[The course of vitamin B6 content in growing rats during vitamin B6-free nutrition]

This experiment was designed in two parts. In the first part the vitamin B6 efficiency in response to increasing dietary vitamin B6 intakes was tested in growing rats; in the second part the reaction of rats, originally supplied with the fourfold requirement and then switched on the vitamin-B6-free basal diet was examined. The experimental animals were male Sprague-Dawley rats, of which weight gains, feed intake, and vitamin-B6-concentrations in blood, liver and whole carcass were measured. At the beginning of the trial nine animals were analyzed; 54 additional animals, divided into six groups, were given a vitamin-B6-free semisynthetic diet for three weeks which was supplemented with 0, 1.5, 3, 6, 12, and 24 mg vitamin B6 per kg feed. For the second part the additional 54 animals were given a diet with 24 mg vitamin B6 for three weeks and then switched to the vitamin-B6-free basal diet. Six animals per group were sacrificed after 2, 5, 8, 12, 16, 20, 25, 30, and 35 days of depletion. Efficiency of dietary vitamin B6 decreased from 38% at 1.5 mg vitamin B6 per kg diet to 4% at the 24 mg dietary level. Also, without dietary vitamin B6 the animals gained weight (from 145 to 300 g live weight), the daily feed intake increased from 14 to 19 g and feed efficiency decreased from 2.2 to 4.3 g feed per g gain. Vitamin B6 concentration in tissues reacted differently.(ABSTRACT TRUNCATED AT 250 WORDS)