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Julian F. R. Paton - One of the best experts on this subject based on the ideXlab platform.
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Autonomic Innervation of the Carotid Body as a Determinant of its Sensitivity - Implications for Cardiovascular Physiology and Pathology
Cardiovascular research, 2020Co-Authors: Fernanda Brognara, Igor Simões Assunção Felippe, Helio Cesar Salgado, Julian F. R. PatonAbstract:The motivation for this review comes from the emerging complexity of the Autonomic Innervation of the carotid body and its putative role in regulating chemoreceptor sensitivity. With the carotid bodies as a potential therapeutic target for numerous cardiorespiratory and metabolic diseases, an understanding of the neural control of its circulation is most relevant. Since nerve fibres track blood vessels and receive Autonomic Innervation, we initiate our review by describing the origins of arterial feed to the carotid body and its unique vascular architecture and blood flow. Arterial feed(s) vary amongst species and, unequivocally, the arterial blood supply is relatively high to this organ. The vasculature appears to form separate circuits inside the carotid body with one having an arterial venous anastomoses. Both sympathetic and parasympathetic nerves are present with postganglionic neurons located within the carotid body or close to it in the form of paraganglia. Their role in arterial vascular resistance control is described as is how carotid blood flow relates to carotid sinus afferent activity. We discuss non-vascular targets of Autonomic nerves, their possible role in controlling glomus cell activity, and how certain transmitters may relate to function. We propose that the Autonomic nerves sub-serving the carotid body provide a rapid mechanism to tune the gain of peripheral chemoreflex sensitivity based on alterations in blood flow and oxygen delivery, and might provide future therapeutic targets. However, there remain a number of unknowns regarding these mechanisms that require further research that is discussed.
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differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and wistar rats
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Julian F. R. Paton, Sergey Kasparov, Davi J A MoraesAbstract:KEY POINTS Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (α-VAChT) and vasoactive intestinal peptide (α-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative to Wistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic Innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion.
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Differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats.
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Sergey Kasparov, Davi J A Moraes, Julian F. R. PatonAbstract:KEY POINTS: Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT: Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P
Eva V. L. Roloff - One of the best experts on this subject based on the ideXlab platform.
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differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and wistar rats
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Julian F. R. Paton, Sergey Kasparov, Davi J A MoraesAbstract:KEY POINTS Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (α-VAChT) and vasoactive intestinal peptide (α-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative to Wistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic Innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion.
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Differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats.
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Sergey Kasparov, Davi J A Moraes, Julian F. R. PatonAbstract:KEY POINTS: Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT: Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P
Agostino Baruzzi - One of the best experts on this subject based on the ideXlab platform.
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peripheral Autonomic neuropathy diagnostic contribution of skin biopsy
Journal of Neuropathology and Experimental Neurology, 2012Co-Authors: Vincenzo Donadio, Alex Incensi, Maria Pia Giannoccaro, Fabio Pizza, Masen Abdel Jaber, Pietro Cortelli, Vitantonio Di Stasi, Agostino Baruzzi, Rocco LiguoriAbstract:: Skin biopsy has gained widespread use for the diagnosis of somatic small-fiber neuropathy, but it also provides information on sympathetic fiber morphology. We aimed to ascertain the diagnostic accuracy of skin biopsy in disclosing sympathetic nerve abnormalities in patients with Autonomic neuropathy. Peripheral nerve fiber Autonomic involvement was confirmed by routine Autonomic laboratory test abnormalities. Punch skin biopsies were taken from the thigh and lower leg of 28 patients with various types of Autonomic neuropathy for quantitative evaluation of skin Autonomic Innervation. Results were compared with scores obtained from 32 age-matched healthy controls and 25 patients with somatic neuropathy. The Autonomic cutoff score was calculated using the receiver operating characteristic curve analysis. Skin biopsy disclosed a significant Autonomic Innervation decrease in Autonomic neuropathy patients versus controls and somatic neuropathy patients. Autonomic Innervation density was abnormal in 96% of patients in the lower leg and in 79% of patients in the thigh. The abnormal findings disclosed by routine Autonomic tests ranged from 48% to 82%. These data indicate the high sensitivity and specificity of skin biopsy in detecting sympathetic abnormalities; this method should be useful for the diagnosis of Autonomic neuropathy, together with currently available routine Autonomic testing.
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Autonomic Innervation IN MULTIPLE SYSTEM ATROPHY AND PURE Autonomic FAILURE
Journal of Neurology Neurosurgery and Psychiatry, 2010Co-Authors: Vincenzo Donadio, Maria Pia Giannoccaro, Pietro Cortelli, Vitantonio Di Stasi, Pasquale Montagna, Mikael Elam, Björn Holmberg, Enrico Bugiardini, Patrizia Avoni, Agostino BaruzziAbstract:Background. Pure Autonomic failure (PAF) and multiple system atrophy (MSA) are both characterized by chronic dysautonomia although presenting different disability and prognosis. Skin Autonomic function evaluation by indirect tests has disclosed conflicting results in these disorders. Here we report the first direct analysis of skin sympathetic fibers including structure and function in PAF and MSA to ascertain different underlying Autonomic lesion sites which may help differentiate the two conditions. Methods. We studied 8 patients with probable MSA (mean age 60±5 years) and 9 patients fulfilling diagnostic criteria for PAF (64±8 years). They underwent head-up tilt test (HUTT), extensive microneurographic search for muscle and skin sympathetic nerve activities from peroneal nerve and punch skin biopsies from finger, thigh and leg to evaluate cholinergic and adrenergic Autonomic dermal annexes Innervation graded by a semiquantitative score presenting a high level of reliability. Results. MSA and PAF patients presented a comparable neurogenic orthostatic hypotension during HUTT and high failure rate of microneurographic trials to record sympathetic nerve activity, suggesting a similar extent of chronic dysautonomia. In contrast, they presented different skin Autonomic Innervation in the immunofluorescence analysis. MSA patients showed a generally preserved skin Autonomic Innervation with a significantly higher score than PAF patients showing a marked postganglionic sympathetic denervation. In MSA patients with long disease duration morphological abnormalities and/or a slightly decreased Autonomic score could be found in the leg reflecting a mild postganglionic involvement. Conclusion. Autonomic Innervation study of skin annexes is a reliable method which may help differentiate MSA from PAF.
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Autonomic Innervation in multiple system atrophy and pure Autonomic failure
Journal of neurology neurosurgery and psychiatry, 2010Co-Authors: Vincenzo Donadio, Maria Pia Giannoccaro, Pietro Cortelli, Vitantonio Di Stasi, Pasquale Montagna, Mikael Elam, Björn Holmberg, Enrico Bugiardini, Patrizia Avoni, Agostino BaruzziAbstract:Background Pure Autonomic failure (PAF) and multiple system atrophy (MSA) are both characterised by chronic dysautonomia although presenting different disability and prognosis. Skin Autonomic function evaluation by indirect tests has revealed conflicting results in these disorders. Here, the authors report the first direct analysis of skin sympathetic fibres including structure and function in PAF and MSA to ascertain different underlying Autonomic lesion sites which may help differentiate between the two conditions. Methods The authors studied eight patients with probable MSA (mean age 60±5 years) and nine patients fulfilling diagnostic criteria for PAF (64±8 years). They underwent head-up tilt test (HUTT), extensive microneurographic search for muscle and skin sympathetic nerve activities from peroneal nerve and punch skin biopsies from finger, thigh and leg to evaluate cholinergic and adrenergic Autonomic dermal annexes Innervation graded by a semiquantitative score presenting a high level of reliability. Results MSA and PAF patients presented a comparable neurogenic orthostatic hypotension during HUTT and high failure rate of microneurographic trials to record sympathetic nerve activity, suggesting a similar extent of chronic dysautonomia. In contrast, they presented different skin Autonomic Innervation in the immunofluorescence analysis. MSA patients showed a generally preserved skin Autonomic Innervation with a significantly higher score than PAF patients showing a marked postganglionic sympathetic denervation. In MSA patients with a long disease duration, morphological abnormalities and/or a slightly decreased Autonomic score could be found in the leg reflecting a mild postganglionic involvement. Conclusion Autonomic Innervation study of skin annexes is a reliable method which may help differentiate MSA from PAF.
Davi J A Moraes - One of the best experts on this subject based on the ideXlab platform.
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differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and wistar rats
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Julian F. R. Paton, Sergey Kasparov, Davi J A MoraesAbstract:KEY POINTS Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (α-VAChT) and vasoactive intestinal peptide (α-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative to Wistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic Innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion.
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Differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats.
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Sergey Kasparov, Davi J A Moraes, Julian F. R. PatonAbstract:KEY POINTS: Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT: Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P
Sergey Kasparov - One of the best experts on this subject based on the ideXlab platform.
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differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and wistar rats
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Julian F. R. Paton, Sergey Kasparov, Davi J A MoraesAbstract:KEY POINTS Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (α-VAChT) and vasoactive intestinal peptide (α-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative to Wistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic Innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion.
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Differences in Autonomic Innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats.
The Journal of Physiology, 2018Co-Authors: Eva V. L. Roloff, Dawid Walas, Sergey Kasparov, Davi J A Moraes, Julian F. R. PatonAbstract:KEY POINTS: Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic Innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the Autonomic Innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic Innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic Innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT: Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic Innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the Innervation density of noradrenergic sympathetic fibres in adult SH rats (P
