scholarly journals Amylin Acts in the Central Nervous System to Increase Sympathetic Nerve Activity

Endocrinology ◽  
2013 ◽  
Vol 154 (7) ◽  
pp. 2481-2488 ◽  
Author(s):  
Caroline Fernandes-Santos ◽  
Zhongming Zhang ◽  
Donald A. Morgan ◽  
Deng-Fu Guo ◽  
Andrew F. Russo ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Weight ◽  
Food Intake ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Nerve Activity ◽  
Peripheral Tissues ◽  
Brown Adipose ◽  
The Central Nervous System

Abstract The pancreatic hormone amylin acts in the central nervous system (CNS) to decrease food intake and body weight. We hypothesized that amylin action in the CNS promotes energy expenditure by increasing the activity of the sympathetic nervous system. In mice, ip administration of amylin significantly increased c-Fos immunoreactivity in hypothalamic and brainstem nuclei. In addition, mice treated with intracerebroventricular (icv) amylin (0.1 and 0.2 nmol) exhibited a dose-related decrease in food intake and body weight, measured 4 and 24 hours after treatment. The icv injection of amylin also increased body temperature in mice. Using direct multifiber sympathetic nerve recording, we found that icv amylin elicited a significant and dose-dependent increase in sympathetic nerve activity (SNA) subserving thermogenic brown adipose tissue (BAT). Of note, icv injection of amylin also evoked a significant and dose-related increase in lumbar and renal SNA. Importantly, icv pretreatment with the amylin receptor antagonist AC187 (20 nmol) abolished the BAT SNA response induced by icv amylin, indicating that the sympathetic effects of amylin are receptor-mediated. Conversely, icv amylin-induced BAT SNA response was enhanced in mice overexpressing the amylin receptor subunit, RAMP1 (receptor-activity modifying protein 1), in the CNS. Our data demonstrate that CNS action of amylin regulates sympathetic nerve outflow to peripheral tissues involved in energy balance and cardiovascular function.

scholarly journals Cardiovascular and Metabolic Crosstalk in the Brain: Leptin and Resistin

2021 ◽  
Vol 12 ◽  
Author(s):  
Emilio Badoer
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adipose Tissue ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Nerve Activity ◽  
Metabolic Complications ◽  
Brown Adipose ◽  
The Central Nervous System ◽  
The Brain

Leptin and resistin are cytokines whose plasma levels correlate with adiposity. Leptin is a hormone synthesised and released from adipocytes and can be transported into the brain. Resistin is produced in adipocytes in rodents and in macrophages in humans, particularly macrophages that have infiltrated adipose tissue. Both hormones can act within the brain to influence sympathetic nerve activity. Leptin appears to have a generalised sympatho-excitatory actions whilst resistin appears to increase sympathetic nerve activity affecting the cardiovascular system but inhibits sympathetic nerve activity to brown adipose tissue, which contrasts with leptin. Since both hormones can be elevated in conditions of metabolic dysfunction, interactions/crosstalk between these two hormones in the brain is a real possibility. This review describes the current knowledge regarding such crosstalk within the central nervous system. The evidence suggests that with respect to sympathetic nerve activity, crosstalk between leptin and resistin can elicit enhanced sympatho-excitatory responses to the kidneys. In contrast, with respect to food intake, resistin has weaker effects, but in regard to insulin secretion and thermogenesis, leptin and resistin have opposing actions. Thus, in conditions in which there is increased resistin and leptin levels, the result of crosstalk in the central nervous system could contribute to worse cardiovascular and metabolic complications.

scholarly journals Renin-Angiotensin System and Sympathetic Neurotransmitter Release in the Central Nervous System of Hypertension

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Kazushi Tsuda
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sympathetic Nerve ◽  
Neurotransmitter Release ◽  
Sympathetic Nerve Activity ◽  
Renin Angiotensin System ◽  
Nerve Activity ◽  
Angiotensin System ◽  
The Central Nervous System ◽  
The Brain

Many Studies suggest that changes in sympathetic nerve activity in the central nervous system might have a crucial role in blood pressure control. The present paper discusses evidence in support of the concept that the brain renin-angiotensin system (RAS) might be linked to sympathetic nerve activity in hypertension. The amount of neurotransmitter release from sympathetic nerve endings can be regulated by presynaptic receptors located on nerve terminals. It has been proposed that alterations in sympathetic nervous activity in the central nervous system of hypertension might be partially due to abnormalities in presynaptic modulation of neurotransmitter release. Recent evidence indicates that all components of the RAS have been identified in the brain. It has been proposed that the brain RAS may actively participate in the modulation of neurotransmitter release and influence the central sympathetic outflow to the periphery. This paper summarizes the results of studies to evaluate the possible relationship between the brain RAS and sympathetic neurotransmitter release in the central nervous system of hypertension.

Is there a central nervous system component to acute baroreflex resetting in rats?

1992 ◽  
Vol 262 (2) ◽  
pp. H503-H510 ◽  
Author(s):  
C. M. Heesch ◽  
K. W. Barron
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Stimulation ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
System Component ◽  
Nerve Activity ◽  
Linear Portion ◽  
Aortic Nerve ◽  
Maximum Inhibition

This study was designed to evaluate a possible central nervous system (CNS) component to acute baroreflex resetting. In nine arterial baroreceptor-denervated, chloralose-urethan-anesthetized rats, a control (C) aortic nerve stimulation curve (3-5 V, 1 ms, 0-64 Hz) was obtained. Next, a constant "baroreceptor" input was delivered to the CNS (left aortic nerve stimulation, 10 min, 10.2 +/- 1.5 Hz). Within the first 13 s of aortic nerve stimulation, maximum inhibition of lumbar sympathetic nerve activity (LSNA) was 60 +/- 7.8% of baseline and at 1 min it increased to 68 +/- 5.6% of baseline. At the end of the 10-min aortic nerve stimulation, LSNA was not different from the response at 1 min (68 +/- 5.6% = 74 +/- 4.1%). Immediately after the constant stimulation (within 30 s), a test or reset (RS) curve was obtained (0-64 Hz). A recovery (RC) curve was obtained 10-20 min later. The slope of the linear portion of the curve and the stimulation frequency that produced 50% maximum inhibition (ES50) were compared among the three baroreflex curves (C, RS, RC,) and no significant differences were found. Thus, although a CNS component to baroreflex adaptation was evident during the first minute of aortic nerve stimulation, a longer term acute resetting of the baroreflex curve did not occur.

Insulin: its relationship to the central nervous system and to the control of food intake and body weight

1985 ◽  
Vol 42 (5) ◽  
pp. 1063-1071 ◽  
Author(s):  
S C Woods ◽  
D Porte ◽  
E Bobbioni ◽  
E Ionescu ◽  
J F Sauter ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Weight ◽  
Food Intake ◽  
The Central Nervous System

scholarly journals Identification of PACAP-Expressing Neurons in the Hypothalamic Origins of Sympathetic Outflow Tracts Terminating in Brown Adipose Tissue of Mice

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A541-A541
Author(s):  
Ekaterina Filatov ◽  
Alex P Rudecki ◽  
Alina-Geta Constantin ◽  
Sarah Louise Gray
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Cold Stress ◽  
Brown Adipose Tissue ◽  
Sympathetic Nerve ◽  
Energy Homeostasis ◽  
Sympathetic Nerve Activity ◽  
Sympathetic Outflow ◽  
Nerve Activity ◽  
Brown Adipose

Abstract Adaptive thermogenesis in brown adipose tissue is stimulated by the sympathetic nervous system (SNS) in response to cold stress. Using retrograde viral transneuronal tract tracers, previous studies have identified that the paraventricular nucleus (PVN), ventromedial hypothalamus (VMH), and median preoptic nucleus (MnPO) contain neurons that are part of sympathetic outflow tracts to brown adipose tissue, presumptively involved in SNS stimulation of interscapular brown adipose tissue (iBAT). Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is a peptide hormone known to regulate energy homeostasis, acting in both the central (CNS) and peripheral nervous system (PNS). Mice lacking PACAP have impaired adrenergic-induced thermogenesis and a cold-sensitive phenotype. In the CNS, PACAP is highly expressed in the VMH, MnPO, and PVN of the hypothalamus. Injection of PACAP into the VMN increased core body temperature and sympathetic nerve activity to brown adipose tissue. While these studies show exogenous PACAP can activate sympathetic outflow tracts to brown adipose tissue, they do not confirm that endogenously expressed PACAP induces sympathetic nerve activity as an adaptive mechanism to cold stress, or if sympathetic outflow tracts originating in the hypothalamus express PACAP. We hypothesize that PACAP is expressed in neurons of sympathetic outflow tracts originating in the hypothalamus. To test this hypothesis, PACAP-eGFP transgenic mice were injected with the retrograde neural tracer, pseudorabies virus tagged with β-galactosidase (β-gal, PRV-BaBlu), in iBAT where postganglionic nerves innervate the tissue. Five-days post-infection, animals were culled, brains removed and cryosectioned. Neurons positive for green fluorescent protein (eGFP) and/or β-gal immunoreactivity (ir) were identified by immunohistochemistry in serial coronal and sagittal brain cryo-sections. Co-occurrence of eGFP-ir and β-gal-ir, inferred PACAP expressing neurons present in sympathetic outflow tracts (ImageJ). Co-occurrence was identified in several structures in the hypothalamus and thalamus. In conclusion, this study presents neuroanatomical evidence for populations of PACAPinergic neurons in the hypothalamus that are part of sympathetic outflow tracts to brown adipose tissue, providing further evidence of a central role for PACAP in regulating energy homeostasis.

Sildenafil acts on the central nervous system increasing sympathetic activity

2008 ◽  
Vol 104 (6) ◽  
pp. 1683-1689 ◽  
Author(s):  
Rubens Fazan ◽  
Domitila A. Huber ◽  
Carlos Alberto A. Silva ◽  
Valdo J. Dias da Silva ◽  
Maria Cristina O. Salgado ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Arterial Pressure ◽  
Sympathetic Activity ◽  
Baroreflex Sensitivity ◽  
Sympathetic Nerve Activity ◽  
Systolic Arterial Pressure ◽  
Nerve Activity ◽  
The Central Nervous System ◽  
Spontaneous Baroreflex

Sildenafil induces vasodilation and is used for treating erectile dysfunction. Although its influence on resting heart function appears to be minimal, recent studies suggest that sildenafil can increase sympathetic activity. We therefore tested whether sildenafil injected into the central nervous system alters the autonomic control of the cardiovascular system in conscious rats. The effect of sildenafil citrate injected into the lateral cerebral ventricle was evaluated in conscious rats by means of the recording of lumbar sympathetic nerve activity (LSNA), spectral analysis of systolic arterial pressure and heart rate variability, spontaneous baroreflex sensitivity, and baroreflex control of LSNA. Intracerebroventricular (ICV, 100 μg/5 μl) administration of sildenafil caused remarkable tachycardia without significant change in basal arterial pressure and was associated with a conspicuous increase (47 ± 14%) in LSNA. Spectral analysis demonstrated that systolic arterial pressure oscillations in the low frequency (LF) range were increased (from 6.3 ± 1.5 to 12.8 ± 3.8 mmHg2), whereas the high frequency (HF) range was not affected by ICV administration of sildenafil. Sildenafil increased pulse interval oscillations at LF and decreased them at HF. The LF-HF ratio increased from 0.04 ± 0.01 to 0.17 ± 0.06. Spontaneous baroreflex sensitivity measured by the sequence method and the baroreflex relationship between mean arterial pressure and LSNA were not affected by ICV administration of sildenafil. In conclusion, sildenafil elicited an increase in sympathetic nerve activity that is not baroreflex mediated, suggesting that this drug is able to elicit an autonomic imbalance of central origin. This finding may have implications for understanding the cardiovascular outcomes associated with the clinical use of this drug.

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