Deficient Response to Experimentally Induced Alkalosis in Mice with the Inactivated insrr Gene

Abstract

Currently, the molecular mechanisms of the acid-base equilibrium maintenance in the body remain poorly understood. The development of alkalosis under various pathological conditions poses an immediate threat to human life. Understanding the physiological mechanisms of alkalosis compensation may stimulate the development of new therapeutic approaches and new drugs for treatment. It was previously shown that the orphan insulin receptor-related receptor (IRR) is activated by mildly alkaline media. In this study, we analyzed mutant mice with targeted inactivation of theinsrr gene encoding IRR, and revealed their phenotype related to disorders of the acid-base equilibrium. Higher concentrations of bicarbonate and CO(2)were found in the blood ofinsrr knockout mice in response to metabolic alkalosis.

Keywords: IRR; alkalosis.

Fig. 1

Analysis of the inactivation of the insrr gene in mice. ( А ) – PCR on the genomic DNA of the wild-type and insrr knockout mice with the use of the primers to the wild-type allele of IRR, IR and the insrr knockout allele. ( B ) – Western blotting with the use of antibodies against the IRR ectodomain. Lysates from transfected HEK293 cells with IRR-HA expressing plasmid and non-transfected cells (as the negative control) were blotted with the anti-ectodomain IRR antibodies. ( C ) – Equal amounts of WGA-eluates (about 10 µg) from the kidney membrane fraction of wild-type and insrr knockout mice were blotted with anti-ectodomain antibodies.

Fig. 2

Blood gas analysis of blood from wild-type (WT) and insrr knockout (KO) mice before and after injection of a bicarbonate solution. ( А ) – рН of blood; ( B ) – concentration of bicarbonate in blood (mmol/l); ( C ) – concentration of СО ₂ in blood (mm Hg). * p  < 0.05 by the Student’s test.