Cardiopulmonary Response to Vasopressin-Induced Activation on V(subscript 1A) Receptors in the Lateral Ventrolateral Medulla in the Rat

Meng-Tzu Cheng ； Ching-Wen Chuang ； Jin-Tun Lin ； Ji-Chuu Hwang

《The Chinese Journal of Physiology》 47卷1期 (2004/03) Pp. 31-42

並列摘要

The aim of the study was to examine whether or not arginine vasopressin (AVP) might modulate cardiopulmonary functions by acting on the lateral area of the ventrolateral medulla (VLM) in the rat. The rat was anesthetized, bilaterally vagotomized, paralyzed, ventilated, and then placed on a stereotaxic instrument in a prone position. Activity of the phrenic nerve (PNA) was monitored at normocapnia and hypercapnia in hyperoxia. Microinjection of AVP into the lateral region of the VLM resulted in a brief apnea followed by a significant decrease in PNA amplitude and a concomitant significant increase in blood pressure. The inhibition of PNA with AVP treatment could be partly attenuated by hypercapnia but not by phentolamine. Both inhibition of PNA and pressor response with AVP microinjection into the lateral VLM were totally abolished after pretreatment with AVP V(subscript 1A) receptor antagonist. These results suggest that a vasopressinergic pathway projects to the lateral VLM and modulates cardiopulmonary functions via AVP V(subscript 1A) receptors on neurons within the lateral VLM.

並列關鍵字

arginine vasopressin ； AVP V(subscript 1A)-receptor antagonist ； ventrolateral medulla ； phrenic nerve activity ； hypercapnia ； blood pressure ； rat

參考文獻

Alescio-Lautier, B.,Soumircu-Mourat, B.(1998).Role of vasoprcsin in learning and memory in the hippocampus.Frog. Brain Res.199,501-521.

Böngianni, F.,Mutolo, D.,Pantaleo, T.(1997).Depressant effects on inspiratory and expiratory activity produced by chemical activation of Bötzinger complex neurons in the rabbit.Brain Res.749,1-9.

Böngianni, F.,Corda M.,Fontana, G. A.,Pantaleo, T.(1993).Expiratory and depressant respiratory responses to chemical stimulation of the rostral ventrolateral medulla in the cat.Acta Physiol. Scand.148,315-325.

Chitravanshi, V. C.,Sapru, H. N.(1999).Phrenic nerve responses to chemical stimulation of the subregions of ventral medullary respiratory neuronal group in the rat.Brain Res.821,443-460.

Chuang, C.-W.,Cheng, M.-T.,Lin, J.-T.,Hsien, H.-Y.,Hung, H.Y.,Hwang, J.-C.(2003).Arginine vasopressin produces inhibition upon respiration without pressor effect in the rat.Chinese J. Physiol.46,71-78.