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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pesticide p-p'-DDT and its persistent metabolite p-p'-DDE cause thinning of the eggshells in several species of birds. In earlier investigations on ducks this thinning was found to be associated with a reduction of the ATP-dependent Ca2+ binding to a homogenate of the shell gland mucosal cells by DDE. The activity of a Ca2+-Mg2+-activated ATPase in the homogenate was also decreased on administration of DDE in vivo. We have therefore investigated the in vitro effects of some other chlorinated hydrocarbon pesticides of ecotoxicological interest on the ATP-dependent Ca2+ binding and the Ca2+-Mg2+-activated ATPase activity in a homogenate of the eggshell gland mucosa of the hen and determined the molar concentrations that produced 50% inhibition (=IC50). Several of the investigated compounds, namely toxaphene, chlordane, p-p'-DDD, o-p'-DDE, p-p'-DDT, methoxychlor and PCB (Arochlor 1242), had a similar IC50 to inhibit the Ca2+ binding as p-p'-DDE. Lindane, p-p'-DDA and biphenyl had an IC50 3.3-4 times higher and that of 2.4 D was 13.5 times higher than that of p-p'-DDE. When the IC50 of some of the compounds (p-p'-DDE, PCB, toxaphene, Lindane) was determined that decreased the Ca2+-Mg2+-activated ATPase of the homogenate it was found to be only 18 to 29 per cent of that needed to inhibit the Ca2+ binding by the homogenate. It is therefore probable that some other effect than inhibition of this enzyme is also involved in the Ca2+-binding process and affected by the compounds.
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PMID:The inhibitory effect of some chlorinated hydrocarbon pesticides on the ATP-dependent Ca2+ binding of the particulate fraction of the eggshell gland mucosa cells. 613 49

In a strain of ducks sensitive to the eggshell-thinning effect of p-p'-DDE, administration of 40 mg kg of the compound in the food for 45 days reduced the eggshell index (EI) by 13% and the content of calcium in the fluid of the shell gland forming an eggshell by 36%, and raised the calcium content of the shell gland mucosa by 19%, compared with the control values. DDE inhibited the translocation (secretion) of calcium between the gland mucosa and the uterine cavity. The ATP-dependent binding of Ca2+ to the subcellular fractions of the gland mucosa was reduced in DDE-treated ducks. The Ca2+ binding to a microsomal subfraction (FI) rich in fragments of the plasma membrane was reduced by 16%, whereas that to a subfraction FIII which bound Ca2+ at a very high rate was reduced by 36%. The latter may contain calcium-secreting granules of the gland. In the mitochondrial fraction the Ca2+ binding was reduced by 35%. In the domestic fowl DDE did not lower EI or interfered with the translocation of calcium between the shell gland mucosa and uterine cavity. DDE administration increased the Ca2+ binding to FI by 26%; the binding to other subfractions was not changed significantly. DDE may interfere with the stimulus-secretion mechanism of the eggshell gland in ducks through its effect on Ca2+ binding.
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PMID:Comparison of the effect of DDE on the Ca metabolism of the eggshell gland and its subcellular fractions of the duck and the domestic fowl. 646 84

DDE, TDE, and polychlorinated biphenyls (PCBs) as Aroclors 1260 and 1254 were detected in low concentrations in eggs of western grebes (Aechmophorus occidentalis) from Bear River Migratory Bird Refuge, Utah. DDE was the only contaminant which was both negatively correlated with eggshell thickness and a significant variable in a multiple regression model for predicting eggshell thickness. The eggshell thickness index for western grebe decreased 2.3 percent from pre- to post-DDT-use periods. Incubation stage appeared to have no measurable correlation with eggshell thickness. The small amount of eggshell thinning seen in western grebe eggs at Bear River Migratory Bird Refuge appeared to have no detectable effect on reproduction.
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PMID:Effects of DDE, TDE, and PCBs on shell thickness of western grebe eggs, Bear River Migratory Bird Refuge, Utah--1973-74. 678 Sep 70

Organochlorine residues and shell thicknesses were surveyed in eggs of the clapper rail (Rallus longirostris), purple gallinule (Porphyrula martinica), common gallinule (Gallinula chloropas), and limpkin (Aramus guarauna) from the eastern and southern United States. Clapper rail eggs were collected during 1972-73 in New Jersey, Virginia, and South Carolina. During 1973-74, gallinule eggs were collected in Florida, South Carolina, and Louisiana, and limpkin eggs were collected in Florida. Egg contents were analyzed for residues of organochlorine pesticides, including DDT, TDE, DDE, dieldrin, mirex, heptachlor epoxide, oxychlordane, cis-chlordane (and/or trans-nonachlor), cis-nonachlor, hexachlorobenzene (HCB), toxaphene, and endrin, and for polychlorinated biphenyls (PCBs). Shell thicknesses of recent eggs of these species were compared with archival eggs that had been collected before 1947. With the exception of the limpkin, the majority of eggs analyzed contained residues of p,p'-DDE and PCBs. Geometric means ranged from 0.10 ppm to 1.3 ppm. Small amounts (less than 1.0 ppm) of mirex, dieldrin, cis-chlordane (and/or trans-nonachlor), TDE, and DDT were detected in a few eggs. No evidence of eggshell thinning was found for any of the species studied. DDE residues in clapper rail eggs were higher in New Jersey and Virginia than in South Carolina.
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PMID:Organochlorine residues and shell thicknesses in eggs of the clapper rail, common gallinule, purple gallinule, and limpkin (class Aves), eastern and southern United States, 1972-74. 678 Sep 71

The bald eagle (Haliaeetus leucocephalus) population in North America declined greatly after World War II due primarily to the eggshell thinning effects of p,p'-DDE, a biodegradation product of DDT. After the banning of DDT in the United States and Canada during the early 1970s, the bald eagle population started to increase. However, this population recovery has not been uniform. Eagles nesting along the shorelines of the North American Great Lakes and rivers open to spawning runs of anadromous fishes from the Great Lakes still exhibit impaired reproduction. We have explored both ecological and toxicological factors that would limit reproduction of bald eagles in the Great Lakes region. Based on our studies, the most critical factors influencing eagle populations are concentrations of environmental toxicants. While there might be some continuing effects of DDE, total PCBs and most importantly 2,3,7,8-tetrachlordibenzo-p-dioxin equivalents (TCDD-EQ) in fishes from the Great Lakes and rivers open to spawning runs of anadromous fishes from the Great Lakes currently represent a significant hazard to bald eagles living along these shorelines or near these rivers and are most likely related to the impaired reproduction in bald eagles living there.
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PMID:A review of factors affecting productivity of bald eagles in the Great Lakes region: implications for recovery. 755 24

Eggshell thinning in ducks was induced by administration of p,p'-DDE in the diet (40 mg/kg food) for 45 days. This treatment resulted in a 19% reduction of the Eggshell Index (EI). Shells from calcifying eggs obtained at the time of slaughter showed a 36% reduction of EI. Prostaglandin synthesis by a homogenate of eggshell gland mucosa from p,p'-DDE-treated ducks was reduced by 24%. HCO3(-)-stimulated ATPase activity by a homogenate of eggshell gland mucosa from p,p'-DDE-treated ducks was not significantly changed. The calcium content of eggshell gland mucosa was increased to 127% in p,p'-DDE-treated ducks. p,p'-DDE-treated ducks showed profound changes in the shell gland luminal content of several ions. Calcium (-43%), sodium (-15%), potassium (-15%), bicarbonate (-33%) and chloride (-29%) were all significantly reduced in p,p'-DDE-treated ducks. The content of phosphate was unchanged. These findings are discussed in relation to a proposed mechanism for p,p'-DDE-induced eggshell thinning that involves inhibition of prostaglandin synthesis in eggshell gland mucosa.
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PMID:Changes in the levels of different ions in the eggshell gland lumen following p,p'-DDE-induced eggshell thinning in ducks. 788 10

1. The focus of this review is the effects and mechanism of action of p,p'-DDE on eggshell formation in birds. Inhibition of prostaglandin synthesis in the eggshell gland mucosa is a probable mechanism for p,p'-DDE-induced eggshell thinning. 2. The duck is sensitive to p,p'-DDE-induced eggshell thinning but the domestic fowl is not, and studies comparing the two species in regard to the calcium and prostaglandin metabolism of the eggshell gland have shown that eggshell thinning induced by p,p'-DDE in ducks is accompanied by reduced activity of prostaglandin synthetase, reduced levels of prostaglandin E2, and reduced uptake of 45Ca by the eggshell gland mucosa. The content of calcium, bicarbonate, chloride, sodium, and potassium are also reduced in the eggshell gland lumen in ducks exhibiting eggshell thinning. None of these effects are seen in the domestic fowl. 3. Inhibition of prostaglandin synthesis is a specific effect of p,p'-DDE. The detrimental effects of p,p'-DDE on the eggshell gland seem to be unique when comparing the compound with structurally related substances, i.e., similar treatment regimens with o,p'-DDE, p,p'-DDT, o,p'-DDT, and p,p'-DDD do not cause eggshell thinning in ducks. Neither do they inhibit prostaglandin synthesis in the eggshell gland mucosa. 4. Administration of other compounds that do inhibit prostaglandin synthesis, e.g., indomethacin, does cause the same effects as those seen with p,p'-DDE, i.e., eggshell thinning and the described effects on the calcium and prostaglandin metabolism of the eggshell gland.
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PMID:DDE-induced eggshell thinning in birds: effects of p,p'-DDE on the calcium and prostaglandin metabolism of the eggshell gland. 949 Jan 82

Polychlorinated biphenyl (PCB) and chlorinaed pesticide levels in eggs of two terrestrial (kestrel and sparrowhawk) and two aquatic (heron and mallard) birds were determined in inhabited areas and woodlands of Calabria. The eggs of the two terrestrial raptors were more polluted than those of the aquatic birds. Among the raptors, the kestrel demonstrated the highest level of pollution because it lives close to villages, whereas sparrowhawk lives in forests. The highest PCB and DDT residue concentrations found in kestrel (11.3 and 8.7 mg g-1 lipid, respectively) could cause shell thinning. Aquatic species show a higher DDT/DDE ratio than terrestrial species, probably because DDT is degraded more slowly in aquatic environments. However, point DDT sources seem to be present in this region.
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PMID:Polychlorinated biphenyls and chlorinated pesticides in bird eggs from Calabria (southern Italy). 1033 Mar 26

4,4'-DDT and 4,4'-DDE are widespread environmental contaminants that cause eggshell thinning in birds, altered sex ratios in the American alligator, and changes in the anal-genital distance in rodents. These contaminants are known to cause some of their toxicity by altering steroid receptor-mediated mechanisms. However, chemical-specific alterations in the expression of hormone-metabolizing enzymes may also be a mechanism for endocrine disruption, by altering the half-life of hormones in critical tissues. Previously, we showed that 4,4'-DDE causes a dose-dependent increase in ethoxyresorufin-O-deethylase (EROD) activity, but not pentoxyresorufin-O-dealkylase (PROD) activity, in the deer mouse. In this study, we demonstrated that 4,4'-DDE elicited a corresponding increase in CYP1A protein expression but not CYP2B using Western blotting and immunoprecipitation. 4,4'-DDE-mediated changes in phase II conjugating enzymes; UDP-glucuronosyltransferase (UGT) and phenolsulfotransferase (ST), were also investigated for the first time. Prepubescent female deer mice were dosed with 4,4'-DDE by gavage on days 1 and 2, then euthanized on day 4. As anticipated, dose-dependent increases in hepatic EROD and MROD activities, but not PROD or BROD, were observed. UGT activity was monitored by incubating liver microsomes and 14C-UDP-GA with potential substrates and measuring incorporation of radioactivity into TLC-resolved glucuronides. Dose-dependent increases in conjugation were observed with p-nitrophenol (a general UGT substrate) but not testosterone. Interestingly, a biphasic dose-response curve was observed for ST activity, with a peak at the 3 mg/kg dose. Dose-dependent increases in CYP1A1 and UGT-specific immunoreactive proteins were observed, suggesting de novo synthesis as a consequence of 4,4'-DDE exposure. We also measured Phase I and II enzymes in deer mouse platelets. Preliminary results indicate that the 4,4'-DDE-induced changes in liver Phase I and II enzyme activity were similar, but not identical, to those found in platelets. These results indicate that environmentally-relevant levels of 4,4'-DDE modulate the activity and expression of CYP1A1 and phase II enzymes in the deer mouse and that certain changes may be measured non-lethally.
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PMID:Modulation of endocrine pathways by 4,4'-DDE in the deer mouse Peromyscus maniculatus. 1049

Many wildlife species may be exposed to biologically active concentrations of endocrine-disrupting chemicals. There is strong evidence obtained from laboratory studies showing the potential of several environmental chemicals to cause endocrine disruption at environmentally realistic exposure levels. In wildlife populations, associations have been reported between reproductive and developmental effects and endocrine-disrupting chemicals. In the aquatic environment, effects have been observed in mammals, birds, reptiles, fish, and mollusks from Europe, North America, and other areas. The observed abnormalities vary from subtle changes to permanent alterations, including disturbed sex differentiation with feminized or masculinized sex organs, changed sexual behavior, and altered immune function. For most reported effects in wildlife, however, the evidence for a causal link with endocrine disruption is weak or nonexisting. Crucial in establishing causal evidence for chemical-induced wildlife effects appeared semifield or laboratory studies using the wildlife species of concern. Impaired reproduction and development causally linked to endocrine-disrupting chemicals are well documented in a number of species and have resulted in local or regional population changes. These include: Masculinization (imposex) in female marine snails by tributyltin, a biocide used in antifouling paints, is probably the clearest case of endocrine disruption caused by an environmental chemical. The dogwhelk is particularly sensitive, and imposex has resulted in decline or extinction of local populations worldwide, including coastal areas all over Europe and the open North Sea. DDE-induced egg-shell thinning in birds has caused severe population declines in a number of raptor species in Europe and North America. Endocrine-disrupting chemicals have adversely affected a variety of fish species. In the vicinity of certain sources (e.g., effluents of water treatment plants) and in the most contaminated areas is this exposure causally linked with the effects on reproductive organs that could have implications for fish populations. However, there is also a more widespread occurrence of endocrine disruption in fish in the U.K., where estrogenic effects have been demonstrated in freshwater systems, in estuaries, and in coastal areas. In mammals, the best evidence comes from the-field studies on Baltic gray and ringed seals, and from the Dutch semifield studies on harbor seals, where both reproduction and immune functions have been impaired by PCBs in the food chain. Reproduction effects resulted in population declines, whereas impaired immune function has likely contributed to the mass mortalities due to morbillivirus infections. Distorted sex organ development and function in alligators has been related to a major pesticide spill into a lake in Florida, U.S.A. The observed estrogenic/antiandrogenic effects in this reptile have been causally linked in experimental studies with alligator eggs to the DDT complex. Although most observed effects currently reported concern heavily polluted areas, endocrine disruption is a potential global problem. This is exemplified by the widespread occurrence of imposex in marine snails and the recent findings of high levels of persistent potential endocrine-disrupting chemicals in several marine mammalian species inhabiting oceanic waters.
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PMID:Health effects of endocrine-disrupting chemicals on wildlife, with special reference to the European situation. 1068 Jul 69


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