Fuentes J, Eddy F B
Department of Biological Sciences, University of Dundee, Scotland, UK.
J Comp Physiol B. 1997 Aug;167(6):438-43. doi: 10.1007/s003600050094.
Drinking in Atlantic salmon (Salmo salar) juveniles was investigated in fresh water and following transfer to sea water. There was a significant effect of fish size on drinking, and smolts (20-30 g) imbibed about ten times less water than alevins of 0.2-0.3 g. Freshwater smolts drank at a rate of 0.15 +/- 0.03 ml.kg-1.h-1 and administration of doses of 10 or 20 mg.kg-1 of papaverine (stimulator of the renin-angiotensin system RAS) or [Asn1, Val5]-Angiotensin II (0.4 mumol.kg-1) resulted in significant increases in drinking, while administration of the angiotensin converting enzyme inhibitor, enalapril (50 mg.kg-1) had no effect on drinking. Transfer of Atlantic salmon smolts to 1/3, 2/3 and full strength sea water resulted in significant increases in drinking to 1.06 +/- 0.12, 1.24 +/- 0.0.16 and 3.89 +/- 0.28 ml.kg-1.h-1, respectively. In sea water, stimulation of the endogenous RAS by administration of papaverine (20 mg.kg-1) resulted in a 20% increase in drinking, while administration of enalapril to doses of 50 and 200 mg.kg-1 lowered drinking to 1.99 +/- 0.48 and 0.32 +/- 0.06 ml.kg-1.h-1, respectively. All treatments were without effect on blood plasma levels of Na+ and Cl- in fresh water, while in sea water smolts both stimulation and inhibition of drinking resulted in hemoconcentration of Na+ and Cl-. The role of the renin angiotensin system in control of drinking and hydromineral balance in Atlantic salmon is discussed.
研究了大西洋鲑幼鱼在淡水环境以及转入海水环境后的饮水情况。鱼的大小对饮水有显著影响，银化鲑（20 - 30克）的饮水量比0.2 - 0.3克的仔鱼少约十倍。淡水环境中的银化鲑饮水速率为0.15±0.03毫升·千克⁻¹·小时⁻¹，给予10或20毫克·千克⁻¹的罂粟碱（肾素 - 血管紧张素系统RAS的刺激剂）或[天冬酰胺¹，缬氨酸⁵] - 血管紧张素II（0.4微摩尔·千克⁻¹）会导致饮水量显著增加，而给予血管紧张素转换酶抑制剂依那普利（50毫克·千克⁻¹）对饮水无影响。将大西洋鲑银化鲑转移到1/3、2/3和全强度海水中，饮水量分别显著增加到1.06±0.12、1.24±0.16和3.89±(0.28)毫升·千克⁻¹·小时⁻¹。在海水中，给予罂粟碱（20毫克·千克⁻¹）刺激内源性RAS会使饮水量增加20%，而给予50和200毫克·千克⁻¹剂量的依那普利会使饮水量分别降至1.99±0.48和0.32±0.06毫升·千克⁻¹·小时⁻¹。所有处理对淡水中血浆Na⁺和Cl⁻水平均无影响，而在海水中，无论是刺激还是抑制饮水都会导致银化鲑血浆中Na⁺和Cl⁻的浓度升高。文中讨论了肾素 - 血管紧张素系统在控制大西洋鲑饮水和水盐平衡中的作用。
