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PubMed2002

A logical starting point for developing priorities for lizard and snake ecotoxicology: a review of available data.

Reptiles, specifically lizards and snakes, usually are excluded from environmental contamination studies and ecological risk assessments. This brief summary of available lizard and snake environmental contaminant data is presented to assist in the development of priorities for lizard and snake ecotoxicology. Most contaminant studies were not conducted recently, list animals found dead or dying after pesticide application, report residue concentrations after pesticide exposure, compare contaminant concentrations in animals from different areas, compare residue concentrations found in different tissues and organs, or compare changes in concentrations over time. The biological significance of the contaminant concentrations is rarely studied. A few recent studies, especially those conducted on modern pesticides, link the contaminant effects with exposure concentrations. Nondestructive sampling techniques for determining organic and inorganic contaminant concentrations in lizards and snakes recently have been developed. Studies that relate exposure, concentration, and effects of all types of environmental contaminants on lizards and snakes are needed. Because most lizards eat insects, studies on the exposure, effects, and accumulation of insecticides in lizards, and their predators, should be a top priority. Because all snakes are upper-trophic-level carnivores, studies on the accumulation and effects of contaminants that are known to bioaccumulate or biomagnify up the food chain should be the top priority.

Animals↗
PubMed2003

Toxicity and pathogenicity of Metarhizium anisopliae var. acridum (Deuteromycotina, Hyphomycetes) and fipronil to the fringe-toed lizard Acanthodactylus dumerili (Squamata: Lacertidae).

Reptiles in arid and semiarid zones are frequently exposed to insecticides sprayed to control locusts and grasshoppers. We evaluated the toxicity and pathogenicity of new biological and chemical control agents to the fringe-toed lizard Acanthodactylus dumerili in Mauritania, West Africa. A mycoinsecticide based on spores of the entomopathogenic fungus Metarhizium anisopliae var. acridum (isolate IMI 330189, Green Muscle) was tested at high challenge concentrations, using three exposure routes. Thirty-minute inhalation exposure to 3.9 x 10(8) viable conidia/L had no adverse effect. Locomotor activity, feeding activity, food consumption, body weight, and liver-to-body weight ratio were similar among treatments. Gross necropsy revealed no pulmonary lesions, hyphal mats, clumps of spores, or other abnormalities associated with fungal infections. Oral exposure to an oil-miscible flowable concentrate administered at approximately 10(7) viable conidia/g body weight had no effect on locomotor activity, food consumption, and body weight of survivors. However, two of the treated lizards died within one week of exposure. Feeding activity (sexes pooled) and relative liver mass of female survivors were significantly reduced. This was also observed in lizards treated with deactivated (nonviable) conidia, indicating an inherent toxicity of the formulation. Limited necropsy examination at four weeks posttreatment revealed that one lizard treated with viable spores had developed a pulmonary mycetoma that contained a clump of viable spores and fungal mycelium. The toxicity of mycotoxins was tested by feeding mycosed nymphs of desert locust Schistocerca gregaria to lizards. An average consumption of 231 mg (females) or 260 mg (males) nymphs/g body weight showed no adverse effect for any of the endpoints. No risk due to the pathogen is anticipated at recommended field application rates. The second agent tested was fipronil (Adonis), a phenylpyrazole insecticide. A single dose of 30 microg fipronil/g body weight was administered via contaminated prey or stomach instillation. The percentage of dead or moribund lizards at four weeks posttreatment was 62.5% in animals fed contaminated prey and 42.0% in gavaged animals. In both tests, survivors showed significantly reduced feeding activity, food consumption, body weight, and organ-to-body-weight ratios (liver and/or fat body). The high toxicity of fipronil to lizards was not previously known, suggesting that follow-up studies (e.g., subacute dietary tests) are needed to provide adequate data for risk assessment.

Animals↗
PubMedDate not supplied

Effect of partial water deprivation and restricted feeding on age-related changes in two enzymes of energy metabolism in the brain of male garden lizards.

The lactate dehydrogenase (LDH) activity of garden lizard brain did not change with advancing age. On the other hand the succinate dehydrogenase (SDH) activity showed a decline during maturation (young to middle-aged) remaining stabilized thereafter. Seven days of partial water deprivation did not alter the LDH activity of lizards of all three age groups but caused an increase in SDH activity of old lizards only. Restricted feeding led to a decline in the activities of both the enzymes (LDH and SDH) in young lizards and an increase in LDH activity of only the old, the response in middle-aged being insignificant. The protein content of the brain did not change during maturation, but declined in old lizards. Partial water deprivation caused an increase in protein content of the brain of both middle-aged and old lizards but not in young counterparts. Only the young lizards showed an increase in protein content of the brain in response to food restriction.

Journal Article↗
PubMed2026

Chromosome-Level Reference Genome of the Desert Night Lizard Xantusia vigilis.

We present a reference-quality genome assembly for the desert night lizard (Xantusia vigilis). The night lizards (Xantusiidae) are a family of small-bodied lizards found in North America (Xantusia), Central America (Lepidophyma), and Cuba (Cricosaura). The night lizard family has an independent evolutionary history of at least 80 million years from its sister taxa within Scincoidea. The Xantusiids have several unique ecological, behavioral and evolutionary characteristics. For instance, the family contains the only squamate species that form diploid, unisexual, parthenogenic lineages. In addition, most night lizards are viviparous and form stable kin groups that are maintained over multiple years, an unusual life history strategy among lizards. Combining PacBio long-read sequencing, Hi-C, and RNAseq data we developed a reference-quality genome for the desert night lizard, X. vigilis. We assembled a complete mitochondrion and ~ 2.2 Gb nuclear genome, with 20 scaffolds that correlate in size to the X. vigilis karyotype. In addition, we found that X. vigilis chromosome 1 aligns with gene content of both of macrochromosome 1 and microchromosome 9 from a genome assembly of a species in the sister family Cordylidae (Hemicordylus capensis).

Xantusia↗
PubMed1996

Regulation of skeletal muscle metabolism in the lizard Dipsosaurus dorsalis by fructose-2,6-bisphosphate.

Changes in liver and skeletal muscle fructose-2,6-bisphosphate (Fru-2,6-P2) concentrations were compared during fasting, exercise, and recovery in the lizard Dipsosaurus dorsalis and in outbred mice (Mus musculus). We present the first correlative evidence that suggests that a decrease in the content of Fru-2,6-P2 may mediate elevated gluconeogenesis in lizard skeletal muscle. Contents of Fru-2,6-P2 in lizard gastrocnemius and red and white iliofibularis (IF) were significantly lower (as much as 55% in white IF) during recovery from exhaustive exercise than at rest. Recovery from exhaustive exercise had no significant effect on Fru-2,6-P2 concentrations in any mouse muscle examined. Fasting significantly depressed lizard and mouse liver Fru-2,6-P2 contents and decreased lizard red IF by over 84% from the fed condition. Lizard red and white muscle fiber bundles incubated in 20 mM lactate had significantly lower Fru-2,6-P2 (94 and 61% depression, respectively) than those incubated in 8.5 mM glucose. These results are consistent with the hypothesis that Fru-2,6-P2 acts as a signal for controlling gluconeogenesis in lizard skeletal muscle.

Animals↗
PubMed1996

Size-dependence of water-running ability in basilisk lizards (Basiliscus basiliscus)

In the past, it has been proposed that basilisk lizards (Basiliscus basiliscus) are able to reach high population densities because the juveniles and adults have differing water-running abilities and therefore live in different habitats. However, there is no a priori reason to expect juveniles to be better able to run on water than adults. To determine the causal relationship between body size and water-running ability, we made three types of measurements: (1) direct morphological measurements on preserved specimens; (2) hydrodynamic measurements on physical models of the lizards' feet; and (3) kinematic measurements on basilisk lizards running on water. The information gathered from these investigations was used to develop an allometric model which predicted the maximum upward force impulses that the lizards could generate. We find that small lizards have a capacity to generate large force surpluses. A 2 g lizard can generate a maximum upward impulse that is more than twice that needed to support its body weight (225 %). In contrast, a 200 g lizard, under optimal conditions, can just barely support its body weight (111 %).

Journal Article↗
PubMed1989

Chemical access to the vomeronasal organs of the lizard Chalcides ocellatus.

A functional association between tongue flicking and vomeronasal organ chemoreception in lizards has been assumed frequently, but never tested. To test this hypothesis, a cotton swab soaked in prey extract mixed with [3H]proline was touched ten times to the snouts of normal and tongueless lizards (Chalcides ocellatus), as well as normal lizards whose vomeronasal organ (VNO) ducts had been sealed with a tissue adhesive. Additionally, such a swab was held approximately 0.5 cm in front of the snout of normal and tongueless lizards for 1 min, which allowed no contact by tongueless animals and tongue contact only by normal lizards. Using autoradiography, substantial and comparable concentrations of labeled molecules were detected in the mouths, VNO ducts, and VNOs of normal subjects in both conditions, as well as tongueless lizards whose snouts made physical contact with swabs. No label was evident in VNOs of tongueless animals that did not contact swabs or normal animals with sealed VN ducts. Labeling was not apparent generally in the olfactory epithelium. These results suggest that: 1) the tongue is not required for, nor does it increase, chemical delivery to VNOs when snout contact occurs; 2) the tongue transfers molecules from the external environment to the oral region; 3) it is unlikely that nonvolatile chemicals reach the olfactory epithelium via an oral route; and 4) tissue adhesive is an effective means of preventing chemical access to the VN organs.

Animals↗
PubMed2005

Influence of stress on gonadotrophin induced testicular recrudescence in the lizard Mabuya Carinata.

Administration (ip) of FSH (10 IU/0.1 ml distilled water (dw)/lizard/alternate days/30 days) to adult male lizards, Mabuya carinata, during the early recrudescence phase of the reproductive cycle caused activation of spermatogenic and steroidogenic activity of the testis, as shown by a significant increase in mean number of spermatogonia, primary spermatocytes and spermatids, and serum levels of testosterone, as compared to initial controls. In addition, there were abundant spermatozoa in the lumen of the seminiferous tubules. Interestingly, administration of a similar dosage of FSH to lizards exposed to stressors (handling, chasing, and noise randomly applied, five times a day for 30 days) resulted in a significant increase in mean number of spermatogonia and primary spermatocytes over initial control values, whereas the number of secondary spermatocytes and spermatids and serum levels of testosterone did not significantly differ from those of initial controls, and were significantly lower than FSH treated normal lizards. Further, spermatozoa were infrequently found in the seminiferous tubules of these lizards. Treatment controls (receiving 0.1 ml dw/lizard/alternate days for 30 days) did not show significant variation in mean number of spermatogonia, spermatocytes and spermatids, and serum levels of testosterone from initial controls. Another group of lizards was exposed to stressors and did not receive FSH. These lizards showed a significant decrease in mean number of secondary spermatocytes compared to treatment controls and all other parameters did not significantly differ from those of both control groups. The results reveal that gonadotrophin-induced spermatogonial proliferation occurs under stressful conditions, whereas progress of spermatogenesis beyond primary spermatocyte stage is impaired due to inhibition (under stress) of gonadotrophin induced steroidogenic activity in M. carinata.

Analysis of Variance↗
PubMed2001

Plasma progesterone levels and luteal activity during gestation and prolonged oviductal egg retention in a tropical lizard, Calotes versicolor.

Plasma progesterone (P) levels and luteal and adrenal activities were studied during normal gestation and unusual prolonged period of oviductal egg retention in a polyautochronic, multiclutched lizard, Calotes versicolor. The normal gestation period (approximately 15 days) was categorized into four stages: stage I--a few hours following ovulation, stage II--eggs with shell and embryo at primitive streak, stage III--embryonic stages 16-20, and stage IV--prior to ovipostion (stages 26-27). The gravid lizards maintained in captivity retained eggs in their oviducts for 45 days. Plasma P levels were low in stage I, increased significantly during stage II, declined in stage III, and reached their lowest in stage IV of gestation. 3Beta-hydroxysteroid dehydrogenase (3beta-HSDH) activity was greater in lutein cells at stage II and was present in traces in stage IV gestation. Interestingly, plasma P titers that were high in lizards with eggs retained longer though the corpora lutea (CL) showed a trace 3beta-HSDH activity. However, 3beta-HSDH activity was greater in the adrenocortical cells in these lizards than that in lizards during a normal gestation period. The present study on C. versicolor shows that the CL remains active and secretes P only during the early part of the gestation. The drop in P level during the later part of gestation might facilitate growth of a second set of vitellogenic follicles. During unfavorable conditions when the lizards are forced to retain eggs in the oviduct, the adrenal glands seem to secrete progesterone to help in egg retention and in inhibition of oviposition.

3-Hydroxysteroid Dehydrogenases↗
PubMed2002

Corticotropin-releasing factor antagonist attenuates stress-induced inhibition of seasonal ovarian recrudescence in the lizard Mabuya carinata.

Whether administration of the corticotropin-releasing factor (CRF) antagonist alpha-helical CRF(9-41) (hCRF) prevents stress response of the ovary, the oviduct, the adrenals, and the spleen was studied in the lizard Mabuya carinata. Stressors (handling, chasing, and noise) applied randomly, five times a day, for 1 month to lizards during the recrudescence phase of the ovarian cycle caused a significant increase in mean nuclear diameter of the adrenal cortical cells and a significant reduction in mean number of islands of white pulp in the spleen. These results, albeit indirectly, indicated an activation of the adrenal gland and immune suppression. There was a significant decrease in the mean relative weight of the ovary and the oviduct and in the mean number of oocytes and the primordial follicles compared to those of controls. Furthermore, vitellogenic follicles were absent in the ovary of lizards exposed to stressors in contrast to their presence in controls. However, administration of hCRF to the lizards exposed to stressors (stress + hCRF) resulted in vitellogenesis and follicular growth. The mean relative weight of the ovary and the oviduct and the mean number of oocytes and the primordial follicles in stress + hCRF-treated lizards were significantly higher than those in the lizards exposed to stressors, whereas they did not significantly differ from those of controls. The results indicate that hCRF attenuates stress-induced inhibition of ovarian follicular and oviductal development in M. carinata. To the best of our knowledge, this is the first report revealing that CRF antagonist can prevent ovarian stress response in lower vertebrates.

Animals↗
PubMed1981

Histological and immunohistochemical studies of the endocrine pancreas of lizards.

The endocrine pancreas of the grass lizard, Mabuya quinquetaenia-ta, and of the desert lizard, Uromastyx aegyptia, was investigated histologically and immunohistochemically. In both lizard species four cell types were observed in the endocrine pancreas, namely insulin (B), glucagon (A), somatostatin (D) and pancreatic polypeptide (PP) cells. In both species in B, A and D cells could be detected by their cross-reactivity with antisera raised against mammalian insulin, glucagon and somatostatin. However, these cells showed different tinctorial propertis in the two lizard species. In both species the endocrine tissues were concentrated in the splenic lobe of the pancreas. In the grass lizard the endocrine tissue in the splenic lobe of consisted mainly of B, A and D cells and in the ventral lobe the major cell types were PP and D cells. In the desert lizard, on the other hand, the frequency and the pattern of orientation of B, A and D cells were the same in both the splenic and the ventral lobes, but PP cells in the ventral lobe outnumbered those of the splenic lobe. The PP and D cells scattered in the exocrine parenchyma and the long protrusions which they exhibited suggested that these cell exerted paracrine control on the acinar cells. It is speculated that this control by PP cells may be trophic and by D cells inhibitory.

Animals↗
PubMed2001

Laser vibrometric studies of sound-induced motion of the body walls and lungs of salamanders and lizards: implications for lung-based hearing.

A laser Doppler vibrometer was used to measure the acoustic responses of different body surfaces of several species of salamanders and lizards. The lateral body wall over the lung displayed sound-induced motion up to 30 dB greater than the lateral head surface from 300-1,000 Hz in salamanders and from 200-2,500 Hz in lizards. The lateral body wall of lungless plethodontid salamanders showed no such enhanced motion to sound. The lateral body wall of lizards was more responsive than their tympanum to sound frequencies below about 1,250-2,000 Hz. The frequency of the peak response of lizard body walls matched the resonant frequency of a Helmholtz resonator with the volume and dimensions of their lungs. In contrast, the frequency of peak response of salamander body walls was well below the resonant frequencies calculated for both Helmholtz resonators and closed tubes with the dimensions and volumes of their lungs. Nonetheless, filling the lungs with saline dramatically reduced the responsiveness of the lateral body walls of both the lunged salamanders and the lizards. As previously demonstrated in anuran amphibians, the lateral body wall and lungs of salamanders and lizards may function in sound reception, especially at relatively low frequencies.

Acoustics↗
PubMed2001

Infection dynamics of Hemolivia mariae in the sleepy lizard Tiliqua rugosa.

The blood parasite Hemolivia mariae was experimentally transmitted to lizards under laboratory and field conditions. Weekly blood samples from experimentally infected lizards were used to demonstrate the changes in composition of the different developmental stages of the parasite as infection progressed. The prepatent period and time to peak infection was longer for field-infected lizards compared to those held under laboratory conditions. Infections in naturally infected field lizards had longer pre-patent periods and lower mean-peak parasitaemia than those in lizards that were uninfected at the time of experimental infection. The results are discussed in relation to the natural field-transmission dynamics of H. mariae in its lizard and tick hosts.

Animals↗
PubMed1992

Growth and behavior of thyroid-deficient lizards (Sceloporus undulatus).

This study investigates thyroid control of growth and energy metabolism plus growth-dependent and growth-independent behavioral effects of thyroid manipulation in lizards. Experiments were done on surgically thyroidectomized (Tx) and sham-operated (Sh) yearling Sceloporus undulatus enclosed in their natural habitat. Lizards were placed in an outdoor enclosure in early August. Growth rate was measured and behavior was observed until mid-October. Subsequently, lizards were returned to the lab for measurements of plasma thyroxine (T4), standard metabolic rate (SMR), and running endurance. Thyroidectomy reduced plasma T4 from 4.3 +/- 0.56 ng/ml to undetectable levels (P = 0.006) and SMR by 44% (P less than 0.0001). Thyroid deficiency produced a threefold reduction in growth rate (Tx: 0.04 +/- 0.010 mm/day, n = 12 vs Sh: 0.11 +/- 0.006 mm/day, n = 11, P less than 0.0001). Growth rate was correlated with SMR among individuals (length-specific: r = 0.55, P = 0.027, n = 16), even after statistical removal of mass and treatment effects. The total volume of oxygen consumed for standard metabolism during the growth period, as estimated from allometric equations, was correlated with cumulative growth (R2 = 0.94, P = 0.013) and was significantly lower for thyroid-deficient lizards than for controls (P less than 0.0001). Distance moved in the field and running endurance on a treadmill both scaled on body mass (M0.98 +/- 0.418, P = 0.030 and M1.72 +/- 0.763, P = 0.040, respectively), indicating that larger lizards moved farther and had greater stamina than their smaller counterparts. Neither of these behavioral factors was affected directly by thyroid status. Thyroid-deficient lizards were active for a smaller percentage of the day than controls (Tx: 42.6 +/- 5.7%, n = 11 vs Sh: 57.4 +/- 3.2%, n = 12, P = 0.040), independent of differences in body size. On an interindividual basis, the frequency of activity was significantly correlated with SMR (r = 0.57, P = 0.020, n = 16) and growth rate (mass-specific: r = 0.47, P = 0.025, n = 23).

Animals↗
PubMed1995

Daily melatonin infusions entrain the locomotor activity of pinealectomized lizards.

Previously, it was shown that the locomotor activity rhythms of pineal-intact lizards (Sceloporus occidentalis) could be entrained to a periodicity of 24 h by 10-micrograms melatonin injections administered every other day at the same time. The present study examined the response of the circadian activity rhythm of pinealectomized S. occidentalis to daily 12-h infusions of smaller quantities of melatonin (0.1 or 5 micrograms melatonin/day). The results show that entrainment is achieved by infusion of 0.1 microgram of melatonin/day in pinealectomized lizards, as well as by 5 micrograms of melatonin/day in pinealectomized and pineal-intact lizards. Serum melatonin levels in pinealectomized lizards receiving 0.1 microgram melatonin/day (measured in the middle of the infusion period) were comparable to mid-dark levels in intact lizards. These results provide further support for the hypothesis that the pineal, via its daily rhythm of melatonin secretion, plays an important role in the circadian organization of lizards.

Animals↗
PubMed2005

Total lactate dehydrogenase activity of tail muscle is not cold-adapted in nocturnal lizards from cool-temperate habitats.

The dependence of metabolic processes on temperature constrains the behavior, physiology and ecology of many ectothermic animals. The evolution of nocturnality in lizards, especially in temperate regions, requires adaptations for activity at low temperatures when optimal body temperatures are unlikely to be obtained. We examined whether nocturnal lizards have cold-adapted lactate dehydrogenase (LDH). LDH was chosen as a representative metabolic enzyme. We measured LDH activity of tail muscle in six lizard species (n=123: three nocturnal, two diurnal and one crepuscular) between 5 and 35 degrees C and found no differences in LDH-specific activity or thermal sensitivity among the species. Similarly, the specific activity and thermal sensitivity of LDH were similar between skinks and geckos. Similar enzyme activities among nocturnal and diurnal lizards indicate that there is no selection of temperature specific LDH enzyme activity at any temperature. As many nocturnal lizards actively thermoregulate during the day, LDH may be adapted for a broad range of temperatures rather than adapted specifically for the low temperatures encountered when the animals are active. The total activity of LDH in tropical and temperate lizards is not cold-adapted. More data are required on biochemical adaptations and whole animal thermal preferences before trends can be established.

Adaptation, Physiological↗
PubMed2004

Development of a terrestrial vertebrate model for assessing bioavailability of cadmium in the fence lizard (Sceloporus undulatus) and in ovo effects on hatchling size and thyroid function.

In the terrestrial environment, standardized protocols are available for measuring the exposure and effects of contaminants to invertebrates, but none currently exist for vertebrates. In an effort to address this, we proposed that developing lizard embryos may be used as a terrestrial vertebrate model. Lizard eggs may be particularly susceptible to soil contamination and in ovo exposure may affect hatchling size, mortality, as well as thyroid function. Toxicant-induced perturbations of thyroid function resulting from in ovo chemical exposure may result in toxicity during the critical perinatal period in reptiles. Fertilized Eastern fence lizard (Sceloporus undulatus) eggs were placed in cadmium (Cd)-spiked expanded perlite (0, 1.48, 14.8, 148, 1480, 14,800 microg Cd/g, nominal concentrations), artificially incubated at 28 degrees C, and examined daily for mortality. Whole lizard hatchlings as well as failed hatches were homogenized in ethanol and the homogenate was divided for Cd body residue analysis and thyroid hormone (triiodothyronine (T3) and thyroxine (T4)) analyses. Acute mortality was observed in the two highest doses (1480 and 14800 microg Cd/g). Cadmium body residues showed a higher internal concentration with increasing exposure concentration indicating uptake of Cd. There was a decrease in T3:T4 ratio at the highest surviving dose (148 microg Cd/g), however, there were no differences observed in hatchling size measured as weight and snout-vent length, or in whole body thyroid hormone levels. In summary, this study has shown Cd amended to a solid phase representing soil (perlite) can traverse the thin, parchment-like shell membrane of the fence lizard egg and bioaccumulate in lizard embryos. We believe this study is a good first step in investigating and evaluating this species for use as a model.

Animals↗
PubMed2004

Inhibition of plasma butyrylcholinesterase activity in the lizard Gallotia galloti palmae by pesticides: a field study.

A field study was performed to evaluate the effect of exposure to organophosphorus (OP) and carbamate (CB) pesticides on the lizard Gallotia galloti palmae. Butyrylcholinesterase (BChE) activity was measured in the plasma of 420 lizards collected from agricultural and reference areas on the Island of La Palma (Canary Islands, Spain) in two sampling periods. Exposure to cholinesterase-inhibiting pesticides was evaluated by a statistical criterion based on a threshold value (two standard deviations below the mean enzyme activity) calculated for the reference group, and a chemical criterion based on the in vitro reactivation of BChE activity using pyridine-2-aldoxime methochloride (2-PAM) or after water dilution of the sample. Mean (+/- SD) BChE activity for lizards from agricultural areas was significantly lower (Fuencaliente site = 2.00 +/- 0.98 micromol min(-1) ml(-1), Tazacorte site = 2.88 +/- 1.08) than that for lizards from the reference areas (Los Llanos site = 3.06 +/- 1.17 micromol min(-1) ml(-1), Tigalate site = 3.96 +/- 1.62). According to the statistical criterion, the number of lizards with BChE depressed was higher at Fuencaliente (22% of males and 25.4% of females) than that sampled at Tazacorte (7.8% of males and 6.2% of females). According to the chemical criterion, Fuencaliente also yielded a higher number of individuals (112 males and 47 females) with BChE activity inhibited by both OP and CB pesticides. CBs appeared to be the pesticides most responsible for BChE inhibition because most of the samples showed reactivation of BChE activity after water treatment (63.3% from Fuencaliente and 29% from Tazacorte). We concluded that the use of reactivation techniques on plasma BChE activity is a better and more accurate method for assessing field exposure to OP/CB pesticides in this lizard species than making direct comparisons of enzyme activity levels between sampling areas.

Animals↗