Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cold tolerance”

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 937 records · Page 52Linked to original sources

Lacosamide, a new anti-epileptic, alleviates neuropathic pain-like behaviors in rat models of spinal cord or trigeminal nerve injury.

The effect of systemic administration of lacosamide, a newly developed anti-epileptic, on neuropathic pain-like behaviors was examined in rats after ischemic injury to the infraorbital nerve or spinal cord using a photochemical method. In rats with infraorbital nerve injury, lacosamide reduced mechanical hypersensitivity and the effect was markedly stronger in female than in male rats. In spinal cord injured female rats 10-20 mg/kg lacosamide dose-dependently alleviated the mechanical and cold allodynia-like behaviors without causing motor impairments or marked sedation. Administration of lacosamide twice daily at 20 mg/kg for 7 days totally alleviated the allodynia-like state in spinally-injured rats with no tolerance. Following treatment cessation the cold and the static allodynia reappeared but the effect on dynamic mechanical allodynia (brushing) was maintained until day 11. Lacosamide also produced hypothermia at antinociceptive doses in rats. It is suggested that this novel compound may be useful as an analgesic for treating central and trigeminal neuropathic pain. Furthermore, there may be a gender difference to the effect of lacosamide with female rats being more responsive to the treatments.

Acetamides↗

Induction of baroresistance by hydrogen peroxide, ethanol and cold-shock in Saccharomyces cerevisiae.

The acquisition of tolerance to high hydrostatic pressure of 220 MPa (HHP) in response to a 0.4 mM hydrogen peroxide, 6% ethanol and cold-shock (10 degrees C) pretreatment for different lengths of times was studied in the yeast Saccharomyces cerevisiae. The protection conferred by these different treatments was similar ( approximately 3 log cycles) and time-dependent. Analysis of the induction of the most pressure up-regulated genes under these conditions was investigated by RT-PCR. Our results revealed that the cell stress response to HHP shares common features with hydrogen peroxide and ethanol stresses, but differs in some way to cold-shock.

Actins↗

Ectopic expression of ABI3 gene enhances freezing tolerance in response to abscisic acid and low temperature in Arabidopsis thaliana.

The plant hormone abscisic acid (ABA) regulates several physiological and developmental processes in plants, including stress adaptation and seed maturation. ABA-mediated processes appear to be central in plant cold acclimation and expression of cold acclimation-related genes. Ectopic expression of ABI3 encoding a seed-specific transcriptional activator confers on Arabidopsis vegetative tissues the ability to accumulate seed-specific transcripts in response to ABA, and also influences some ABA-mediated vegetative responses. In the present study we characterized the effect of ectopic expression of ABI3 on cold acclimation and development of freezing tolerance in Arabidopsis. We first determined the effect of ABI3 on ABA-induced expression of cold acclimation-related genes. Expression of ABI3 increased the ABA-induced accumulation of transcripts for several ABA/cold/drought-responsive genes such as RAB18 and LTI78. Enhanced expression of these genes was evident even after transient application of ABA, and the enhanced expression was correlated with increased freezing tolerance in ABI3 transgenic plants. Ectopic expression of ABI3 also appeared to modulate low temperature-induced freezing tolerance. The ABI3 transgenic plants acclimated faster than the wild-type plants, and the maximum tolerance obtained was significantly higher. These data showed that lower levels of ABA were needed to trigger the expression of the genes and to maintain the freezing-tolerant state in the ABI3 transgenic plants, and indicate that ectopic expression of ABI3 leads to enhanced responsiveness to ABA. The ectopic expression of ABI3 could provide a new strategy for engineering plant stress tolerance.

Abscisic Acid↗

Nucleation of ice and its management in ecosystems.

In addition to the gas and liquid phases, water can exist in many different solid states. Some of these are the well-studied crystalline ice polymorphs and the clathrate hydrates, but at least two distinguishable amorphous solid forms have also been shown to exist. This diversity of possible condensed states implies a multiplicity of transitions, each of them presumably associated with a nucleation step. Disagreement still exists as to whether the amorphous states can be regarded as metastable phases, and whether the phenomenon of polyamorphism can be treated in terms of phase transitions. In the Earth's hydrosphere, several of the crystalline and amorphous water phases can be formed from vapour, under given conditions of temperature, pressure and supersaturation, and classical nucleation theory is believed to account reasonably well for the observed growth of condensed forms of water in the upper atmosphere. Many terrestrial organisms are able to activate mechanisms to control the nucleation and growth of ice when exposed to sub-zero temperatures, thus enabling them to minimize the lethal effects of extreme freeze desiccation. The substances involved in these mechanisms include carbohydrates, amino acids and so-called cold-shock proteins, but the actual mechanisms of interfering with ice nucleation, although quite well documented, are as yet imperfectly understood. This is particularly true for the genetic control associated with biochemical processes that produce freeze resistance and freeze tolerance. The molecular biology of cold stress is currently a subject of intensive study.

Amino Acids↗

Linking biogeography to physiology: Evolutionary and acclimatory adjustments of thermal limits.

Temperature-adaptive physiological variation plays important roles in latitudinal biogeographic patterning and in setting vertical distributions along subtidal-to-intertidal gradients in coastal marine ecosystems. Comparisons of congeneric marine invertebrates reveal that the most warm-adapted species may live closer to their thermal tolerance limits and have lower abilities to increase heat tolerance through acclimation than more cold-adapted species. In crabs and snails, heart function may be of critical importance in establishing thermal tolerance limits. Temperature-mediated shifts in gene expression may be critical in thermal acclimation. Transcriptional changes, monitored using cDNA microarrays, have been shown to differ between steady-state thermal acclimation and diurnal temperature cycling in a eurythermal teleost fish (Austrofundulus limnaeus). In stenothermal Antarctic notothenioid fish, losses in capacity for temperature-mediated gene expression, including the absence of a heat-shock response, may reduce the abilities of these species to acclimate to increased temperatures. Differences among species in thermal tolerance limits and in the capacities to adjust these limits may determine how organisms are affected by climate change.

Journal Article↗

Acclimation of entomopathogenic nematodes to novel temperatures: trehalose accumulation and the acquisition of thermotolerance.

The effect of thermal acclimation on trehalose accumulation and the acquisition of thermotolerance was studied in three species of entomopathogenic nematodes adapted to either cold or warm temperatures. All three Steinernema species accumulated trehalose when acclimated at either 5 or 35 degrees C, but the amount of trehalose accumulation differed by species and temperature. The trehalose content of the cold adapted Steinernema feltiae increased by 350 and 182%, of intermediate Steinernema carpocapsae by 146 and 122% and of warm adapted Steinernema riobrave by 30 and 87% over the initial level (18.25, 27.24 and 23.97 microg trehalose/mg dry weight, respectively) during acclimation at 5 and 35 degrees C, respectively. Warm and cold acclimation enhanced heat (40 degrees C for 8h) and freezing (-20 degrees C for 4h) tolerance of S. carpocapsae and the enhanced tolerance was positively correlated with the increased trehalose levels. Warm and cold acclimation also enhanced heat but not freezing tolerance of S. feltiae and the enhanced heat tolerance was positively correlated with the increased trehalose levels. In contrast, warm and cold acclimation enhanced the freezing but not heat tolerance of S. riobrave, and increased freezing tolerance of only warm acclimated S. riobrave was positively correlated with the increased trehalose levels. The effect of acclimation on maintenance of original virulence by either heat or freeze stressed nematodes against the wax moth Galleria mellonella larvae was temperature dependent and differed among species. During freezing stress, both cold and warm acclimated S. carpocapsae (84%) and during heat stress, only warm acclimated S. carpocapsae (95%) maintained significantly higher original virulence than the non-acclimated (36 and 47%, respectively) nematodes. Both cold and warm acclimated S. feltiae maintained significantly higher original virulence (69%) than the non-acclimated S. feltiae (0%) during heat but not freezing stress. In contrast, both warm and cold acclimated S. riobrave maintained significantly higher virulence (41%) than the non-acclimated (14%) nematodes during freezing, but not during heat stress. Our data indicate that trehalose accumulation is not only a cold associated phenomenon but is a general response of nematodes to thermal stress. However, the extent of enhanced thermal stress tolerance conferred by the accumulated trehalose differs with nematode species.

Acclimatization↗

Effects of polycyclic aromatic compounds on the drought tolerance of Folsomia fimetaria (Collembola, Isotomidae).

Drought tolerance (survival at 98.2% relative humidity and 20 degress C) was investigated for adult individuals of the springtail Folsomia fimetaria after three weeks of exposure to different polycyclic aromatic compounds (PACs). Seven PACs were investigated (acridine, dibenzofuran, carbazole, fluorene, dibenzothiophene, fluoranthene, and pyrene), with each substance used at several exposure concentrations. Sublethal concentrations of dibenzothiophene, fluorene, fluoranthene, and pyrene caused a dose-related decrease in drought tolerance in exposed adults, whereas no such relationship was found for acridine, dibenzofuran, and carbazole. The organisms used in the drought tolerance study were taken directly from standard ecotoxicity tests that had just been completed, hence the concentrations causing subsequent effects on drought tolerance and those affecting survival and reproduction in the ecotoxicity tests could be compared. Some of the tested substances significantly reduced the drought tolerance of F. fimetaria at concentrations that had little effect on survival, indicating a synergistic effect of the two stressors. However, drought tolerance was affected at concentrations below the threshold value for toxicity in standard tests (no-observed-effect concentration for reproduction) only for dibenzothiophene. In the field, soil organisms exposed to contaminants also face multiple environmental stressors such as drought and cold. Because the reduced drought tolerance is a side effect of chemical exposure, such effects should be considered when extrapolating from laboratory to field conditions.

Adaptation, Physiological↗

Drought acclimation and lipid composition in Folsomia candida: implications for cold shock, heat shock and acute desiccation stress.

Many of the physiological adaptations evolved in terrestrial invertebrates to resist desiccation have also been shown to enhance the survival of low temperatures. In this study we have examined temporal changes in the physiology of the collembolan Folsomia candida during acclimation to mild desiccation stress (98.2% RH), and how physiological changes correlate with resistance to subsequent cold shock, heat shock and acute desiccation stress. Drought-acclimation increased the resistance to cold and acute drought but reduced the resistance to heat shock. The composition of membrane phospholipid fatty acids (PLFA) changed during acclimation resulting in a higher degree of unsaturation by the end of the 192-h acclimation period. This resembles typical membrane alterations seen in ectothermic animals exposed to cold. Only small changes were seen in the neutral lipid fraction. The temporal changes in cold resistance and drought resistance correlated well with changes in PLFA composition and accumulation of sugars and polyols ('cryoprotectives'). It is proposed that the drought-induced PLFA desaturation, combined with the membrane protecting accumulation of cryoprotectives, are important physiological adaptations providing tolerance to both desiccation and cold.

Journal Article↗

Methadone maintenance patients are cross-tolerant to the antinociceptive effects of very high plasma morphine concentrations.

Opioid dependent patients require higher than normal doses of opioid analgesics. However, this regimen has not been formally tested. This study utilised a double-blind placebo-controlled design to examine antinociceptive responses to saline and pseudo-steady-state plasma morphine concentrations (173+/-11 (mean+/-SEM), range 106-305 ng/ml) in 18 methadone participants in three stable, once daily methadone dose ranges 11-45 mg (n=6), 46-80 mg (n=6), 81-115 mg (n=6) and 10 controls. Testing commenced approximately 20 h after the maintenance dose with the next dose given 1h after morphine cessation. Nociceptive stimuli (cold pressor (seconds) and electrical stimulation (volts)) were used to measure pain detection threshold and pain tolerance. Blood samples were analysed by HPLC for plasma morphine and R-(-)-methadone concentrations. Methadone participants were hyperalgesic to cold pressor pain. High plasma morphine concentrations failed to significantly change cold pressor and electrical stimulation pain tolerance for methadone patients, but in controls, morphine significantly (P<0.05) increased mean pain tolerance to cold pressor by 59+/-29% (range -17% to 311%) and electrical stimulation by 19+/-6% (range 0% to 58%). Morphine significantly (P<0.05) decreased respiration rates by 12+/-3% (range -29% to 8%) in methadone subjects. On saline days, rising methadone concentrations significantly (P<0.01) increased cold pressor pain detection threshold by 32+/-6% (range 1-81%) and cold pressor pain tolerance by 23+/-6% (range -32% to 56%). Methadone maintained patients are hyperalgesic and cross-tolerant to the antinociceptive effects of very high plasma morphine concentrations. While even higher morphine doses may achieve some pain relief, this may be at the cost of unacceptable respiratory depression.

Adult↗

A molecular marker to select for freezing tolerance in Gramineae.

We isolated, and expressed in Escherichia coli, a gene (Wcs120) that is strongly induced during cold acclimation of wheat. The gene product was purified and used to produce antibodies. Immunoblotting experiments with the anti-WCS120 antibody identified several cold-induced proteins named FTMs for Freezing Tolerance Markers since they are associated with the development of freezing tolerance. This protein family was found to be coordinately regulated specifically by low temperature, highly hydrophilic, stable to boiling, and to have a pI above 6.5. The accumulation kinetics during the acclimation period indicated a positive correlation with the capacity of each genotype to develop freezing tolerance. Accumulation of the proteins was higher in the freezing-tolerant genotype than in the less tolerant one. In addition, their accumulation was more pronounced in the crown and leaf tissues compared with roots, confirming a relationship to the capacity of the different tissues to develop freezing tolerance. Analysis of different species (eight monocots and four dicots) indicated that this protein family is specific for freezing-tolerant cereals. The antibody did not cross-react with any of the non-cereal species examined. The anti-FTMs antibody represents a potential tool for breeders to select for freezing tolerance traits in the Gramineae.

Adaptation, Physiological↗

Sensitivity to cold pressor pain in dysmenorrheic and non-dysmenorrheic women as a function of menstrual cycle phase.

Pain responses (threshold, tolerance, and visual analog ratings) to the cold pressor task were studied in 46 normally menstruating dysmenorrheic and non-dysmenorrheic women during 2 phases of the menstrual cycle. Twenty-six women provided measurements during the follicular (days 8-14) and 20 during the luteal (days 15-21) phases of the menstrual cycle. A significantly lower pain threshold was obtained during the luteal as compared to the follicular phase. Pain tolerance showed a similar but non-significant trend. Visual analog ratings were significantly lower in dysmenorrheic women during the follicular than the luteal phase. Also, these ratings were lower than those of non-dysmenorrheic women in the follicular phase. This finding may support an adaptation-levels model, in that dysmenorrheic women report less pain than do non-dysmenorrheic women because they compare cold pressor pain with internal menstrual pain.

Adolescent↗

Personality correlates of pain perception and tolerance.

Explored personality correlates of pain perception and tolerance in a nonmedical sample and setting. In a counter-balanced design, 70 Ss were administered several personality questionnaires and a cold-pressor test for pain perception and tolerance. In Experiment 1, 39 Ss were given the Adjective Check List and Rosenberg's Self-esteem Scale, while in Experiment 2, 31 different Ss received the Beck Depression Inventory. Results showed no significant correlations with personality measures and cold-pressor scores, but a significant relationship between pain tolerance and cognitive focus; those who focused on the experimental situation had much shorter tolerance times than those who used cognitive distraction. It is suggested that while chronic pain in a medical patient population may be related to personality characteristics, tolerance of pain in a non-patient population is related to situational variables, such as cognitive focus and distraction.

Adolescent↗

Pain and emotion: effects of affective picture modulation.

OBJECTIVE AND METHODS: Two experiments examined the impact of viewing unpleasant, pleasant, and neutral photographic slides on cold-pain perception in healthy men and women. In each experiment, participants viewed one of three slide shows (experiment 1 = fear, disgust, or neutral; experiment 2 = erotic, nurturant, or neutral) immediately before a cold-pressor task. Skin conductance and heart rate were recorded during the slide shows, whereas visual analog scale ratings of pain intensity and unpleasantness thresholds and pain tolerance were recorded during the cold-pressor task. RESULTS: Viewing fear and disgust slides decreased pain intensity and unpleasantness thresholds, but only the fear slides decreased pain tolerance. In contrast, viewing erotic, but not nurturant, slides increased pain intensity and unpleasantness threshold ratings on the visual analog scale in men, whereas neither nurturant nor erotic slides altered pain tolerance. CONCLUSIONS: These results are consistent with a motivational priming model that predicts that unpleasant affective states should enhance pain and that pleasant affective states should attenuate it.

Adult↗

Promoters from kin1 and cor6.6, two Arabidopsis thaliana low-temperature- and ABA-inducible genes, direct strong beta-glucuronidase expression in guard cells, pollen and young developing seeds.

The ability of most higher plants to withstand freezing can be enhanced by cold acclimation, although the freezing tolerance of plant tissues is also affected by their developmental stage. In addition, low temperature has pleiotropic effects on many plant developmental processes such as vernalization. The interaction between plant development and low temperature implies that some genes are regulated by both environmental factors and developmental cues. Although a number of cold-inducible genes from plants have been identified, information concerning their regulation during plant development is limited. In order to understand their developmental regulation and obtain possible clues as to function, the promoters of kin1 and cor6.6, two cold- and abscisic acid (ABA)-regulated genes from Arabidopsis thaliana, were fused to the beta-glucuronidase (GUS)-coding sequence and the resulting constructs were used to transform tobacco and A. thaliana. Transgenic plants with either the kin1 or cor6.6 promoter showed strong GUS expression in pollen, developing seeds, trichomes and, most interestingly, in guard cells. During pollen development, maximum GUS activity was found in mature pollen. In contrast, the maximum GUS activity during seed development was during early embryogenesis. These patterns of expression distinguish kin1 and cor6.6 from related lea genes which are strongly expressed during late embryogenesis. There was no major qualitative difference in patterns of GUS expression between kin1 and cor6.6 promoters and the results were similar for transgenic tobacco and Arabidopsis. Considering the results described, as well as those in an accompanying paper (Wang et al., 1995, Plant Mol Biol 28: 605-617 (this issue), we suggest that osmotic potential might be a major factor in regulating the expression of kin1 and cor6.6 during several developmental processes. The implication of the results for possible function of the gene products is discussed.

Abscisic Acid↗

Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads.

BACKGROUND: Anesthetic requirement in redheads is exaggerated, suggesting that redheads may be especially sensitive to pain. Therefore, the authors tested the hypotheses that women with natural red hair are more sensitive to pain and that redheads are resistant to topical and subcutaneous lidocaine. METHODS: The authors evaluated pain sensitivity in red-haired (n = 30) or dark-haired (n = 30) women by determining the electrical current perception threshold, pain perception, and maximum pain tolerance with a Neurometer CPT/C (Neurotron, Inc., Baltimore, MD). They evaluated the analogous warm and cold temperature thresholds with the TSA-II Neurosensory Analyzer (Medoc Ltd., Minneapolis, MN). Volunteers were tested with both devices at baseline and with the Neurometer after 1-h exposure to 4% liposomal lidocaine and after subcutaneous injection of 1% lidocaine. Data are presented as medians (interquartile ranges). RESULTS: Current perception, pain perception, and pain tolerance thresholds were similar in the red-haired and dark-haired women at 2,000, 250, and 5 Hz. In contrast, redheads were more sensitive to cold pain perception (22.6 [15.1-26.1] vs. 12.6 [0-20] degrees C; P = 0.004), cold pain tolerance (6.0 [0-9.7] vs. 0.0 [0.0-2.0] degrees C; P = 0.001), and heat pain (46.3 [45.7-47.5] vs. 47.7 [46.6-48.7] degrees C; P = 0.009). Subcutaneous lidocaine was significantly less effective in redheads (e.g., pain tolerance threshold at 2,000-Hz stimulation in redheads was 11.0 [8.5-16.5] vs. > 20.0 (14.5 to > 20) mA in others; P = 0.005). CONCLUSION: Red hair is the phenotype for mutations of the melanocortin-1 receptor. Results indicate that redheads are more sensitive to thermal pain and are resistant to the analgesic effects of subcutaneous lidocaine. Mutations of the melanocortin-1 receptor, or a consequence thereof, thus modulate pain sensitivity.

Adult↗

Changes in the Electrophoretic Patterns of the Soluble Proteins of Winter Wheat and Rye following Cold Acclimation and Desiccation Stress.

The degrees of freezing tolerance acquired by winter wheat (Triticum aestivium L.) and rye (Secale cereale L. cv Puma) were similar following a 4-week cold conditioning and a 24-hour desiccation stress. Soluble proteins were extracted from shoots of cold-conditioned or desiccation-stressed seedlings and electrophoresed on sodium dodecyl sulfate-polyacrylamide gels. Quantitative changes in the electrophoretic patterns of the soluble proteins of the different cultivars grown in different environments were detected, but the changes were not equivalent following cold conditioning and desiccation stress. The abundance of two polypeptide bands showed a significant increase correlated to the degree of freezing tolerance and, hence, the polypeptides in these bands may play a role in the development of freezing tolerance.

Journal Article↗

Cold exposure reverses the diabetogenic effects of high-fat feeding.

Long-term cafeteria feeding, cold exposure, and the combination of treatments increased energy intake in female Wistar rats by 25%, 113%, and 150%, respectively, in comparison with controls (P less than 0.01). Although cafeteria feeding at room temperature markedly increased the insulin response to an intravenous glucose tolerance test (IVGTT), glucose tolerance was deteriorated (P less than 0.01). In contrast, cold exposure significantly improved glucose tolerance in the presence of a reduced insulin response in Purina- and cafeteria-fed animals. Moreover, cold exposure also decreased body weight gain and increased brown adipose tissue mass, total cytochrome-oxidase activity, and cellularity by approximately 600-800%. The results suggest that cold exposure enhances insulin sensitivity of peripheral tissues, whereas hyperphagia on a high-fat, low-protein diet leads to insulin resistance. In addition, the results demonstrate that prolonged stimulation of energy expenditure by cold exposure not only reverses the diabetogenic effects of cafeteria feeding but also improves glucose tolerance. This phenomenon could result from a combination of two factors: (1) a cold-induced prevention of obesity; and (2) an enhanced disposal of circulating glucose into peripheral tissues, including brown adipose tissue.

Adipose Tissue↗

Myocardial function following cold ischemic storage is improved by cardiac-specific overexpression of A1-adenosine receptors.

Cold ischemic storage of hearts for transplantation is limited to 4-6 h, and therefore the development of strategies to extend preservation time may increase the donor pool of hearts. Overexpression of A1-adenosine receptors (A1AR) can protect hearts from acute ischemic injury, and the purpose of this study was to test the hypothesis that overexpression of A1AR will improve tolerance to longer periods of cold ischemic preservation. Hearts from 18 wild type and 16 transgenic mice with overexpression of A1AR (A1AR Trans) were isolated and perfused, and then subjected to 18 h of preservation in 5 degrees C University of Wisconsin solution followed by 2 h of reperfusion. Left ventricular end diastolic pressure and left ventricular developed pressure were measured as indices of ventricular function. Cell viability was assessed by determination of infarct size and myocardial cell apoptosis. A1AR Trans hearts showed improved function following 18 h of ischemia, as shown by lower end diastolic pressure (p < 0.05) and higher recovery of left ventricular developed pressure (p < 0.05) during reperfusion. A1AR Trans hearts had markedly reduced infarct size (p < 0.05) and decreased apoptosis (p < 0.05). Overexpression of cardiac A1AR imparts cardioprotection during long-term cold ischemic preservation.

Animals↗