Pathological effects of chronic myocardial infarction on peripheral neurons mediating cardiac neurotransmission

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• 作者：Keijiro Nakamura¹ ; Olujimi A. Ajijola ; ¹ ; ^{oajijola@mednet.ucla.edu" class="auth_mail" title="E-mail the corresponding author} ; Eric Aliotta ; J. Andrew Armour ; Jeffrey L. Ardell ; Kalyanam Shivkumar
• 关键词：ANS ; autonomic nervous system ; MI ; myocardial infarction ; ICNS ; intrinsic cardiac nervous system ; LCN ; local circuit neuron ; ECG ; electrocardiogram ; LAD ; left anterior descending coronary artery ; IV ; intravenous ; VIV GP ; ventral interventricular ganglionated plexus ; DRG ; dorsal root ganglion ; LV ; left ventricle/ventricular ; RVOT ; right ventricular outflow tract ; MRI ; magnetic resonance imaging ; SG ; stellate ganglion
• 刊名：Autonomic Neuroscience: Basic and Clinical
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：197
• 期：Complete
• 页码：34-40
• 全文大小：1351 K

文摘

To determine whether chronic myocardial infarction (MI) induces structural and neurochemical changes in neurons within afferent and efferent ganglia mediating cardiac neurotransmission.

Methods

Neuronal somata in i) right atrial (RAGP) and ii) ventral interventricular ganglionated plexi (VIVGP), iii) stellate ganglia (SG) and iv) T1–2 dorsal root ganglia (DRG) bilaterally derived from normal (n = 8) vs. chronic MI (n = 8) porcine subjects were studied. We examined whether the morphology and neuronal nitric oxide synthase (nNOS) expression in soma of RAGP, VIVGP, DRG and SG neurons were altered as a consequence of chronic MI. In DRG, we also examined immunoreactivity of calcitonin gene related peptide (CGRP), a marker of afferent neurons.

Chronic MI increased neuronal size and nNOS immunoreactivity in VIVGP (but not RAGP), as well as in the SG bilaterally. Across these ganglia, the increase in neuronal size was more pronounced in nNOS immunoreactive neurons. In the DRG, chronic MI also caused neuronal enlargement, and increased CGRP immunoreactivity. Further, DRG neurons expressing both nNOS and CGRP were increased in MI animals compared to controls, and represented a shift from double negative neurons.

Conclusions

Chronic MI impacts diverse elements within the peripheral cardiac neuraxis. That chronic MI imposes such widespread, diverse remodeling of the peripheral cardiac neuraxis must be taken into consideration when contemplating neuronal regulation of the ischemic heart.