Neurotransmission of the Bezold-Jarisch reflex in the nucleus tractus solitarii of sino-aortic deafferentated rats

Brain Research
D A ChiancaB H Machado

Abstract

The Bezold-Jarisch (B-J) reflex was activated by serotonin (5-HT, i.v.) before and 10 min after bilateral microinjection of increasing doses of kynurenic acid, a non-selective antagonist of excitatory amino acid (EAA) receptors, into the commissural nucleus tractus solitarii (NTS) of sino-aortic deafferentated (SAD) and sham-operated (SO) unanesthetized rats. Increasing doses of kynurenic acid produced a dose-dependent blockade of the bradycardic and hypotensive responses to B-J reflex activation in both SO (from 0.1 to 10.0 nmol/100 nl) and SAD (from 0.1 to 2.0 nmol/100 nl). Comparison of the effect of kynurenic acid on the hypotension and bradycardic dose-response curves showed a significant difference between SO and SAD rats, indicating that smaller doses of kynurenic acid are required in SAD rats than in SO rats to block the neurotransmission of the B-J reflex in the NTS. The data also showed that bilateral microinjection of kynurenic acid into the NTS at doses of 0.5 (131 +/- 7 vs. 115 +/- 8 mmHg) and 2.0 nmol/100 nl (140 +/- 11 vs. 116 +/- 9 mmHg) produced an acute and significant increase in the basal mean arterial pressure of SAD rats similar to that observed with the same doses in SO rats, which was back to control val...Continue Reading

References

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Citations

Jul 23, 2002·Autonomic Neuroscience : Basic & Clinical·Colleen J ThomasRobyn L Woods
Nov 21, 2007·Nutritional Neuroscience·Leonardo Máximo CardosoDeoclécio Alves Chianca Júnior
Sep 22, 2015·Frontiers in Physiology·Fernanda C SilvaDeoclécio A Chianca
May 4, 2011·Autonomic Neuroscience : Basic & Clinical·Vanessa Moraes BezerraDeoclécio Alves Chianca
Nov 16, 2010·Neuroscience Letters·Vanessa Moraes BezerraDeoclécio Alves Chianca
Oct 15, 2011·Experimental Biology and Medicine·Anteneh AddisuJohn R Dietz
Apr 2, 2004·Revista Do Instituto De Medicina Tropical De São Paulo·Janaína Valadares GuimarãesMarlene Antônia dos Reis

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