Fozard J R, Carruthers A M
Preclinical Research, Sandoz Pharma Ltd., Basel, Switzerland.
Br J Pharmacol. 1993 May;109(1):3-5. doi: 10.1111/j.1476-5381.1993.tb13522.x.
The cardiovascular effects of N6-2-(4-aminophenyl)ethyladenosine (APNEA), which when radiolabelled with 125I shows high affinity for the newly described adenosine A3 receptor, have been investigated in the angiotensin II-supported circulation of the pithed rat. APNEA induces hypotensive responses which are unaffected by high doses (20-40 mg kg-1) of the broad spectrum, adenosine receptor antagonist, 8-(p-sulphophenyl)theophylline (8-SPT). 8-SPT-resistant falls in blood pressure are also seen, in the absence of bradycardia, with 5'-N-ethylcarboxamidoadenosine (NECA) and the R- and S-enantiomers of N6-phenylisopropyladenosine (PIA). Xanthine insensitivity, high potencies of APNEA, NECA and R-PIA, and an enantiomeric selectivity favouring R- over S-PIA are distinguishing features of the adenosine A3 receptor. We suggest that hypotension in the pithed rat may be a functional correlate of this site.
N6-2-(4-氨基苯基)乙基腺苷(APNEA)的心血管效应已在去大脑大鼠的血管紧张素II支持的循环中进行了研究,当用125I进行放射性标记时,它对新描述的腺苷A3受体显示出高亲和力。APNEA诱导的降压反应不受高剂量(20 - 40 mg kg-1)的广谱腺苷受体拮抗剂8-(对-磺基苯基)茶碱(8-SPT)的影响。在没有心动过缓的情况下,5'-N-乙基甲酰胺基腺苷(NECA)以及N6-苯基异丙基腺苷(PIA)的R-和S-对映体也会出现对8-SPT耐药的血压下降。黄嘌呤不敏感性、APNEA、NECA和R-PIA的高效能以及有利于R-而非S-PIA的对映体选择性是腺苷A3受体的显著特征。我们认为去大脑大鼠的低血压可能是该位点的功能相关表现。