Cross-talk between apelin and vasopressin in response to different osmotic stimuli in type 2 diabetic rats.

This study aims to investigate the interaction between apelin and AVP in osmotic regulation in type 2 diabetes mellitus (T2DM), and to explore the underlying mechanism. Forty-eight adult male albino rats were divided into six groups: control (isotonic, ip 0.9% NaCl; hypotonic, ip distilled water; hypertonic, ip 2% NaCl) groups and T2DM (isotonic, hypotonic, hypertonic) groups. Serum levels of AVP, apelin, Na, glucose, serum and urine osmolarity were measured; kidney samples were taken for Aquaporin 2 channels (AQP2) and epithelial sodium channel gamma subunit (ENaCγ) gene expression. Hypothalamic tissue sections were used for immunohistochemical staining of apelin and AVP. Both in control and diabetic groups serum apelin, showed a significant negative correlation with serum AVP (r=-0.533, p≤ 0.001). Serum apelin and AVP were inversely proportional to their hypothalamic protein expression. Serum apelin and AVP were significantly higher in diabetic rats (P= 0.001) yet their percentage change in response to hypo and hyper-osmotic stimuli (1.5±0.7, -0.34±0.15 and -0.38±0.13, 1.95±0.36, respectively) was less pronounced when compared to control rats (3.28±0.52, -0.59±0.12 and -0.45±0.13, 2.58±0.93, respectively). Na and ENaCγ levels significantly increased in hypertonic rats, while AQP2 gene expression significantly increased in hypotonic rats. Both apelin and AVP reacted to osmotic stimuli in T2DM but with less sensitivity than in control rats. In spite of its abnorma...
Source: Journal of Biological Regulators and Homeostatic Agents - Category: Biomedical Science Tags: J Biol Regul Homeost Agents Source Type: research