Baroreceptor reflex inhibition induced by the stimulation of serotonin3 receptors in the nucleus tractus solitarius of the rat

Merahi, Nacera; Orer, Hakan S.; Laporte, Anne-Marie; Gozlan, H.; Hamon, Michel; Laguzzi, Raùl

doi:10.1016/0306-4522(92)90011-p

Cited by 72 publications

(77 citation statements)

References 28 publications

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“…We have previously used this technique to demonstrate the presynaptic location of adenosine A2a receptors (Castillo-Melendez et al, 1994); angiotensin II receptors (Lewis et al, 1986) and vasopressin V1 receptors (Gao et al, 1992) in the rat NTS. In addition, nodose ganglionectomy has also been employed to study the cellular localization in the NTS of glutamate receptors (Lewis et al, 1988), neurotensin receptors (Kessler & Beaudet, 1989), cholecystokinin receptors (Ladenheim et al, 1988), muscarinic cholinoceptor and delta-opioid receptors (Leslie et al, 1989), 5-HT3 receptors (Merahi et al, 1992) and substance P receptors (Manaker & Zucchi, 1993).…”

Section: Discussionmentioning

confidence: 99%

Functional dopamine D₂ receptors on rat vagal afferent neurones

Lawrence

Krstew

Jarrott

1995

British J Pharmacology

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1 In the present study in vitro electrophysiology and receptor autoradiography were used to determine whether rat vagal afferent neurones possess dopamine D2 receptors. 2 Dopamine (10-300IM) elicited a temperature-and concentration-dependent depolarization of the rat isolated nodose ganglion preparation. When applied to the tissue 15 min prior to agonist, raclopride (10 M), clozapine (10I1M) or a mixture of raclopride and clozapine (1O gM each) all produced a threefold parallel shift to the right of the dopamine concentration-response curve. In contrast, SCH 23390 (100 nM), phentolamine and propranolol (1 jAM each) failed to antagonize the dopamine-mediated depolarization.3 [125I]-NCQ 298 (0.5 nM), a D2 selective radioligand, bound topographically to sections of rat brainstem. Densitometric quantification of autoradiograms revealed 93.8 ± 0.5% specific binding of this salicylamide radioligand, as determined by raclopride (1O iM, n = 10 animals). Binding was highest in the nucleus tractus solitarius (NTS), particularly the medial and gelatinous subnuclei. In addition, specific binding was also observed in the interpolar spinal trigeminal nucleus and the inferior olive. 4 Unilateral nodose ganglionectomy caused a 36.6 ± 3.0% reduction in specific binding in the denervated NTS compared to the contralateral NTS. Furthermore, the loss of binding was confined to the dorsal aspect of the medial subnucleus of the NTS. Sham surgery had no effect on the binding of ['25I]-NCQ 298 in rat brainstem. 5 The present data provide evidence for the presence of functionally relevant dopamine D2 receptors on both the soma and central terminals of rat vagal afferent neurones. In addition, the majority of D2 receptors in the rat NTS appear to be located postsynaptically with respect to vagal terminals, and are presumably located either on ascending glossopharyngeal terminals, descending terminals from higher brain regions or on neuronal cell bodies within the NTS.

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Section: Discussionmentioning

confidence: 99%

Functional dopamine D₂ receptors on rat vagal afferent neurones

Lawrence

Krstew

Jarrott

1995

British J Pharmacology

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“…nucleus tractus solitarius; serotonin3 receptors; GABAA receptors; defense/attack MUCH EVIDENCE indicates that serotonin (5-hydroxytryptamine; 5-HT) plays a modulatory role in the central control of cardiovascular parameters (28, 32), notably through actions at the level of the nucleus tractus solitarius (NTS) (13, 15), a key structure for the integration of baroreceptor and other peripheral and central messages involved in the homeostatic control of blood pressure (BP) and heart rate (HR) (9,11,19). In particular, serotonin 3 (5-HT 3 ) receptor stimulation specifically in the NTS was shown to elicit a transitory increase in BP and to block the cardiovagal component (bradycardia) of the baroreceptor reflex (15,25). Interestingly, transient hypertension and inhibition of the cardiac baroreceptor reflex response are also the cardiovascular changes that accompany the defense reaction and other behavioral responses to various stressful conditions (16,17).…”

mentioning

confidence: 99%

“…MUCH EVIDENCE indicates that serotonin (5-hydroxytryptamine; 5-HT) plays a modulatory role in the central control of cardiovascular parameters (28,32), notably through actions at the level of the nucleus tractus solitarius (NTS) (13,15), a key structure for the integration of baroreceptor and other peripheral and central messages involved in the homeostatic control of blood pressure (BP) and heart rate (HR) (9,11,19). In particular, serotonin 3 (5-HT 3 ) receptor stimulation specifically in the NTS was shown to elicit a transitory increase in BP and to block the cardiovagal component (bradycardia) of the baroreceptor reflex (15,25).…”

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confidence: 99%

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Comet¹,

Sévoz‐Couche²,

Hanoun³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

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Comet, Marie-Anne, Caroline Sévoz-Couche, Naïma Hanoun, Michel Hamon, and Raul Laguzzi. 5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat. Am J Physiol Heart Circ Physiol 287: H1641-H1649, 2004. First published May 27, 2004 10.1152 10. /ajpheart.01204.2003ous studies showed that the cardiac response of the baroreceptor reflex (bradycardia) is inhibited during the defense reaction evoked by direct electrical or chemical stimulation of the periaqueductal gray (dPAG) in the rat. Whether central serotonin and nucleus tractus solitarius (NTS) serotonin 3 (5-HT3) receptors might participate in this inhibition was investigated in urethane-anesthetized and atenolol-pretreated rats. Our results showed that both electrical and chemical stimulation of the dPAG produced a drastic reduction of the cardiovagal component of the baroreceptor reflex triggered by either intravenous administration of phenylephrine or aortic nerve stimulation. This inhibitory effect of dPAG stimulation on the baroreflex bradycardia was not observed in rats that had been pretreated with p-chlorophenylalanine (300 mg/kg ip daily for 3 days) to inhibit serotonin synthesis. Subsequent 5-hydroxytryptophan administration (60 mg/kg ip), which was used to restore serotonin synthesis, allowed the inhibitory effect of dPAG stimulation on both aortic and phenylephrine-induced cardiac reflex responses to be recovered in p-chlorophenylalanine-pretreated rats. On the other hand, in nonpretreated rats, the inhibitory effect of dPAG stimulation on the cardiac baroreflex response could be markedly reduced by prior intra-NTS microinjection of granisetron, a 5-HT 3 receptor antagonist, or bicuculline, a GABAA receptor antagonist. These results show that serotonin plays a key role in the dPAG stimulation-induced inhibition of the cardiovagal baroreceptor reflex response. Moreover, they support the idea that 5-HT 3 and GABAA receptors in the NTS contribute downstream to the inhibition of the baroreflex response caused by dPAG stimulation. nucleus tractus solitarius; serotonin3 receptors; GABAA receptors; defense/attack MUCH EVIDENCE indicates that serotonin (5-hydroxytryptamine; 5-HT) plays a modulatory role in the central control of cardiovascular parameters (28, 32), notably through actions at the level of the nucleus tractus solitarius (NTS) (13, 15), a key structure for the integration of baroreceptor and other peripheral and central messages involved in the homeostatic control of blood pressure (BP) and heart rate (HR) (9,11,19). In particular, serotonin 3 (5-HT 3 ) receptor stimulation specifically in the NTS was shown to elicit a transitory increase in BP and to block the cardiovagal component (bradycardia) of the baroreceptor reflex (15,25). Interestingly, transient hypertension and inhibition of the cardiac baroreceptor reflex response are also the cardiovascular changes that accompany the defense reaction and other behavioral responses to various stressful conditions (16,17).Inhibition of the baroreceptor...

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“…Previous studies indicate that the BJ reflex and the arterial baroreflex might share common central pathways, as follows. Autoradiographic studies have shown that most 5-HT 3 receptors in the nucleus tractus solitarius (NTS) are found on the vagal sensory afferent fibers (18). Pires et al (23) demonstrated that intracisternal or NTS injection of the 5-HT 3 receptor antagonist granisetron significantly attenuated the hypotension and bradycardia evoked by intravenous PBG, suggesting that NTS was involved in the central pathways of the BJ reflex.…”

Section: Effects Of Pbg On Neural and Peripheral Arc Transfer Charactmentioning

confidence: 99%

Bezold-Jarisch reflex attenuates dynamic gain of baroreflex neural arc

Kashihara

Kawada²,

Yanagiya³

et al. 2003

American Journal of Physiology-Heart and Circulatory Physiology

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risch reflex attenuates dynamic gain of baroreflex neural arc. Am J Physiol Heart Circ Physiol 285: H833-H840, 2003. First published April 24, 2003 10.1152/ajpheart.01082. 2002-Although acute myocardial ischemia or infarction may induce the Bezold-Jarisch (BJ) reflex through the activation of serotonin receptors on vagal afferent nerves, the mechanism by which the BJ reflex modulates the dynamic characteristics of arterial pressure (AP) regulation is unknown. The purpose of this study was to examine the effects of the BJ reflex induced by intravenous phenylbiguanide (PBG) on the dynamic characteristics of the arterial baroreflex. In seven anesthetized rabbits, we perturbed intracarotid sinus pressure (CSP) according to a white noise sequence while renal sympathetic nerve activity (RSNA), AP, and heart rate (HR) were recorded. We estimated the transfer function from CSP to RSNA (neural arc) and from RSNA to AP (peripheral arc) before and after 10 min of intravenous administration of PBG (100 g ⅐ kg Ϫ1 ⅐ min Ϫ1 ). The intravenous PBG decreased mean AP from 84.5 Ϯ 4.0 to 68.2 Ϯ 4.7 mmHg (P Ͻ 0.01), mean RSNA to 76.2 Ϯ 7.0% (P Ͻ 0.05), and mean HR from 301.6 Ϯ 7.7 to 288.4 Ϯ 9.0 beats/min (P Ͻ 0.01). The intravenous PBG significantly decreased neural arc dynamic gain at 0.01 Hz (1.06 Ϯ 0.08 vs. 0.59 Ϯ 0.17, P Ͻ 0.05), whereas it did not affect that of the peripheral arc (1.20 Ϯ 0.12 vs. 1.18 Ϯ 0.41). In six different rabbits without intravenous PBG, the neural arc transfer function did not change between two experimental runs with intervening interval of 10 min, excluding the possibility that the cumulative effects of anesthetics had altered the neural arc transfer function. In conclusion, excessive activation of the BJ reflex during acute myocardial ischemia may exert an adverse effect on AP regulation, not only by sympathetic suppression, but also by attenuating baroreflex dynamic gain. renal sympathetic nerve activity; transfer function; systems analysis; rabbits; carotid sinus baroreflex THE CIRCULATORY SYSTEM has several mechanoreceptors and chemoreceptors in a variety of regions. The cardiopulmonary region is rich in such receptors. The most vagal afferent fibers from the cardiopulmonary receptors to the vasomotor center are classified as C fibers.Activation of the cardiopulmonary chemosensitive vagal afferent fibers reduces arterial pressure (AP), heart rate (HR), and cardiac output (31). These responses, mediated by 5-hydroxytryptamine (5-HT 3 ) serotonergic receptors on the cardiopulmonary vagal afferent fibers, are known as the Bezold-Jarisch (BJ) reflex (2, 7, 32). Although its physiological importance remains debatable, the BJ reflex could play a significant role in developing pathological responses associated with acute myocardial ischemia (19,20,24). Elucidating the effects of the BJ reflex on the circulatory regulation would be useful for better understanding the pathophysiology of ischemic heart diseases (16, 27). The BJ reflex can be induced chemically with pharmacological agents such as 5-HT and ...

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Baroreceptor reflex inhibition induced by the stimulation of serotonin3 receptors in the nucleus tractus solitarius of the rat

Cited by 72 publications

References 28 publications

Functional dopamine D₂ receptors on rat vagal afferent neurones

Functional dopamine D₂ receptors on rat vagal afferent neurones

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Bezold-Jarisch reflex attenuates dynamic gain of baroreflex neural arc

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Baroreceptor reflex inhibition induced by the stimulation of serotonin3 receptors in the nucleus tractus solitarius of the rat

Cited by 72 publications

References 28 publications

Functional dopamine D2 receptors on rat vagal afferent neurones

Functional dopamine D2 receptors on rat vagal afferent neurones

5-HT-mediated inhibition of cardiovagal baroreceptor reflex response during defense reaction in the rat

Bezold-Jarisch reflex attenuates dynamic gain of baroreflex neural arc

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Functional dopamine D₂ receptors on rat vagal afferent neurones

Functional dopamine D₂ receptors on rat vagal afferent neurones