Gastrocystoplasty and chronic renal failure: an acid-base metabolism study.
OBJECTIVE
To verify in an experimental model whether gastrocystoplasty may protect patients with chronic renal failure from acid loading associated acidosis a wedge-shaped portion of the middle stomach was used to improve bladder capacity in animals with chronic renal failure.


METHODS
An experimental model was used to study 112 adult female Wistar rats (EPM-1) weighing between 156 and 259 gm. The animals were randomly assigned to groups, including 41 controls, 24 undergoing five-sixths nephrectomy to create chronic renal failure, 26 undergoing gastrocystoplasty and 21 undergoing gastrocystoplasty and five-sixths nephrectomy to create renal failure. To provide an acid overload a 5% NH(4)Cl diet was administered to a subgroup of each group. Two months after surgery 24-hour urine was collected, and volume and pH were measured as well as the amount of bicarbonate, ammonium, titratable acidity and chloride. The animals were then exsanguinated through an abdominal aorta puncture. The blood was used for blood gas analysis and to measure sodium, potassium, chloride, ionized calcium and creatinine.


RESULTS
When undergoing an acid overload, the animals with gastrocystoplasty had no acidosis since acid radicals were eliminating in the urine as NH(4)Cl. When given the same acid overload, metabolic acidosis developed in the animals with gastrocystoplasty and chronic renal failure.


CONCLUSIONS
Gastrocystoplasty protected healthy rats from acidosis when they were given an acid overload but failed to protect the rats with chronic renal failure under the same conditions.
de Freitas Filho
L G
LG
Department of Surgery and Nephrology of Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
Carnevale
J
J
Leão
J Q
JQ
Schor
N
N
Ortiz
V
V
D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000503:physiopathology* / Q000517:prevention & control; D000643:Ammonium Chloride / Q000008:administration & dosage / Q000378:metabolism*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D015391:Gastroplasty; D006863:Hydrogen-Ion Concentration; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000601:surgery; D007677:Kidney Function Tests; D009392:Nephrectomy; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D018709:Statistics, Nonparametric; D013270:Stomach / Q000601:surgery*; D016482:Urinalysis; D001743:Urinary Bladder / Q000601:surgery*; D014547:Urinary Diversion / Q000379:methods
D000643:Ammonium Chloride