Biphasic effect of interleukin-1β on arginine vasopressin-induced cellular cyclic adenosine monophosphate production in cultured rat renal papillary collecting tubule cells
Ishikawa S, Saito T. Biphasic effect of interleukin-1β on arginine vasopressin-induced cellular cyclic adenosine monophosphate production in cultured rat renal papillary collecting tubule cells. Eur J Endocrinol 1995;132:472–8. ISSN 0804–4643 The present study was undertaken to determine whether interleukin (IL)-1β affects the response of cellular cyclic adenosine monophosphate production to arginine vasopressin (AVP) in cultured rat renal papillary collecting tubule cells. Arginine vasopressin increased cellular cAMP production in a dose-dependent manner. A 10-min exposure of cells to IL-1β at a concentration of 1 × 10−12 mol/l or higher significantly reduced the AVP-induced increases in cellular cAMP production but did not affect the 2 × 10−8 mol/l forskolin-induced increases in cellular cAMP production. The IL-1β inhibition disappeared totally when cells were pretreated with 100 μg/1 pertussis toxin for 2 h. In contrast, more than a 30-min exposure of cells to IL-1β increased basal cAMP levels and enhanced both the AVP- and forskolin-induced increases in cellular cAMP production. These results indicate that IL-1β produces biphasic regulation of AVP-induced cellular cAMP production in renal papillary collecting tubule cells. The inhibition by IL-1β is dependent on the activation of pertussis toxin-sensitive G protein. However, the mechanism whereby the longer exposure to IL-1β enhances cAMP production remains to be determined. San-e Ishikawa, Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical School, 3311-1 Yakushiji Minamikawachi-machi, Tochigi 329-04. Japan