Belhassen B, Ilia R, Greenspan A M, Horowitz L N
Likoff Cardiovascular Institute, Hahnemann University, Philadelphia, Pennsylvania.
Cardiovasc Res. 1987 Feb;21(2):151-60. doi: 10.1093/cvr/21.2.151.
The influence of aminophylline, a competitive antagonist of adenosine, on the chronotropic and dromotropic effects of adenosine and adenosine triphosphate was studied in pentobarbital anaesthetised dogs under various modifications of the autonomic nervous tone. Adenosine and adenosine triphosphate (3 mumol.kg-1 each) were rapidly (greater than or equal to 1 s) injected into the right atrium during both sinus rhythm and right atrial pacing (cycle length 300 ms) before and after infusion of aminophylline (5 mg.kg-1) (n = 21) as well as after increasing doses of aminophylline (n = 10). Some dogs underwent either muscarinic blockade with atropine (0.2 mg.kg-1) (n = 10), or beta adrenergic blockade with propranolol (1 mg.kg-1) (n = 10), or complete autonomic blockade with atropine and propranolol (n = 10). Aminophylline (5 mg.kg-1) antagonised the negative chronotropic and dromotropic effects of adenosine triphosphate and adenosine in dogs pretreated with atropine or atropine plus propranolol but did not affect them in autonomically intact dogs. In addition, the electrophysiological effects of adenosine were antagonised by only the highest doses of aminophylline in autonomically intact dogs and by aminophylline (5 mg X kg-1) in dogs pretreated with propranolol. It was concluded that (a) alteration of the electrophysiological effects of adenosine triphosphate and adenosine by aminophylline is appreciably influenced by the autonomic nervous tone and (b) autonomic blockade is required for the manifestation of the antagonism by aminophylline of the electrophysiological action of adenosine and adenosine triphosphate.
在戊巴比妥麻醉的犬中，于自主神经张力的各种改变情况下，研究了腺苷的竞争性拮抗剂氨茶碱对腺苷及三磷酸腺苷变时性和变传导性效应的影响。在输注氨茶碱（5mg·kg-1）之前和之后（n = 21）以及在增加氨茶碱剂量之后（n = 10），在窦性心律和右心房起搏（周期长度300ms）期间，将腺苷和三磷酸腺苷（各3μmol·kg-1）快速（≥1s）注入右心房。一些犬接受了阿托品（0.2mg·kg-1）的毒蕈碱阻断（n = 10），或普萘洛尔（1mg·kg-1）的β肾上腺素能阻断（n = 10），或阿托品和普萘洛尔的完全自主神经阻断（n = 10）。氨茶碱（5mg·kg-1）可拮抗在阿托品或阿托品加普萘洛尔预处理的犬中三磷酸腺苷和腺苷的负性变时性和变传导性效应，但在自主神经完整的犬中不影响它们。此外，在自主神经完整的犬中，仅最高剂量的氨茶碱可拮抗腺苷的电生理效应，而在普萘洛尔预处理的犬中，氨茶碱（5mg·kg-1）可拮抗其电生理效应。得出的结论是：（a）氨茶碱对三磷酸腺苷和腺苷电生理效应的改变明显受自主神经张力影响；（b）氨茶碱对腺苷和三磷酸腺苷电生理作用的拮抗作用需要自主神经阻断才能表现出来。
