Plasticity of GABA function in the nucleus tractus solitarius in hypertension

Sved, Alan F.; Sved, Judith C.

doi:10.1152/ajpregu.00441.2003

Cited by 4 publications

(4 citation statements)

References 15 publications

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“…Thus it is possible that SAD could result in long-term increments in sympathetic activity, but little or no hypertension, because of nonneural compensations that reduce arterial pressure. Additionally, because of the plasticity of the nervous system, the central reorganization of the baroreflex circuitry that occurs in response to transection of baroreceptor afferents may alter central neural control of the cardiovascular system (5,20,45). For example, in rats with long-standing SAD, there is a marked increase in GABA-mediated suppression of neurons in the nucleus tractus solitarius (NTS), the primary termination site of baroreceptor afferents (20).…”

Section: Resetting Of the Baroreflex And Sinoaortic Denervationmentioning

confidence: 99%

Recent insights into the interactions between the baroreflex and the kidneys in hypertension

Lohmeier¹,

Hildebrandt²,

Warren³

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

102

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Recent findings in chronically instrumented animals challenge the classic concept that baroreflexes do not play a role in the chronic regulation of arterial pressure. As alterations in renal excretory function are of paramount importance in the chronic regulation of arterial pressure, several of these recent studies have focused on the long-term interactions between the baroreflex and the kidneys during chronic perturbations in arterial pressure and body fluid volumes. An emerging body of evidence indicates that the baroreflex is chronically activated in several experimental models of hypertension, but in most cases, the duration of these studies has not exceeded 2 wk. Although these studies suggest that the baroreflex may play a compensatory role in attenuating the severity of the hypertension, possibly even in primary hypertension with uncertain causes of sympathetic activation, there has been only limited assessment of the quantitative importance of this interaction in the regulation of arterial pressure. In experimental models of secondary hypertension, baroreflex suppression of renal sympathetic nerve activity is sustained and chronically promotes sodium excretion. This raises the possibility that the renal nerves may be the critical efferent link for baroreceptor-induced suppression of central sympathetic output through which long-term compensatory reductions in arterial pressure are produced. This contention is supported by strong theoretical evidence but must be corroborated by experimental studies. Finally, although it is now clear that pressure-induced increases in baroreflex activity persist for longer periods of time than previously suggested, studies using new tools and novel approaches and extending beyond 2 wk of hypertension are needed to elucidate the true role of the baroreflex in the pathogenesis of clinical hypertension.

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Section: Resetting Of the Baroreflex And Sinoaortic Denervationmentioning

confidence: 99%

Recent insights into the interactions between the baroreflex and the kidneys in hypertension

Lohmeier¹,

Hildebrandt²,

Warren³

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

102

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“…Similar to other brain regions, glutamate appears to be the primary excitatory neurotransmitter and GABA appears to be the primary inhibitory neurotransmitter in the NTS (2,26,37,43). Reductions in glutamatergic and enhancement of GABAergic neurotransmission in the NTS would tend to increase sympathetic nervous system activity and have been implicated in various forms of experimental hypertension (32,40,46).It is possible that ExTr alters excitatory and inhibitory processes in the NTS to affect regulation of sympathetic outflow. It has been reported that animal models of ExTr exhibit reduced resting (24) and blunted baroreflex-mediated sympathoexcitation (3,7,10,11,22,33).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Putative role of the NTS in alterations in neural control of the circulation following exercise training in rats

Mueller

Hasser

2006

American Journal of Physiology-Regulatory, Integrative and Comp

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Exercise training (ExTr) has been associated with alterations in neural control of the circulation, including effects on arterial baroreflex function. The nucleus tractus solitarius (NTS) is the primary termination site of cardiovascular afferents and critical in the regulation of baroreflex-mediated changes in heart rate (HR) and sympathetic nervous system outflow. The purpose of the present study was to determine whether ExTr is associated with alterations in neurotransmitter regulation of neurons involved in control of cardiovascular function at the level of the NTS. We hypothesized that ExTr would increase glutamatergic and reduce GABAergic transmission in the NTS and that, collectively, these changes would result in a greater overall sympathoinhibitory drive from the NTS in ExTr animals. To test these hypotheses, male Sprague-Dawley rats were treadmill trained or maintained under sedentary conditions for 8-10 wk. NTS microinjections were performed in Inactin-anesthetized animals instrumented to record mean arterial pressure (MAP), HR, and lumbar sympathetic nerve activity (LSNA). Generalized activation of the NTS with unilateral microinjections of glutamate (1-10 mM, 30 nl) produced dose-dependent decreases in MAP, HR, and LSNA that were unaffected by ExTr. Bilateral inhibition of NTS with the GABAA agonist muscimol (1 mM, 90 nl) produced increases in MAP and LSNA that were blunted by ExTr. In contrast, pressor and sympathoexcitatory responses to bilateral microinjections of the ionotropic glutamate receptor antagonist, kynurenate (40 mM, 90 nl), were similar between groups. Bradycardic responses to bilateral microinjections of the GABAA antagonist bicuculline (0.1 mM, 90 nl) were attenuated by ExTr. These data indicate that alterations in neurotransmission at the level of the NTS contribute importantly to regulation of HR and LSNA in ExTr animals. In addition to alterations at NTS, these experiments suggest indirectly that changes in other cardiovascular nuclei contribute to the observed alterations in neural control of the circulation following ExTr.

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“…Gamma-aminobutyric acid (GABA), a four-carbon non-protein amino acid, is a major inhibitory neurotransmitter in the mammalian brain [1]. Clinical research showed that it can lower blood pressure, prevent cancers, and reduce cardiovascular diseases [2][3][4]. However, the GABA content in natural food is far from meeting the physiological needs of the human body.…”

Section: Introductionmentioning

confidence: 99%

Exogenous Spermidine Promotes γ-Aminobutyric Acid Accumulation and Alleviates the Negative Effect of NaCl Stress in Germinating Soybean (Glycine max L.)

Fang

Yin

et al. 2020

Foods

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We investigated the effects of exogenous spermidine (Spd) on the physiological status, γ-aminobutyric acid (GABA) synthase activity, and gene expressions in germinating soybeans under NaCl stress. The results show that Spd significantly increases sprout growth and biomass, decreases malonaldehyde and H2O2 contents, and markedly promotes the activities of superoxide dismutase, catalase, peroxidase, and glutathione peroxidase of germinating soybeans. The harmful effect of NaCl stress was alleviated by exogenous Spd. GABA accumulation in germinating soybeans was caused by the activation of diamine oxidase, polyamine oxidase, aminoaldehyde dehydrogenase, and glutamate decarboxylase activities and by up-regulating their gene expression under Spd-NaCl treatment. The GABA content decreased by 57% and 46% in germinating soybeans with the application of aminoguanidine under Spd and Spd-NaCl treatments, respectively. In conclusion, spermidine induces the accumulation of GABA and increases sprouts biomass, thereby enhancing the functional quality of germinating soybeans.

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Plasticity of GABA function in the nucleus tractus solitarius in hypertension

Cited by 4 publications

References 15 publications

Recent insights into the interactions between the baroreflex and the kidneys in hypertension

Recent insights into the interactions between the baroreflex and the kidneys in hypertension

Putative role of the NTS in alterations in neural control of the circulation following exercise training in rats

Exogenous Spermidine Promotes γ-Aminobutyric Acid Accumulation and Alleviates the Negative Effect of NaCl Stress in Germinating Soybean (Glycine max L.)

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