RESUMO
Bilateral electrolyte lesions of the Anterior Hypothalamus (AH) were placed in rats to determine the extent to which this area participates in the regulation of Arterial Blood Pressure (ABP). Experiments were performed in two groups of rats; in one ABP was measured continuously for 44 hr subsequent to the lesion, and in a second group ABP was measured 24 hr after the placement of the lesion. The destruction of this area results in a rapid development of arterial hypertension, hypermotility and hyperexcitability. 24 hr later these effects are attenuated. We conclude that arterial hypertension is probably due to a disinhibition of sympathetic activity through central interruption of baroreceptors reflexes.
Assuntos
Pressão Sanguínea , Hipotálamo Anterior/fisiologia , Hipotálamo/fisiologia , Animais , Homeostase , Hipertensão/etiologia , Hipertensão/patologia , Hipotálamo Anterior/patologia , Masculino , Pressorreceptores/fisiologia , Ratos , Ratos EndogâmicosRESUMO
Bilateral electrolyte lesions of the Anterior Hypothalamus (AH) were placed in rats to determine the extent to which this area participates in the regulation of Arterial Blood Pressure (ABP). Experiments were performed in two groups of rats; in one ABP was measured continuously for 44 hr subsequent to the lesion, and in a second group ABP was measured 24 hr after the placement of the lesion. The destruction of this area results in a rapid development of arterial hypertension, hypermotility and hyperexcitability. 24 hr later these effects are attenuated. We conclude that arterial hypertension is probably due to a disinhibition of sympathetic activity through central interruption of baroreceptors reflexes.
RESUMO
Bilateral electrolyte lesions of the Anterior Hypothalamus (AH) were placed in rats to determine the extent to which this area participates in the regulation of Arterial Blood Pressure (ABP). Experiments were performed in two groups of rats; in one ABP was measured continuously for 44 hr subsequent to the lesion, and in a second group ABP was measured 24 hr after the placement of the lesion. The destruction of this area results in a rapid development of arterial hypertension, hypermotility and hyperexcitability. 24 hr later these effects are attenuated. We conclude that arterial hypertension is probably due to a disinhibition of sympathetic activity through central interruption of baroreceptors reflexes.
RESUMO
In the current study a) cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (2nd week) and a later period (10th week) of hypertension elicited by unilateral renal ischemia and contralateral nephrectomy in the rat have been described. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this type of hypertension. An increase in the activity of the nervous system apparently contributes to hypertension in the early period but would disappear when the one-kidney renovascular hypertension is chronically established; in both phases some other still undefined factor/s are present for fuller development of high arterial pressure.
Assuntos
Modelos Animais de Doenças , Hipertensão Renal/fisiopatologia , Hipertensão Renovascular/fisiopatologia , Obstrução da Artéria Renal/fisiopatologia , Animais , Nefrectomia , Inibição Neural/efeitos dos fármacos , Norepinefrina/farmacologia , Tartarato de Pentolínio/farmacologia , Ratos , Fatores de TempoRESUMO
In the current study a) cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (2nd week) and a later period (10th week) of hypertension elicited by unilateral renal ischemia and contralateral nephrectomy in the rat have been described. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this type of hypertension. An increase in the activity of the nervous system apparently contributes to hypertension in the early period but would disappear when the one-kidney renovascular hypertension is chronically established; in both phases some other still undefined factor/s are present for fuller development of high arterial pressure.
RESUMO
In the current study a) cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (2nd week) and a later period (10th week) of hypertension elicited by unilateral renal ischemia and contralateral nephrectomy in the rat have been described. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this type of hypertension. An increase in the activity of the nervous system apparently contributes to hypertension in the early period but would disappear when the one-kidney renovascular hypertension is chronically established; in both phases some other still undefined factor/s are present for fuller development of high arterial pressure.
RESUMO
The role of some mechanisms in the development of hypertension due to unilateral renal artery stenosis is influenced by the presence or absence of the intact opposite kidney. In this paper: a) the cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (first two weeks) and later periods (ten weeks) of hypertension elicited by unilateral renal ischemia in the presence of the untouched contralateral kidney in the rat have been reported. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this specific type of renovascular hypertension. An increase in the activity of the nervous system apparently contributes in early and late periods to the fuller development of high arterial pressure (AP).
Assuntos
Sistema Cardiovascular/fisiopatologia , Hipertensão Renal/fisiopatologia , Sistema Nervoso/fisiopatologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Sistema Cardiovascular/efeitos dos fármacos , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/fisiopatologia , Sistema Nervoso/efeitos dos fármacos , Norepinefrina/farmacologia , Tartarato de Pentolínio/farmacologia , Ratos , Obstrução da Artéria Renal/fisiopatologia , SimpatectomiaRESUMO
The role of some mechanisms in the development of hypertension due to unilateral renal artery stenosis is influenced by the presence or absence of the intact opposite kidney. In this paper: a) the cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (first two weeks) and later periods (ten weeks) of hypertension elicited by unilateral renal ischemia in the presence of the untouched contralateral kidney in the rat have been reported. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this specific type of renovascular hypertension. An increase in the activity of the nervous system apparently contributes in early and late periods to the fuller development of high arterial pressure (AP).
RESUMO
The role of some mechanisms in the development of hypertension due to unilateral renal artery stenosis is influenced by the presence or absence of the intact opposite kidney. In this paper: a) the cardiovascular reactivity (CR) to norepinephrine (NE) and b) the effect of a ganglionic blocker (pentolinium, P) during the early (first two weeks) and later periods (ten weeks) of hypertension elicited by unilateral renal ischemia in the presence of the untouched contralateral kidney in the rat have been reported. Neither the threshold doses nor the dose-pressor response curves have shown a greater reactivity of the cardiovascular system to NE in this specific type of renovascular hypertension. An increase in the activity of the nervous system apparently contributes in early and late periods to the fuller development of high arterial pressure (AP).
