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At least 37 records · Page 2Linked to original sources

Acute oral and percutaneous toxicity of pesticides to mallards: Correlations with mammalian toxicity data

Acute oral (po) and 24-hr percutaneous (perc) LD50 values for 21 common pesticides (19 anticholinesterases, of which 18 were organophosphates, and one was a carbamate; one was an organochlorine central nervous system stimulant; and one was an organonitrogen pneumotoxicant) were determined in mallards ( Anas platyrhynchos ). Three of the pesticides tested were more toxic percutaneously than orally. An index to the percutaneous hazard of a pesticide, the dermal toxicity index (DTI = po LD50/perc LD50 × 100), was also calculated for each pesticide. These toxicity values in mallards were compared with toxicity data for rats from the literature. Significant positive correlations were found between log po and log percutaneous LD50 values in mallards ( r = 0.65, p < 0.01), between log po LD50 values in mallards and in rats ( r = 0.71, p < 0.01), and between log DTI values in mallards and in rats ( r = 0.52, p < 0.05). Percutaneous toxicity values were not significantly correlated between mallards and rats ( r = 0.36, p > 0.10). Variations in percutaneous methodologies are discussed with reference to interspecies variation in toxicity values. It is recommended that a mammalian DTI value approaching 30 be used as a guideline for the initiation of percutaneous toxicity studies in birds, when the po LD50 and/or projected percutaneous LD50 are less than expected field exposure levels.

Toxicology and Applied Pharmacology

Dopamine and norepinephrine depletion in ring doves fed DDE, dieldrin, and Aroclor 1254

The levels of dopamine and norepinephrine were measured in one-half of the brain of ring doves fed a control diet or a diet containing 2, 20, or 200 ppm DDE; 1, 4, or 16 ppm dieldrin; or 1, 10, or 100 ppm Aroclor 1254. Levels of DDE, dieldrin, or Aroclor 1254 were determined in the other half of each brain. The intermediate and high levels of each chemical caused depletions in both neurotransmitters, and brain residues of each chemical were negatively correlated with levels of neurotransmitters. The highest concentrations of DDE, dieldrin, and Aroclor 1254 depressed averages of dopamine to 42.4, 41.4, and 45.2% of the control level and norepinephrine to 61.6, 62.0, and 56.9% of controls, respectively. Depletions of dopamine and norepinephrine could result in abnormal behavior of contaminated birds in the wild, and the detection of such depletions could become an important tool in assessing contaminant-induced behavioral aberrations in birds.

Toxicology and Applied Pharmacology

Embryotoxic and biochemical effects of waste crankcase oil on birds' eggs

Waste crankcase oil (WCO) is a major source of oil pollution in both the aquatic and terrestrial environment and has been implicated in the poisoning of mammals and fish. It is also mutagenic. Since birds' eggs are highly sensitive to external microliter applications of environmentally polluting oils, we examined the developmental effects of external applications of WCO on eggs of the mallard duck (Anas platyrhynchos) and the bobwhite quail (Colinus virginianus). At 48 hr of development, mallard eggs were exposed externally to 2, 5, or 15 :l of WCO or 15 :l of clean crankcase oil (CCO) while bobwhite eggs received proportional doses of 0.5, 1, or 3 :l of WCO and 3 :l of CCO in a similar manner. WCO was highly embryotoxic to both species compared to CCO and resulted in dose-dependent mortality, reduced growth, and abnormal survivors. Application of 15 :l WCO resulted in 84% mortality in mallards and 3 :l WCO resulted in 88% mortality in bobwhites. Abnormal survivors included embryos with subcutaneous edema, incomplete ossification, and eye and brain defects. Red blood cell *-aminolevulinic acid dehydratase (ALAD) activity, liver ALAD activity, and hemoglobin concentration were significantly lower after treatment with WCO in embryos and hatchlings of both species. Plasma uric acid, plasma alanine aminotransferase (ALT), and plasma aspartate aminotransferese (AST) were significantly elevated in WCO-treated mallards after hatching. Biochemical effects, growth retardation, and mortality at proportionally lower dose levels were more pronounced in mallards than in bobwhites. Chemical analysis of the WCO and CCO revealed a considerably higher content of aromatic hydrocarbons in WCO than in CCO. Lead levels were highly elevated in WCO (4600 ppm) compared to CCO (2 ppm).

Toxicology and Applied Pharmacology

Subchronic organophosphorus ester-induced delayed neurotoxicity in mallards

Eighteenweek-old mallard hens received 0, 10, 30, 90, or 270 ppm technical grade EPN (phenylphosphonothioic acid O -ethyl- O -4-nitrophenyl ester) in the diet for 90 days. Ataxia was first observed in the 270-ppm group after 16 days, in the 90-ppm group after 20 days, in the 30-ppm group after 38 days; 10 ppm failed to produce ataxia. By the end of 90 days all 6 birds in the 270-ppm group exhibited ataxia or paralysis whereas 5 of 6 birds in the 90-ppm group and 2 of 6 birds in the 30-ppm group were visibly affected. Treatment with 30 ppm or more resulted in a significant reduction in body weight. Brain neurotoxic esterase activity was inhibited by averages of 16, 69, 73, and 74% in the 10-, 30-, 90-, and 270-ppm groups, respectively. Brain acetylcholinesterase, plasma cholinesterase, and plasma alkaline phosphatase were significantly inhibited as well. Distinct histopathological effects were seen in the 30-, 90-, and 270-ppm groups which included demyelination and degeneration of axons of the spinal cord. Additional ducks were exposed in a similar manner to 60-, 270-, or 540-ppm leptophos (phosphonothioic acid O -4-bromo-2,5-dichlorophenyl- O -methylphenyl ester) which resulted in similar behavioral, biochemical, and histopathological alterations. these findings indicate that adult mallards are probably somewhat less sensitive than chickens to subchronic dietary exposure to organophosphorus insecticides that induce delayed neurotoxicity.

Toxicology and Applied Pharmacology

Neurotoxic and teratogenic effects of an organophosphorus insecticide (phenyl phosphonothioic acid- O -ethyl- O -[4-nitrophenyl] ester) on mallard development

Phenyl phosphonothioic acid- O -ethyl- O -[4-nitrophenyl] ester (EPN) is one of the 10 most frequently used organophosphorus insecticides and caused delayed neurotoxicity in adult chickens and mallards. Small amounts of organophosphorus insecticides placed on birds' eggs are embryotoxic and teratogenic. For this reason, the effects of topical egg application on EPN were examined on mallard ( Anas platyrhynchos ) embryo development. Mallard eggs were treated topically at 72 hr of incubation with 25 μl of a nontoxic oil vehicle or with EPN in the vehicle at concentrations of approximately 12, 36, or 108 μg/g egg, equivalent to one, three, and nine times the agricultural level of application used to spray crops. Treatment with EPN resulted in 22 to 44% mortality over this dose range by 18 days of development compared with 4 and 5% for untreated and vehicle-treated controls. EPN impaired embryonic growth and was highly teratogenic: 37–42% of the surviving embryos at 18 days were abnormal with cervical and axial scoliosis as well as severe edema. Brain weights were significantly lower in EPN-treated groups at different stages of development including hatchlings. Brain neurotoxic esterase (NTE) activity was inhibited by as much as 91% at 11 days, 81% at 18 days, and 79% in hatchlings. Examination of brain NTE activity during the course of normal development revealed an increase of nearly sixfold from Day 11 through hatching. The most rapid increase occurred between Day 20 and hatching. Brain acetylcholinesterase (AChE) activity was inhibited by as much as 41% at 11 days, 47% at 18 days, and 20% in hatchlings. Plasma cholinesterase and alkaline phosphatase activities were inhibited and plasma aspartate aminotransferase activity was increased at one or more stages of development. Hatchlings from EPN-treated eggs were weaker and slower to right themselves. Histopathological examination did not reveal demyelination and axonopathy of the spinal cord that was characteristic of delayed neurotoxicity in adult birds.

Toxicology and Applied Pharmacology

Suppression of guinea pig ileum induced contractility by plasma albumin of hibernators

Previous studies suggest that hibernation may be regulated by internal opioids and that the putative “hibernation induction trigger” (HIT) may itself be an opioid. This study examined the effect of plasma albumin (known to bind HIT) on induced contractility of the guinea pig ileum muscle strip. Morphine (400 nM) depressed contractility and 100 nM naloxone restored it. Ten milligrams of lyophilized plasma albumin fractions from hibernating ground squirrels, woodchucks, black bears, and polar bears produced similar inhibition, with partial reversal by naloxone. Five hundredths mg of d-Ala2-d-Leu5-enkephalin (DADLE) also inhibited contractility and naloxone reversed it. Conclusions are that hibernating individuals of these species contain an HIT substance that is opioid in nature and summer animals do not; an endogenous opioid similar to leu-enkephalin may be the HIT compound or give rise to it.

Pharmacology Biochemistry and Behavior

Residue dynamics of quinaldine and TFM in rainbow trout

Study of the residue dynamics of 2-methylquinoline (quinaldine) and 3-trifluoromethyl-4-nitrophenol (TFM) in rainbow trout yielded the following findings: 1. Uptake and distribution of TFM by trout was influenced by the biotransformation of the lipidsoluble free phenol. No such effect was observed with quinaldine. 2. Disappearance of quinaldine and TFM from gallbladder bile was slower than from plasma or muscle during 24 hr of withdrawal in fresh water. 3. The concentration of TFM conjugate may exceed that of free TFM in bile by a factor of 10 3 .

General Pharmacology

Effect on tricaine methanesulfonate (MS-222) on hematocrit values in rainbow trout ( Salmo gairdneri )

1. Anesthesia of rainbow trout ( Salmo gairdneri ) with 70 ppm tricaine methanesulfonate (MS-222) for 3-9 min resulted in a linear increase in hematocrit. 2. Handling of unanesthetized trout caused a higher and more variable hematocrit reading than did exposure to MS-222 for up to 3 min. 3. The range and standard error of hematocrit readings was smallest in trout treated with MS-222 for 1 min.

Comparative Biochemistry and Physiology, Part C: C

Six different plasma enzymes in bald eagles ( Haliaeetus leucocephalus ) and their usefulness in pathological diagnosis

1. Activities of creatine phosphokinase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase, fructose diphosphate aldolase and cholinesterase were measured in plasma of bald eagles. 2. There were no sex differences in the plasma enzyme activities. 3. An acute dieldrin dosage (10 mg/kg) of a female bald eagle resulted in 400% increases in activities of plasma creatine phosphokinase and glutamic oxalacetic transaminase and 250% increases in activities of lactate dehydrogenase and glutamic pyruvic transaminase. 4. At 11 days post-dosage all but one of the plasma enzyme activities had returned to normal; glutamic oxalacetic transaminase activity remained 100% above pre-dosage values. 5. Plasma enzyme assays constitute a non-destrcutive procedure that can be used in valuable wildlife species to screen for the presence and prevalence of environmental contaminants.

Comparative Biochemistry and Physiology, Part C: C

Allantoinase in lake trout ( Salvelinus namaycush ): In vitro effects of PCBs, DDT and metals

1. Allantoinase, an enzyme in the purine-urea cycle, was found in livers of Salvelinus namaycush (Osteichthyes: Salmoniformes). 2. The enzyme was active from pH 6.6 to 8.2 at 37°C and from pH 7.4 to 9.0 at 10°C and had an Arrhenius energy was activation of 11.0 kcal/mol and a temperature quotient of 2.0. The K m of the enzyme homogenate was 8.4 mM allantoin. 3. The concentrations of inorganic metals at which 50% inhibition occurred during in vitro exposure were 6.0 mg/l Cu 2+ , 6.7 mg/l Cd 2+ , 34 mg/l Hg 2+ and 52 mg/l Pb 2+ . The in vitro sensitivity to PCBs, DDT and DDE and kinetics in the presence of metals were determined. 4. Allantoinase activity was negatively correlated with body length for fish from Lake Michigan but not from Lake Superior or the laboratory.

Comparative Biochemistry and Physiology, Part C: C

Effects of petroleum hydrocarbons on hepatic function in the duck

1. The indocyanine green dye clearance test for hepatic function was determined in mallard ducks before and during the chronic ingestion (7 months) of representative paraffinic or aromatic petroleum hydrocarbons (PH). 2. No mortality or visible symptoms of toxicity occurred in any of the tests. Ingestion of 4000 ppm aromatic PH produced significant increases in liver (25%), plasma clearance of indocyanine green (33%) and hepatic blood flow (30%). 3. Although the aromatics elicited a greater hepatic stress response than the paraffins, the ducks tolerated high concentrations of PH for extended periods.

Comparative Biochemistry and Physiology, Part C: C

Plasma corticosterone and thyroxine concentrations during chronic ingestion of crude oil in mallard ducks ( Anas platyrhynchos )

1. Blood samples were collected from mallard ducks after 6, 12, and 18 weeks of dietary exposure to mash containing 0.015%, 0.150%, and 1.500% crude oil. 2. Plasma corticosterone concentrations in ducks fed mash containing 0.150% or 1.500% Alaskan Prudhoe Bay crude oil were uniformly depressed when compared to values in untreated control birds. 3. Plasma thyroxine concentration was not altered in ducks chronically exposed to crude oil. 4. The observed alteration in corticosterone concentration could reduce tolerance to temperature and dietary fluctuations in the environment.

Comparative Biochemistry and Physiology, Part C: C

Organophosphate inhibition of avian salt gland Na, K-ATPase activity

1. Adult black ducks ( Anas rubripes ) were given freshwater or saltwater (1.5% NaCl) for 11 days and half of each group was also given an organophosphate (17 p.p.m. fenthion) in the diet on days 6–11. 2. After 11 days, ducks drinking saltrwater had lost more weight and had higher plasma Na and uric acid concentration and osmolalities than birds drinking freshwater. 3. Saltwater treatment stimulated the salt gland to increased weight and Na, K-ATPase activity. 4. Fenthion generally reduced plasma and brain cholinesterase activity and depressed cholinesterase and Na, K-ATPase activities in salt glands of birds drinking saltwater.

Comparative Biochemistry and Physiology, Part C: C

Avian species differences in the intestinal absorption of xenobiotics (PCB, dieldrin, Hg 2+ )

1. Intestinal absorption of a polychlorinated biphenyl, dieldrin, and mercury (from HgCl 2 ) was measured in adult Northern bobwhites, Eastern screech owls, American kestrels, black-crowned night-herons and mallards in vivo by an in situ luminal perfusion technique. 2. Bobwhites, screech owls and kestrels absorbed much more of each xenobiotic than black-crowned night-herons and mallards. 3. Mallards absorbed less dieldrin and mercury than black-crowned night-herons. 4. Mercury absorption by kestrels was more than twice that in screech owls and eight times that observed in mallards. 5. Pronounced differences in xenobiotic absorption rates between bobwhites, screech owls and kestrels on the one hand, and black-crowned night-herons and mallards on the other, raise the possibility that absorptive ability may be associated with the phylogenetic classification of birds.

Comparative Biochemistry and Physiology, Part C: C

Biochemical and hematological effects of lead ingestion in nestling American kestrels ( Falco sparverius )

1. One-day old American kestrel ( Faico sparverius ) nestlings were orally dosed daily with 5 μl/g of corn oil (controls), 25, 125 or 625 mg/kg of metallic lead in corn oil for 10 days. 2. Forty per cent of the nestlings receiving 625 mg/kg of lead died after 6 days and growth rates were significantly depressed in the two highest lead dosed groups. At 10 days hematocrit values were significantly lower in the two highest lead treated groups, and hemoglobin content and red blood cell (δ-aminolevulinic acid dehydratase (ALAD) activity was depressed in all lead treated groups. Plasma creatine phosphokinase decreased in the two highest treatment groups. 3. Brain, liver and kidney ALAD activities, brain RNA to protein ratio and liver protein concentration decreased after lead exposure whereas liver DNA, DNA to RNA ratio and DNA to protein ratio increased. Brain monoamine oxidase and ATPase were not significantly altered. 4. Measurements of the ontogeny of hematological variants and enzymes in normal development, using additional untreated nestlings, revealed decreases in red blood cell ALAD, plasma aspartate amino transferase, lactate dehydrogenase, brain DNA and RNA and liver DNA, whereas hematocrit, hemoglobin, plasma alkaline phosphatase, brain monoamine oxidase, brain ALAD and liver ALAD increased during the first 10 days of posthatching development. 5. Biochemical and hematological alterations were more severe than those reported in adult kestrels or precocial young birds exposed to lead. Alterations may be due in part to delayed development.

Comparative Biochemistry and Physiology, Part C: C

Depression of plasma luteinizing hormone concentration in quail by the anticholinesterase insecticide parathion

1. To examine the effects of parathion on basal plasma luteinizing hormone (LH) concentration, male Japanese quail ( Coturnix japonica ) were orally intubated with 0, 5 or 10 mg/kg parathion and sacrificed after 4, 8 and 24 hr. 2. At the 5 mg/kg dose, plasma LH levels were reduced at 4 and 8 hr, but returned to control values by 24 hr. Brain acetylcholinesterase activity was substantially reduced by 10 mg/kg parathion (52, 75 and 37% inhibition at 4, 8 and 24 hr, respectively) and plasma LH concentration remained depressed through the 24-hr period. 3. These findings suggest that the organophosphorus insecticide parathion may alter plasma LH concentration in a manner which might impair reproductive activity, and provide indirect evidence for a cholinergic component in the regulation of LH secretion in quail.

Comparative Biochemistry and Physiology, Part C: C

Comparative cardiovascular effects of four fishery anesthetics in spinally transected rainbow trout, oncorhynchus mykiss

1. We compared the effects of four anesthetics on heart rate, dorsal and ventral aortic blood pressure, and electrocardiograms of rainbow trout ( Oncorhynchus mykiss ). 2. Exposure to the local anesthetics tricaine methanesulfonate (MS-222) and benzocaine hydrochloride (BZH) produced minimal cardiovascular alterations. Mean dorsal aortic pressure (DAP) decreased during exposure to MS-222, and mean DAP and mean ventral aortic pressure (VAP) increased 15% during recovery from BZH. 3. Exposure to the general anesthetic 2-phenoxyethanol (2-PE) or the hypnotic agent etomidate (ET) dramatically decreased heart rate and blood pressures and altered EKG patterns. 4. During recovery, VAP and DAP increased above baseline for an extended period. Heart rate and EKG patterns rapidly returned to normal.

Comparative Biochemistry and Physiology, Part C: C

A review of lead poisoning in swans

Nearly 10,000 swans of six species or subspecies from 14 countries have died from poisoning caused by lead that originated from ingestion of fishing weights, shotgun pellets (shot), or contaminated vegetation or sediments associated with mining and smelting wastes. Lead contamination in mute swans in England caused local population declines during the late 1970s and 1980s. More tundra swans died from lead poisoning than any other species. The extreme record involved an estimated 7200 tundra swans that died over five winters at one locality in North Carolina. The recent legislation to ban lead fishing weights in most of England and Wales and recent replacement of lead shot with steel shot for waterfowl hunting in the United States and a few areas of Europe, including Denmark, are expected to reduce the incidence of lead poisoning in swans.

Comparative Biochemistry and Physiology, Part C: P