Antidiuretic hormone didn′t cause water retention in adriamycin nephrotic rats
10.3760/j.issn:0578-1310.2001.01.010
- VernacularTitle:抗利尿激素在阿霉素肾病大鼠水潴留机制中的作用
- Author:
Siguang LU
1
;
Zhiqiang XIA
;
Chen DONG
Author Information
1. Affiliated Hospital Xuzhou Medical College
- From:
Chinese Journal of Pediatrics
2001;39(1):31-34
- CountryChina
- Language:Chinese
-
Abstract:
The sodium and water retention is one of the characteristics in nephrotic syndrome. Its mechanism remains to be determined though it has been suggested that vasopressin may play an important role on the water retention. Objective To explore the possible effect of antidiuretic hormone on water retention in experimental nephrotic rats. Methods Urine and blood osmolalities were determined by using the cryoscopic method for evaluation of clearance of solute-free water (CH2O). The activities of adenosine cyclase (AC), adenosine 3′,5′-cyclic monophosphate phosphodiesterase (cAMP-PDE) and the amount of cAMP in renal medulla of experimental nephrotic rats were measured by using radioimmunoassay. The study included 6 groups of rats. Rats in group 1 were normal controls, in group 2 were injected with DDAVP, in group 3 injected with DDAVP antagonist, in group 4 injected with adriamycin, in group 5 injected with Adriamycin + DDAVP, and in group 6 injected with adriamycin + DDAVP antagonist. Results The urine osmolalities were (1 772±879), (2 145±936), (1 764±498), (1 050±272), (1145±243) and (993±196) mOsm/kg H2O in rats of group 1 to group 6, respectively ( F=113.069, P=0.000 4). The plasma osmolalities were (302±9), (296±10), (308±6), (286±5), (289±6) and (290±7) mOsm/kg water, respectively (F=17.302, P=0.014 2). CH2O were (-0.8±0.4), (-1.4±0.7), (-1.1±0.6), (-1.0±0.4), (-1.0±0.6) and (-0.9±0.5) ml/h, respectively (F=0.024, P=0.884 3). AC activities were (237±109)，(329±36)，(231±10)，(251±64)，(249±26) and (252±38) pmol/mg protein* min, respectively（F=0.659, P=0.4630）. The amounts of cAMP were (652±152)，(709±84)，(567±39), (77±16), (83±21) and (84±26) pmol/mg protein(F=177.033，P= 0.000 2), respectively. The percentages of cAMP-PDE transformation were (0.19±0.09), (0.18±0.07), (0.20±0.11), (0.34±0.08), (0.35±0.05) and (0.32±0.03) %, respectively (F=11.209, P=0.029 0) in rats of group 1 to group 6. Conclusion The antidiuretic hormone may not play a role on water retention in rats with adriamycin nephropathy, which might result from the decreased amount of cAMP accompanied with the increased cAMP-PDE activity, and the un-increased AC activity stimulated by DDAVP in renal medulla of rats after ADR injection.
