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PubMed2006

Argentinean cultivars of Vitis vinifera grow better than European ones when cultured in vitro under salinity.

Argentinean Vitis vinifera cultivars although originated from Europe, have clear ampelographic and genotypic differences as compared with the European cultivars currently used in wine making. In vitro evaluation of salt tolerance has been used in many species. Our hypothesis was that Argentinean cultivars are more tolerant to salinity than European ones. Three European cultivars, Malbec, Cabernet Sauvignon and Chardonnay and four Argentincan cultivars, Cereza, Criolla Chica, Pedro Gimcnez and Torrontes Riojano were tested by in vitro culture. Treatments included: 1) Control, 2) 60 mEq/L of a mixture of three parts of NaCl and one part of CaCl2 and 3) 90 mEq/L of the salt mixture. Results from two experiments (I and II) are reported. No differences were found in plant survival, expressed as % of the respective control, among cultivars. Leaf area, leaf, stem and total dry matter (DM) in Experiment I and leaf area, leaf number and leaf, stem, root and total DM in Experiment II, were higher in Argentinean cultivars than in European ones. We conclude that Argentinean cultivars show better performance in growing under salinity, especially in the highest salt concentration. Differences among cultivars, inside each group, were found for most of the measured variables.

Argentina↗
PubMed1989

Effects of NaCl on metabolic heat evolution rates by barley roots.

The effect of salinity stress on metabolic heat output of barley (Hordeum vulgare L.) root tips was measured by isothermal microcalorimetry. Several varieties differing in tolerance to salinity were compared and differences quantified. Two levels of inhibition by increasing salt were found. Following the transition from the initial rate of the first level, inhibition remained at about 50% with further increases in salt concentration up to 150 millimolar. The concentration of salt required to inhibit to this level was cultivar dependent. At highter concentrations (>150 millimolar) of salt, metabolism was further decreased. This decrease was not cultivar dependent. The decreased rate of metabolic heat output at the first transition could be correlated with decreases in uptake of NO3-, NH4+, and Pi that occurred as the salt concentration was increased. The high degree of dependence of the inhibition of metabolic heat output on NaCl concentration points to a highly cooperative reaction responsible for the general inhibition of metabolism and nutrient uptake. The time required to attain the first level of salt inhibition is less than 20 minutes. Inhibition of root tips was not reversible by washing with salt free solutions. In addition to revealing these features of salt inhibition, isothermal microcalorimetry is a promising method for convenient and rapid determination of varietal differences in response to increasing salinity.

Biological Transport↗
PubMed2001

Salt-induced expression of the vacuolar H+-ATPase in the common ice plant is developmentally controlled and tissue specific.

For salinity stress tolerance in plants, the vacuolar type H+-ATPase (V-ATPase) is of prime importance in energizing sodium sequestration into the central vacuole and it is known to respond to salt stress with increased expression and enzyme activity. In this work we provide information that the expressional response to salinity of the V-ATPase is regulated tissue and cell specifically under developmental control in the facultative halophyte common ice plant (Mesembryanthemum crystallinum). By transcript analysis of subunit E of the V-ATPase, amounts did not change in response to salinity stress in juvenile plants that are not salt-tolerant. In a converse manner, in halotolerant mature plants the transcript levels increased in leaves, but not in roots when salt stressed for 72 h. By in situ hybridizations and immunocytological protein analysis, subunit E was shown to be synthesized in all cell types. During salt stress, signal intensity declined in root cortex cells and in the cells of the root vascular cylinder. In salt-stressed leaves of mature plants, the strongest signals were localized surrounding the vasculature. Within control cells and with highest abundance in mesophyll cells of salt-treated leaves, accumulation of subunit E protein was observed in the cytoplasm, indicating its presence not only in the tonoplast, but also in other endoplasmic compartments.

Gene Expression Regulation, Developmental↗
PubMed2006

Chronic effect of NaCl salinity on a freshwater strain of Daphnia magna Straus (Crustacea: Cladocera): a demographic study.

Daphnia magna is mainly recognized as a freshwater cladoceran, but there are some strains that grow in brackish waters. The tolerance to salinity of a freshwater strain was assessed at NaCl concentrations of 0, 2, 4, 6, and 7 g L(-1). The green microalga Ankistrodesmus falcatus was fed at optimal concentration (4 x 10(5)cells mL(-1)). Reproduction and survival were recorded in two experimental series: in the first one, 20 female neonates were individually studied for each treatment. In the second, cohorts of 10 female neonates were distributed in each of five replicates per treatment. In both cases, experiments were conducted over a full life-cycle. The determined 48-h LC(50) for NaCl was 5.48 g L(-1), but we recorded reproduction at up to 7 g NaCl L(-1). The average clutch size, total progeny, number of clutches, and longevity were significantly reduced by the NaCl concentration (P<0.01); total progeny ranged from 467 to 25 neonates as edge values for NaCl concentrations of 0-7 g L(-1). Inter-brood time was significantly higher for females grown at 7 g NaCl L(-1) (3.9 days). The Life Table analysis demonstrates that average lifespan, life expectancy at birth, net reproductive rate and intrinsic rate of growth were also significantly reduced according to NaCl concentration. Based on the results for the two highest NaCl concentrations (6 and 7 g L(-1)), we conclude that the used D. magna strain was acclimated to develop satisfactorily under concentrations of up to 6 g NaCl L(-1); however, the established salinity conditions reduced significantly reproduction and survival in this strain.

Animals↗
PubMed1988

Morphine effects on gentamicin disposition and toxicity in mice.

Morphine has been shown to reduce renal and hepatic clearance of several xenobiotics in rodents. After iv administration of gentamicin, 10 to 30 mg/kg, its plasma levels were elevated in mice given morphine, 20 mg/kg sc. Plasma clearance of gentamicin was nearly halved by morphine, due primarily to lowering of the elimination constant of gentamicin from 0.03 to 0.02 min-1 (p less than 0.01). Morphine also significantly reduced urine levels of gentamicin and urine volume. In mice given naloxone, 2 mg/kg sc, morphine did not significantly raise plasma levels of gentamicin nor reduce its elimination into urine. Mice were made tolerant by morphine administration for 9 days at ascending doses to 100 mg/kg twice daily. An acute challenge with morphine, 20 mg/kg, was less effective in raising plasma levels of gentamicin or lowering its urinary elimination in tolerant mice than after chronic saline treatment. Partial tolerance to acutely administered morphine and reversal of morphine effects by naloxone suggest opioid receptor-mediated reduction of glomerular filtration by morphine in mice. Despite marked elevation of plasma gentamicin levels in morphine-treated mice, narcotic administration did not significantly increase the acute toxicity of a single dose of gentamicin. LD50 of acutely administered iv gentamicin was 51.6 mg/kg after saline and 45.3 mg/kg after treatment with morphine, 20 mg/kg sc. However, this dose of morphine enhanced the lethality of intravenously infused gentamicin. Morphine administration significantly reduced the dose of infused gentamicin needed to achieve the critical lethal plasma level.

Animals↗
PubMed1976

Evidence for the presence of nasal salt glands in the roadrunner and the Coturnix quail.

The purpose of this investigation was to determine whether or not the nasal glands of the roadrunner and the Coturnix quail show cytological specializations for salt secretion. In addition, the Na-K ATPase content of the quail gland was determined before and after drinking of saline solutions, in an effort to evaluate the functional status of the gland. The ability to maintain weight while drinking salt water was also measured as a general index of tolerance to saline conditions. The ultrastructure of the nasal glands of the roadrunner injected with salt and of quail drinking 200 mM NaCl was similar to that of salt glands in reptiles and the fresh-water acclimated duck. Numerous lateral cell evaginations and abundant mitochondria were present in the principal cell types. There was a significant increase in quail nasal gland Na-K ATPase when young birds were offered only saline solutions to drink. The ability of Coturnix quail to maintain weight while drinking saline solutions improves with age and at adulthood is comparable to that of some North American desert quail. Roadrunners were previously known to possess functional salt glands whereas quail were not. However the characteristic fine structure and the high Na-KATPase content of the quail nasal gland suggest that it is a salt gland.

Adenosine Triphosphatases↗
PubMed2004

Spermine accumulation under salt stress.

Polyamines have long been recognized to be linked to stress situations, and it is generally accepted that they have protective characteristics. However, little is known about their physiological relevance in plants subjected to long-term salt stress. In order to precise their importance, two rice (Oryza sativa) cultivars differing in their salt tolerance were salinized for 7, 14 and 21 days. The activities of some of the enzymes involved in polyamine metabolism, free polyamines and proline contents were evaluated. Arginine decarboxylase and S-adenosyl-L-methionine decarboxylase activities were reduced in both cultivars as a consequence of salt treatment. However, spermidine synthase activity was reduced in the salt tolerant cultivar (var Giza) but not in the salt sensitive (var El Paso), while no polyamine oxidase activity was detected. During the salinization period, putrescine and spermidine levels decreased in both cultivars, although less dramatically in Giza. Simultaneously, spermine accumulations occur in both varieties, while proline accumulation was major in the sensitive one. However, spermine accumulation induced by treatment with spermidine synthase inhibitor cyclohexylamine, determined no reduction in leaf injury associated with salt stress in both cultivars. The data presented suggest that spermine accumulation is not a salt tolerance trait.

Oryza↗
PubMed2004

Effect of caudal epidural xylazine on intraoperative distress and post-operative pain in Holstein heifers.

OBJECTIVE: To compare the effects of caudal epidural xylazine versus saline on tolerance of paravertebral nerve block and flank surgery and on post-operative pain in heifers used for a veterinary student training laboratory. STUDY DESIGN: Randomized controlled prospective study. ANIMALS: Fourteen one-year-old, nongravid, healthy Holstein heifers, weighing 360 +/- 5 kg. METHODS: Xylazine (0.05 mg kg(-1)) or 0.9% saline (5 mL) was injected using a caudal epidural technique to seven heifers undergoing a flank surgery. Nerve block of the right paravertebral fossa was performed using equal parts of lidocaine 2% and bupivacaine 0.5%. Heart and respiratory rates, rectal temperature, rumination frequency, and appetite were recorded before and at 4, 8, and 24 hours after surgery. Scores were recorded for: tolerance of local anesthesia injections (pre-operatively), sedation, ataxia and distress (intraoperatively, every 30 minutes), and pain (4, 8, and 24 hours post-operatively). RESULTS: The animals reaction to local anesthetic injection was judged to be less in the xylazine group by both an experienced observer (p<0.001) and student surgeons (p<0.01). The xylazine group required less local anesthetic (82.9 +/- 13.8 mL) versus the saline group (108.4 +/- 19.6 mL, p=0.035). Intraoperatively, xylazine heifers were more sedated at all times (p-values from <0.001 to 0.017), were more ataxic for the first 1.5 hours (p-values from <0.001 to 0.026), and lower in distress at all times (p-values from <0.001 to 0.007). No difference in post-operative pain or physiologic variables was found, except immediately post-operatively, rectal temperature was higher in the xylazine group (39.5 +/- 0.3 degrees C) than in the saline group (38.6 +/- 0.2 degrees C, p<0.001). CONCLUSION AND CLINICAL RELEVANCE: Compared with epidural saline, caudal epidural xylazine reduced distress of anesthetic injection and surgical manipulation in heifers and an improvement in animal well-being was apparent. This effect may have been as a result of sedation. Pre-operative epidural xylazine did not appear to improve post-surgical analgesia in our study.

Analgesia, Epidural↗
PubMed1985

Tolerance to alcohol's anticonvulsant effect is not under Pavlovian control.

Tolerance to the anticonvulsant effect of alcohol has been shown to be contingent on the presence of convulsive stimulation during the period of intoxication. In the present experiments, manipulation of the environmental stimuli associated with alcohol administration had no effect on the development of tolerance to alcohol's anticonvulsant effect in kindled rats. Such tolerance was found not to be specific to the alcohol-predictive environment, nor was its development retarded by pre-exposing the subjects to an environment that was subsequently associated with alcohol administration. Moreover, an injection of saline to tolerant subjects in the alcohol-predictive environment did not elicit a conditioned compensatory increase in seizure duration. Thus, the Pavlovian theory of drug tolerance cannot account for the contingent tolerance that develops to alcohol's anticonvulsant effect.

Amygdala↗
PubMedDate not supplied

Rhizosphere acidification and cadmium uptake by strawberry clover.

Strawberry clover (Trifolium fragiferum L.) is a hardy legume found in indigenous or introduced populations throughout the world. Tolerance to saline and alkaline soils, flooding, and heavy metals make it a good prospect for reclamation projects. The research, described here, was conducted to: (i) characterize the morphological variation in plants from available seed sources, (ii) evaluate cadmium uptake and tolerances over a wide range of morphological variants, and (iii) elucidate the variability in the effects of roots on rhizosphere pH and the relationship to cadmium uptake. Seeds from selected accessions were planted in the greenhouse for comparison of morphological variation. The accessions examined had a mean height of 10.7+/-7 cm. Accessions 254916 and 237925 are tall with high rhizosphere pH values and might be useful in phytoremediation. Strawberry clover accessions were also grown hydroponically to examine differences in cadmium uptake. The ability of strawberry clover roots to change rhizosphere pH and take up cadmium was examined using culture tubes containing nutrient agar, a moderate level of cadmium, and a pH indicator dye. The results provided evidence for a negative correlation between rhizosphere pH and cadmium uptake.

Biodegradation, Environmental↗
PubMed2005

Comparative transcriptional profiling of two contrasting rice genotypes under salinity stress during the vegetative growth stage.

Rice (Oryza sativa), a salt-sensitive species, has considerable genetic variation for salt tolerance within the cultivated gene pool. Two indica rice genotypes, FL478, a recombinant inbred line derived from a population developed for salinity tolerance studies, and IR29, the sensitive parent of the population, were selected for this study. We used the Affymetrix rice genome array containing 55,515 probe sets to explore the transcriptome of the salt-tolerant and salt-sensitive genotypes under control and salinity-stressed conditions during vegetative growth. Response of the sensitive genotype IR29 is characterized by induction of a relatively large number of probe sets compared to tolerant FL478. Salinity stress induced a number of genes involved in the flavonoid biosynthesis pathway in IR29 but not in FL478. Cell wall-related genes were responsive in both genotypes, suggesting cell wall restructuring is a general adaptive mechanism during salinity stress, although the two genotypes also had some differences. Additionally, the expression of genes mapping to the Saltol region of chromosome 1 were examined in both genotypes. Single-feature polymorphism analysis of expression data revealed that IR29 was the source of the Saltol region in FL478, contrary to expectation. This study provides a genome-wide transcriptional analysis of two well-characterized, genetically related rice genotypes differing in salinity tolerance during a gradually imposed salinity stress under greenhouse conditions.

Base Sequence↗
PubMed1991

Novel biotreatment process for glycol waters.

Propylene oxide (PO), propylene glycol (PG), and polyols are produced from propylene via propylene chlorohydrin. Effluents from these plants contain biological oxygen demand/chemical oxygen demand (BOD/COD) loads besides high chloride concentrations. The high salinity poses severe problem to adopt conventional methods like activated sludge processes. Presently, a simple, economically viable and versatile microbiological process has been developed to get more than 90% biodegradation in terms of BOD/COD, utilizing specially developed Pseudomonas and Aerobacter. The process can tolerate high salinity up to 10 wt% NaCl or 5 wt% CaCl2 and can withstand wide variations in pH (5.5-11.0) and temperature (15-45 degrees C). The biodegradation of glycols involves two steps. The enzymatic conversion of glycols to carboxylic and hydroxycarboxylic acids is aided by Pseudomonas. Further degradation to CO2 and H2O by carboxylic acid utilizing Aerobacter, and possible metabolic degradative pathway of glycols are discussed. Various process parameters obtained in the lab scale (50 L bioreactor) and pilot scale (20 m3 bioreactor), and unique features of our process are also discussed.

Biodegradation, Environmental↗
PubMedDate not supplied

Place-aversion conditioned by phencyclidine in rats: development of tolerance and pharmacologic antagonism.

The pharmacologic properties of phencyclidine were assessed in adult, male rats using a three-chambered, place-conditioning apparatus. Phencyclidine hydrochloride (PCP), at doses of 0.5 to 4 mg/kg, produced a dose-related place-aversion after three drug/environment pairings. During the place-conditioning procedure, 4 mg/kg of PCP significantly increased spontaneous locomotor activity compared to saline-control. Tolerance to PCP-induced place-aversion developed after four daily administrations of 4 mg/kg of PCP. d-Butaclamol, 0.4 mg/kg, given 1 min before each of the three conditioning-doses of PCP decreased the development of the place-aversion induced by PCP. 1-Butaclamol was without significant effect. Spiroperidol, 0.06 mg/kg, completely blocked the development of PCP place-aversion. Spiroperidol and the stereoisomers of butaclamol did not have significant place-conditioning activity when administered alone in the place-conditioning paradigm. The data suggest that PCP induces place-aversion in rats in the place-conditioning model, and that tolerance to this effect develops within 4 days. Furthermore, since d-butaclamol or spiroperidol, but not 1-butaclamol, antagonized this effect of PCP, PCP-induced place-aversion may be mediated in part by a dopaminergic mechanism.

Animals↗
PubMed1998

The effects of salinity, pH and temperature on the half-life and longevity of Echinostoma caproni miracidia.

Miracidia of Echinostoma caproni were exposed to solutions varying in salinity, pH, and temperature in 1 ml concavity slides. Half-lives of the miracidial populations were determined and longevity curves constructed to find maximum life spans of the miracidia in the different conditions. Control miracidia in aquarium water at pH 7.2 and 22 degrees C. had a half-life of 3.6 h and a maximum life span of 9 h. Miracidia of E. caproni were not very tolerant of saline solutions from 0.1% to 0.4%, the latter being lethal within an hour. A bimodal effect was found with exposure to aquarium water of varying pH, with a peak at pH 5 in acid solutions and pH 9 in alkaline solutions. Miracidia tolerated pH ranges from 3 to 11 exhibiting half-lives of 2.4 h or greater in these solutions. At lower than ambient temperatures, E. caproni miracidia lived longer, the greatest being a half-life of 5.0 h and a maximum life span of 15 h at 5 degrees C. At warmer temperatures, the half-life was reduced until lethality was reached at 40 degrees C. ANCOVA analysis of log transformed longevity curves supported the observation that in pH trials many miracidia survived initially with a major die-off after 3.3 h. The opposite trend of early die-off and gradual mortality of the survivors was supported in the temperature trials.

Animals↗
PubMed1986

Differential protracted effects of morphine and ethylketocyclazocine challenges on EEG and behavior in the rat.

One group of six adult female Sprague-Dawley rats was given a series of automatically administered i.v. morphine injections over eight days. Similarly, a second group of six rats was given ethylketocyclazocine (EKC). Control rats received chronic i.v. saline injections. Tolerance to EEG and behavioral effects of morphine and EKC was demonstrated. At 15 days morphine post-withdrawal, morphine challenges produced EEG and behavioral stupor for a mean of 5 min, followed by EEG and behavioral arousal for a mean of 131 min. In contrast, morphine challenges in saline control rats produced a biphasic EEG and behavioral response consisting of a mean of 85 min of stupor, followed by a mean of 88 min of arousal. However, at 15 days EKC post-withdrawal, EKC challenges produced a biphasic EEG and behavioral response consisting of a mean of 57 min of depression followed by a mean of 55 min of arousal; control saline rats demonstrated similar responses to EKC challenges. Similar results were obtained at one month post-withdrawal for all groups. Thus, protracted effects on EEG and behavior were evident in rats chronically treated with morphine, but not in rats chronically treated with EKC.

Animals↗
PubMed1991

The role of opioid receptor density in morphine tolerance.

The effect of chronic opioid antagonist-induced functional supersensitivity and receptor upregulation on morphine tolerance was examined in Swiss Webster mice obtained from Taconic Farms and Charles River Laboratories. Mice were implanted s.c. with either naltrexone (NTX) or placebo pellets for 8 days. After 8 days, the pellets were removed, and 24 h later mice were either injected with morphine (50 or 100 mg/kg) or saline (acute tolerance protocol) or implanted with a 75-mg morphine or placebo pellet for 72 h (chronic tolerance protocol). Mice were tested for morphine analgesia 24 h after injections or 72 h after pellet implantations. Mice from Taconic Farms were more sensitive to morphine analgesia than Charles River mice, although the degree of tolerance in both strains was similar. Acute morphine produced a 1.7- and 1.9-fold increase in the ED50 for morphine analgesia in NTX and placebo pretreated mice, respectively. the chronic tolerance protocol produced the same shift (2.4-fold) in the ED50 in both NTX and placebo pretreated mice. In both tolerance protocols, NTX-pretreated mice were significantly more sensitive to the analgesic effects of morphine than placebo pretreated controls. Binding studies ([3H][D-Ala,2NMePhe4,Gly-ol5]enkephalin) indicated an approximately 40% increase in opioid receptor density with no significant alteration in affinity after chronic NTX treatment. These results indicate that acute and chronic tolerance to morphine develops comparably in control and upregulated, supersensitive mice. These findings suggest that new binding sites in upregulated mice mediate tolerance similarly to existing binding sites and that the degree of tolerance is unrelated to the density of opioid receptors.

Animals↗
PubMed2006

Interdose interval effects on the development of contextual tolerance to nicotine's analgesic effects in rats (Rattus norvegicus).

Learning models of associative and nonassociative drug tolerance predict that the development of contextual tolerance to drug effects is disrupted when the drug is delivered at short interdose intervals (IDIs). The authors examined the impact of 1 long IDI and 2 short IDIs in the development of contextual nicotine tolerance. Associative tolerance was investigated by giving rats (Rattus norvegicus) 10 subcutaneous injections of nicotine at either long (72-hr) IDIs or short (6-hr and 4.5-hr) IDIs. The delivery of nicotine was either explicitly paired or explicitly unpaired with a distinctive context. A 3rd group of rats was exposed to the experimental procedures but received only saline. Associative tolerance to nicotine's analgesic effects was defined as a shift to the right of the dose-response curve (DRC) of rats in the explicitly paired condition with respect to the DRC of rats in the explicitly unpaired condition. Analgesia was assessed with the tail-flick and hot-plate devices. In the tail-flick assessment, associative tolerance was evident in the 72-hr and the 6-hr IDI conditions only. In the hot-plate assessment, associative tolerance was present in the 72-hr IDI condition only. The findings suggest that contextual tolerance to nicotine's analgesic effects are positively related to IDI length and are more readily demonstrated with the tail-flick method than with the hot-plate method. Overall, the results supported the thesis that nicotine tolerances that develop to different IDIs are qualitatively different and may be mediated by different psychological and physiological mechanisms.

Analgesics↗
PubMed2000

Alfin1 transcription factor overexpression enhances plant root growth under normal and saline conditions and improves salt tolerance in alfalfa.

Plant root development is an essential determinant of plant growth and crop yield that could be enhanced by induced changes in the expression of root-specific regulatory factors. We reported previously that Alfin1 binds DNA in a sequence-specific manner and that Alfin1 overexpression in transgenic alfalfa (Medicago sativa L.) enhances expression of the salt-inducible MsPRP2 gene in roots, suggesting that Alfin1 functions to regulate gene expression in roots. Here we show that Alfin1 is an essential gene for root growth and that its overexpression in transgenic plants confers a many-fold increase in root growth under normal and saline conditions. Alfin1-binding sites occur in promoters of genes expressed in roots of a wide variety of plant species and we propose that it is a general root growth regulator. Even though Alfin1 overexpression was under the control of the CaMV 35S promoter, plant shoot growth was not adversely affected. We show further that introduction of the Alfin1 transgene in plants confers a dominant characteristic that significantly increases plant growth and salt tolerance.

Caulimovirus↗