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1.
Braz J Med Biol Res ; 42(1): 105-13, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19219303

RESUMO

Besides other physiological functions, adenosine-5'-triphosphate (ATP) is also a neurotransmitter that acts on purinergic receptors. In spite of the presence of purinergic receptors in forebrain areas involved with fluid-electrolyte balance, the effect of ATP on water intake has not been investigated. Therefore, we studied the effects of intracerebroventricular (icv) injections of ATP (100, 200 and 300 nmol/microL) alone or combined with DPCPX or PPADS (P1 and P2 purinergic antagonists, respectively, 25 nmol/microL) on water intake induced by water deprivation. In addition, the effect of icv ATP was also tested on water intake induced by intragastric load of 12% NaCl (2 mL/rat), acute treatment with the diuretic/natriuretic furosemide (20 mg/kg), icv angiotensin II (50 ng/microL) or icv carbachol (a cholinergic agonist, 4 nmol/microL), on sodium depletion-induced 1.8% NaCl intake, and on food intake induced by food deprivation. Male Holtzman rats (280-320 g, N = 7-11) had cannulas implanted into the lateral ventricle. Icv ATP (300 nmol/microL) reduced water intake induced by water deprivation (13.1 +/- 1.9 vs saline: 19.0 +/- 1.4 mL/2 h; P < 0.05), an effect blocked by pre-treatment with PPADS, but not DPCPX. Icv ATP also reduced water intake induced by NaCl intragastric load (5.6 +/- 0.9 vs saline: 10.3 +/- 1.4 mL/2 h; P < 0.05), acute furosemide treatment (0.5 +/- 0.2 vs saline: 2.3 +/- 0.6 mL/15 min; P < 0.05), and icv angiotensin II (2.2 +/- 0.8 vs saline: 10.4 +/- 2.0 mL/2 h; P < 0.05), without changing icv carbachol-induced water intake, sodium depletion-induced 1.8% NaCl intake and food deprivation-induced food intake. These data suggest that central ATP, acting on purinergic P2 receptors, reduces water intake induced by intracellular and extracellular dehydration.


Assuntos
Trifosfato de Adenosina/administração & dosagem , Ingestão de Líquidos/efeitos dos fármacos , Fosfato de Piridoxal/análogos & derivados , Privação de Água/fisiologia , Xantinas/administração & dosagem , Trifosfato de Adenosina/farmacologia , Animais , Ingestão de Líquidos/fisiologia , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Injeções Intraventriculares , Masculino , Agonistas do Receptor Purinérgico P1 , Antagonistas de Receptores Purinérgicos P1 , Agonistas do Receptor Purinérgico P2 , Antagonistas do Receptor Purinérgico P2 , Fosfato de Piridoxal/administração & dosagem , Fosfato de Piridoxal/farmacologia , Ratos , Ratos Sprague-Dawley , Xantinas/farmacologia
2.
Braz. j. med. biol. res ; 42(1): 105-113, Jan. 2009. graf
Artigo em Inglês | LILACS | ID: lil-505425

RESUMO

Besides other physiological functions, adenosine-5'-triphosphate (ATP) is also a neurotransmitter that acts on purinergic receptors. In spite of the presence of purinergic receptors in forebrain areas involved with fluid-electrolyte balance, the effect of ATP on water intake has not been investigated. Therefore, we studied the effects of intracerebroventricular (icv) injections of ATP (100, 200 and 300 nmol/µL) alone or combined with DPCPX or PPADS (P1 and P2 purinergic antagonists, respectively, 25 nmol/µL) on water intake induced by water deprivation. In addition, the effect of icv ATP was also tested on water intake induced by intragastric load of 12 percent NaCl (2 mL/rat), acute treatment with the diuretic/natriuretic furosemide (20 mg/kg), icv angiotensin II (50 ng/µL) or icv carbachol (a cholinergic agonist, 4 nmol/µL), on sodium depletion-induced 1.8 percent NaCl intake, and on food intake induced by food deprivation. Male Holtzman rats (280-320 g, N = 7-11) had cannulas implanted into the lateral ventricle. Icv ATP (300 nmol/µL) reduced water intake induced by water deprivation (13.1 ± 1.9 vs saline: 19.0 ± 1.4 mL/2 h; P < 0.05), an effect blocked by pre-treatment with PPADS, but not DPCPX. Icv ATP also reduced water intake induced by NaCl intragastric load (5.6 ± 0.9 vs saline: 10.3 ± 1.4 mL/2 h; P < 0.05), acute furosemide treatment (0.5 ± 0.2 vs saline: 2.3 ± 0.6 mL/15 min; P < 0.05), and icv angiotensin II (2.2 ± 0.8 vs saline: 10.4 ± 2.0 mL/2 h; P < 0.05), without changing icv carbachol-induced water intake, sodium depletion-induced 1.8 percent NaCl intake and food deprivation-induced food intake. These data suggest that central ATP, acting on purinergic P2 receptors, reduces water intake induced by intracellular and extracellular dehydration.


Assuntos
Animais , Masculino , Ratos , Trifosfato de Adenosina/administração & dosagem , Ingestão de Líquidos/efeitos dos fármacos , Fosfato de Piridoxal/análogos & derivados , Privação de Água/fisiologia , Xantinas/administração & dosagem , Trifosfato de Adenosina/farmacologia , Ingestão de Líquidos/fisiologia , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Injeções Intraventriculares , Fosfato de Piridoxal/administração & dosagem , Fosfato de Piridoxal/farmacologia , Ratos Sprague-Dawley , Receptores Purinérgicos P1/agonistas , Receptores Purinérgicos P1/antagonistas & inibidores , /agonistas , /antagonistas & inibidores , Xantinas/farmacologia
3.
Rev. esp. enferm. metab. óseas (Ed. impr.) ; 9(3): 109-111, mayo 2000. ilus
Artigo em Es | IBECS | ID: ibc-8489

RESUMO

Presentamos el caso clínico de una mujer de 68 años de edad que tenía convulsiones debido a una hipocalcemia como consecuencia de un hipoparatiroidismo primario, y que posteriormente evoluciona a una hipercalcemia debido a un deterioro de la función renal por deshidratación, uso de inhibidores de la enzima convertidora de la angiotensina y posiblemente una intoxicación por vitamina D (AU)


Assuntos
Idoso , Feminino , Humanos , Hipercalcemia/complicações , Hipoparatireoidismo/complicações , Vitamina D/intoxicação , Hipocalcemia/complicações , Convulsões/etiologia , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Tomografia Computadorizada por Raios X , Testes de Função Tireóidea
4.
Eur J Clin Invest ; 30(3): 210-4, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10691997

RESUMO

BACKGROUND: The aim of this study was to determine the sensitivity of bone mineral density (BMD), ultrasounds (SOS) and resistance to torsion (T) to detect experimental osteopenia induced in rats 3 and 6 months after ooforectomy. MATERIALS AND METHODS: Seventy-four rats were used, divided into four groups, ooforectomized rats analysed 3 and 6 months after the operation and their respective control groups, in which BMD (Hologic QDR 1000 S/N 277), SOS (DBM Sonic 1200) and T (adapted test machine) were determined in the right femur. RESULTS: The results of the three techniques distinguished the ooforectomized groups from the controls, both 3 and 6 months after the ooforectomy, obtaining more significant differences with BMD (P = 0.0006, P = 0. 001, respectively) than SOS and T, where a significance of only P = 0.05 was obtained. In the correlation study among the three techniques, a significant correlation was observed between BMD and SOS (r = 0.39, P = 0.0008), as well as between BMD and T (r = 0.31, P = 0.03). However, significance was not observed between the SOS and T tests. CONCLUSION: In the study of sensitivity and specificity of the techniques used to detect the osteopenia caused by the ooforectomy, by means of calculation of the area under the receiver operation characteristic (ROC) curve, it was proven that although the three techniques distinguished between the two analysed populations, BMD presented an area under the ROC curve that was superior (0.87, 0.85) to that obtained with SOS (0.73, 0.67) and T (0.73, 0.68), both 3 and 6 months after the operation.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/diagnóstico , Osso e Ossos/fisiologia , Animais , Doenças Ósseas Metabólicas/diagnóstico por imagem , Doenças Ósseas Metabólicas/fisiopatologia , Osso e Ossos/diagnóstico por imagem , Feminino , Osteoporose/diagnóstico por imagem , Ovariectomia , Ratos , Ratos Wistar , Anormalidade Torcional , Ultrassom , Ultrassonografia
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