Effects of Different Levels of Pyridoxine Fed during Pregnancy Superimposed upon Growth in the Rat

Abstract

Effects of pregnancy superimposed upon a rapid phase of growth in the rat on the vitamin B-6 needs during gestation were examined. Rats were fed 1.2, 2.4, 4.8, 9.6, or 19.2 mg pyridoxine-HCl/kg diet from weaning. Some animals from each dietary treatment were mated at 55 (P-55) and 115 (P-115) days of age; others of the same ages served as nonpregnant controls. Analyses were made on day 21 of gestation. Excepting the 1.2-mg diet treatment, maternal weight gains during gestation were greater for P-55 groups compared with gains of the P-115 groups, possibly reflecting maternal growth. Both maternal weight gains and fetal weights were less for the 1.2-mg, P-55 group; otherwise reproductive performance was similar among the groups. On the basis of stimulation of erythrocyte alanine aminotransferase activity by pyridoxal phosphate added in vitro, the needs in all pregnant and nonpregnant groups were met by 2.4 mg pyridoxine/kg diet. However, on the basis of vitamin B-6 saturation of tissues, the pyridoxine needs were 9.6 mg/kg diet for young growing animals and 4.8 mg/kg diet for older animals in which growth had almost ceased. The needs for both young and older pregnant animals possibly exceeded 19.2 mg pyridoxine/kg diet for vitamin B-6 saturation of maternal liver, fetus, and fetal brain. Pregnancy superimposed upon a rapid phase of growth in conjunction with a restricted intake of pyridoxine resulted in low values for most parameters used in the assessments compared with values for animals fed the same vitamin level but mated after growth velocity had diminished.

Effect of feeding various dietary vitamin B6concentrations during gestation and lactation on vitamin B6level in liver and carcass of rat dams

“…This might be due to the fact that in a deficiency of vitamin B 6 the vitamin was first released from other tissues like muscle before liver (Kirksey et al, 1975;Brin and Thiele, 1967). This means that feeding a vitamin B 6 -deficient diet during gestation did not cause a total exhaustion of hepatic vitamin B 6 storage if rats were fed 3 or 6 mg/kg dietary vitamin B 6 during lactation.…”

Zum Einfluss einer variierten Vitamin-B₆-Versorgung auf den Vitamin-B₆- Status in Feten und Reproduktionsorganen

“…Wie aus Tabelle I hervorgeht, scheint sich ab einer Zufuhr von 6 ppm Vitamin B6 ein Konzen trationsplateau bei etwa 1,4 pg Vitamin B6/g FS zu bilden. Auch von Kirksey et al [1975] wurden bei ähnlichen Vitamin-B6-Gehalten im Futter im Milchdrüsengewebe hochtra gender Ratten Vitamin-B6-Konzentrationen zwischen 0,4 und 2,0 pg Vitamin B6/g FS ermittelt. Diese Autoren vermuten aufgrund der erreichten Werte ab einem Vitamin-B6-Gehalt der Diät von 9,6 ppm eine Absätti gung des Gewebes mit Vitamin B6.…”

Growth and development in rats and deficiency of magnesium and pyridoxine.

“…Deficiencies of either of these nutrients during reproduction may impair reproductive success, as well as growth and development of offspring [7][8][9][10]. Since pyridoxine has been reported to have a beneficial effect on magnesium utilization [6], a deficiency of the vitamin might be expected to ex acerbate magnesium depletion.…”