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

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.

2006 ◽  
Vol 96 (4) ◽  
pp. 1877-1886 ◽  
Author(s):  
Christopher T. Simons ◽  
Yves Boucher ◽  
Mirela Iodi Carstens ◽  
E. Carstens

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.


2010 ◽  
Vol 25 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Vinicius von Diemen ◽  
Manoel Roberto Maciel Trindade

PURPOSE: Determine the effects of the MSG (monosodium glutamate) in the offspring of pregnant rats through the comparison of the weight, NAL (nasal-anal length) and IL (Index of Lee) at birth and with 21 days of life. METHODS: Pregnant Wistar rats and their offspring were divided into 3 groups: GC, G10 and G20. Each of the groups received 0%, 10% and 20% of MSG, respectively from coupling until the end of the weaning period. RESULTS: Neither weight nor NAL were different among the groups at birth. The group G20 at birth had an IL lower than the group GC (p<0,05) and with 21 days of life presented weight and NAL lower than the groups G10 and this lower than the GC (p<0,01). Otherwise the G20 at 21 days of life had the IL similar to the other two groups. The weight profit percentage from birth to the 21st day of life was lower in the G20 regarding the other two groups (p<0,01). The G20 had a NAL increase percentage from birth to the 21st day of life lower than the G10 and this lower than the GC (p<0,01). CONCLUSIONS: MSG presented a dose-dependent relation in the variables weight and NAL. It caused a decrease in the growth pattern as well as in the weight gain pattern until the 21st day of life. The IL of the group 20% had an increased in relation to the control group after 3 weeks of follow up.


2008 ◽  
Vol 56 (3) ◽  
pp. 581-586
Author(s):  
Jonathan Bank ◽  
Aharon Ben-David ◽  
Ram Doolman ◽  
Ben-Ami Sela ◽  
Ilan Bank

BackgroundThe α1β1 integrin is a cell surface membrane heterodimer composed of noncovalently linked α1 and β1 polypeptides that is up-regulated on activated and proliferating mesangial cells.MethodsA double-sandwich enzyme-linked immunosorbent assay that detects α1 integrin in a specific and dose-dependent manner at concentrations greater than 150 ng/mL was used to evaluate whether intact α1 polypeptides are secreted in the urine samples of 29 patients with various kidney diseases and in those of 5 healthy individuals.Resultsα1 Integrin was detected in 8 of the 29 patients including 3 of 3 patients with biopsy-proven immunoglobulin A nephropathy and 3 of 3 clinically suspected but non-biopsy-proven immunoglobulin A nephropathy with evidence of active nephritis. No α1 integrins were found in samples of 5 healthy controls.Conclusionsα1 Integrin polypeptides can be detected in human urine, particularly in immunoglobulin A nephropathy. Further extensive studies are required to clarify the significance of secretion of α1 integrins in urine of patients with kidney disease.


2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Jakub Chlebek ◽  
Kateřina Macáková ◽  
Lucie Cahlíková ◽  
Milan Kurfürst ◽  
Jiří Kuneš ◽  
...  

Tubers of Corydalis cava were extracted with ethanol and fractionated using n-hexane, chloroform and ethanol. Repeated column chromatography, preparative TLC and crystallization led to the isolation of fifteen isoquinoline alkaloids. The chemical structures of the isolated compounds were determined on the basis of spectroscopic techniques and by comparison with literature data. All isolated compounds were tested for human blood acetylcholinesterase (HuAChE) and human plasma butyrylcholinesterase (HuBuChE) inhibitory activity. (+)-Canadaline inhibited acetylcholinesterase as well as butyrylcholinesterase in a dose-dependent manner with IC50 values of 20.1 ± 1.1 μM and 85.2 ± 3.2 μM, respectively. (+)-Canadine, with an IC50 value of 12.4 ± 0.9 μM, was the most potent inhibitor of acetylcholinesterase, whilst (±)-corycavidine and (+)-bulbocapnine were effective inhibitors of butyrylcholinesterase with IC50 values of 46.2 ± 2.4 uM and 67.0 ± 2.1 μM, respectively. The other isolated alkaloids were considered inactive (IC50 > 100 μM).


2020 ◽  
Vol 9 (6) ◽  
pp. 392-398
Author(s):  
Philemon C Anuforo ◽  
◽  
Anthony Cemaluk C Egbuonu ◽  
Elizabeth U Egu ◽  
Ejike Chukwunyere ◽  
...  

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.


Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 265 ◽  
Author(s):  
Jeong Ah Lee ◽  
Seok Joon Hwang ◽  
Sung Chan Hong ◽  
Cheol Hwan Myung ◽  
Ji Eun Lee ◽  
...  

Melanosomes undergo a complex maturation process and migrate into keratinocytes. Melanophilin (Mlph), a protein complex involving myosin Va (MyoVa) and Rab27a, enables the movement of melanosomes in melanocytes. In this study, we found six miRNAs targeting Mlph in mouse using two programs (http://targetscan.org and DianaTools). When melan-a melanocytes were treated with six synthesized microRNAs, miR-342-5p, miR-1839-5p, and miR-3082-5p inhibited melanosome transport and induced melanosome aggregation around the nucleus. The other microRNAs, miR-5110, miR-3090-3p, and miR-186-5p, did not inhibit melanosome transport. Further, miR-342-5p, miR-1839-5p, and miR-3082-5p decreased Mlph expression. The effect of miR-342-5p was the strongest among the six synthesized miRNAs. It inhibited melanosome transport in melan-a melanocytes and reduced Mlph expression in mRNA and protein levels in a dose-dependent manner; however, it did not affect Rab27a and MyoVa expressions, which are associated with melanosome transport. To examine miR-342-5p specificity, we performed luciferase assays in a mouse melanocyte-transfected reporter vector including Mlph at the 3′-UTR (untranslated region). When treated with miR-342-5p, luciferase activity that had been reduced by approximately 50% was restored after inhibitor treatment. Therefore, we identified a novel miRNA affecting Mlph and melanosome transport, and these results can be used for understanding Mlph expression and skin pigmentation regulation.


2001 ◽  
Vol 29 (01) ◽  
pp. 161-172 ◽  
Author(s):  
Lii-Tzu Wu ◽  
Jing-Gung Chung ◽  
Jung-Chou Chen ◽  
Wei Tsauer

The inhibition of arylamine N-acetyltransferase (NAT) activity by norcantharidin (NCTD), the demethylated form of cantharidin, in human hepatocellular carcinoma HepG2 cells was investigated. By using high performance liquid chromatography, NAT activity on acetylation of 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) were examined. Two assay system were performed, one with cellular cytosols, the other with intact HepG2 cell suspensions. The NAT activity in HepG2 cell line was inhibited by norcantharidin in a dose-dependent manner in both types of examined systems: i.e. the greater the concentration of norcantharidin in the reaction, the greater the inhibition of NAT activities. This report is the first to show that norcantharidin has an inhibitory effect on NAT activity in HepG2 cell.


2019 ◽  
Vol 47 (2) ◽  
pp. 253-262
Author(s):  
Umme Habiba ◽  
W Islam ◽  
Selina Parween

The present study was planned to evaluate the effect of spinosad on the survivability and development of Sitophilus oryzae on four wheat varieties viz., BARI-26, BARI-28, Shatabdi-21 and Prodip-24. Three doses in three replications for spinosad were applied to four wheat varieties. Spinosad concentrations significantly increased the total developmental period compared to the control in a dose-dependent manner on four wheat varieties. The highest developmental period took 41.67 ± 0.33 days to become adult was recorded in S-21 at 0.0003 μl/g of spinosad in F1. All adults of F1 did not reach in F2 because surprisingly all adults died after emergence. So, no developmental period was found in S-21 (0.00±0.00) and B-28 (0.00 ± 0.00) days at 0.0003 μl/g spinosad in F2. On the other hand, five mated females were released on the treated wheat with different concentrations of spinosad for 10 - 15 days; then they were removed. Treated wheat was checked for up to 30 to 60 days and observed the progeny for two successive generations (1st and 2nd). Each combination of insect species, insecticide rate, and exposure duration were replicated three times. Among four wheat varieties, the lowest adult emergence was recorded as 08.00 ± 0.58 in F1 and totally controlled in F2 generation in S-21 variety at 0.0003 μl/g. Spinosad concentrations significantly increased the total developmental period compared to the control in a dosedependent manner on four wheat varieties. Bangladesh J. Zool. 47(2): 253-262, 2019


1999 ◽  
Vol 54 (3-4) ◽  
pp. 186-190 ◽  
Author(s):  
Dahabada Helena José Lopes ◽  
José Roberto Meyer-Fernandes ◽  
Mauro Sola-Penna

Trehalose has been described to protect several enzymes against destabilizing conditions. This sugar is naturally accumulated by yeast as a stress protectant. A common stress condition that yeast is normally submitted is the presence of ethanol, the by-product of fermentation process of several yeast. In this paper we show the effects of trehalose and ethanol, alone or together, on yeast pyrophosphatase, and the effects of these compounds on inhibition and unfolding of pyrophosphatase promoted by urea. We show that both trehalose and ethanol inhibit pyrophosphatase in a dose-dependent manner, and that the presence of ethanol does not modify the inhibition promoted by trehalose as well as the presence of trehalose does not modify the inhibition promoted by ethanol. The effects of trehalose on pyrophosphatase are completely reversible, but the inhibition caused by ethanol was only partially reversible. Incubation of pyrophosphatase with 10% (v/v) ethanol promoted an inhibition of 15%, and the control activity was completely recovered after removal of ethanol. On the other hand, when pyrophosphatase was incubated with 20% (v/v) ethanol an inhibition of 40% of the control activity was observed which persisted after removal of ethanol. Ethanol also potentiates the inhibition of pyrophosphatase promoted by urea, and contributes for an irreversible inactivation and unfolding of pyrophosphatase in the presence of urea. Trehalose, that protects this enzyme against the inhibition and unfolding promoted by the chaotropic compound urea, was inefficient to protect against the effects of ethanol. Trehalose was also efficient to prevent an irreversible inactivation induced by urea.


1988 ◽  
Vol 118 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Grietje Dijkstra ◽  
J. Martje Fentener van Vlissingen ◽  
C. J. G. Wensing ◽  
P. M. M. van Dorst-Bruijns ◽  
H.J. Degenhart ◽  
...  

Abstract. The effect of chronic pulsatile low-dose GnRH treatment on the juvenile testis and associated structures was evaluated in relation to hormonal parameters in the peripheral blood in the pig. Starting at 8 weeks of age, male pigs (crossbreds of Dutch Landrace and Yorkshire breeds) were injected 6 times daily im with 0, 75 or 250 ng GnRH/kg body weight during 4 weeks. Immediately after the treatment period, a GnRH stimulation test with 750 ng GnRH/kg iv was carried out. Samples for plasma LH, FSH, testosterone and 5αDHT measurement were obtained weekly (basal level) and after GnRH stimulation. The pigs were castrated at 12 weeks of age and the weights and lengths of the testis, epididymis and cremaster muscle were recorded. Intratesticular testosterone and 5αDHT concentrations were determined, and the testis and epididymis were evaluated for histological changes. Basal plasma hormone concentrations, intratesticular androgen concentrations and the response of the pituitary gland to stimulation had not been affected by GnRH treatment. Pigs receiving the higher treatment dose of GnRH showed less increase in testosterone levels in response to the stimulation dose at 12 weeks of age than the other pigs. Morphologically, no changes were observed in the epididymis and cremaster muscle after GnRH treatment and no signs of reactivation of structures that can provoke testicular descent could be seen. The development of the seminiferous epithelium was more advanced in the GnRH-treated groups, apparently in a dose-dependent manner.


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