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

• Published in: Archives of insect biochemistry and physiology Vol. 43; no. 2; pp. 72 - 77
• Main Authors: Caruso-Neves, Celso, Monteiro, Sérgio Oliveira, de Oliveira, Charles Farias, Filho, Carlos Chagas, Lopes, Aníbal Gil
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.02.2000
• Subjects: (Na++K+)ATPase; adenosine; Malpighian tubule; Rhodnius
• ISSN: 0739-4462; 1520-6327
• DOI: 10.1002/(SICI)1520-6327(200002)43:2<72::AID-ARCH3>3.0.CO;2-E

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 N6‐cyclohexyladenosine (CHA) at 10–8 M, an agonist for A1 adenosine receptor, and was reversed by 10–9 M 8‐cyclopentyl‐1,3‐dipropylxanthine (DPCPX), an antagonist for A1 adenosine receptor. On the other hand, 5′‐N‐ethyl‐carboxamide adenosine (NECA), an agonist for A2 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 A2 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 A1 adenosine receptor activation. Arch. Insect Biochem. Physiol. 43:72–77, 2000. © 2000 Wiley‐Liss, Inc.