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, C, Monteiro, S O, de Oliveira, C F, Filho, C C, Lopes, A G
• Format: Journal Article
• Language: English
• Published: United States 01.02.2000
• Subjects: Adenosine - pharmacology; Adenosine-5'-(N-ethylcarboxamide) - pharmacology; Animals; Malpighian Tubules - enzymology; Receptors, Purinergic P1 - metabolism; Rhodnius - drug effects; Rhodnius - enzymology; Sodium-Potassium-Exchanging ATPase - metabolism; Theobromine - analogs & derivatives; Theobromine - pharmacology; Xanthines - pharmacology
• ISSN: 0739-4462; 1520-6327

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.