Genotoxicity of soil from farmland irrigated with wastewater using three plant bioassays.

Three well known plant bioassays, the Allium root chromosome aberration (AL-RAA) assay, the Tradescantia micronucleus (Trad-MCN) assay, and the Tradescantia stamen hair (Trad-SHM) mutation assay were validated in 1991 by the International Programme on Chemical Safety (IPCS) under the auspices of the World Health Organization, and the United Nations Environment Programme (UNEP). These plant bioassays have proven to be efficient tests for chemical screening and especially for in situ monitoring for genotoxicity of environmental pollutants. As a result of this validation study, standard protocols of these three plant bioassays were used by some of the 11 participating countries in the IPCS to carry on genotoxicity tests on air, water and soil as a follow up activity. In the city of Queretaro, Mexico, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the farm crops, polluting the soil. Potentially the pollutants could reach the food chain. For the above reason, soil irrigated with wastewater was sampled and monitored for the presence of genotoxic agents using the above three bioassays. Extracts from soil samples were made using distilled water and organic solvents by shaking the sample for about 12 h under a relatively low temperature (15-20 degrees C). Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the extracts. Three replicates of each sample were analyzed in each of the three bioassays. Extracts using DMSO, ethanol and distilled water tested positive in the three bioassays and there were no differences for the genotoxicity of the extracts with the different solvents.     

Anticlastogenic effect of Spirulina maxima extract on the micronuclei induced by maleic hydrazide in Tradescantia

The aim of this investigation was to determine if extracts of Spirulina maxima reduce the genotoxic damage induced by maleic hydrazide (MH) using the Tradescantia biosssay. Two types of extracts from the alga were prepared: an aqueous extract with two different concentrations, 100 and 500 mg/ml, and a second one, the extract of a 1% solution of dimethyl sulfoxide (DMSO) which corresponded to 100 mg/ml of the alga. The capacity of MH to induce micronuclei (MN) was initially established by administering 0.005, 0.01, and 0.015 mg/ml of the chemical to the Tradescantia inflorescences, and observing its effect after 24 h.The results of this experiment showed a significant MN increase with the two high concentrations tested, although no dose-response effect was observed. For the anticlastogenic assay, the extracts of Spirulina were applied to the inflorescences alone or immediately before the application of MH (0.01 mg/ml) and the induced MN were observed 24 h later. We found that none of the extracts increased the MN level with respect to the untreated plants; also, that MH more or less doubled the basal micronuclei frequency, and finally, that all tested extracts reduced the genotoxic damage caused by MH. The inhibitory indices obtained for the aqueous extracts (100 and 500 mg/ml) and for the DMSO extract were respectively 59, 85, and 56.3%. These data indicate that Spirulina is an anticlastogenic agent and suggest that it is advisable to extend studies on this matter using other biological models.     

Assessment of the genotoxicity of contaminated soil with the Allium/Vicia-micronucleus and the Tradescantia-micronucleus assays.

The present study concerns the genotoxicity of contaminated soil near Metz, France. Three plant bioassays, the Vicia faba (broad bean), the Allium cepa (white onion) and the Tradescantia (spiderwort) micronuclei tests were used to evaluate for genotoxicity. Two soil samples were tested: soil sample A (from an industrial waste site) and soil sample B (from a cokeworks waste site). Maleic hydrazide was used as the positive control. Aqueous extracts of the soil samples were used to treat the roots of Vicia and Allium, and plant cuttings of Tradescantia according to the standard protocol for these plant assays established by the International Program on Chemical Safety and the World Health Organization. The results of these tests showed differential sensitivity in the three different bioassays. Soil sample A was more toxic than soil sample B.     

Impact of microgravity on radiobiological processes and efficiency of DNA repair

Three major plant bioassays, i.e., the Allium root anaphase aberration (Allium-AA), the Tradescantia-micronucleus (Trad-MCN) and the Tradescantia stamen hair mutation (Trad-SHM) tests, were utilized in soil solutions or shallow well water samples to determine the degree of their genotoxicity. Shallow well water samples were collected from five different farms, and soil solutions were extracted with distilled water or dimethyl sulfoxide (DMSO) from pesticide-contaminated (metolachlor, atrazine, extrazine, and 2, 4-D) and pesticide-free soil samples. Genotoxicity was expressed in terms of anaphase aberration (AA) frequencies in the Allium-AA test, in terms of micronuclei frequencies in the Trad-MCN test, and in terms of pink mutation events in the Trad-SHM test. On average, results of Allium-AA tests showed a 2.78-3.01 fold increase in anaphase aberration frequencies in contaminated soil solution samples and well water samples as compared with the negative control. Results of Trad-MCN tests showed a 1.66-4.75 fold increase of MCN frequencies in contaminated soil solution samples and shallow well water samples as compared with the frequencies of the controls. Results of Trad-SHM tests showed a 2.7-2.86 fold increase of pink mutation events in the contaminated soil solution samples over that of the controls. Control groups of the Allium-AA tests had an average of 0.75/1000 anaphase figures, and control groups of the Trad-MCN tests had an average of 3.2 MCN/100 tetrads, while control groups of the Trad-SHM tests had an average of 1.4 mutation events/1000 hairs. In general, soil solutions of DMSO extracts showed higher genotoxicity than that of distilled water extracts. Among these three plant bioassays, the Trad-MCN test has the highest efficiency. The highest toxicity, based upon the Trad-MCN test results, was found in the pesticide contaminated soil samples from Monroe's farm. Water samples from the Fountain Green/Bushnell area ranked second in genotoxicity.     

Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. III. Concentration and genotoxicity of mercury in the industrial effluent and contaminated water of Rushikulya estuary, India.

Aquatic mercury pollution of the Rushikulya estuary in the vicinity of the chloralkali plant at Ganjam, India was monitored over a period from October 1987 to May 1989. The concentrations of aquatic mercury in the water samples taken from the effluent channel and from different sites along the course of the estuary covering a distance of 2 km were periodically recorded and ranged from 0 to 0.5 mg/l. The bioconcentration and genotoxicity of aquatic mercury in the samples were assessed by the Allium micronucleus (MNC) assay. The frequency of cells with MNC was highly correlated not only with bioconcentrated mercury (root mercury) but also with the levels of aquatic mercury. The threshold assessment values such as effective concentration fifty (EC50) for root growth, lowest effective concentration tested (LECT), and highest ineffective concentration tested (HICT) for induction of MNC in Allium MNC assay for the present aquatic industrial mercury were determined to be 0.14, 0.06 and 0.02 mg/l, respectively.     

Nitric oxide facilitates delivery and mediates improved outcome of autologous bone marrow mononuclear cells in a rodent stroke model

Background

Bone marrow mononuclear cells (MNC) represent an investigational treatment for stroke. The objective of this study was to determine the relevance of vasoactive mediators, generated in response to MNC injection, as factors regulating cerebral perfusion (CP), the biodistribution of MNC, and outcome in stroke.

Methods

Long Evans rats underwent transient middle cerebral artery occlusion. MNC were extracted from the bone marrow at 22 hrs and injected via the internal carotid artery or the femoral vein 2 hours later. CP was measured with MRI or continuous laser Doppler flowmetry. Serum samples were collected to measure vasoactive mediators. Animals were treated with the Nitric Oxide (NO) inhibitor, L-NAME, to establish the relevance of NO-signaling to the effect of MNC. Lesion size, MNC biodistribution, and neurological deficits were assessed.

Results

CP transiently increased in the peri-infarct region within 30 min after injecting MNC compared to saline or fibroblast control. This CP increase corresponded temporarily to serum NO elevation and was abolished by L-NAME. Pre-treatment with L-NAME reduced brain penetration of MNC and prevented MNC from reducing infarct lesion size and neurological deficits.

Conclusions

NO generation in response to MNC may represent a mechanism underlying how MNC enter the brain, reduce lesion size, and improve outcome in ischemic stroke.     

Tradescantia bioassays for the determination of genotoxicity of water in the Panlong River, Kunming, People's Republic of China.

The Panlong river passes through Kunming City and receives a large quantity of municipal sewage and wastewater from industrial effluent. Along the river, 20 sites were selected to collect water samples to assess the genotoxicity using two Tradescantia assays, the micronucleus (Trad-MCN) and the stamen-hair-mutation (Trad-SHM) assays. The lowest frequencies in the Trad-MCN assay and the Trad-SHM assay are 3.19 MCN/100 tetrads and 1.32 M/1000 stamen hairs, respectively. In the water samples obtained from the Songhua Reservoir, the MCN frequencies and mutation rates are not statistically significantly different from the data found for the negative control (2.49 MCN/100 tetrads and 0.71 M/1000 stamen hairs). Among the other water samples, 19 in Trad-MCN assay and 17 in Trad-SHM assay show significantly higher genotoxicity than the control. The highest genotoxicity was in samples No. 19 for the MCN assay (8.73 MCN/100 cells), over three times higher than the negative control, and in sample No. 11 for the SHM assay (4.30 M/1000), six times higher than the negative control, and were about the same as for the positive control (10.0 mg/l NaN3, 9.28 MCN/100 tetrads and 7.44 SHM/1000 stamen hairs), respectively. The peak frequencies for the Trad-MCN assays were observed in the water samples obtained from the sites that were near industrial and municipal wastewater that ran into the river as effluent. In general, the frequency of MCN and SHM mutations increased where the river passed through Kunming. The Trad-MCN assay seemed more sensitive than that of the Trad-SHM assay in detecting genotoxicity of the river water pollution.     

The use of Tradescantia and Vicia faba bioassays for the in situ detection of mutagens in an aquatic environment.

Tests have shown plant bioassays to be excellent for mutagenicity studies. Most studies with plant bioassays, however, have been carried out either in the laboratory, or if, in situ, as monitors of atmospheric contaminants. The primary purpose of this study was to assess the utility of in situ plant mutagenicity bioassays in monitoring water contaminants. The assay systems tested were the Tradescantia stamen hair and micronucleus assays for the detection of gene mutations and chromosomal aberrations respectively, and the Vicia faba bioassay system which detects chromosomal aberrations in root tips. The assays were used to test the effluent from a pulp and paper mill located on the north shore of Lake Superior. Assays were performed in a creek containing raw effluent and in the bay of Lake Superior into which the creek emptied. All in situ treatments were carried out for 24 h. The effluent from the creek was heavy with pulp and debris which coated the plant cuttings and the Vicia faba seedlings and may have restricted the uptake from the effluent. In the creek, at test sites 11.5 km from the source, the effluent was toxic to the Vicia faba roots as evidenced by a reduction in the mitotic index. The data for the Tradescantia stamen hair assay in the creek were equivocal. The cuttings from the creek test sites and the air and water control sites appeared to have undergone a physiological delay. Within a day or two after the return to the laboratory, that is 6-8 days after testing, flowering almost ceased and did not fully resume until about day 35. This reduction in flowering was particularly severe with the cuttings from the effluent and air control sites, making it very difficult to interpret the results. In contrast, the Tradescantia micronucleus and Vicia faba chromosomal aberration data were unequivocal; each produced positive responses at both test sites relative to the air and water controls. The results obtained for the bay sites with all 3 assays were in agreement. In that section of the bay visibly contaminated by the creek effluent, increases in stamen hair mutants, micronuclei, and chromosome aberrations were measured. In general, there was a considerable reduction in the number of mutant events observed for the water samples brought back from the test sites and tested in the laboratory.(ABSTRACT TRUNCATED AT 400 WORDS)     

Tradescantia-micronucleus (Trad-MCN) bioassay on clastogenicity of wastewater and in situ monitoring.

The Tradescantia-micronucleus (Trad-MCN) bioassay was used to determine the clastogenicity of wastewater samples collected from the Arena canal which contains effluent from the industrial district Benito Juarez of the city of Queretaro, Mexico. Fifteen wastewater samples which were collected, in most cases, at bi-weekly intervals beginning in September 1986 through February 1988, after a 3-fold dilution were used to treat Tradescantia plant cuttings. The clastogenicity expressed in terms of micronucleus frequencies of treated groups (30 h of treatment without recovery time) was significantly (0.01) higher than that of the tapwater control groups. The Trad-MCN bioassay was also used for in situ monitoring of air pollutants for the clastogenicity at 3 sites near the industrial and residential areas (Flores Magon, Conalep and Bellas Artes) of the city of Queretaro. Fourteen monitoring trips were made to each of the 3 sites at monthly intervals beginning in May 1988 through June 1990. Seasonal variation of micronucleus frequencies was exhibited with the peak clastogenicities shown in May and June 1988, June 1989 and April 1990 at the three sites. Micronucleus frequencies of all the exposed groups at the Conalep site, a predominantly industrial area, were markedly higher than that of the laboratory control groups throughout the 2-year period.     

不同干湿交替频率对土壤速效养分、水溶性有机碳的影响

为了探究不同干湿交替频率对速效养分、DOC的影响机理,选择北京褐土(表层0—10cm土壤)为研究对象,采用室内模拟控制实验法,控制其他变量,设计一系列不同频率的干湿交替实验,在58d内设置了10d土壤培育期和48d试验期,其中48d试验期设置0、1、2、3、4次干湿交替,试验结束(第58天)进行速效养分、水溶性有机碳(DOC,Dissolved organic carbon)等主要土壤速效养分指标测定。采用单因素方差分析与LSD多重比较法进行数据分析,研究结果显示:恒湿组的速效钾、硝态氮含量比干湿交替组高;低频率的干湿交替使得土壤速效钾含量减少,高频率可能在后期出现释钾现象,速效钾含量随着干湿交替频率增加可能会有所增加,趋近恒湿组速效钾水平,4次干湿交替频率是出现速效钾回升的临界次数;硝态氮含量随着频率增加也有增加趋势,低频率的1次干湿交替(DW1,1 drying-rewetting cycle)硝态氮含量最低,高频率的4次干湿交替(DW4,4 dryingrewetting cycles)最高,干湿交替频率增加更频繁的打破平衡,促进矿化,干湿交替组也趋近恒湿组的硝态氮水平。经过干湿交替,土壤中速效钾、铵态氮、DOC的含量下降,硝态氮含量增加,速效磷、pH的变化不明显。在固定时间内(48d),随着干湿交替的频率增加(从1次到2、3、4次),周期变短(从48d到24、16、12d),干燥与湿润的持续时间变短(从24d到12、8、6d),干湿交替组的速效钾、硝态氮含量分别趋于恒湿组的速效钾、硝态氮水平。     

Climate warming alters the relative importance of plant root and microbial community in regulating the accumulation of soil microbial necromass carbon in a Tibetan alpine meadow

Climate warming is predicted to considerably affect variations in soil organic carbon (SOC), especially in alpine ecosystems. Microbial necromass carbon (MNC) is an important contributor to stable soil organic carbon pools. However, accumulation and persistence of soil MNC across a gradient of warming are still poorly understood. An 8-year field experiment with four levels of warming was conducted in a Tibetan meadow. We found that low-level (+0–1.5°C) warming mostly enhanced bacterial necromass carbon (BNC), fungal necromass carbon (FNC), and total MNC compared with control treatment across soil layers, while no significant effect was caused between high-level (+1.5–2.5°C) treatments and control treatments. The contributions of both MNC and BNC to soil organic carbon were not significantly affected by warming treatments across depths. Structural equation modeling analysis demonstrated that the effect of plant root traits on MNC persistence strengthened with warming intensity, while the influence of microbial community characteristics waned along strengthened warming. Overall, our study provides novel evidence that the major determinants of MNC production and stabilization may vary with warming magnitude in alpine meadows. This finding is critical for updating our knowledge on soil carbon storage in response to climate warming.     

Mutagenicity of drinking water detected by the Tradescantia micronucleus test

Spring Lake reservoir of Macomb, Illinois, is a typical model of the drinking water supply of some midwestern towns of the United States. Water samples collected periodically in 1980 and 1981 from this lake were tested for mutagenicity using the Tradescantia micronucleus (Trad-MCN) test, a highly sensitive mutagen-detecting bioassay. Water samples from 1981 were also analyzed chemically. The micronucleus (MCN) frequency peaked (12-14 MCN/100 tetrads) in mid-July in both years, as compared with the average frequency (5 MCN/100 tetrads) of the base-line control that was maintained in nutrient solution (prepared with distilled water and pure chemicals). Drinking water from the tap was tested in parallel with lake water, and its mutagenicity tended to fluctuate with the mutagenicity of the lake water.     

Effect of cryoprotectants on certain seminal attributes and on the fertility of buck spermatozoa

Semen samples were obtained from 12 bucks (3 Beetal, 3 Black Bengal and 6 Beetal x Black Bengal) and 10 different extenders were constituted with varying concentrations of glycerol, DMSO, glycerol + DMSO and glycerol + lactose as the sperm cryoprotective agents. After the collection of semen samples, they were assessed for quality, diluted in different extenders after removal of seminal plasma, packaged in ministraws and frozen after equilibration (5'C) for 5 h. The samples were evaluated immediately after equilibration and again 24 h after freezing for progressive motility, percentage of live spermatozoa and acrosome, head and tail abnormalities. Both motility and the percentage of live spermatozoa were most affected by extenders containing only DMSO and these values improved in glycerol + DMSO extenders as the concentration of glycerol was increased while DMSO was decreased. However, these values were significantly higher in extenders containing glycerol + lactose as the cryoprotective agents, and were found to increase with increased concentration of lactose, being highest in TYGL (180). Acrosomal and tail abnormalities tended to increase between post equilibration and post thawing stage, and were higher in extenders containing the higher levels of DMSO. Significantly (P < 0.01) lower percentages of abnormalities were recorded in the glycerol + lactose extenders. The fertility results showed nonsignificant effect of extenders on the conception rate of does.     

Genotoxicity evaluation in chronic renal patients undergoing hemodialysis and peritoneal dialysis, using the micronucleus test

Patients with chronic renal disease have an increased incidence of cancer. It is well known that long periods of hemodialysis treatment are linked to DNA damage due to oxidative stress. This genotoxic effect may cause the loss of chromosome fragments, or even entire chromosomes, which form micronuclei after cell division, and can be detected by the micronucleus test. In the present case-control study, we evaluated the genotoxic effect of hemodialysis treatment in 20 patients undergoing hemodialysis, and 20 subjected to peritoneal dialysis, matched for gender and age with 40 controls. Genetic damage was assessed by examining the frequency of micronuclei in 2000 exfoliated buccal cells per individual. Our results revealed that patients undergoing hemodialysis treatment have a significantly higher frequency of micronucleated cells (MNC; 5.60 +/- 5.31) compared to control subjects (1.50 +/- 2.01, p < 0.01). Interestingly, the same was not observed for the peritoneal dialysis patients who showed no significant differences in MNC (2.85 +/- 2.96) frequency compared to control individuals (3.25 +/- 3.85). In addition, we evaluated the possible association between creatine levels, smoking, alcohol intake, age, duration of treatment, and incomes of the individuals (separately analyzed according to their gender) and the frequency of micronuclei. The results reported here indicate that the duration of treatment is the only factor associated with increased MNC frequency among hemodialysis patients (Spearman coefficient of 0.414, p = 0.01). The number of MNC found in individuals with six years or less of treatment was significantly lower (2.91 +/- 2.74) compared to patients with seven or more years of treatment (8.89 +/- 5.96, p < 0.05). Overall, peritoneal dialysis may be a safer choice of treatment, but further studies need to be performed to investigate the risks and benefits of both treatments.     

Adrenomedullin enhances therapeutic potency of bone marrow transplantation for myocardial infarction in rats

Adrenomedullin (AM), a potent vasodilator, induces angiogenesis and inhibits cell apoptosis through the phosphatidylinositol 3-kinase/Akt pathway. Transplantation of bone marrow-derived mononuclear cells (MNC) induces angiogenesis. We investigated whether infusion of AM enhances the therapeutic potency of MNC transplantation in a rat model of myocardial infarction. Immediately after coronary ligation, bone marrow-derived MNC (5 x 10(6) cells) were injected into the ischemic myocardium, followed by subcutaneous administration of 0.05 microg x kg(-1) x min(-1) AM (AM-MNC group) or saline (MNC group) for 3 days. Another two groups of rats received subcutaneous administration of AM alone (AM group) or saline (control group). Hemodynamic and histological analyses were performed 4 wk after treatment. Cardiac infarct size was significantly smaller in the MNC and AM groups than in the control group. A combination of AM infusion and MNC transplantation demonstrated a further decrease in infarct size. Left ventricular (LV) maximum change in pressure over time and LV fractional shortening were significantly improved only in the AM-MNC group. AM significantly increased capillary density in ischemic myocardium, suggesting the angiogenic potency of AM. AM infusion plus MNC transplantation demonstrated a further increase in capillary density compared with AM or MNC alone. Although MNC apoptosis was frequently observed 72 h after transplantation, AM markedly decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells among the transplanted MNC. In conclusion, AM enhanced the angiogenic potency of MNC transplantation and improved cardiac function in rats with myocardial infarction. This beneficial effect may be mediated partly by the angiogenic property of AM itself and by its antiapoptotic effect on MNC.     

Evaluation of the genotoxicity of treated urban sludge in the Tradescantia micronucleus assay

The sludge produced in sewage treatment plants can contain toxic substances. Among these, the genotoxic substances are of great concern. The present paper aimed at evaluating the genotoxicity of treated sludge samples collected at four different sewage treatment plants (STP) located in the State of S?o Paulo, Brazil using the Trad-MN assay. Another objective of the study was to compare the responses of the Clone #4430 with the Tradescantia pallida. Sludge samples mixed with reference soil in concentrations of 10, 25 and 50% (v/v) were tested in experiments with 3 months exposure in the field. Negative and positive controls (arsenic trioxide) were also tested with both plants. In Clone #4430 two sludge samples induced genotoxicity while in T. pallida three were positive, although no clear dose-response were observed for both plants. Results with the negative and positive controls suggest that T. pallida presented similar results when compared to the Clone #4430. The protocol using plants chronically exposed to sludge mixed with soil seems to be a promising tool to assess the genotoxicity of sludge although time consuming.     

Biomonitoring of low levels of mercurial derivatives in water and soil by Allium micronucleus assay

The Allium micronucleus (MNC) assay was developed to monitor low levels of mercury in aquatic and terrestrial environments. Four mercurial derivatives namely mercuric chloride (MC), methyl mercuric chloride (MMC), phenyl mercuric acetate (PMA) and a methoxy ethyl mercuric chloride based fungicide, Emisan-6, were tested to assess the sensitivity and versatility of the Allium MNC assay. Allium bulbs were set directly on water and soil contaminated with known levels of mercurial derivatives (0.0001-10.00 ppm). On the 5th day the endpoints measured were root length, mitoses with spindle abnormality and cells with MNC in root meristems. The effective concentrations of the test chemicals that cause 50% of root length as compared to control (EC50) were determined from dose-response curves so obtained. The lowest effective concentration tested (LECT) and highest ineffective concentration tested (HICT) for each of the mercurial derivatives for the induction of spindle malfunction and MNC were determined. It was found that EC50, LECT and HICT values for mercurial derivatives in soil were higher than those in water. The frequencies of cells with MNC and mitoses with spindle abnormality were highly correlated indicating that MNC is a good parameter of spindle malfunction. The present approach increased the sensitivity of the Allium assay by 10-fold, the detection limit being 0.001-0.1 ppm and 0.1-1.0 ppm in aquatic and terrestrial environments respectively, depending on the species of mercury.     

Hypothalamic sites of catecholamine inhibition of luteinizing hormone in the anestrous ewe.

Norepinephrine (NE) and dopamine (DA) actively inhibit the release of LH in anestrous ewes. This can be detected as an increase in LH pulse frequency following i.v. injection of NE and DA antagonists. The objective of this study was to determine the sites of these inhibitory actions in the ovine hypothalamus by using local administrations of the NE antagonist, phenoxybenzamine (PBZ), or the DA antagonist, pimozide (PIM), into specific hypothalamic areas. Each neurotransmitter antagonist was administered via a chronically implanted steel guide tube into either the preoptic area (POA), retrochiasmatic area (RCh), or the median eminence region (ME). Blood samples were taken every 15 min for 2 h before and 4 h during implantation of these drugs and were analyzed for LH and prolactin by RIA. Control (no treatment) samples were obtained similarly from the same animals on another day. Placement of PBZ into the POA significantly increased LH pulse frequency and mean LH concentrations over control values whereas PIM did not. In contrast, PIM significantly increased LH pulse frequency and mean LH concentrations when placed in the ME or in the RCh, but PBZ did not. No effects of PIM on prolactin concentrations were detected. These results suggest that an NE neural system operates in the POA and that a DA system acts in the medial basal hypothalamus (RCh or ME) to suppress GnRH pulse frequency in the ovary-intact anestrous ewe.     

Mutagenicity of ground water (in the bore-holes) in Ararat Valley (Armenia) detected by Trad-SHM bioassay

The genotoxicity of ground water from four bore-holes of different depths (40-120m) in the Ararat valley (Armenia) used both for drinking and irrigation was investigated. The frequency of recessive somatic mutations was determined using the Tradescantia-stamen-hair-mutation (Trad-SHM) test. The Tradescantia clone 02 was used. The pink mutation events (PMEs) were increased by 3.18-6.81-fold in comparison with the control depending both on the depth of subterranean water location and the increase of Na(+) ion concentration in these water samples. The peak frequency was found in water from the 40-45m depth. The deeper the bore-holes, the lower the mutagenicity of water and the concentration of Na(+) ions. Different types of mutant sector arrangements and their frequencies changed depending on the subterranean water depth.