84 research outputs found
Effect of intracerebroventricularly injected insulin on urinary sodium excretion by cerebroventricular streptozotocin-treated rats
Recent evidence suggests that insulin may influence many brain functions. It is known that intracerebroventricular (icv) injection of nondiabetogenic doses of streptozotocin (STZ) can damage insulin receptor signal transduction. In the present study, we examined the functional damage to the brain insulin receptors on central mechanisms regulating glomerular filtration rate and urinary sodium excretion, over four periods of 30 min, in response to 3 ”l insulin or 0.15 NaCl (vehicle) injected icv in STZ-treated freely moving Wistar-Hannover rats (250-300 g). The icv cannula site was visually confirmed by 2% Evans blue infusion. Centrally administered insulin (42.0 ng/”l) increased the urinary output of sodium (from 855.6 ± 85.1 to 2055 ± 310.6 delta%/min; N = 11) and potassium (from 460.4 ± 100 to 669 ± 60.8 delta%/min; N = 11). The urinary sodium excretion response to icv insulin microinjection was markedly attenuated by previous central STZ (100 ”g/3 ”l) administration (from 628 ± 45.8 to 617 ± 87.6 delta%/min; N = 5) or by icv injection of a dopamine antagonist, haloperidol (4 ”g/3 ”l) (from 498 ± 39.4 to 517 ± 73.2 delta%/min; N = 5). Additionally, insulin-induced natriuresis occurred by increased post-proximal tubule sodium rejection, despite an unchanged glomerular filtration rate. Excluding the possibility of a direct action of STZ on central insulin receptor-carrying neurons, the current data suggest that the insulin-sensitive response may be processed through dopaminergic D1 receptors containing neuronal pathways.1193119
Desenvolvimento folicular e desempenho produtivo no inĂcio do ciclo de postura em duas raças de poedeiras
Efeito residual da silicatagem no solo e na produtividade do capim-marandu sob pastejo
Soybean meal or cotton by-products associated with urea as source of nitrogen in the diet of lactating goats
Effect of intracerebroventricularly injected insulin on urinary sodium excretion by cerebroventricular streptozotocin-treated rats
Comportamento ingestivo de ovinos recebendo dietas com diferentes nĂveis de bagaço de laranja em substituição Ă silagem de sorgo na ração
Revegetação espontùnea de voçoroca na região de Cerrado, Mato Grosso do Sul, Brasil
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Valor nutritivo do capim-braquiĂĄria no primeiro ano de recuperação com aplicaçÔes de nitrogĂȘnio e enxofre
Influence of gender on carcass yield of twin lambs Blackbelly x Pelibuey at 56 days of age
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