INTRACAROTID INJECTION OF ENDOTHELIN-1 FACILITATES THE ACTIVITY OF ROSTRAL VENTROLATERAL MEDULLARY NEURONS VIA AREA POSTREMA IN RATS
10.3321/j.issn:0371-0874.1999.03.005
- VernacularTitle:内皮素通过最后区易化大鼠延髓腹外侧头端区神经元活动
- Author:
DE-PEI LI
1
;
RUI-RONG HE
Author Information
1. Hebei Medical University
- Keywords:
endothelin;
rostral ventrolateral medulla (RVLM);
area postrema;
spontaneous discharge units;
BQ-123
- From:
Acta Physiologica Sinica
1999;51(3):263-271
- CountryChina
- Language:Chinese
-
Abstract:
To observe the effect of intracarotid administration of endothelin (ET-1) on electrical activity of neurons within rostral ventrolateral medulla (RVLM) region, 87 spontaneous active units were extracellularly recorded in 35 Sprague-Dawley rats with sino-aortic denervation. The results obtained are as follows. (1) Intracarotid administration of ET-1 (0.3nmol/kg) increased the discharge firing rate from 17.8±1.5 to 20.9±1.4 spikes/s (P<0.01) in 30 out of 36 RVLM neurons, while blood pressure and heart rate had no significant change. (2) BQ-123 (0.67nmol/kg), a selective ETA blocker, completely blocked the facilitatory effects of ET-1 in 11 out of 14 units. (3) In 10 out of 11 units, glibenclamide (3.3 nmol/kg), a blocker of ATP-sensitive potassium channel, had no effect on the action of ET-1. (4) After ablation of area postrema (AP), the facilitatory action of intracarotid administration of ET-1 on 19 units of RVLM was abolished, while in 7 units of sham ablation animals the response of neurons to ET-1 remained unchanged. Taken together, intracarotid-administered ET-1 may act on the ETA receptors in neurons of AP, thereby resulting in the facilitating effect on RVLM neurons through the efferent projection of AP.
