The autonomic nervous system and chromaffin tissue: Neuroendocrine regulation of catecholamine secretion in non-mammalian vertebrates

摘要: If severe enough, periods of acute stress in animals may be associated with the release catecholamine hormones (noradrenaline and adrenaline) into circulation; a response termed humoral adrenergic response. The catecholamines from sites storage, chromaffin cells, is under neuroendocrine control, complexity which appears to increase through phylogeny. In agnathans, earliest branching vertebrates, cells are localized predominantly within heart, lack neuronal innervation thus secretion these initiated solely by mechanisms. more advanced teleost fish, largely confined walls posterior cardinal vein at level head kidney where they intermingled steroidogenic interrenal cells. Catecholamine regulated host cholinergic non-cholinergic pathways that ensure sufficient redundancy flexibility process permit synchronized responses myriad stressors. control mechanisms continues amphibians, reptiles birds although neural (cholinergic) regulation become increasingly important birds. Discrete adrenal glands present non-mammalian tetrapods but unlike mammals, there no clear division cortex cell enriched medulla. However, all groups, an obvious intermingling steroiodogenic association two types particularly amphibians because like enzyme catalysing methylation noradrenaline adrenaline, PNMT, steroid cortisol.