyte culture

2007 ◽  
pp. 619-626
Author(s):  
V Pavlović ◽  
S Cekić ◽  
G Kocić ◽  
D Sokolović ◽  
V Živković
Keyword(s):  
Apoptotic Cell ◽  
Monosodium Glutamate ◽  
Annexin V ◽  
Dependent Manner ◽  
Trypan Blue Exclusion ◽  
Trypan Blue Exclusion Method ◽  
Bax Protein ◽  
Thymocyte Apoptosis ◽  
Vitro Effect ◽  
Dose Dependent

Monosodium glutamate (MSG), the sodium salt of glutamate, is commonly used as a flavor enhancer in modern nutrition. Recent studies have shown the existence of glutamate receptors on lymphocytes, thymocytes and thymic stromal cells. In this study, we evaluated the in vitro effect of different MSG concentrations on rat thymocyte apoptosis and expression of two apoptosis-related proteins, Bcl-2 and Bax. Rat thymocytes, obtained from male Wistar rats, were exposed to increasing concentrations of MSG (ranging from 1 mM to 100 mM) for 24 h. Apoptosis was detected using the Annexin V-FITC/PI apoptosis detection kit and cells were analyzed using a flow cytometer. Expression of Bcl-2 and Bax proteins were determined with flow cytometry using respective monoclonal antibodies. Exposure to MSG resulted in a dose-dependent decrease in cell survival (as determined by trypan blue exclusion method). Annexin V-FITC/PI also confirmed that MSG increased, in a dose-dependent manner, apoptotic cell death in rat thymocyte cultures. MSG treatment induced downregulation of Bcl-2 protein, while Bax protein levels were not significantly changed. Our data showed that MSG significantly modulates thymocyte apoptosis rate in cultures. The temporal profile of Bcl-2 and Bax expression after MSG treatment suggests that downregulation of Bcl-2 protein and the resulting change of Bcl-2/Bax protein ratio may be an important event in thymocyte apoptosis triggered by MSG.

Effect of platelet-activating factor on airway vascular permeability: possible mechanisms

1987 ◽  
Vol 63 (2) ◽  
pp. 479-484 ◽  
Author(s):  
T. W. Evans ◽  
K. F. Chung ◽  
D. F. Rogers ◽  
P. J. Barnes
Keyword(s):  
Vascular Permeability ◽  
Evans Blue ◽  
Platelet Activating Factor ◽  
Blue Dye ◽  
Base Line ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Lipoxygenase Inhibitor ◽  
Dose Dependent ◽  
Evans Blue Extravasation

We studied the effects of the potent inflammatory mediator, platelet-activating factor (PAF), on vascular permeability in airways (and other tissues) of guinea pigs by measuring extravasation of circulating Evans blue dye. PAF caused a dose-dependent increase in vascular permeability. At 1 ng/kg iv, PAF caused an increase in Evans blue extravasation of 220% (P less than 0.05) in the trachea, with the greatest effect at a dose of 100 ng/kg (858%; P less than 0.01). Histamine (150 micrograms/kg iv) caused a 320% increase over base line in the trachea and 200% in main bronchi; this effect was equivalent to that induced by 10 ng/kg PAF in the trachea and 1 ng/kg in main bronchi. The duration of effect of PAF was greatest in main bronchi (less than 10 min). Platelet depletion with a cytotoxic antibody, or the cyclooxygenase inhibitor, indomethacin, or the cyclooxygenase-lipoxygenase inhibitor, BW 7556, did not affect the vascular permeability response to PAF. The PAF-receptor antagonist, BN 52063, inhibited Evans blue extravasation in the airways in a dose-dependent manner, with complete inhibition at 5 mg/kg. Thus PAF-induced airway vascular leakage is mediated by specific receptors but not by products of arachidonic acid metabolism or by platelets. Increased airway microvascular leakage induced by PAF may lead to plasma extravasation and airway edema, factors that may contribute to the airway narrowing and hyperresponsiveness induced by PAF.

scholarly journals Effects and Mechanisms of Tastants on the Gustatory-Salivary Reflex in Human Minor Salivary Glands

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Shizuko Satoh-Kuriwada ◽  
Noriaki Shoji ◽  
Hiroyuki Miyake ◽  
Chiyo Watanabe ◽  
Takashi Sasano
Keyword(s):  
Significant Positive Correlation ◽  
Monosodium Glutamate ◽  
Minor Salivary Gland ◽  
The Other ◽  
Dependent Manner ◽  
Mixed Solution ◽  
Minor Salivary Glands ◽  
Healthy Individuals ◽  
Parasympathetic Regulation ◽  
Dose Dependent

The effects and mechanisms of tastes on labial minor salivary gland (LMSG) secretion were investigated in 59 healthy individuals. Stimulation with each of the five basic tastes (i.e., sweet, salty, sour, bitter, and umami) onto the tongue induced LMSG secretion in a dose-dependent manner. Umami and sour tastes evoked greater secretion than did the other tastes. A synergistic effect of umami on LMSG secretion was recognized: a much greater increase in secretion was observed by a mixed solution of monosodium glutamate and inosine 5′-monophosphate than by each separate stimulation. Blood flow (BF) in the nearby labial mucosa also increased following stimulation by each taste except bitter. The BF change and LMSG secretion in each participant showed a significant positive correlation with all tastes, including bitter. Administration of cevimeline hydrochloride hydrate to the labial mucosa evoked a significant increase in both LMSG secretion and BF, while adrenaline, atropine, and pirenzepine decreased LMSG secretion and BF. The change in LMSG secretion and BF induced by each autonomic agent was significantly correlated in each participant. These results indicate that basic tastes can induce the gustatory-salivary reflex in human LMSGs and that parasympathetic regulation is involved in this mechanism.

Effects of Low Molecular Weight Heparin and Unfragmented Heparin on Induction of Osteoporosis in Rats

1990 ◽  
Vol 63 (03) ◽  
pp. 505-509 ◽  
Author(s):  
Thomas Mätzsch ◽  
David Bergqvist ◽  
Ulla Hedner ◽  
Bo Nilsson ◽  
Per Østergaar
Keyword(s):  
Molecular Weight ◽  
Bone Mineral ◽  
Low Molecular Weight Heparin ◽  
Zinc Content ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Bone Mineral Mass ◽  
Bone Ash ◽  
Dose Dependent ◽  
Mineral Mass

SummaryA comparison between the effect of low molecular weight heparin (LMWH) and unfragmented heparin (UH) on induction of osteoporosis was made in 60 rats treated with either UH (2 IU/ g b w), LMWH in 2 doses (2 Xal U/g or 0.4 Xal U/g) or placebo (saline) for 34 days. Studied variables were: bone mineral mass in femora; fragility of humera; zinc and calcium levels in serum and bone ash and albumin in plasma. A significant reduction in bone mineral mass was found in all heparin-treated rats. There was no difference between UH and LMWH in this respect. The effect was dose-dependent in LMWH-treated animals. The zinc contents in bone ash were decreased in all heparin-treated rats as compared with controls. No recognizable pattern was seen in alterations of zinc or calcium in serum. The fragility of the humera, tested as breaking strength did not differ between treatment groups and controls. In conclusion, if dosed according to similar factor Xa inhibitory activities, LMWH induces osteoporosis to the same extent as UH and in a dose-dependent manner. The zinc content in bone ash was decreased after heparin treatment, irrespective of type of heparin given.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

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