1. The aim of the study was to investigate the interactions between angiotensin II (AII) and adrenoceptor-mediated pressor responses in the pithed rat. Emphasis was placed on the effects of AII on blood pressure per se and the possibility of differential effects on alpha 1- and alpha 2-adrenoceptor-mediated pressor responses. 2. A low concentration of the angiotensin converting enzyme (ACE) inh...

We have compared the vasopressor response of alpha-adrenoceptor agonists in young (2 month-old) and older (12 month-old) pithed rats both in the presence and absence of triiodo-L-thyronine (T3)-induced hyperthyroidism. There was no age-related changes in the pressor response to either the alpha 1-selective agonist phenylephrine or the alpha 2-selective agonists clonidine and UK-14,304. However,...

β2-adrenoceptor agonists are the mainstay therapy for patients with asthma but their effectiveness in cigarette smoke (CS)-induced lung disease such as chronic obstructive pulmonary disease (COPD) is limited. In addition, bronchodilator efficacy of β2-adrenoceptor agonists is decreased during acute exacerbations of COPD (AECOPD), caused by respiratory viruses including influenza A. Therefore, t...

Epinephrine plays a key role in the control of vasomotor tone; however, the participation of the NO/cGMP pathway in response to beta-adrenoceptor activation remains controversial. To evaluate the involvement of the endothelium in the vascular response to epinephrine, we assessed NO production, endothelial NO synthase phosphorylation, and tissue accumulation of cGMP in the perfused arterial mese...

we investigated the a,-adrenoceptor subtypes of rabbit saphenous vein which has a mixed functional population of α1 and α2 -adrenoceptors. lateral saphenous veins were obtained from male rabbits weighing 3.20-4 kg, which were killed by overdose with pentobarbitone sodium (i.v. injection). they were easily dissected out and placed in cold, oxygenated modified krebs-henselite solution (krebs). ea...

The present study examined the influence of alpha-2 adrenoceptor ligands on circling behavior in rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway. The alpha-2 adrenoceptor agonists, clonidine and UK 14304, inhibited both the ipsilateral rotation induced by the indirect dopaminergic agonist, methylphenidate, and the contralateral circling induced by the direct dopamine...