Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Menthol”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed2001

Response properties of isolated mouse olfactory receptor cells.

Response properties of isolated mouse olfactory receptor cells were investigated using the suction pipette technique. Cells were exposed to the odour cineole or to solutions of modified ionic content by rapidly changing the solution superfusing the cilia. All experiments were performed at 37 degrees C. Mouse olfactory receptor cells displayed a steep dependence of action potential frequency on stimulus concentration, a 3-fold increase in stimulus concentration often saturating the firing frequency at 200-300 Hz. The receptor current increased more gradually with increasing cineole concentration and did not saturate within the 100-fold range of cineole concentrations applied. When stimulated for 30 s with a low odour concentration, cells responded with sporadic spike firing. Higher concentrations led to the generation of a large receptor current at the onset of stimulation which returned to baseline levels within a few seconds, accompanied during its rising phase by a short burst of action potentials. Thereafter an oscillating response pattern was observed during the remainder of the stimulus, consisting of repetitive increases in receptor current of around 1 s duration accompanied by short bursts of action potentials. Olfactory adaptation was studied by comparing the responses to two closely spaced odour stimuli. The response to the second odour stimulus recovered to 80% of its original magnitude when the cell was superfused with Ringer solution during the 5 s interval between odour exposures. In contrast, exposure to a choline-substituted low Na+ solution between odour stimuli had two effects. First, the receptor current response to the first odour stimulus did not terminate as quickly as in the presence of Na+, suggesting the presence of a Na+ -Ca2+ exchanger. Second, the response to the second stimulus only recovered to 55% of its original magnitude, demonstrating the involvement of Na+-Ca2+ exchange in the recovery of sensitivity in mouse olfactory receptor cells following stimulation.

Action Potentials↗
PubMed1994

Effects of odorants on pigment aggregation and cAMP in fish melanophores.

Odor perception within olfactory neuroepithelium and pigment translocation within melanophores both seem to rely on a cAMP-based second messenger system. From studies on cultured frog melanophores, Lerner et al. (Proc. Natl. Acad. Sci. USA 85:261-264, 1988) suggested that some aspect of odor perception may be mediated by a nonspecific mechanism whose signal is transduced by a cAMP-based second messenger system. In the present study, odorants (beta-ionone, benzylaldehyde, cineole, cinnamaldehyde, and octanol), which previously have been shown to stimulate formation of cAMP in the olfactory neuroepithelium, were investigated for possible pigment dispersing and cAMP-increasing effects. Pretreatment of fish melanophores with the adenylate cyclase activator forskolin (1 microM) resulted in an approximately 300% increase in cAMP and an almost complete blockage of noradrenaline-induced pigment aggregation. However, none of the tested odorants were able to increase the cAMP level and only cinnaldehyde and beta-ionone were found to have any pigment dispersing activity.

1-Octanol↗
PubMed1989

Relationship between exposure to icterogenic agents, glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice in Nigeria.

In a study of the relationship between exposure to icterogenic agents, G-6-PD deficiency and severe neonatal jaundice (NNJ) (serum bilirubin greater than or equal to 205 mumol/l) in 234 Nigerian term male neonates, 106 infants with severe NNJ and 128 controls, it was found that 62.3% of the jaundiced infants and 13.3% of the infants without NNJ were G6PD deficient (p less than 0.01). The proportion of infants exposed to icterogenic agents in the two groups was very similar (p greater than or equal to 0.5). There was a strong association between exposure to icterogenic agents and NNJ in 83 G6PD deficient infants (p less than 0.01), but there was no association between exposure to icterogenic agents and NNJ in the whole group of 234 infants or in 151 infants with normal G6PD status. It is concluded that there is an association between genetically determined G-6-PD deficiency and exogenous agents in causing severe NNJ in Nigerian infants.

Aspirin↗
PubMed2001

Simulated microgravity [bed rest] has little influence on taste, odor or trigeminal sensitivity.

Anecdotal evidence suggests that astronauts' perceptions of foods in space flight may differ from their perceptions of the same foods on Earth. Fluid shifts toward the head experienced in space may alter the astronauts' sensitivity to odors and tastes, producing altered perceptions. Our objective was to determine whether head-down bed rest, which produces similar fluid shifts, would produce changes in sensitivity to taste, odor or trigeminal sensations. Six subjects were rested three times prior to bed rest, three times during bed rest and two times after bed rest to determine their threshold sensitivity to the odors isoamylbutyrate and menthone, the tastants sucrose, sodium chloride, citric acid, quinine and monosodium glutamate, and to capsaicin. Thresholds were measured using a modified staircase procedure. Self-reported congestion was also recorded at each test time. Thresholds for monosodium glutamate where slightly higher during bed rest. None of the other thresholds were altered by bed rest.

Adult↗
PubMed1989

An in vitro comparison of the single cone and lateral condensation techniques using 'friction-fitted' and 'solvent dip-fitted' primary gutta-percha cones.

Extracted teeth, root-filled by single cone and lateral condensation techniques, using friction fitted and solvent (chloroform and eucalyptol) dip-fitted primary gutta-percha cones, were compared with respect to apical sealing as measured by length of dye penetration and frequency of no dye penetration. Overall, the single cone techniques were significantly more effective than lateral condensation techniques regarding length of dye penetration. The single cone techniques were not significantly different from the lateral condensation technique which employed chloroform dip-fitted primary gutta-percha cones regarding length of dye penetration. The single cone and lateral condensation techniques which utilized chloroform dip-fitted cones ranked first and second with respect to frequency of no dye penetration.

Chloroform↗
PubMed1990

Antihistaminic activity of pulegone on the guinea-pig ileum.

Pulegone, a natural monoterpene compound, has an antihistamine effect on guinea-pig ileum. Its antagonism is of the competitive type (PA2 = 6.35) like that of mepyramine and dexchlorpheniramine, two H1-antagonists, with PA2 values of 10.15 and 8.74, respectively.

Animals↗
PubMed1993

The relation between stimulus and response in olfactory receptor cells of the tiger salamander.

1. Olfactory receptor cells were isolated from the adult tiger salamander Ambystoma tigrinum and the current in response to odorant stimuli was measured with the whole-cell voltage-clamp technique while odorants at known concentrations were rapidly applied for controlled exposure times. 2. Three odorants, cineole, isoamyl acetate and acetophenone, were first applied at 5 x 10(-4) M. Out of forty-nine cells tested, 53% responded to one odorant only, 22% to two odorants and 25% to all three odorants. 3. The amplitude of the current in response to a given odorant concentration was found to be dependent on the duration of the odorant stimulus and reached a saturating peak value at 1.2 s of stimulus duration. 4. The current measured at the peak of the response for odorant steps of 1.2 s as a function of odorant concentration was well described by the Hill equation for the three odorants with Hill coefficients higher than 1 and K1/2 (odorant concentration needed to activate half the maximal current) ranging from 3 x 10(-6) to 9 x 10(-5) M. 5. It is concluded that olfactory receptor cells are broadly tuned and have a low apparent affinity for odorants, integrate stimulus information over time, and have a narrow dynamic range.

Acetophenones↗
PubMed1990

Evaluation of antifungal volatile compounds on the basis of the elongation rate of a single hypha.

A novel method is proposed for the evaluation of the activity of an antifungal agent administered as a gas. This system is composed of a batch-flow type reaction vessel, a gas flow system, and a microscopic observation system. The agar plate was prepared on the ceiling of the reaction vessel, and the mycelium of a fungus (Aspergillus niger or Rhizoctonia solani) was inoculated onto it. After preincubation at 25 degrees C for 24 h, the reaction vessel was connected to the gas flow system. An appropriate hypha was selected, and its elongation rate was measured. Then a sample holder containing an antifungal compound was inserted into the reaction vessel from the side hole to saturate the atmosphere inside with its vapor. The retardation or inhibition of the hypha elongation was observed on a television monitor and recorded on a video tape recorder. The antifungal compound was then removed, and the reaction vessel was flushed with air. If the hypha lived, it began to elongate again. By this method, antifungal activity of seven odor compounds could be evaluated quantitatively within several hours.

Acrolein↗
PubMed2000

Amplification of odor-induced Ca(2+) transients by store-operated Ca(2+) release and its role in olfactory signal transduction.

A critical role of Ca(2+) in vertebrate olfactory receptor neurons (ORNs) is to couple odor-induced excitation to intracellular feedback pathways that are responsible for the regulation of the sensitivity of the sense of smell, but the role of intracellular Ca(2+) stores in this process remains unclear. Using confocal Ca(2+) imaging and perforated patch recording, we show that salamander ORNs contain a releasable pool of Ca(2+) that can be discharged at rest by the SERCA inhibitor thapsigargin and the ryanodine receptor agonist caffeine. The Ca(2+) stores are spatially restricted; emptying produces compartmentalized Ca(2+) release and capacitative-like Ca(2+) entry in the dendrite and soma but not in the cilia, the site of odor transduction. We deplete the stores to show that odor stimulation causes store-dependent Ca(2+) mobilization. This odor-induced Ca(2+) release does not seem to be necessary for generation of an immediate electrophysiological response, nor does it contribute significantly to the Ca(2+) transients in the olfactory cilia. Rather, it is important for amplifying the magnitude and duration of Ca(2+) transients in the dendrite and soma and is thus necessary for the spread of an odor-induced Ca(2+) wave from the cilia to the soma. We show that this amplification process depends on Ca(2+)-induced Ca(2+) release. The results indicate that stimulation of ORNs with odorants can produce Ca(2+) mobilization from intracellular stores without an immediate effect on the receptor potential. Odor-induced, store-dependent Ca(2+) mobilization may be part of a feedback pathway by which information is transferred from the distal dendrite of an ORN to its soma.

Animals↗
PubMed2004

Evidence that TRPM8 is an androgen-dependent Ca2+ channel required for the survival of prostate cancer cells.

The Ca(2+)-permeable channel TRPM8 is thought to play an important role in the pathophysiology of prostate cancer. We have investigated the intracellular location of TRPM8 and its role as a Ca(2+)-permeable channel in an androgen-responsive and an androgen-insensitive prostate cancer cell line. We report evidence from immunofluorescence experiments that in the androgen-responsive LNCaP cell line, the TRPM8 protein is expressed in the endoplasmic reticulum and plasma membrane, acts as a Ca(2+)-permeable channel (assessed using Fura-2 to measure increases in the cytoplasmic Ca(2+) concentration) in each of these membranes, and is regulated by androgen. Although TRPM8 was detected in the androgen-insensitive PC-3 cell line, no evidence was obtained for regulation of its expression by androgen. The results of experiments using LNCaP cells, the TRPM8 antagonist capsazepine, and small interference RNA targeted to TRPM8 indicate that TRPM8 is required for cell survival. These results indicate that TRPM8 is an important determinator of Ca(2+) homeostasis in prostate epithelial cells and may be a potential target for the action of drugs in the management of prostate cancer.

Androgens↗
PubMed1999

Anaphylactic shock reaction to dibutyl-phthalate-containing capsules.

We report on a patient who was taking a Gelomyrtol forte capsule, a mucosecretolytic herbal product, to treat an infection of the upper respiratory tract. Itching, urticaria and respiratory distress occurred after 20 min which culminated in anaphylactic shock. Prick tests were carried out with the individual substances from Gelomyrtol forte capsules. Dibutyl phthalate produced a strong positive result. It is used as a plasticizer in films covering tablets, dragées and capsules. As a triggering agent of anaphylactic reactions to drugs, the auxiliary materials, e.g. dibutyl phthalate, should also be taken into consideration.

Adult↗