Differentiated sympathetic neural control of the kidney
| Autor: | Linda L. Sawin, S Y Jones, Gerald F. DiBona |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
Sympathetic nervous system Sympathetic Nervous System Time Factors Physiology Urinary system Neural Conduction Kidney urologic and male genital diseases Nerve conduction velocity Renal Circulation Rats Sprague-Dawley Nerve Fibers Physiology (medical) Reflex Neural control Animals Medicine business.industry Splanchnic Nerves Anatomy Neurophysiology Electric Stimulation Diuresis Rats Autonomic nervous system Electrophysiology medicine.anatomical_structure Female business |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 271:R84-R90 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.1996.271.1.r84 |
| Popis: | Anatomic and neurophysiological methods were used to identify functionally specific subgroups of renal sympathetic nerve fibers. The distribution of diameters of the predominating unmyelinated fibers showed a major mode at 1.1 microns and a minor mode at 1.6 microns. The conduction velocity was 2.10 +/- 0.10 m/s, consistent with unmyelinated C fibers. Analysis of strength-duration relationships during renal nerve stimulation showed that both rheobase and chronaxie values for renal blood flow were greater than those for urinary flow rate and were independent of stimulation frequency. This difference suggests a higher stimulation threshold (smaller diameter) for those renal nerve fibers involved in the renal blood flow response (renal vasoconstriction) compared with those for the urinary flow rate response (antidiuresis) to renal nerve stimulation. Single renal units that responded to preganglionic splanchnic nerve stimulation were studied. Those with spontaneous activity (88%) responded to stimulation of arterial baroreceptors, arterial and central chemoreceptors, and peripheral thermoreceptors, whereas those that lacked spontaneous activity (12%) responded only to stimulation of peripheral thermoreceptors (known to produce renal vasoconstriction). A minority population of single renal units has been identified that, although renal vasoconstrictor, does not exhibit other characteristic features of vasoconstrictor neurons (i.e., responsiveness to stimulation of arterial baroreceptors and arterial and central chemoreceptors). These findings suggest the existence of functionally specific subgroups of renal nerve fibers. |
| Databáze: | OpenAIRE |
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