Sympathetic and sensory-motor nerves in peripheral small arteries

Small arteries, which play important roles in controlling blood flow, blood pressure and capillary pressure, are under nervous influence. Their innervation is predominantly sympathetic and sensory-motor in nature and while some arteries are densely innervated others are only sparsely so. Innervation of small arteries is a key mechanism in regulating vascular resistance. In the second half of the previous century the physiology and pharmacology of this innervation was very actively investigated. In the past 10-20 years the activity in this field was more limited. With this review we highlight what has been learned during recent years with respect to development of small arteries and their innervation, some aspects of excitation-release coupling, interaction between sympathetic and sensory-motor nerves, cross-talk between endothelium and vascular nerves, and some aspects of their role in vascular inflammation and hypertension. We also highlight what remains to be investigated to further increase our understanding of this fundamental aspect of vascular physiology.

The role of nervous system in the regulation of hemopoiesis

Plastic change of hemopoietic tissue in experimental neurotic influences is under control of distant and local regulating mechanisms. Changes in compartments of erythroid and granulocitar hemopoiesis are due to specific spectrum of neuro-mediating systems. Receiving instructive information from the central nervous system is via αand β-adrenergic receptors on cell elements of hemopoiesing precursors. Manifestation of tropism of hemopoiesis to αor β-аdrenergic mechanisms is associated with nervous influence type. Existence of two different directions of plastic change of hemopoietic tissue in experimental neuroses : activation of blood system according to stressor type (conflict situation) and hemopoietic disturbances (deprivation of paradox sleep) is explained by the activity of regulation mechanisms.

Epithelial Cells and Their Neighbors. II. New perspectives on efferent signaling between brain, neuroendocrine cells, and gut epithelial cells

Surface sensory enteroendocrine cells are established mucosal taste cells that monitor luminal contents and provide an important link in transfer of information from gut epithelium to the central nervous system. Recent studies now show that these cells can also mediate efferent signaling from the brain to the gut. Centrally elicited stimulation of vagal and sympathetic pathways induces release of melatonin, which acts at MT2 receptors to increase mucosal electrolyte secretion. Psychological factors as well mucosal endocrine cell hyperplasia are implicated in functional intestinal disorders. Central nervous influence on the release of transmitters from gut endocrine cells offers an exciting area of future gastrointestinal research with a clinical relevance.

Low-frequency heart rate variability: reproducibility in cardiac transplant recipients and normal subjects

Heart rate variability is a measure of autonomic nervous influence on the heart. It has been suggested that it could be used to detect autonomic reinnervation to the transplanted heart, but the reproducibility of the measurement is unknown. In the present study, 21 cardiac transplant recipients and 21 normal subjects were recruited. Three measurements of heart rate variability were performed during the day: in the morning, in the early afternoon and in the late afternoon. These tests were then repeated 1 week later and then again 1 week after that, making nine tests in all. The within-subject S.D. was 0.49 log units in normal subjects and 0.79 log units in transplant recipients. In both cases, this is about 15% of the population range. There was significant variation in heart rate variability between different times of day in both groups, and from day to day in transplant recipients. It was concluded that the reproducibility of measurements of heart rate variability is low, and that differences between measurements performed at different times of day should be interpreted with caution.