Renal response to blood volume expansion in Brattleboro rats after acute treatment with vasopressin.
The renal response to iso-oncotic blood volume expansion with bovine serum albumin was studied in anaesthetized homozygous Brattleboro (DI) rats after acute (1 day) pretreatment with 1 U arginine-vasopressin (AVP) compared to heterozygous controls. In AVP-treated DI (DI + AVP) rats, basal urine flow as well as urinary sodium, chloride, and potassium excretion, were not different from controls. Diuresis and kaliuresis induced by volume expansion were blunted in DI + AVP rats. However, natriuresis and chloruresis were exaggerated in DI + AVP rats. They increased faster, reached a higher maximum, but declined earlier, compared to controls. The blunted diuresis resulted in a positive volume balance by the end of the experiment in DI + AVP rats, whereas the controls showed restoration of normal balance. Significant retention of sodium and chloride was observed in controls, but not in DI + AVP rats, over the time of the experiment. DI + AVP rats lost significantly less potassium than controls during the experiment. As judged from the lithium clearance method, the exaggerated saluresis in DI + AVP rats was mainly due to a reduced proximal sodium reabsorption. Plasma immunoreactivity of atrial natriuretic peptide (ANP) rose during blood volume expansion and fell in the recovery period. It was not different between AVP-treated DI rats and controls at any time of the experiment. Inulin clearance was slightly, but not significantly, lower in DI + AVP rats and increased after blood volume expansion in DI + AVP rats only.(ABSTRACT TRUNCATED AT 250 WORDS)
Palluk
R
R
Department of Pharmacology, Boehringer Ingelheim KG, Federal Republic of Germany.
Veress
A T
AT
Sonnenberg
H
H
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D009320:Atrial Natriuretic Factor / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001810:Blood Volume / Q000187:drug effects / Q000502:physiology*; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007668:Kidney / Q000033:anatomy & histology / Q000502:physiology*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011910:Rats, Brattleboro; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D014556:Urine
D001127:Arginine Vasopressin; D012710:Serum Albumin, Bovine; D009320:Atrial Natriuretic Factor