Estimation of the Daily Milk Intake of the Suckling Rat Using the Turnover Rate of Potassium

Abstract

Kinetic parametersof potassium metabolism were utilized for the esti mation of the daily milk intake of the suckling rat. These parameters in cluded the turnover rate of potassium as determined from the whole-body retention curve of 42K, the total potassium content as measured by means of atomic absorption spectrometry, and the potassium content of milk samples from the lactating dams. The daily intake of potassium was cal culated using the whole-body potassium content, the turnover rate con stant, and the assumption that the body is a single instantaneously mixing compartment for potassium. The daily milk intake of suckling rat was calculated from the daily potassium intake and the concentration of potassium in rat milk. The results showed that the daily milk intake varies from 1.6g of milk for a newborn rat to 6g for a 14 day-old suckl ing rat.

Calcium Supplementation Efficiently Reduces Lead Absorption in Suckling Rats*

“…In our experiment, calcium was administered as hydrogen phosphate to suckling rats by increasing the total daily calcium intake by about 1.4, 2 or 3 times compared to the intake from rat's milk. These values are approximate since they are based upon calcium concentration and quantity of rat's milk secreted by lactating dams during 24 hr, from different rat strains and breeding, and under different sampling conditions (Luckey et al 1954;Kametaka et al 1974;Keen et al 1981;Auestad et al 1989;Fiorotto et al 1991;Nicholas & Hartmann 1991). With respect to the strain of rats used in our experiments, we considered 0.25%, measured by Luckey et al (1954) and Nicholas & Hartmann (1991), as an average and approximate calcium concentration of rat's milk in our calculations.…”

Succimer treatment and calcium supplementation reduce tissue lead in suckling rats

“…In this way the daily calcium intake was increased about three to four times above control values. With respect to the litter size and strain of the rats used in our experiments, this value is calculated as in our previous studies (Varnai et al, 2001a) on the basis of the calcium concentration of the rat's milk measured by Luckey et al (1954) and Nicholas & Hartmann (1991) and the quantity of milk secreted by lactating rats according to Kametaka et al (1974).…”