scholarly journals Role of Low-Substituted Hydroxypropylcellulose in Dissolution and Bioavailability of Novel Fine Granule System for Masking Bitter Taste.

1994 ◽  
Vol 17 (3) ◽  
pp. 427-431 ◽  
Author(s):  
Yoshimi SHIRAI ◽  
Kiyomi SOGO ◽  
Hiroshi FUJIOKA ◽  
Yasuhiko NAKAMURA
Keyword(s):  
Bitter Taste ◽  
Fine Granule

scholarly journals Influence of Heat Treatment on Dissolution and Masking Degree of Bitter Taste for a Novel Fine Granule System.

1996 ◽  
Vol 44 (2) ◽  
pp. 399-402 ◽  
Author(s):  
yoshimi SHIRAI ◽  
Kiyomi SOGO ◽  
Hiroshi FUJIOKA ◽  
Yasuhiko NAKAMURA
Keyword(s):  
Heat Treatment ◽  
Bitter Taste ◽  
Fine Granule

Rapid kinetics of second messenger production in bitter taste

1996 ◽  
Vol 270 (3) ◽  
pp. C926-C931 ◽  
Author(s):  
A. I. Spielman ◽  
H. Nagai ◽  
G. Sunavala ◽  
M. Dasso ◽  
H. Breer ◽  
...  
Keyword(s):  
Bitter Taste ◽  
Second Messengers ◽  
Second Messenger ◽  
Mouse Strains ◽  
Protective Mechanism ◽  
Transient Nature ◽  
Sucrose Octaacetate ◽  
Rapid Kinetics ◽  
First Time

The tasting of bitter compounds may have evolved as a protective mechanism against ingestion of potentially harmful substances. We have identified second messengers involved in bitter taste and show here for the first time that they are rapid and transient. Using a quench-flow system, we have studied bitter taste signal transduction in a pair of mouse strains that differ in their ability to taste the bitter stimulus sucrose octaacetate (SOA); however, both strains taste the bitter agent denatonium. In both strains of mice, denatonium (10 mM) induced a transient and rapid increase in levels of the second messenger inositol 1,4,5-trisphosphate (IP3) with a maximal production near 75-100 ms after stimulation. In contrast, SOA (100 microM) brought about a similar increase in IP3 only in SOA-taster mice. The response to SOA was potentiated in the presence of GTP (1 microM). The GTP-enhanced SOA-response supports a G protein-mediated response for this bitter compound. The rapid kinetics, transient nature, and specificity of the bitter taste stimulus-induced IP3 formation are consistent with the role of IP3 as a second messenger in the chemoelectrical transduction of bitter taste.

Bitter stimuli induce Ca2+ signaling and CCK release in enteroendocrine STC-1 cells: role of L-type voltage-sensitive Ca2+ channels

2006 ◽  
Vol 291 (4) ◽  
pp. C726-C739 ◽  
Author(s):  
Monica C. Chen ◽  
S. Vincent Wu ◽  
Joseph R. Reeve ◽  
Enrique Rozengurt
Keyword(s):  
Endocrine Cells ◽  
Bitter Taste ◽  
Dependent Manner ◽  
Gi Tract ◽  
Intracellular Ca ◽  
Α Subunits ◽  
Ca2 Channels ◽  
Cck Release

We previously demonstrated the expression of bitter taste receptors of the type 2 family (T2R) and the α-subunits of the G protein gustducin (Gαgust) in the rodent gastrointestinal (GI) tract and in GI endocrine cells. In this study, we characterized mechanisms of Ca2+ fluxes induced by two distinct T2R ligands: denatonium benzoate (DB) and phenylthiocarbamide (PTC), in mouse enteroendocrine cell line STC-1. Both DB and PTC induced a marked increase in intracellular [Ca2+] ([Ca2+]i) in a dose- and time-dependent manner. Chelating extracellular Ca2+ with EGTA blocked the increase in [Ca2+]i induced by either DB or PTC but, in contrast, did not prevent the effect induced by bombesin. Thapsigargin blocked the transient increase in [Ca2+]i induced by bombesin, but did not attenuate the [Ca2+]i increase elicited by DB or PTC. These results indicate that Ca2+ influx mediates the increase in [Ca2+]i induced by DB and PTC in STC-1 cells. Preincubation with the L-type voltage-sensitive Ca2+ channel (L-type VSCC) blockers nitrendipine or diltiazem for 30 min inhibited the increase in [Ca2+]i elicited by DB or PTC. Furthermore, exposure to the L-type VSCCs opener BAY K 8644 potentiated the increase in [Ca2+]i induced by DB and PTC. Stimulation with DB also induced a marked increase in the release of cholecystokinin from STC-1 cells, an effect also abrogated by prior exposure to EGTA or L-type VSCC blockers. Collectively, our results demonstrate that bitter tastants increase [Ca2+]i and cholecystokinin release through Ca2+ influx mediated by the opening of L-type VSCCs in enteroendocrine STC-1 cells.

scholarly journals Bitter Taste Receptors Expression in Human Granulosa and Cumulus Cells: New Perspectives in Female Fertility

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3127
Author(s):  
Bianca Semplici ◽  
Francesca Paola Luongo ◽  
Sofia Passaponti ◽  
Claudia Landi ◽  
Laura Governini ◽  
...  
Keyword(s):  
Reproductive System ◽  
Bitter Taste ◽  
Receptor Activation ◽  
Female Fertility ◽  
Human Reproduction ◽  
Receptor Subtype ◽  
Taste Receptors ◽  
Female Reproductive System ◽  
Bitter Taste Receptors

Bitter taste receptors (TAS2RS) expression is not restricted to the oral cavity and the presence of these receptors in the male reproductive system and sperm provides insights into their possible role in human reproduction. To elucidate the potential role of TAS2Rs in the female reproductive system, we investigated the expression and localization of bitter taste receptors and the components of signal transduction cascade involved in the pathway of taste receptors in somatic follicular cells obtained from women undergoing assisted reproductive techniques. We found that TAS2R genes are expressed in both cumulus (CCs) and granulosa (GCs) cells, with TAS2R14 being the most highly expressed bitter receptor subtype. Interestingly, a slight increase in the expression of TAS2R14 and TAS2R43 was shown in both GCs and CCs in young women (p < 0.05), while a negative correlation may be established between the number of oocytes collected at the pickup and the expression of TAS2R43. Regarding α-gustducin and α-transducin, two Gα subunits expressed in the taste buds on the tongue, we provide evidence for their expression in CCs and GCs, with α-gustducin showing two additional isoforms in GCs. Finally, we shed light on the possible downstream transduction pathway initiated by taste receptor activation in the female reproductive system. Our study, showing for the first time the expression of taste receptors in the somatic ovarian follicle cells, significantly extends the current knowledge of the biological role of TAS2Rs for human female fertility.

scholarly journals Bitter Taste Receptor T2R14 Modulates Gram-Positive Bacterial Internalization and Survival in Gingival Epithelial Cells

2021 ◽  
Vol 22 (18) ◽  
pp. 9920
Author(s):  
Manoj Reddy Medapati ◽  
Anjali Yadav Bhagirath ◽  
Nisha Singh ◽  
Robert J. Schroth ◽  
Rajinder P. Bhullar ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Gram Positive ◽  
Direct Role ◽  
Gram Positive Bacteria ◽  
Inhibition Of Growth ◽  
Gingival Epithelial Cells ◽  
Underlying Mechanisms

Bitter-taste receptors (T2Rs) have emerged as key players in host–pathogen interactions and important modulators of oral innate immunity. Previously, we reported that T2R14 is expressed in gingival epithelial cells (GECs) and interacts with competence stimulating peptides (CSPs) secreted by the cariogenic Streptococcus mutans. The underlying mechanisms of the innate immune responses and physiological effects of T2R14 on Gram-positive bacteria are not well characterized. In this study, we examined the role of T2R14 in internalization and growth inhibitory effects on Gram-positive bacteria, namely Staphylococcus aureus and S. mutans. We utilized CRISPR-Cas9 T2R14 knockdown (KD) GECs as the study model to address these key physiological mechanisms. Our data reveal that the internalization of S. aureus is significantly decreased, while the internalization of S. mutans remains unaffected upon knockdown of T2R14 in GECs. Surprisingly, GECs primed with S. mutans CSP-1 resulted in an inhibition of growth for S. aureus, but not for S. mutans. The GECs infected with S. aureus induced T2R14-dependent human β-defensin-2 (hBD-2) secretion; however, S. mutans–infected GECs did not induce hBD-2 secretion, but induced T2R14 dependent IL-8 secretion. Interestingly, our results show that T2R14 KD affects the cytoskeletal reorganization in GECs, thereby inhibiting S. aureus internalization. Our study highlights the distinct mechanisms and a direct role of T2R14 in influencing physiological responses to Gram-positive bacteria in the oral cavity.

scholarly journals Role of Bitter Taste Receptor TAS2R38 In Colorectal Cancer

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Sonali Choudhury ◽  
Afreen Asif Ali Sayed ◽  
David Standing ◽  
Scott Weir ◽  
Roy Jensen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Bitter Taste Receptor

Impact of pharmaceutical dosage form on stability and dissolution of roxithromycin

Open Medicine ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Michał Ostrowski ◽  
Ewa Wilkowska ◽  
Tomasz Bączek
Keyword(s):  
High Performance ◽  
Bitter Taste ◽  
Immediate Release ◽  
Oral Suspension ◽  
Pharmaceutical Dosage Form ◽  
Dissolution Tests ◽  
Ph Conditions ◽  
Dispersible Tablets ◽  
Enteric Coated

AbstractThe behavior of dispersible tablets containing enteric-coated pellets and oral suspension, both containing roxithromycin, was investigated using dissolution tests in different media. The dissolution test was performed under different pH conditions. For both dosage forms investigated, the test was conducted at pH 1.2, 4.5, and 6.8. Additionally, for dispersible tablets, the test involving increasing pH was performed at pH 1.2 (acid stage) and afterwards at pH 6.8 (buffer stage). The extent of dissolution was measured using high-performance liquid chromatography (HPLC). In all cases tested, roxithromycin underwent rapid degradation at pH 1.2. Dispersible tablets displayed the features of modified release preparations with a non-complete dissolution during the test times in all media. Conversely, the oral suspension behaved as an immediate release preparation, with degradation at pH 1.2. However, the dissolution of the oral suspension at pH 4.5 and 6.8 was rapid and complete. The role of enteric-coated pellets is to mask the bitter taste of the active substance upon administration. However, the coating showed lack of resistance to media at pH 1.2. Therefore, dispersible tablets containing enteric-coated pellets are not pharmaceutically equivalent to the immediate-release oral suspension.

scholarly journals Expanding the role of bitter taste receptor in extra oral tissues: TAS2R38 is expressed in human adipocytes

Adipocyte ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Raffaella Cancello ◽  
Giancarlo Micheletto ◽  
Dorela Meta ◽  
Rosalia Lavagno ◽  
Emanuele Bevilacqua ◽  
...  
Keyword(s):  
Bitter Taste ◽  
Taste Receptor ◽  
Human Adipocytes ◽  
Bitter Taste Receptor

scholarly journals Evaluation of Mucociliary Clearance by Three Dimension Micro-CT-SPECT in Guinea Pig: Role of Bitter Taste Agonists

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0164399 ◽  
Author(s):  
Jose Luis Ortiz ◽  
Amparo Ortiz ◽  
Javier Milara ◽  
Miguel Armengot ◽  
Celia Sanz ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Mucociliary Clearance ◽  
Bitter Taste ◽  
Three Dimension ◽  
Micro Ct
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