Balance of Net Base in the Rat. I. A Technical Approach

Abstract

A low-cost technique for studies of mineral and net base balance in rodents is described. Metabolic units of plexiglass, modifiable according to special needs, were found to perform satisfactorily in short-term as well as in long-term studies. Young Wistar rats showed normal growth rate, and adult non-growing rats showed mineral and net base balances close to zero.

Balance of Net Base in the Rat. II. Reference Values in Relation to Growth Rate

“…Weights are in grams. For methods o f sample preparation see previous article (36) calcium was found to be a more powerful statistical predictor of the daily weight gain than the balance of any other single mineral (r = 0.76, p < 0.001, n = 60), and the combined balances of calcium and magnesium proved particularly satis factory in this respect (r = 0.83, p < 0.001, n = 60).…”

“…Details of the experimental procedure including melabolic cages, choice of food, col lection of feces and urine, sample preparation, and chemical analyses are given elsewhere (36). All balance studies were carried out for 8 days exactly.…”

“…A standard diet o f finely ground Rostock® pellets (table I) constituted the sole solid food intake in all animals (36). Rates of intake of food and calories, weight responses, and rates of stool production arc summarized in table 1!.…”

“…For urine, the sulphate ions must be considered as well. However, assuming a zero sulphate balance (36), sulphate may be dis regarded, and balances o f net base derived as: NBB = (BNa* + BK* + 2B Ca" + 2 B Mg" ) (Bc l ' + 1.8 Bp)…”

Balance of Net Base in the Rat

“…In previous publications, a technique for the measurement of long-term electrolyte and net base (NB) balance in small experimental ani mals as well as a system of reference values for young male Wistar rats of varying rates of body growth while on a standard laboratory diet were described (13,14). The present report deals with the effect of sustained oral loads of NB (stoichiometrically NaOH) applied as sodi um bicarbonate or sodium citrate at equivalent rates.…”