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1.
Acta Anaesthesiol Scand ; 61(7): 804-812, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28653376

RESUMO

BACKGROUND: The socioeconomic factors have an impact on case mix and outcome in critical illness, but how these factors affect the use of intensive care is not studied. The aim of this study was to evaluate the incidence of intensive care unit (ICU) admissions in patients from residential areas with different annual incomes. METHODS: Single-center, retrospective study in Northern Finland. All the non-trauma-related emergency admissions from the hospital district area were included. The postal codes were used to categorize the residential areas according to each area's annual median income: the low-income area, €18,979 to €28,841 per year; the middle-income area, €28,879 to €33,856 per year; and the high-income area, €34,221 to €53,864 per year. RESULTS: A total of 735 non-trauma-related admissions were included. The unemployment or retirement, psychiatric comorbidities and chronic alcohol abuse were common in this population. The highest incidence, 5.5 (4.6-6.7)/1000/year, was in population aged more than 65 years living in high-income areas. In working-aged population, the incidence was lowest in high-income areas (1.5 (1.3-1.8/1000/year) compared to middle-income areas (2.2 (1.9-2.6)/1000/year, P = 0.001) and low-income areas (2.0 (1.7-2.4)/1000/, P = 0.009). Poisonings were more common in low-income areas. There were no differences in outcome. CONCLUSION: The incidence of ICU admission in working-aged population was 25% higher in those areas where the annual median income was below the median annual income of €38,775 per inhabitant per year in Finland.


Assuntos
Cuidados Críticos/economia , Cuidados Críticos/estatística & dados numéricos , Renda/estatística & dados numéricos , Unidades de Terapia Intensiva/economia , Unidades de Terapia Intensiva/estatística & dados numéricos , Fatores Socioeconômicos , Idoso , Feminino , Finlândia , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
Artigo em Inglês | MEDLINE | ID: mdl-24548908

RESUMO

Composition of membrane lipids from the gills of juvenile Atlantic salmon (Salmo salar) in presmolt and smolt phases of development was compared among anadromous and non-anadromous populations. Three stocks migrating from spawning rivers to either lake (landlocked stock), brackish water or full strength sea water were grown under common garden conditions, and gill lipids and their acyl and alkenyl chains were examined in February (presmolts) and at the end of May (smolts) by mass spectrometry and gas-liquid chromatography. The most remarkable changes upon transition from the presmolt phase to the smolt phase were: (i) increase in the cholesterol/phospholipid ratio, (ii) decrease in the abundance of phosphatidylinositol (PI) content, (iii) increase in the amount of sulfatides, (iv) increase in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) species with two highly unsaturated acyl chains, and finally (v) convergence of interstock differences in PC and PE species composition towards a similar lipid composition. Increases in the gill membrane content of cholesterol and sulfatides are discussed as pre-adaptation of salmon gills for salt-secretion, which may occur by increases in membrane microdomains (rafts) harboring ion channels and pumps. The decreases of PI were likely related to adjusting the gill membrane permeability to ions by diminishing prostanoid production. The similarity of those changes among three salmon stocks and the convergence of initially (presmolt phase) different PC and PE species profiles between the stocks towards similar lipid composition suggests that smoltification process of the gill epithelium is largely similar in anadromous and landlocked populations.


Assuntos
Adaptação Fisiológica , Brânquias/metabolismo , Metabolismo dos Lipídeos , Salmão/fisiologia , Aclimatação/fisiologia , Migração Animal , Animais , População , Salmão/metabolismo , Estações do Ano , Água do Mar
3.
Brain ; 135(Pt 9): 2661-75, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22961545

RESUMO

Mucolipidosis II is a neurometabolic lysosomal trafficking disorder of infancy caused by loss of mannose 6-phosphate targeting signals on lysosomal proteins, leading to lysosomal dysfunction and accumulation of non-degraded material. However, the identity of storage material and mechanisms of neurodegeneration in mucolipidosis II are unknown. We have generated 'knock-in' mice with a common mucolipidosis II patient mutation that show growth retardation, progressive brain atrophy, skeletal abnormalities, elevated lysosomal enzyme activities in serum, lysosomal storage in fibroblasts and brain and premature death, closely mimicking the mucolipidosis II disease in humans. The examination of affected mouse brains at different ages by immunohistochemistry, ultrastructural analysis, immunoblotting and mass spectrometric analyses of glycans and anionic lipids revealed that the expression and proteolytic processing of distinct lysosomal proteins such as α-l-fucosidase, ß-hexosaminidase, α-mannosidase or Niemann-Pick C2 protein are more significantly impacted by the loss of mannose 6-phosphate residues than enzymes reaching lysosomes independently of this targeting mechanism. As a consequence, fucosylated N-glycans, GM2 and GM3 gangliosides, cholesterol and bis(monoacylglycero)phosphate accumulate progressively in the brain of mucolipidosis II mice. Prominent astrogliosis and the accumulation of organelles and storage material in focally swollen axons were observed in the cerebellum and were accompanied by a loss of Purkinje cells. Moreover, an increased neuronal level of the microtubule-associated protein 1 light chain 3 and the formation of p62-positive neuronal aggregates indicate an impairment of constitutive autophagy in the mucolipidosis II brain. Our findings demonstrate the essential role of mannose 6-phosphate for selected lysosomal proteins to maintain the capability for degradation of sequestered components in lysosomes and autophagolysosomes and prevent neurodegeneration. These lysosomal proteins might be a potential target for a valid therapeutic approach for mucolipidosis II disease.


Assuntos
Lisossomos/genética , Mucolipidoses/genética , Degeneração Neural/genética , Animais , Atrofia , Autofagia , Encéfalo/enzimologia , Encéfalo/patologia , Modelos Animais de Doenças , Lisossomos/enzimologia , Lisossomos/patologia , Camundongos , Camundongos Transgênicos , Mucolipidoses/enzimologia , Mucolipidoses/patologia , Degeneração Neural/enzimologia , Degeneração Neural/patologia , Proteínas de Transporte Vesicular/metabolismo , alfa-L-Fucosidase/metabolismo , alfa-Manosidase/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismo
4.
J Toxicol Environ Health A ; 64(5): 427-46, 2001 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-11700007

RESUMO

Minks were fed different fish-based diets and exposed to 1 mg/d of the commercial polychlorinated biphenyl (PCB) mixture Aroclor 1242 for 4 wk (November-December 1995) or 21 wk (July-December 1998). In all the dietary groups, the PCBs increased hepatic phospholipid (PL) content. No significant increase was detected in hepatic triacylglycerols (TGs). In the minks fed the different fish diets, the PCBs caused qualitatively and quantitatively different changes in the microsomal fatty acids. In the minks that were fed a diet rich in fat and low in polyunsaturated fatty acids (PUFAs), the PCBs increased the percentage of oleic acid (18:1n-9, characteristic of the storage TGs) at the expense of n-3 PUFAs. This seemed to be due to inclusions of TGs in the membrane fragments and partly due to incorporation of TG-derived fatty acids into the membrane PLs. In addition, significant decrease of PUFAs was detected also in the hepatic TGs. The concomitant decrease in the concentrations of hepatic vitamin E suggested that lipid oxidation may also contribute to the decrease of the PUFAs. In the liver of the minks fed a low-fat but PUFA- and vitamin E-rich diet, the fatty acid changes due to the PCBs (the 21-wk exposure) remained small but the cytochrome P-450 system was significantly activated. In the minks fed Baltic herring (rich in organochlorines via the foodweb), the cytosolic glutathione S-transferase (GST) activity, levels of microsomal thiobarbituric acid-reactive substances (TBARS), and hepatic PLs were significantly elevated. In conclusion, in the mink the microsomal fatty acid changes were not directly connected with the ethoxyresorufin O-deethylase (EROD) activity or P-450 expression. Apparently, the PCBs produced definite fatty acid changes only in certain lipid matrices of tissue. In addition, a rich dietary supply of PUFAs and vitamin E may prevent these changes, even in a long-term subchronic exposure.


Assuntos
Ração Animal , Arocloros/toxicidade , Ácidos Graxos/metabolismo , Peixes/metabolismo , Metabolismo dos Lipídeos , Microssomos Hepáticos/metabolismo , Vison/fisiologia , Oxigenases de Função Mista/metabolismo , Animais , Citocromo P-450 CYP1A1/metabolismo , Citosol/enzimologia , Citosol/metabolismo , Dieta , Feminino , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Oxigenases de Função Mista/biossíntese , Preparações Farmacêuticas/metabolismo , Vitamina E/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-7584849

RESUMO

Fatty acid composition of the liver, brown fat, thigh muscle and heart of Sorex araneus and Neomys fodiens was determined by GLC and GLC-MS. In both species of shrew the total amounts of omega 3-PUFAs in the phospholipids were greater than those in the triglycerides. Sorex araneus, which feeds solely on a terrestrial diet, had a larger total amount of omega 6-PUFAs in the triglycerides of the brown fat. The phospholipids of the thigh muscle and heart of Neomys fodiens, however, contained more omega 6-PUFAs than did those of Sorex araneus. These results suggest that the fatty acid composition of the membrane phospholipids of shrews is largely genetically regulated and is affected by diet less than the composition of triglycerides. The main C16-monounsaturated fatty acid of most of the specimens studied was 16:1 omega 5, which is unusual among mammals.


Assuntos
Dieta , Ácidos Graxos/análise , Fosfolipídeos/química , Musaranhos/metabolismo , Triglicerídeos/química , Animais , Gorduras Insaturadas na Dieta/análise , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Ômega-6 , Ácidos Graxos Insaturados/análise , Musaranhos/genética , Especificidade da Espécie
6.
Comp Biochem Physiol B Biochem Mol Biol ; 113(1): 113-24, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8936044

RESUMO

Site-specific differences in fatty acid composition of adipose tissues from Finnish beavers (Castor canadensis and Castor fiber) and muskrats (Ondatra zibethicus) were studied by gas liquid chromatography. In the total lipids of heterothermic extremities the proportions of potentially endogenous (delta 9-desaturated) monoenoic fatty acids were 1.5-fold and those of the saturated fatty acids 0.5-fold the proportions of subcutaneous or inner depots. Thus the role of delta 9-desaturation in the biochemical adaptation of the extremity tissues is discussed. Dietary polyunsaturated fatty acids, with the exception of 18:3 omega 3 in the beavers, did not accumulate selectively in the extremity tissues. The liver of the muskrat (which also eats fish and mussels) contained high proportions of 22:6 omega 3, which was a minor component in the beaver (exclusively a herbivore).


Assuntos
Tecido Adiposo/química , Arvicolinae/metabolismo , Ácidos Graxos/análise , Roedores/metabolismo , Análise de Variância , Animais , Extremidades , Fígado/química , Especificidade da Espécie , Tórax , Vísceras
7.
Artigo em Inglês | MEDLINE | ID: mdl-9787792

RESUMO

Fatty acid composition in the liver of four ringed-seal (Phoca hispida ssp.) populations, from ocean (Spitsbergen), brackish water (the Baltic Sea) and freshwater (Lake Saimaa and Lake Ladoga) were determined by gas liquid chromatography. The fatty acid compositions in liver were compared with those of the blubber of the seals, which largely reflect the fatty acid supply from marine or freshwater fish. When the ratios of 20:4n-6/20:5n-3 (arachidonic acid/eicosapentaenoic acid, AA/EPA, from 0.06 to 0.55) and n-6 PUFA/n-3 PUFA (n-6/n-3, from 0.09 to 0.35) increased from the marine to freshwater blubber, the corresponding increase in these ratios in the total lipids of the liver was 10-fold or more (AA/EPA: from 1.2 to 13.5 and n-6/n-3: from 0.9 to 3.2). Thus, when available in the diet, AA is preferentially incorporated into the lipids of pinniped liver.


Assuntos
Ácidos Graxos Insaturados/análise , Fígado/química , Focas Verdadeiras/metabolismo , Tecido Adiposo/química , Tecido Adiposo/metabolismo , Animais , Ácido Araquidônico/análise , Cromatografia Gasosa , Dieta , Gorduras Insaturadas na Dieta/administração & dosagem , Gorduras Insaturadas na Dieta/metabolismo , Ácido Eicosapentaenoico/análise , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/metabolismo , Feminino , Água Doce , Fígado/metabolismo , Masculino , Água do Mar
8.
Artigo em Inglês | MEDLINE | ID: mdl-8829812

RESUMO

Unusual fatty acids in the adipose tissue of the Canadian beaver were analysed by argentation thin-layer chromatography, gas-liquid chromatography and gas chromatography-mass spectrometry of several adducts and spectroscopic measurements. The total proportion of trans-octadecenoic fatty acids and the distribution of double bonds in these acids resembled those of ruminant fats. Because trans-11-18:1 was the main trans-18:1 isomer of beaver fat and a conjugated diene cis-9, trans-11-18:2 was also detected, it can be deduced that linoleic acid (cis-9, cis-12-18:2) is biohydrogenated in the beaver. The ideas that microbial processes intervene before normal absorption and fatty acid metabolism of the beaver is also supported by the larger amounts of anteiso odd-chain fatty acids with respect to the corresponding iso acids in the beaver depots. In addition, the distribution of double bonds in the cis-octadecenoic acids was wide, as it is in the depot fats of ruminants.


Assuntos
Tecido Adiposo/química , Ácidos Graxos/análise , Roedores , Animais , Cromatografia Gasosa , Cromatografia em Camada Fina , Ácidos Graxos Insaturados/análise , Finlândia , Ruminantes , Especificidade da Espécie
9.
Artigo em Inglês | MEDLINE | ID: mdl-9080660

RESUMO

Concentrations of vitamins A1 (retinol), A2 (3,4-didehydroretinol) and E (alpha-tocopherol) in the liver and blubber of ringed seals from Lake Saimaa (Phoca hispida saimensis), Lake Ladoga (P. h. ladogensis), the Baltic Sea (P. h. botnica) and Spitsbergen (P. h. hispida) were determined by high-performance liquid chromatography. The freshwater seals had much lower levels of vitamin A1 but higher levels of vitamin A2 than the marine seals. The concentrations of vitamin E in the livers of the subspecies studied were high compared with earlier reports of seals, but the ranges were large. The livers of the marine seals contained more vitamin E than the livers of the freshwater seals, but the levels in the blubber were uniform in all populations, except in old specimens from the Baltic. The differences between the freshwater and marine seals are suggested to be due mainly to diet. The ratios of A1 to A2 in the liver and blubber and in the fish diet were similar for the marine seals and for the freshwater seals (but differed in the marine and freshwater populations), which suggests no great differences in the absorption, transport and metabolism of the two analogues. Blubber was an important storage site for the vitamins studied, and age-dependent increases were detected, especially for vitamin E. In the 2-month to 2-year-old ringed seals of Lake Saimaa, however, the vitamin E concentration in the blubber was not affected by age.


Assuntos
Tecido Adiposo/química , Fígado/química , Focas Verdadeiras/metabolismo , Vitamina A/análogos & derivados , Vitamina A/análise , Vitamina E/análise , Tecido Adiposo/metabolismo , Animais , Peso Corporal , Cromatografia Líquida de Alta Pressão , Dieta , Feminino , Água Doce , Fígado/metabolismo , Masculino , Água do Mar
10.
Lipids ; 30(8): 725-31, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7475988

RESUMO

Blubbers of four ringed seal subspecies from Lake Saimaa, Lake Ladoga, the Baltic Sea, and Spitsbergen were analyzed for very long chain polyunsaturated fatty acids (VLCPUFA; > C22) using gas-liquid chromatography and gas chromatography/mass spectrometry. The VLCPUFA of the blubber oils were mainly n-3 polyunsaturated fatty acids--23:5n-3, 24:3n-3, 24:4n-3, 24:5n-3, 24:6n-3, 26:5n-3, 26:6n-3, and 28:7n-3. The largest VLCPUFA components in all populations were 24:5n-3 (0.1-0.2 wt% of total fatty acids) and 24:6n-3 (0.1%), but 24:4n-3 (0.1%) was also prominent in the Baltic specimens. The blubber oils of the freshwater species contained considerably more 24:4n-6 and 24:5n-6 than the blubbers of the marine species. The differences among the VLCPUFA in these subspecies appear to be mainly due to different dietary VLCPUFA.


Assuntos
Tecido Adiposo/química , Ácidos Graxos Insaturados/análise , Focas Verdadeiras , Animais , Regiões Árticas , Cromatografia Gasosa , Europa Oriental , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Insaturados/química , Finlândia , Cromatografia Gasosa-Espectrometria de Massas , Federação Russa
11.
Artigo em Inglês | MEDLINE | ID: mdl-10190027

RESUMO

Fatty acid composition was determined in adipose tissue surrounding the mesenteric lymph nodes of mink (Mustela vison) exposed to polychlorinated biphenyls (PCBs: 1 mg Aroclor 1242 in food day-1 for 28 days) and/or copper (62 mg kg-1 food). These specific adipose tissues are known to have functional relationships with lymphocytes, and proliferation of cultured lymphocytes is influenced by the quality of fatty acids available in media. In six experimental groups the diet was based on freshwater fish, and in two groups it was based on marine fish. These basal diets differed in terms of fatty acid composition and content of fat-soluble vitamins A1 and E. The fatty acid composition of membrane phospholipids (PL) responded to PCBs more than that of triacylglycerols (TG). The effects of copper were small. In female minks fed a diet of freshwater fish, the proportion of highly unsaturated fatty acids in PL decreased by 5 wt.% due to PCBs, and the acids seemed to be replaced by monounsaturated fatty acids (9 wt.% increase of total). This decrease of highly unsaturated fatty acids in PL was milder in minks on the marine fish diet rich in fat-soluble vitamins. In TG of minks on the marine diet, however, PCBs decreased the proportion of docosahexaenoic acid (22:6n-3). The possibility that these alterations in the fatty acid metabolism of adipose tissue supporting the lymph nodes affect immune function during PCB exposure should be studied further. Interestingly, the quality of the fish diet affected the magnitude of the alterations. The fatty acid responses may also differ between males and females.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Arocloros/farmacologia , Cobre/farmacologia , Ácidos Graxos/metabolismo , Linfonodos/metabolismo , Vison/metabolismo , Tecido Adiposo/metabolismo , Animais , Arocloros/administração & dosagem , Cobre/administração & dosagem , Ácidos Graxos Insaturados/metabolismo , Feminino , Alimentos , Masculino , Lipídeos de Membrana/metabolismo , Mesentério , Fosfolipídeos/metabolismo , Triglicerídeos/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-10390053

RESUMO

Nickel (10-100 ppm added as NiCl2) was studied to determine its effects on reproduction of Wistar rats. In nine experimental groups, females, males or both were exposed to nickel in drinking water. In one female group and one male group, the drinking water was also supplemented with 0.3 ppm selenium (added as Na2SeO3). Breeding success and the growth and viability of pups were recorded. Nickel, copper and zinc concentrations in kidneys, liver and skin (with fur) of the females, males and pups were determined with an atomic absorption spectrophotometer. In addition, histology of the male testes (from control and nickel-exposed groups) was studied. The female exposures started 14, 28 or 100 days before copulation and continued during pregnancy and lactation. When the males were exposed (for 28 or 42 days before copulation), NiCl2 reduced both the number of pregnancies and the number of pups born. In the testes, NiCl2 induced shrinkage of the seminiferous tubules, which seemed to close some of the tubules. In the tubules, NiCl2 decreased the number of basal spermatogonia. When the females or both parents were exposed to NiCl2, pup mortality during lactation was high. However, when the females were drinking NiCl2 supplemented with selenium, all the pups survived and development of the total mass of the litters was even better than in the control group. In the same way, in males, selenium supplementation of the drinking water protected those pups that were born; but fertility was lower than with the control treatment. In the tissues studied, nickel accumulated most in the kidneys and then in the liver and skin. In each type of organ, there was a clear dose response relationship. In the pups, in particular, selenium (given to the females) increased the amount of nickel in tissues compared with corresponding administration of nickel without selenium. In summary, selenium seemed to counteract the deleterious effects of NiCl2 on the reproduction of rats.


Assuntos
Níquel/antagonistas & inibidores , Níquel/toxicidade , Reprodução/efeitos dos fármacos , Selênio/farmacologia , Animais , Cobre/metabolismo , Feminino , Fertilidade/efeitos dos fármacos , Morte Fetal/induzido quimicamente , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Níquel/farmacocinética , Tamanho do Órgão , Gravidez , Ratos , Ratos Wistar , Túbulos Seminíferos/efeitos dos fármacos , Túbulos Seminíferos/metabolismo , Espectrofotometria Atômica , Espermatogônias/efeitos dos fármacos , Espermatogônias/metabolismo , Zinco/metabolismo
13.
Comp Biochem Physiol B ; 105(3-4): 547-52, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8365110

RESUMO

1. Adipose tissues associated with the mystacial and superciliary vibrissae of the Saimaa seal (Phoca hispida saimensis) contained 31% of hexadecenoic acid (16:1 omega 7), which was almost twice the already high amount in blubber. The amount of tetradecenoic acid (14:1 omega 5) was also double that in blubber. 2. At the same time the levels of long-chain highly unsaturated docosapentaenoic (22:5 omega 3) and docosahexaenoic acids (22:6 omega 3) were only two-thirds of those found in blubber. 3. It is suggested that the excess of low-melting monoenoic fatty acids (14:1 and 16:1) in adipose tissues near the vibrissae might not be compensation for the low supply of dietary polyunsaturated fatty acids in these tissues, but that the self-induced excess of monoenoic fatty acids ensured the proper functioning of these well-developed sense organs.


Assuntos
Tecido Adiposo/química , Ácidos Graxos/análise , Focas Verdadeiras , Vibrissas/química , Animais , Cílios/química , Ácidos Docosa-Hexaenoicos/análise , Ácidos Graxos Insaturados/análise , Ácido Mirístico , Ácidos Mirísticos/análise , Ácidos Palmíticos/análise
14.
Comp Biochem Physiol B ; 105(3-4): 553-65, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8365111

RESUMO

1. The main differences in fatty acid composition of blubber between the Saimaa seal (Phoca hispida saimensis) and the Baltic seals (Phoca hispida botnica and Halichoerus grypus) were, that in fresh water the proportions of polyunsaturated C18 acids and arachidonic acid (20:4 omega 6) were high. 2. The trend became more evident when data on ringed seals from northern oceans were compared with the present data. 3. The proportions of exogenous 20:1 and 22:1 were extremely low in ringed seals from Lake Saimaa and in Baltic seals compared with seals living in oceans.


Assuntos
Tecido Adiposo/química , Ácidos Graxos/análise , Fígado/química , Focas Verdadeiras , Animais , Ácido Araquidônico/análise , Ácidos Graxos Insaturados/análise , Água Doce , Água do Mar , Especificidade da Espécie
15.
Artigo em Inglês | MEDLINE | ID: mdl-11154948

RESUMO

Female minks (Mustela vison) fed diets based on freshwater, marine or mixed fish were exposed to 1 mg of polychlorinated biphenyls (PCBs) a day for 21 weeks. The plasma leptin and thyroxine concentrations and the glucose-6-phosphatase and glycogen phophorylase activities in the liver were measured at the end of the experiment. The plasma thyroxine concentrations were significantly higher in the group exposed to PCBs. The mean plasma leptin concentration and glucose-6-phosphatase activity was the highest in the group that had the lowest body-mass index (BMI). The glycogen phophorylase activity was the highest in the freshwater fish-control group. The results suggest that the amount of fat in the body of the female minks is not the only determinant of the plasma leptin levels, but the leptin levels seem to rise with a lowered BMI unlike in rodents or humans. The positive correlation between the leptin levels and the glucose-6-phosphatase activity suggests increased gluconeogenesis with high leptin levels. Subchronic exposure to PCBs seems to have no effect on the plasma leptin levels or the glucose-6-phophatase activities, but it elevates significantly the plasma thyroxine levels with a mechanism that remains unknown.


Assuntos
Dieta , Poluentes Ambientais/farmacologia , Peixes , Leptina/sangue , Vison/fisiologia , Bifenilos Policlorados/farmacologia , Tiroxina/sangue , Tecido Adiposo/efeitos dos fármacos , Animais , Arocloros/farmacologia , Peso Corporal/efeitos dos fármacos , Feminino , Glucose-6-Fosfatase/metabolismo , Fígado/enzimologia , Masculino , Fosforilases/metabolismo , Caracteres Sexuais
16.
J Exp Zool ; 284(3): 241-51, 1999 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10404115

RESUMO

Many cyprinid fish are able to compensate for a decrease in ambient temperature by process of physiological adaptation in the function of muscles. In the winter habitat of crucian carp (Carassius carassius L.), low temperature is associated with simultaneous oxygen shortage. Because of the oxygen deprivation, there is probably little space for compensatory adaptation because positive thermal compensation would increase energy demand and accelerate depletion of glycogen reserves. Thus, we assumed that the crucian carp, unlike many other cyprinid fish, would not show positive thermal compensation but either no compensation or inverse compensation in muscle function. To test this hypothesis in the relaxation system of skeletal muscles, we determined the parvalbumin content and the activity of sarcoplasmic reticular (SR) Ca-ATPase in white myotomal muscle of winter- and summer-acclimated crucian carp. In the laboratory, the winter fish were kept at 2 degrees C and the summer fish at 22 degrees C for a minimum of 3 weeks before the experiments. The specific activity of SR Ca-ATPase at low experimental temperature (2 degrees C) was similar in summer- and winter-acclimated fish (0.26 +/- 0.04 vs. 0.25 +/- 0.04 mM/mg/min; P > 0.05). Because of the bigger Q(10) of cold-acclimated carp, the enzyme activity at 30 degrees C was higher in cold-acclimated winter fish than in warm-acclimated summer fish (7.42 +/- 0.90 vs. 5.18 +/- 0.53 mM/mg/min; P < 0.05). In contrast, the yield of SR protein was 70% higher in summer than winter fish (0.315 +/- 0.045 vs. 0.187 +/- 0.017 mg/g; P < 0.001). Because of these opposing changes, total Ca-ATPase activity of SR (per gram muscle weight) remained relatively constant. Similarly, the parvalbumin content of the myotomal muscle was not different between summer (4.09 +/- 0.95 mg/g) and winter (3.70 +/- 0.60 mg/g) fish. Although there were no seasonal changes in the total relaxing system of the crucian carp white myotomal muscle, the same activity of SR Ca-ATPase in winter fish was obtained with less amount of SR pump protein, owing to the increased catalytic activity of the enzyme. The higher catalytic activity of winter fish SR Ca-ATPase might be caused by differences in fatty acid composition noted in membrane lipids; i.e., fewer saturated fatty acids and more n-6 polyunsaturated fatty acids (PUFAs), at the expense of n-3 PUFAs, were present in the SR of cold-acclimated winter fish. Temperature-induced changes in enzyme protein, however, cannot be excluded. Thus, the present results indicate the absence of positive thermal compensation in the relaxing system of crucian carp white muscle. It seems, however, that lipid composition of SR membranes and temperature dependence of SR Ca-ATPase are altered by seasonal acclimation.


Assuntos
Adaptação Fisiológica , Carpas/fisiologia , Fibras Musculares de Contração Rápida/fisiologia , Relaxamento Muscular/fisiologia , Temperatura , Animais , ATPases Transportadoras de Cálcio/metabolismo , Ácidos Graxos/metabolismo , Membranas/metabolismo , Parvalbuminas/metabolismo , Retículo Sarcoplasmático/enzimologia
17.
Comp Biochem Physiol C Toxicol Pharmacol ; 128(2): 203-11, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11239833

RESUMO

Exogenous melatonin as subcutaneous 2.7-mg implants was given to eight female and male minks in late July with an equal number of animals in the control groups. The liver enzyme activities and major lipids of liver and plasma were measured in October-November. Melatonin had very pronounced effects on the lipid and carbohydrate metabolism of the minks and there was also a clear sexual dimorphism. In the males, melatonin decreased the lipase esterase activity of the liver. In the liver of the females, however, melatonin increased the glucose-6-phosphatase activity. Due to melatonin treatment the liver triacylglycerol contents diminished in both sexes. At the same time, in the females the liver cholesterol levels were decreased. In the plasma lipids, the only change was a fall in the polar lipids of the melatonin-treated females. Melatonin seems to be responsible for the metabolic changes associated with the onset of wintering, especially for the acceleration of the deposition of subcutaneous fat reserves. The smaller females experience the effects of exogenous melatonin more rapidly than the males. Perhaps the smaller body size requires an earlier onset of metabolic preparation for the winter.


Assuntos
Antioxidantes/farmacologia , Metabolismo dos Lipídeos , Fígado/efeitos dos fármacos , Melatonina/farmacologia , Fosfatase Ácida/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Feminino , Glucose-6-Fosfatase/metabolismo , Lipídeos/sangue , Fígado/enzimologia , Fígado/metabolismo , Masculino , Vison , Fosforilases/metabolismo , Aumento de Peso/efeitos dos fármacos
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