Cardiovascular responses elicited by continuous versus intermittent electrical stimulation of the aortic depressor nerve in conscious rats

As microinjection of atrial natriuretic factor (ANF) into the nucleus of the solitary tract (NTS) has been shown to elicit depressor responses [D. J. McKitrick and F. R. Calaresu. Am. J. Physiol. 255 (Regulatory Integrative Comp. Physiol. 24): R182-R187, 1988], we investigated the possibility that these responses might be facilitated either by electrical stimulation of arterial baroreceptor fibers in the aortic depressor nerve (ADN) or by simultaneous microinjection of L-glutamate (Glu) into the same sites in the NTS. Male Wistar rats (n = 51) were anesthetized with urethan (1.4 g/kg ip), artificially ventilated, and the dorsal medulla was exposed. The ADN was isolated, cut distally, and the central end was placed on bipolar stimulating electrodes. Threshold doses of 10(-7) M ANF microinjected into the NTS were combined with threshold electrical stimulation of the ADN (n = 37) or threshold doses of 0.13-0.5 M Glu (n = 14) microinjected into the NTS. There was a significant interaction between ANF microinjection and ADN stimulation in producing changes in mean arterial pressure (MAP) and heart rate [HR; P less than 0.05; -20.2 +/- 2.3 (SE) mmHg and -30.8 +/- 6.9 (SE) beats/min, respectively; n = 18]. There was also a significant interaction between ANF and Glu in producing changes in MAP and HR [P less than 0.05; -16.3 +/- 1.8 (SE) mmHg and -15.0 +/- 3.0 (SE) beats/min, respectively; n = 8]. These results indicate that ANF influences neurons in the NTS, which are also influenced by activation of arterial baroreceptors, and ANF and Glu interact in the NTS to produce facilitated cardiovascular responses.

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Electrical stimulation of the aortic depressor nerve in conscious rats still causes a hypotensive effect after blockade of the autonomic nervous system and nitric oxide production

The FASEB Journal ◽

10.1096/fasebj.23.1_supplement.956.5 ◽

2009 ◽

Vol 23 (S1) ◽

Author(s):

Marina de Toledo Durand ◽

Jaci Airton Castania ◽

Maria Cristina Oliveira Salgado ◽

Helio Cesar Salgado

Keyword(s):

Nitric Oxide ◽

Nervous System ◽

Electrical Stimulation ◽

Autonomic Nervous System ◽

Hypotensive Effect ◽

Nitric Oxide Production ◽

Conscious Rats ◽

Autonomic Nervous ◽

Aortic Depressor Nerve ◽

Stimulation Of

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Electrical stimulation of the aortic depressor nerve in conscious rats overcomes the attenuation of the baroreflex in chronic heart failure

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00392.2015 ◽

2016 ◽

Vol 310 (7) ◽

pp. R612-R618 ◽

Cited By ~ 2

Author(s):

Tomás O. C. Teixeira Pinto ◽

Renata M. Lataro ◽

Jaci A. Castania ◽

Marina T. Durand ◽

Carlos A. A. Silva ◽

...

Keyword(s):

Heart Failure ◽

Electrical Stimulation ◽

Chronic Heart Failure ◽

Arterial Pressure ◽

Cardiovascular Responses ◽

Control Male ◽

Aortic Depressor Nerve ◽

Male Wistar Rats ◽

Parasympathetic Function ◽

Stimulation Of

Chronic heart failure (CHF) is characterized by autonomic dysfunction combined with baroreflex attenuation. The hypotensive and bradycardic responses produced by electrical stimulation of the aortic depressor nerve (ADN) were examined in conscious CHF and control male Wistar rats (12–13 wk old). Furthermore, the role of parasympathetic and sympathetic nervous system in mediating the cardiovascular responses to baroreflex activation was evaluated by selective β1-adrenergic and muscarinic receptor antagonists. CHF was induced by myocardial infarction. After 6 wk, the subjects were implanted with electrodes for ADN stimulation. Twenty-four hours later, electrical stimulation of the ADN was applied for 20 s using five different frequencies (5, 15, 30, 60, and 90 Hz), while the arterial pressure was recorded by a catheter implanted into the femoral artery. Electrical stimulation of the ADN elicited progressive and similar hypotensive and bradycardic responses in control ( n = 12) and CHF ( n = 11) rats, while the hypotensive response was not affected by methylatropine. Nevertheless, the reflex bradycardia was attenuated by methylatropine in control, but not in CHF rats. Atenolol did not affect the hypotensive or bradycardic response in either group. The ADN function was examined under anesthesia through electroneurographic recordings. The arterial pressure-ADN activity relationship was attenuated in CHF rats. In conclusion, despite the attenuation of baroreceptor function in CHF rats, the electrical stimulation of the ADN elicited a stimulus-dependent hypotension and bradycardia of similar magnitude as observed in control rats. Therefore, electrical activation of the aortic baroreflex overcomes both the attenuation of parasympathetic function and the sympathetic overdrive.

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Continuous and intermittent electrical stimulation of the aortic depressor nerve in conscious rats: time course of the hemodynamic responses

The FASEB Journal ◽

10.1096/fasebj.27.1_supplement.1118.31 ◽

2013 ◽

Vol 27 (S1) ◽

Author(s):

Helio Salgado ◽

Fernanda Brognara ◽

Daniel Penteado Martins Dias ◽

Jaci Airton Castania ◽

Rubens Fazan

Keyword(s):

Electrical Stimulation ◽

Time Course ◽

Hemodynamic Responses ◽

Conscious Rats ◽

Aortic Depressor Nerve ◽

Stimulation Of

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Electrical stimulation of the carotid sinus lowers arterial pressure and improves heart rate variability in l-NAME hypertensive conscious rats

Hypertension Research ◽

10.1038/s41440-020-0448-7 ◽

2020 ◽

Vol 43 (10) ◽

pp. 1057-1067 ◽

Cited By ~ 1

Author(s):

Gean Domingos-Souza ◽

Fernanda Machado Santos-Almeida ◽

César Arruda Meschiari ◽

Nathanne S. Ferreira ◽

Camila A. Pereira ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Electrical Stimulation ◽

Arterial Pressure ◽

Carotid Sinus ◽

Conscious Rats ◽

Stimulation Of

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Role of paraventricular and supraoptic nuclei in central cardiovascular regulation in the cat

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1980.239.1.r137 ◽

1980 ◽

Vol 239 (1) ◽

pp. R137-R142 ◽

Cited By ~ 12

Author(s):

J. Ciriello ◽

F. R. Calaresu

Keyword(s):

Heart Rate ◽

Cardiovascular Responses ◽

Inhibitory Influence ◽

Sympathetic Nervous Systems ◽

Aortic Depressor Nerve ◽

Bilateral Lesions ◽

Alpha Chloralose ◽

Supraoptic Nuclei ◽

Stimulation Of

To investigate the role of the paraventricular (PAH) and supraoptic (SON) nuclei in regulation of the cardiovascular system experiments were done in 26 cats anesthetized with alpha-chloralose, paralyzed, and artificially ventilated. Electrical stimulation of histologically verified sites in the region of the PAH and SON elicited increases in arterial pressure in bilaterally vagotomized animals and increases in heart rate both in spinal (C2) animals and in animals bilaterally vagotomized, In addition, stimulation of either the PAH or SON inhibited the reflex vagal bradycardia elicited by stimulation of the carotid sinus nerve (CSN) and bilateral lesions of these areas increased the magnitude of the response. On the other hand, stimulation and lesions of these hypothalamic regions did not alter the magnitude of the cardiovascular responses to stimulation of the aortic depressor nerve. These results demonstrate that stimulation of the PAH and SON elicit cardiovascular responses due to reciprocal changes in activity of the parasympathetic and sympathetic nervous systems and that these structures maintain a tonic inhibitory influence on the heart rate component of the CSN reflex.

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Rebound cardiovascular responses following stimulation of canine vagosympathetic complexes or cardiopulmonary nerves

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y85-184 ◽

1985 ◽

Vol 63 (9) ◽

pp. 1122-1132 ◽

Cited By ~ 10

Author(s):

J. A. Armour ◽

W. C. Randall

Keyword(s):

Electrical Stimulation ◽

Arterial Pressure ◽

Cardiovascular System ◽

Cardiovascular Responses ◽

Systemic Arterial Pressure ◽

Cardiac Responses ◽

Stimulation Of

Electrical stimulation of a canine vagosympathetic complex or a cardiopulmonary nerve can elicit a variety of negative chronotropic and inotropic cardiac responses, with or without alterations in systemic arterial pressure. In the period immediately following cessation of such a stimulation "rebound" tachycardia, increased inotropism above control values in one or more regions of the heart, and (or) elevation in systemic arterial pressure can occur. These "rebound" phenomena are abolished by propranolol or ipsilateral chronic sympathectomy. It is proposed that "vagal" poststimulation "rebound" of the canine cardiovascular system is primarily the result of activation of sympathetic neural elements present in the vagosympathetic complexes or cardiopulmonary nerves.

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