"Efeito modulatório da nicotina sobre a neurotransmissão em núcleos encefálicos responsáveis pelo controle cardiovascular em ratos geneticamente hipertensos e normotensos" / "Nicotine modulatory effects on neurotransmiter systems in the cardiovascular brain areas of spontaneously hypertensive and normotensive rats"

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Nicotine is one of the most important agents for cardiovascular diseases in tobacco smoking. This alkaloid acts in the blood stream, but it also crosses the blood-brain-barrier and participate in the regulation of pivotal neurotransmitter systems for the blood pressure control and, eventually, for hypertension development. In this context, nicotine abuse could be very relevant to individuals carrying genetic factors to hypertension. The objectives of the present work were to study neurotransmitter system in brain cardiovascular areas involved in the control of blood pressure after chronic peripheral nicotine exposure, as well as to evaluate nicotine influence on essential hypertension development in spontaneously hypertensive (SHR) and normotensive rats (WKY). By means of immunohistochemistry, binding, in situ hybridization, neuron and glial culture, real time PCR and Western Blotting, we have demonstrated that chronic treatment with nicotine not only anticipated but also intensified hypertension on SHR. WKY rats did not showed any change on blood pressure. We observed no evidences of the involvement of neuropeptide Y and catecolamines systems in the development of hypertension after nicotine treatment. However, it seems that the glutamatergic system is, at least in part, responsible for the hypertension development after chronic nicotine exposure. To study the angiotensinergic system we cultivated neuron and glial cells from SHR and WKY rats and treated them with nicotine. The responses of this system agree with the hypothesis that nicotine interacts with angiotensin to promote hypertension only in the hypertensive strain. In conclusion, results presented herein support the hypothesis that nicotine modulates neurotransmitter systems that might have relevant functions in the development and intensification of hypertension in SHR.

ASSUNTO(S)

neurotransmissão western blotting central nervous system in situ hybridization radioautografia radioautography pcr em tempo real hplc immunohistochemistry western blotting hplc neuron culture nicotine imunohistoquímica sistema nervoso central neurotransmission nicotina cultura de neurônios hibridização in situ real time pcr hypertension hipertensão

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