Roberts J R, Dantzler W H
Department of Physiology, College of Medicine, University of Arizona, Tucson 85724.
Am J Physiol. 1989 Apr;256(4 Pt 2):R836-9. doi: 10.1152/ajpregu.1989.256.4.R836.
Glomerular filtration rate (GFR) was measured in conscious unrestrained starlings, Sturnis vulgaris. Alzet osmotic minipumps were inserted into the peritoneal cavity under lidocaine local anesthesia and served to infuse the GFR marker [14C]sodium ferrocyanide. GFR was measured in hydrated birds and again after a 24-h period of water deprivation. GFR in dehydrated birds was 1.15 +/- 0.09 ml.min-1.kg-1, significantly lower (P less than 0.001) than the 2.71 +/- 0.31 ml.min-1.kg-1 in fully hydrated animals. In addition, the GFR of the hydrated birds was significantly lower (P less than 0.01) than values of 4.43 +/- 0.24 ml.min-1.kg-1 measured in hydrated anesthetized birds during micropuncture studies. A 24-h period of water deprivation caused significant increases in plasma osmolality and concentration of sodium, chloride, and phosphate. The osmolality and concentrations of calcium, magnesium, and phosphate were significantly elevated in both cloacal urine supernatant and in ureteral urine of dehydrated birds. In both hydrated and dehydrated states, the concentration of magnesium, phosphate, potassium, and total osmolality were significantly higher in cloacal urine than in ureteral urine.
在清醒自由活动的家八哥（Sturnis vulgaris）身上测量了肾小球滤过率（GFR）。在利多卡因局部麻醉下将Alzet渗透微型泵插入腹腔，用于输注GFR标记物[14C]亚铁氰化钠。在水分充足的鸟类中测量了GFR，并在禁水24小时后再次测量。脱水鸟类的GFR为1.15±0.09毫升·分钟-1·千克-1，显著低于（P<0.001）完全水分充足动物的2.71±0.31毫升·分钟-1·千克-1。此外，水分充足鸟类的GFR显著低于（P<0.01）在微穿刺研究中水分充足麻醉鸟类所测得的4.43±0.24毫升·分钟-1·千克-1的值。禁水24小时导致血浆渗透压以及钠、氯和磷酸盐浓度显著升高。脱水鸟类的泄殖腔尿上清液和输尿管尿中的钙、镁和磷酸盐浓度均显著升高。在水分充足和脱水状态下，泄殖腔尿中的镁、磷酸盐、钾浓度和总渗透压均显著高于输尿管尿。
