Quinine Hydrochloride

1. Activities of 35 taste-responsive neurons in the cortical gustatory area were recorded with chronically implanted fine wires in freely ingesting Wistar rats. Quantitative analyses were performed on responses to distilled water, food solution, and four taste stimuli: sucrose, NaCl, HCl, and quinine hydrochloride. 2. Taste-responsive neurons were classified into type-1 and type-2 groups according to the response patterns to licking of the six taste stimuli. Type-1 neurons (n = 29) responded in excitatory or inhibitory directions to one or more of the taste stimuli. Type-2 neurons (n = 6) showed responses in different directions depending upon palatability of the liquids to rats: neurons showing excitatory (or inhibitory) responses to palatable stimuli exhibited inhibitory (or excitatory) responses to unpalatable stimuli. 3. Correlation coefficients of responses to pairs of stimuli across neurons suggested that palatable stimuli (water, food solution, sucrose, and NaCl) and unpalatable stimuli (HCl and quinine) elicited reciprocal (excitatory vs. inhibitory) responses in type-2 neurons, whereas type-1 neurons showed positively correlated responses to specific combinations of stimuli such as food solution and NaCl, sucrose and HCl, NaCl and quinine, and HCl and quinine. 4. A tendency toward equalization of effectiveness in eliciting responses among the four basic taste stimuli was detected on the cortex. The ratios of mean evoked responses in 29 type-1 neurons in comparison with spontaneous rate (4.4 spikes/s) were 1.7, 1.9, 1.8, and 1.9 for sucrose, NaCl, HCl, and quinine, respectively. 5. The breadth of responsiveness to the four basic taste stimuli was quantified by means of the entropy measure introduced by Smith and Travers (33). The mean entropy value was 0.540 for 29 type-1 neurons, which was similar to 0.588 previously reported for rat chorda tympani fibers, suggesting that breadth of tuning is not more narrowly tuned in a higher level of the gustatory system in the rat. 6. Convergent inputs of other sensory modalities were detected exclusively in type-1 neurons. Thirteen (45%) of 29 type-1 neurons also responded to cold and/or warm water, but none of 6 type-2 neurons responded to thermal stimuli. Two (7%) of 29 type-1 neurons responded to almond and acetic acid odors, but the 6 type-2 neurons did not. Two (13%) of 16 type-1 neurons responded to interperitoneal injection of LiCl, which is known to induce gastrointestinal disorders, with a latency of approximately 5 min, but 4 type-2 neurons tested were not responsive to this stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

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Effects of melanin-concentrating hormone on licking microstructure and brief-access taste responses

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00143.2006 ◽

2006 ◽

Vol 291 (5) ◽

pp. R1265-R1274 ◽

Cited By ~ 15

Author(s):

John-Paul Baird ◽

Catalina Rios ◽

Nora Elizabeth Gray ◽

Caroline Elizabeth Walsh ◽

Shannon Glenora Fischer ◽

...

Keyword(s):

Third Ventricle ◽

Taste Stimulus ◽

Water Solutions ◽

The Third ◽

Sucrose Solutions ◽

Quinine Hydrochloride ◽

Inhibitory Feedback ◽

Melanin Concentrating Hormone ◽

Taste Evaluation ◽

The Mean

The effects of intracerebroventricular application of melanin-concentrating hormone (MCH) on licking for sucrose, quinine hydrochloride (QHCl), and water solutions were evaluated in two experiments. In experiment 1, rats received 90-min access to sucrose and water solutions after MCH or vehicle microinjection to the third ventricle (3V). MCH increased intake largely through increases in the rate of licking early in the meal and in the mean duration of lick bursts, suggesting an effect on gustatory evaluation. Therefore, in experiment 2, brief access tests were used with a series of sucrose and QHCl concentrations to behaviorally isolate the effects of intracerebroventricular MCH on gustatory evaluation. MCH uniformly increased licking for all sucrose solutions, water, and weak concentrations of QHCl; however, it had no effect on licking for the strongest concentrations of QHCl, which were generally avoided under control conditions. Thus MCH did not produce nonspecific increases in oromotor activity, nor did it change the perceived intensity of the tastants. We conclude that MCH enhanced the gain of responses to normally accepted stimuli at a phase of processing after initial gustatory detection and after the decision to accept or reject the taste stimulus. A comparison of 3V NPY and MCH effects on licking microstructure indicated that these two peptides increased intake via dichotomous behavioral processes; although NPY suppressed measures associated with inhibitory feedback from the gut, MCH appeared instead to enhance measures associated with hedonic taste evaluation.

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The endocrine effects of bitter tastant administration in the gastrointestinal system - Intragastric versus intraduodenal administration

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00636.2020 ◽

2021 ◽

Author(s):

Wout Verbeure ◽

Eveline Deloose ◽

Joran Tóth ◽

Jens F. Rehfeld ◽

Lukas Van Oudenhove ◽

...

Keyword(s):

Feeding Tube ◽

Gut Peptides ◽

Nasogastric Feeding ◽

Physiological Relevance ◽

Quinine Hydrochloride ◽

Healthy Female ◽

Glucagon Like Peptide ◽

Glucagon Like Peptide 1 ◽

Acyl Ghrelin ◽

Intraduodenal Administration

Bitter tastants are recently introduced as potential hunger-suppressive compounds, the so-called "Bitter pill". However, the literature about bitter administration lacks consistency in methods and findings. We want to test whether hunger ratings and hormone plasma levels are affected by: 1) the site of administration: intragastrically (IG) or intraduodenally (ID), 2) the bitter tastant itself, quinine hydrochloride (QHCl) or denatonium benzoate (DB), and 3) the timing of infusion. Therefore, 14 healthy, female volunteers participated in a randomized, placebo-controlled six-visit crossover study. After an overnight fast, DB (1µmol/kg), QHCl (10µmol/kg) or placebo were given IG or ID via a nasogastric feeding tube. Blood samples were taken 10 min prior to administration and every 10 min after administration for a period of 2 hours. Hunger was rated at the same timepoints on a visual analogue scale (VAS). ID bitter administration did not affect hunger sensations, motilin or acyl-ghrelin release compared with its PLC infusion. IG QHCl infusion tended to suppress hunger increase, especially between 50-70 minutes after infusion, simultaneously with reduced motilin values. Here, acyl-ghrelin was not affected. IG DB did not affect hunger or motilin, however acyl-ghrelin levels were reduced 50-70 minutes after infusion. Plasma values of glucagon-like peptide 1 and cholecystokinin were too low to be properly detected or to have any physiological relevance. In conclusion, bitter tastants should be infused into the stomach to reduce hunger sensations and orexigenic gut peptides. QHCl has the best potential to reduce hunger sensations, and it should be infused 60 minutes before food intake.

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101 Amyotrophic Lateral Sclerosis (ALS) - Not Just a Motor Disease? Isolated Bitter and Sweet Taste Loss in ALS

CNS Spectrums ◽

10.1017/s109285292000019x ◽

2020 ◽

Vol 25 (2) ◽

pp. 266-266

Author(s):

Ahmed A Ashary ◽

Dev N Patel ◽

Alan R Hirsch

Keyword(s):

Weight Loss ◽

Insular Cortex ◽

Sweet Taste ◽

Voluntary Contraction ◽

Upper Extremities ◽

Taste Perception ◽

Study Objective ◽

Quinine Hydrochloride ◽

Abductor Digiti Minimi ◽

The Right

Abstract:Study Objective:Specific taste quality deficits in ALS has not heretofore been described.METHOD:Case Study: A 71 year old right handed female presented with a two year course of progressive reduction in strength in her hands, arms and legs with difficulty tying shoe laces, opening jars, writing and walking. She described nocturnal muscle spasms involving all extremities. Gradually, over eight months prior to presentation, all food began to taste bad and horribly bitter. Associated with no appetite and a seven pounds weight loss.RESULTS:Abnormalities in Neurological examination: Cranial Nerve (CN) examination: CN IX and X: Gag absent bilaterally. Motor examination: Bulk: atrophy in thenar and hypothenar eminences and intrinsics in both upper extremities. Percussion induced fasciculation and myotonia in both shoulders and arms. Fasciculation of tongue with percussion myotonia of tongue. Strength: Intrinsic 4/5 in both upper extremities, 3/5 in abductor policis brevis bilaterally, 3/5 right gastrocnemius soleus, 4/5 bilateral anterior tibialis. Drift testing: left abductor digiti minimi sign. Gait: Heel and toe walking unstable with circumduction of left leg. Tandem gait unstable. Cerebellar: Holmes rebound phenomena positive in the left upper extremity. Deep tendon reflexes: 1+ left brachioradialis. 1+ left triceps. 3+ right ankle jerks. 0 left ankle jerk. Positive jaw jerk. Chemosensory Testing: Normosmia to: Alcohol Sniff Test (46), Pocket Smell Test (3/3) and Retronasal Smell Index (9). Taste Quadrant Testing: ageusia in the palate to sodium chloride and citric acid. Ageusia throughout the palate, tongue and whole mouth to sucrose and quinine hydrochloride. Fungiform papillae count: left 18, right 20 (normal). Lip biopsy (normal). MRI: T2 flair in bilateral corticospinal tracts, left greater than right in the spinal cord and the brain. EMG: fibrillation, positive waves with fasciculation in all four extremities. Voluntary contraction with polyphasic unstable motor unit action potentials.CONCLUSION:While Lang found no taste loss in ALS (Lang, 2011), Pelletier found reduction in intensity of taste to all modalities in different sectors of the tongue, but paradoxically demonstrated normogeusia in whole mouth taste perception (Pelletier, 2013). Pathological specimens of those with ALS revealed degeneration in the nucleus parabrachialis medialis and tractus trigeminothalamicus dorsalis (Oyanagi, 2015), suggesting that taste deficit may be due to central white matter abnormalities. Sweet taste is localized in the most posterior and rostral aspect of the right insular cortex, immediately adjacent to bitter (Prinster, 2017), suggesting a neighborhood effect phenomena. Weight loss in ALS may be due to sensory distortion and secondary impairment of appetite. It would be worthwhile to investigate those with ALS for evidence of otherwise overlooked gustatory deficits, correction of which may improve appetite and nutritional state.

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Pruning of rat cortical taste neurons by an artificial neural network model

Journal of Neurophysiology ◽

10.1152/jn.1995.74.3.1010 ◽

1995 ◽

Vol 74 (3) ◽

pp. 1010-1019 ◽

Cited By ~ 3

Author(s):

T. Nagai ◽

H. Katayama ◽

K. Aihara ◽

T. Yamamoto

Keyword(s):

Learning Algorithm ◽

Back Propagation ◽

Quantitative Measure ◽

Response Patterns ◽

Input Unit ◽

Basic Taste ◽

Relative Contribution ◽

Quinine Hydrochloride ◽

Taste Discrimination ◽

Hidden Layer

1. Taste qualities are believed to be coded in the activity of ensembles of taste neurons. However, it is not clear whether all neurons are equally responsible for coding. To clarify the point, the relative contribution of each taste neuron to coding needs to be assessed. 2. We constructed simple three-layer neural networks with input units representing cortical taste neurons of the rat. The networks were trained by the back-propagation learning algorithm to classify the neural response patterns to the basic taste stimuli (sucrose, HCl, quinine hydrochloride, and NaCl). The networks had four output units representing the basic taste qualities, the values of which provide a measure for similarity of test stimuli (salts, tartaric acid, and umami substances) to the basic taste stimuli. 3. Trained networks discriminated the response patterns to the test stimuli in a plausible manner in light of previous physiological and psychological experiments. Profiles of output values of the networks paralleled those of across-neuron correlations with respect to the highest or second-highest values in the profiles. 4. We evaluated relative contributions of input units to the taste discrimination of the network by examining their significance Sj, which is defined as the sum of the absolute values of the connection weights from the jth input unit to the hidden layer. When the input units with weaker connection weights (e.g., 15 of 39 input units) were "pruned" from the trained network, the ability of the network to discriminate the basic taste qualities as well as other test stimuli was not greatly affected. On the other hand, the taste discrimination of the network progressively deteriorated much more rapidly with pruning of input units with stronger connection weights. 5. These results suggest that cortical taste neurons differentially contribute to the coding of taste qualities. The pruning technique may enable the evaluation of a given taste neuron in terms of its relative contribution to the coding, with Sj providing a quantitative measure for such evaluation.

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Development of taste responses in the rat parabrachial nucleus

Journal of Neurophysiology ◽

10.1152/jn.1987.57.2.481 ◽

1987 ◽

Vol 57 (2) ◽

pp. 481-495 ◽

Cited By ~ 34

Author(s):

D. L. Hill

Keyword(s):

Citric Acid ◽

Hydrochloric Acid ◽

Age Groups ◽

Developmental Differences ◽

Average Response ◽

Chorda Tympani Nerve ◽

Ontogenetic Changes ◽

Quinine Hydrochloride ◽

Sodium Saccharin ◽

Parabrachial Nuclei

Extracellular responses from neurons in the parabrachial nuclei (PBN) were studied in rats 4 days old to adulthood during chemical stimulation of the tongue with monochloride salts, citric and hydrochloric acids, sucrose, sodium saccharin, and quinine hydrochloride. Multiunit taste responses were recorded in rats at 4-7 days of age and single-unit responses were recorded from 121 neurons in four other age groups of 14-20 days, 25-35 days, 50-60 days, and adults. PBN neurons in rats 4-7 days old consistently responded to 0.1 M solutions of NH4Cl and NaCl, to 0.5 M solutions of NH4Cl, NaCl, and KCl, and to 1.0 M sucrose, 0.1 M sodium saccharin, 0.1 M citric acid, and 0.1 N HCl. They often did not respond, however, to 0.1 M KCl and 0.01 M quinine hydrochloride. Single PBN neurons in rats 14 days old and older characteristically responded to all stimuli, which consisted of 0.1 and 0.5 M salts, acids, sucrose, sodium saccharin, and quinine hydrochloride. Thus no developmental differences occurred in the number of stimuli to which neurons responded after rats were 14 days old. With the exception of responses to hydrochloric acid, there were significant increases in response frequencies to all stimuli after 14 days of age. Average response frequencies to NH4Cl and citric acid increased after 20 days of age and those to NaCl, LiCl, KCl, sucrose, sodium saccharin, and quinine hydrochloride increased after 35 days of age. Average response frequencies for hydrochloric acid did not alter after 14 days of age. The proportion of single PBN neurons that responded maximally to specific monochloride salts did not change during development. Most single neurons in all age groups responded equally well to NH4Cl, NaCl, and LiCl. No PBN neuron responded maximally to KCl. Developmental differences in response frequencies of third-order gustatory neurons in the PBN generally reflect developmental response changes in first-order neurons of the chorda tympani nerve and second-order neurons of the solitary nucleus. However, unique developmental changes are evident in the PBN. Thus the ontogenetic changes that occur in PBN responses likely relate to modifications of lower-order peripheral and central nervous system afferents and peripheral receptor sensitivities.

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Quinine Hydrochloride 130-89-2

Sax's Dangerous Properties of Industrial Materials ◽

10.1002/0471701343.sdp21921 ◽

2004 ◽

Keyword(s):

Quinine Hydrochloride

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Distribution of Non-tasters for Phenylthiocarbamide and High Sensitivity to Quinine Hydrochloride of the Non-tasters in Japanese

Chemical Senses ◽

10.1093/chemse/22.5.547 ◽

1997 ◽

Vol 22 (5) ◽

pp. 547-551 ◽

Cited By ~ 14

Author(s):

Toshihide Sato ◽

Yukio Okada ◽

Takenori Miyamoto ◽

Rie Fujiyama

Keyword(s):

High Sensitivity ◽

Quinine Hydrochloride

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Response properties of macaque monkey chorda tympani fibers.

The Journal of General Physiology ◽

10.1085/jgp.66.6.781 ◽

1975 ◽

Vol 66 (6) ◽

pp. 781-810 ◽

Cited By ~ 56

Author(s):

M Sato ◽

H Ogawa ◽

S Yamashita

Keyword(s):

Macaque Monkey ◽

Squirrel Monkeys ◽

Taste Quality ◽

Chorda Tympani ◽

Macaque Monkeys ◽

Response Properties ◽

Basic Taste ◽

Quinine Hydrochloride ◽

Positive Correlations ◽

Higher Sensitivity

Many of the chorda tympani fibers of crab-eating monkeys respond to more than one of the four basic stimuli (NaCl, sucrose, HCl, and quinine hydrochloride) as well as cooling or warming of the tongue. Fibers could be classified into four categories depending on their best sensitivity to any one of the four basic stimuli. Sucrose-best and quinine-best fibers are rather specifically sensitive to sucrose and quinine, respectively, while salt-best and acid-best fibers respond relatively well to HCl and NaCl, respectively. Saccharin, dulcin, and Pb acetate produce a good response in sucrose-best fibers, but quinine-best and salt-best fibers also respond to saccharin. Highly significant positive correlations exist between amounts of responses to sucrose and those to saccharin, dulcin, and Pb acetate, indicating that these substances produce in the monkey a taste quality similar to that produced by sucrose. Compared with chroda tympani fibers of rats, hamsters, and squirrel monkeys, macaque monkey taste fibers are more narrowly tuned to one of the four basic taste stimuli and more highly developed in sensitivity to various sweet-tasting substances. Also LiCl and NaCl are more effective stimuli for gustatory receptors in macaque monkeys than NH4Cl and KCl. This contrasts with a higher sensitivity to KCl and NH4Cl than to NaCl in chorda tympani fibers of squirrel monkeys.

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Substitution reactions of benzethonium chloride with ion associates of bromocresol green – quinine and bromophenol blue – quinine in dichloromethane

Canadian Journal of Chemistry ◽

10.1139/v91-139 ◽

1991 ◽

Vol 69 (6) ◽

pp. 937-944 ◽

Cited By ~ 3

Author(s):

Alberto Hernandez Gainza ◽

Roy Ikemefula Konyeaso

Keyword(s):

Thermodynamic Parameters ◽

Equilibrium Constants ◽

Formation Constants ◽

Bromocresol Green ◽

Bromophenol Blue ◽

Substitution Reactions ◽

Dichloromethane Solution ◽

Benzethonium Chloride ◽

Quinine Hydrochloride ◽

Ion Associate

An excess concentration of base quinine (Q) reacts with a sulphonphthalein diacidic dye XH2, (bromocresol green, BCGH2, or bromophenol blue, BPBH2) in dichloromethane solution to form an ion associate (X2−(QH+)2) of stoichiometry 1:2 (dye:amine). Benzethonium chloride (ClB) reacts with the 1:2 ion associate to form an ion associate (QH+,X2−,B+) and quinine hydrochloride ClQH+. This substitution reaction is a chemical equilibrium with formation constants of 1.50 ± 0.67, 1.61 ± 0.54, 1.07 ± 0.29, 1.04 ± 0.20, and 0.84 ± 0.26 for BCG and 1.86 ± 0.59, 1.47 ± 0.23, 1.40 ± 0.65, 1.13 ± 0.37, and 1.11 ± 0.27 for BPB at 283.16, 288.16, 293.16, 298.16, and 303.16 K respectively. The thermodynamic parameters determined by van't Hoff's equation are ΔH0 = −21.766 ± 7.482 kJ mol−1, ΔS0 = −73 ± 51 J mol−1 K−1, and ΔG0 = −1.134 ± 0.972 kJ mol−1for BCG and ΔH0 = −18.678 ± 7.482 kJ mol−1, ΔS0 = −61 ± 26 J mol−1 K−1, ΔG0 = −0.916 ± 0.401 kJ mol−1 for BPB (ΔG0 at 293.16 K; and ΔH0 and ΔS0 determined in the range 283–303 K). Key words: bromocresol green – quinine–benzethonium, ion associate mixture, bromophenol blue – quinine–benzethonium, equilibrium constants, thermodynamic parameters.

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