The occurrence of nephrogenic diabetes insipidus in domestic fowl

Abstract

Nephrogenic diabetes insipidus (NDI) results from an inability of the kidney to concentrate the urine. The underlying cause of NDI is the failure of the collecting ducts to respond to antidiuretic hormone, however, the specific tubular defect is not well understood. In the present investigation an apparent case of NDI was studied in a strain of White Leghorn domestic fowl. In this strain, water intake of the males equaled 24.0% (controls 5.4%) of their body mass (BM) per day while that of the females equaled 51.4% (controls 11.7%) of their BM per day. Plasma osmolality (mosmol/kgH2O) of the NDI birds was significantly higher than that of controls (males 319 +/- 1.7 vs. 311 +/- 1.2; females 323 +/- 1.5 vs. 310 +/- 2.2). Urine osmolality of NDI birds was substantially lower than that of controls (males 90 +/- 6.2 vs. 524 +/- 4.0; females 70 +/- 4.7 vs. no value). In response to water deprivation, plasma osmolality of the NDI birds increased more markedly than that of the control animals (males 357 +/- 2.5 vs. 331 +/- 1.2; females 375 +/- 6.0 vs. 348 +/- 1.4 at 48 h of water deprivation). Basal plasma antidiuretic hormone (plasma arginine vasotocin, PAVT) levels in male NDI birds (9.9 +/- 0.7 microU/ml) and in female NDI birds (7.0 +/- 0.5 microU/ml) were nearly sixfold or nearly threefold higher, respectively, than in control birds. In response to water deprivation, PAVT of both NDI and control birds increased to similar levels, although the absolute increases in PAVT levels were substantially less in NDI birds.(ABSTRACT TRUNCATED AT 250 WORDS)