Effect Of Nesfatin - 1 On Drinking Water Behavior In Rats

Objective:To observe the effects of nesfatin-1on water intake of rats, and to explore the mechanisms of nesfatin-1in the control of water and electrolyte balance in hypothalamus.Methods:Lateral ventricle implantation tube, drugs and molecular biology were used to observe the effects of exogenous and endogenous nesfatin-1on water intake in drug causing thirsty rats and on physiological thirsty rats. Meanwhile the gene expression of NUCB2/Nesfatin-1of water ban rats has been observed.Results:①Lateral ventricle injection of150,450pmol exogenous nesfatin-1, the water intake in0-120min of rats significantly reduced (150pmol:1.3±0.2～1.85±0.3ml/100g;450pmol:0.8±0.4～1.2±0.4ml/100g vs NS:2.5±0.3～3.1±0.2ml/100g) and showed a significant dose-response relationship (P<0.05～0.01), but the water intake in2-24h had no significant change (P>0.05).②Angiotensin Ⅱ were administrated to lateral ventricle10min after injection of nesfatin-1. After injection of150pmol nesfatin-1, water intake in15-30min of rats significantly reduced (150pmol:2.17±0.6ml/100g vs NS:3.62±1.0ml/100g, P<0.05). After injection of450pmol nesfatin-1, water intake in each time period within120min of rats reduced significantly (450pmol:0.31±0.1～2.87±0.8ml/100gvs NS:2.31±0.7-7.05±0.2ml/100g) and presented a dose-response manner (P<0.05～0.01), but5-24h water intake had no significant change (P>0.05).③Subcutaneous injection of hypertonic saline, and water intake in rats increase rapidly,(The water intake of rats with subcutaneous injection of hypertonic saline increase rapidly, while the water intake of rats with150pmol nesfatin-1injection in lateral ventricle within15-30min and the water intake of rats with450pmol nesfatin-1injection in lateral ventricle within120min significantly reduced.) lateral ventricle injection of150or450pmol nesfatin-1, water intake of each time period within60min in rats significantly reduced (150pmol:0.25±0.2～1.6±0.25ml/100g;450pmol:0.1±0.15～1.92±0.2ml/100g vs NS:0.9±0.2～2.9±0.2ml/100g, P<0.05～0.01), but after restore water supply60-120min or2-24h, the water intake had no significant difference (P>0.05).④Three hours After the second time hypothalamus PVN injection of antisense RNA nesfatin-1, angiotensin Ⅱ (50pmol/2mu1) were given and water intake in rats increased significantly (Antisense nesfatin-1:1.87±0.4～2.77±0.6ml/100g vs NS:0.72±0.1～1.17±0.4ml/100g, P<0.01)), but the body weight and food intake in rats had no significant difference (P>0.05).⑤NUCB2gene expression was significantly reduced in the hypothalamus (water ban:-7.2±1.1%vs free drinking water:0.82±0.4%, P<0.01) in rats after18hours water ban; The hypothalamus NUCB2gene expression had a significant rise (water supply restore:8.1±1.1%vs free drinking water:0.82±0.4%, P<0.01) in rats with water supply restore.Conclusion:Nesfatin-1involved in the regulation of water intake in physiology or drug causing thirsty. Nesfatin-1plays an important role in the hypothalamus to regulate water-electrolyte balance and thirsty mechanisms.