AREGU July 46/1
نویسندگان
چکیده
De Paula, Patrı́cia M., Jaci A. Castania, Leni G. H. Bonagamba, Hélio C. Salgado, and Benedito H. Machado. Hemodynamic responses to electrical stimulation of the aortic depressor nerve in awake rats. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R31–R38, 1999.—Changes in mean arterial pressure (MAP), heart rate (HR), and vascular resistance (hindquarter and mesenteric territories) in response to electrical stimulation (ES) of the aortic depressor nerve (ADN) were evaluated in conscious freely moving rats. Platinum electrodes were implanted into the ADN of all rats studied, and some of these animals were also implanted with miniaturized Doppler probes around the superior mesenteric artery and inferior abdominal aorta (hindquarter). In both groups, the femoral artery and vein were catheterized one day before the experiments. In the first group of rats (n 5 7), the control ES of the ADN in the range from 0.5 to 3.0 V (50 Hz, 10 ms) produced bradycardia and hypotension in an intensity-dependent manner, and treatment with methylatropine (intravenously) blocked the bradycardia but produced no significant changes in the hypotensive response. In a second group (n 5 6), ES of the ADN was performed with the intensity fixed at 3 V and the frequency of the stimuli varying from 10 to 50 Hz. In this group, the hypotensive response was frequency dependent, whereas the bradycardic response was not. In a third group of rats (n 5 6), ES of the ADN (2.5 V) produced hypotension (235 6 4 mmHg), minor changes in the mesenteric (15 6 14%), and vasodilation in hindquarter (232 6 6%) vascular beds. The data show that 1) ES of the ADN produces a fall in pressure, bradycardia, vasodilation in the hindquarter, and no changes in the mesenteric vascular resistance, 2) methylatropine blocked the bradycardia and produced no effect on the hypotensive response to ES of the ADN, and 3) the baroreceptor afferent fibers involved in the hypotensive response to ES of ADN are sensitive to the variation of the frequency of the stimuli, whereas the fibers involved in the bradycardic response are not.
منابع مشابه
AREGU July 46/1
JACINTA BALDWIN,1 RODNEY J. SNOW,2 MICHAEL F. CAREY,3 AND MARK A. FEBBRAIO1 1Exercise Physiology and Metabolism Laboratory, Department of Physiology, The University of Melbourne, Parkville, 3052 Victoria; 2School of Human Movement, Deakin University, Burwood, 3125 Victoria; and 3Exercise Metabolism Unit, Department of Biomedical Sciences, Victoria University of Technology, Footscray, 3011 Victo...
متن کاملAREGU July 46/1
MICHAEL KJÆR,1 BIRGITTE HANEL,2 LARS WORM,2 GRAZYNA PERKO,2 STEVEN F. LEWIS,2 KENT SAHLIN,2 HENRIK GALBO,3 AND NIELS H. SECHER2 2Department of Anesthesia, Copenhagen Muscle Research Center, Rigshospitalet University Hospital; 3Department of Medical Physiology, Panum Institute; and 1Sports Medicine Research Unit, Department of Rheumatology H, Bispebjerg Hospital, University of Copenhagen, DK-240...
متن کاملAREGU July 46/1
PATRICK PAYAN, ANAICK EDEYER, HÉLÈNE DE PONTUAL, GIL BORELLI, GILLES BOEUF, AND NICOLE MAYER-GOSTAN Laboratoire de Physiologie et Toxicologie Environnementales, EA 2138; Laboratoire de Physiologie Cellulaire et Moléculaire, Centre National de la Recherche Scientifique, UMR 6548; Université de Nice-Sophia Antipolis, Faculté des Sciences, 06108 Nice Cedex; and Laboratoire de Sclérochronologie des...
متن کاملAREGU July 46/1
Thunhorst, Robert L., Terry G. Beltz, and Alan Kim Johnson. Effects of subfornical organ lesions on acutely induced thirst and salt appetite. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R56–R65, 1999.—We examined the role of the subfornical organ (SFO) in stimulating thirst and salt appetite using two procedures that initiate water and sodium ingestion within 1–2 h of extrac...
متن کاملAREGU July 46/1
Teff, Karen L., and Raymond R. Townsend. Early phase insulin infusion and muscarinic blockade in obese and lean subjects. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R198–R208, 1999.—The effect of early phase insulin on postprandial levels of insulin, C-peptide, glucose, and glucagon was investigated in lean (n 5 10) and obese (n 5 12) subjects. Subjects underwent four condi...
متن کاملAREGU July 46/1
Shafton, Anthony D., Andrew Ryan, Barry McGrath, and Emilio Badoer. Volume expansion does not activate neuronal projections from the NTS or depressor VLM to the RVLM. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R39–R46, 1999.—We investigated whether a monosynaptic connection from the nucleus tractus solitarius (NTS) or the depressor ventrolateral medulla (VLM) to the pressor...
متن کامل