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Effects of protein tyrosine kinase wihin the brainstem nucleus tractus solitarius on the ventilatory responses of peripheral chemoreflex

Li Yanchun, Wang Hui, Cao Ying, Tang Di, Wang Guimin, Yu Shuyan, Song Gang, Zhang Heng

Institute of Physiology, School of Medicine, Shandong University. Jinan 250012, Shandong, China

Abstract

The aim of the present study was to observe whether protein tyrosine kinase (PTK) within the nucleus tractus solitarius (NTS) was involved in the regulation of ventilatory responses of peripheral chemoreflex. The experiments were performed on anesthetized, immobilized and artificially ventilated rabbits. Peripheral chemoreflex was elicited by ventilating the animal with 10% O_(2)-balance 90% N_(2). Changes in the peak amplitude and frequency of integrated phrenic nerve activity were observed. The ventilatory responses of peripheral chemoreflex following 0.1 #mu#l microinjection within the NTS of either PTK inhibitor genistein(10 mol/L), AMPA glutamate receptor inhibitor CNQX (10 mol/L),or inactive PTK inhibitor daidzein (10 mol/L) were recorded. The results are as follows: Both genistein and CNQX attenuated the ventilatory responses of peripheral chemoreflex, while no changes occurred following daidzein. The amplitude of integrated phrenic nerve discharge and the phrenic burst frequency were decreased by (-21.77±6.93)% and (-24.70±7.61)% respectively after administration of genistein. CNQX resulted in similar decreases in the amplitude of phrenic nerve discharge (-27.13±7.63)% and the burst frequency (-21.34±4.88)%. In addition, the inhibitory effects of CNQX and genistein were the same whether they were applied alone or one after another, indicating that they had no cooperative effects. The results obtained suggest that PTK within the NTS regulates the peripheral chemoreflex control of respiration and that this regulation of PTK may be mediated through the phosphorylation of AMPA receptors in NTS neurons.

Key words: Solitary nucleus;Protein tyrosine kinase;Respiration;Reflex;Rabbit

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Citing This Article：

Li Yanchun, Wang Hui, Cao Ying, Tang Di, Wang Guimin, Yu Shuyan, Song Gang, Zhang Heng. Effects of protein tyrosine kinase wihin the brainstem nucleus tractus solitarius on the ventilatory responses of peripheral chemoreflex. Acta Physiol Sin 2005; 57 (3): (in Chinese with English abstract).