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Effect of adenosine on the formation of prostacyclin in the rabbit isolated heart
Author(s) -
KarwatowskaProkopczuk Ewa,
Ciabattoni Giovanni,
Wennmalm Åke
Publication year - 1988
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1988.tb11581.x
Subject(s) - adenosine , prostacyclin , theophylline , medicine , perfusion , endocrinology , chemistry , radioimmunoassay , metabolite , coronary circulation , prostaglandin , blood flow
1 The effect of adenosine on cardiac biosynthesis of prostacyclin (PGI 2 ) was investigated. Rabbit hearts were perfused according to Langendorff at controlled pressure (with or without theophylline), or at controlled flow. The content of 6‐keto‐prostaglandin lflt (6‐keto‐PGF 1α , metabolite of PGI 2 ) in the coronary effluent under basal conditions and during infusion of adenosine was determined using a highly specific radioimmunoassay. 2 In other experiments, rings of rabbit aorta were incubated with or without adenosine and the production of 6‐keto‐PGF 1α was analysed as above. 3 Administration of adenosine (10 μ m ) to hearts perfused at controlled pressure increased the coronary flow by up to 38%. The peak concentration of 6‐keto‐PGF 1α in the effluent exceeded the control by 177% ( P < 0.01), and the total efflux of 6‐keto‐PGF 1α exceeded the control by 179% ( P < 0.001). Theophylline (50 μ m ) reduced these effects of adenosine by 23%, 43% and 51%, respectively, without influencing the uptake of adenosine into the heart. 4 When adenosine (1–10 μ m ) was administered to hearts perfused at controlled flow, a dose‐dependent decrease in the perfusion pressure, by 27% and 44% respectively, was observed. In parallel, the resulting increase in 6‐keto‐PGF 1α efflux was considerably lower (49% ( P < 0.05) and 43% (NS), respectively). A similar decrease in perfusion pressure induced in the absence of adenosine decreased the efflux of 6‐keto‐PGF 1α , by 15% ( P < 0.01) and 32% ( P < 0.001), respectively. 5 Addition of adenosine (1–10 μ m ) to incubates of rabbit aortic rings did not significantly affect the concentration of 6‐keto‐PGF 1α in the incubation medium in comparison with control. 6 We conclude that adenosine stimulates rabbit heart PGI 2 formation, mainly by an action related to the vasodilator effect of the nucleoside.