Influence of peripheral alpha 1-adrenergic receptors on the toxicity of dexmedetomidine
10.3867/j.issn.1000-3002.2025.03.007
- VernacularTitle:小鼠α1肾上腺素受体分布及其对右美托咪定急性毒性的介导作用
- Author:
Beibei SHI
1
;
Zhen WANG
;
Xiaoxuan WANG
;
Peilan ZHOU
;
Ruibin SU
Author Information
1. 南京中医药大学,江苏 南京 210023;军事医学研究院,北京 100850
- Publication Type:Journal Article
- Keywords:
alphα-1 adrenergic receptor;
alphα-2 adrenergic receptor;
dexmedetomidine;
toxicity
- From:
Chinese Journal of Pharmacology and Toxicology
2025;39(3):216-223
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To investigate α1-adrenergic receptors(α1-AR)distribution in mouse tissues and its function on dexmetomidine(DMED)induced toxic effects.METHODS ① Real-time fluorescence quantita-tive PCR was used to detect the relative expression of α1A-AR,α1B-AR,α1D-AR,α2A-AR,α2B-AR and α2C-AR mRNAs in the heart,apical potion of heart,lungs,apical potion of lung,liver,kidneys,abdominal aorta,prefrontal cortex,hippocampus,striatum,brainstem,thalamus,olfactory bulb,and the rest of the brain tissues of the mouse.The relative expression of mRNA were analyzed.② C57BL/6J mice were pretreated with α2 adrenergic receptor antagonist atipamezole ATI(0.005,0.010,0.020,0.025,0.040,0.050 mg·kg-1,im),orα1-adrenoceptor antagonist prazosin(1 mg·kg-1,im)for 15 min,and then DMED(0.20 mg·kg-1,iv)was given to observe the rate of the loss of righting reflex and the immobilization time in mice.③ C57BL/6J mice were treated with DMED(16.38,20.48,25.60,32.00,40.00,and 50.00 mg·kg-1,iv)to observe the lethality of the mice in 24 h.The dose-effect relationship curves of the lethality rate and the half lethal-dose(LD50)were detected.ATI(1,2,4,and 8 mg·kg-1,im)or prazosin(1 mg·kg-1,im)were pretreated 15 min followed by the administration of DMED(25.60 mg·kg-1,iv).The lethality of the mice were recorded for 24 h.HE staining to observe the lung tissue damage in the mice.RESULTS ① The mRNA expression levels of three α1-AR subtype were higher than those of α2-AR subtype.α2A-AR and α2C-AR were highly expressed in the central nervous system.α2B-AR was highly expressed in the brainstem and peripheral tissues.The mRNA expres-sion levels of α1-AR subtypes were higher than those of α2-AR subtypes in heart,apical potion of heart or lung(P＜0.05).② ATI(0.005 to 0.05 mg·kg-1,im)dose dependently antagonized the loss of righting reflex and decreased the immobilization time induced by DMED(0.20 mg·kg-1,iv).In contrast,prazosin(1 mg·kg-1,im)had no effect on the loss of righting reflex induced by DMED(0.20 mg·kg-1,iv).③ The LD50 of DMED in mice was 26.734 mg·kg-1(iv)with a 95％Cl of 23.606-30.000 mg·kg-1.DMED(25.6 mg·kg-1)was selected for subsequent toxicity.ATI(1,2,4,and 8 mg·kg-1,im)did not antagonize the lethality induced by DMED(25.6 mg·kg-1,iv).The high dose of ATI resulted in elevated death rate and accelerated mortality induced by DMED(25.6 mg·kg-1,iv)in the mice.However,prazosin(1 mg·kg-1,im)reduced the lethality of DMED(25.6 mg·kg-1,iv)(P＜0.01).After administration of DMED(25.6 mg·kg-1),the mice lungs showed significant congestion.HE staining of lung tissues revealed obvious vascular hemorrhage,alveolar rupture,and erythrocyte spillage.Prazosin(1 mg·kg-1,im)effectively attenuated the tissue damage in the lungs,but ATI(1 mg·kg-1,im)aggravated the pulmonary hemorrhage.CONCLU-SIONS In cardiopulmonary tissues,the high expression levels of α1 adrenoceptor overactivation,might related with the lethality induced by DMED.
