title: Influence of short-term versus prolonged cardiopulmonary receptor stimulation on renal and preganglionic adrenal sympathetic nerve activity in rats.
abstract: Renal and preganglionic adrenal sympathetic nerve activities (RSNA, ASNA) are regulated differentially. Various cardiopulmonary receptor (CPR) stimulation procedures were performed to distinguish short-term and prolonged as well as mechanical and chemical stimulatory effects on RSNA and ASNA. In anesthetized male Sprague-Dawley rats blood pressure, heart rate, left ventricular end-diastolic pressure (LVEDP), RSNA and ASNA were recorded. CPRs were stimulated as follows: Short-term mechanical: LVEDP changes (+/-4, +/-6, +/-8 mmHg) via aortic and caval vein occlusion; Short-term chemical: phenylbiguanide (PBG-bolus, 0.1, 1, 10 microg IV); Prolonged mechanical (15 min): volume expansion (0.9% NaCl, 5% body weight) and hemorrhage, to modulate LVEDP; Prolonged chemical: PBG infusion (32 microg/min IV, for 15 min); Stimulations were done with 1) all afferents intact, 2) bilateral cervical vagotomy (VX), 3) VX + SAD (sino-aortic denervation; short-term protocols and hemorrhage).1) Short-term mechanical stimuli decreased RSNA (-52 +/- 12%) and ASNA (-37 +/- 13%). 2) PBG-bolus decreased RSNA (-54 +/- 12%) but increased ASNA (+40 +/- 13%). 3) Volume expansion decreased RSNA (-55 +/- 7%), ASNA was unaffected. 4) PBG infusion persistently decreased RSNA (-60 +/- 6%) but just shortly increased ASNA (+120 +/- 15%); VX abolished all responses. 5) Hypotensive hemorrhage decreased RSNA (-39 +/- 9%) but increased ASNA (+42 +/- 9%). VX abolished RSNA response; ASNA response only disappeared with VX + SAD.Short-term mechanical CPR stimulation uniformly decreased sympathetic activities, whereas chemical stimulation had opposing effects on renal and adrenal sympathetic responses. All prolonged stimuli decreased RSNA, whereas ASNA was virtually unaffected: Sympathetic out.ow is differentially controlled not only with regard to target organs or afferent receptors but also stimulus time pattern.
authors.affiliation: Department of Nephrology Medicine IV, Friedrich-Alexander University Erlangen-Nürnberg, Loschgestrasse 8, 91054 Erlangen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Ditting
authors.forename: K F
authors.initials: KF
authors.lastname: Hilgers
authors.forename: K E
authors.initials: KE
authors.lastname: Scrogin
authors.forename: P
authors.initials: P
authors.lastname: Linz
authors.forename: R
authors.initials: R
authors.lastname: Veelken
mesh_terms: D000311:Adrenal Glands / Q000294:innervation*; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000187:drug effects / Q000502:physiology*; D001645:Biguanides / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D001810:Blood Volume / Q000502:physiology; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006706:Homeostasis / Q000502:physiology; D007668:Kidney / Q000294:innervation*; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014628:Vagotomy; D017725:Ventricular Pressure / Q000502:physiology
chemical_list: D001645:Biguanides; D017366:Serotonin Receptor Agonists; C008846:phenyl biguanide