Adenosine modulates the (Na++K+)ATPase activity in Malpighian tubules isolated from Rhodnius prolixus

✍ Scribed by Celso Caruso-Neves; Sérgio Oliveira Monteiro; Charles Farias de Oliveira; Carlos Chagas Filho; Aníbal Gil Lopes

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 112 KB
• Volume: 43
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/(sici)1520-6327(200002)43:2<72::aid-arch3>3.0.co;2-e

✦ Synopsis

The role of adenosine on regulation of the (Na(+)+K(+))ATPase activity present in the Malpighian tubules isolated from Rhodnius prolixus was investigated. Adenosine decreases the (Na(+)+K(+)) ATPase specific activity by 88%, in a dose-dependent manner, with maximal effect at a concentration of 10(-9) M. This effect was mimicked by N(6)-cyclohexyladenosine (CHA) at 10(-8) M, an agonist for A(1) adenosine receptor, and was reversed by 10(-9) M 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an antagonist for A(1) adenosine receptor. On the other hand, 5'-N-ethyl-carboxamide adenosine (NECA), an agonist for A(2) adenosine receptor, used in the range of 10(-9)-10(-5) M, did not change the (Na(+)+K(+))ATPase specific activity. In the same way, 10(-8) M 3, 7-dimethyl-1-propargylxanthine (DMPX), an antagonist for A(2) adenosine receptor, did not modify the inhibitory effect of adenosine. These data suggest that the inhibitory effect of adenosine on the (Na(+)+K(+))ATPase specific activity present in Malpighian tubules from Rhodnius prolixus is mediated by A(1) adenosine receptor activation. Arch.