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Titolo:
Hemodynamic responses to electrical stimulation of the aortic depressor nerve in awake rats
Autore:
De Paula, PM; Castania, JA; Bonagamba, LGH; Salgado, HC; Machado, BH;
Indirizzi:
Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 RibeiraoPreto, Brazil Univ Sao Paulo Ribeirao Preto Brazil BR-14049900 BCRibeiraoPreto, Brazil
Titolo Testata:
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
fascicolo: 1, volume: 46, anno: 1999,
pagine: R31 - R38
SICI:
0363-6119(199907)46:1<R31:HRTESO>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
VASCULAR-RESISTANCE; PULSATILE PRESSURE; BLOOD-FLOW; BARORECEPTORS; NEURONS; DOGS;
Keywords:
arterial baroreceptors; heart rate; blood pressure; blood flow; vascular resistance; baroreflex; frequency; intensity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
27
Recensione:
Indirizzi per estratti:
Indirizzo: Machado, BH Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 RibeiraoPreto, Brazil Univ Sao Paulo Ribeirao Preto Brazil BR-14049900 BCo, Brazil
Citazione:
P.M. De Paula et al., "Hemodynamic responses to electrical stimulation of the aortic depressor nerve in awake rats", AM J P-REG, 46(1), 1999, pp. R31-R38

Abstract

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 = 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 = 6), ES of the ADN was performed with the intensity fixed at3 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 = 6), ES of the ADN (2.5 V) produced hypotension (-35 +/- 4 mmHg), minor changes in the mesenteric (+5 +/- 14%), and vasodilation in hindquarter (-32 +/- 6%) vascular beds. Thedata 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.

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Documento generato il 27/09/20 alle ore 00:59:18