The Accumulation of Amino Acids in the Products of Conception of the Rat and in the Young Animal after Birth

Southgate, D. A. T.

doi:10.1159/000240422

Cited by 14 publications

(4 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, there is some indication of a difference in fetal development between the two dietary groups since the protein:DNA value in fetuses from animals in the marginal-Zn group was significantly higher than that in fetuses from control-fed animals. The effect on fetal growth of marginal-Zn intake in late pregnancy was demonstrated more clearly in fetuses taken on the 21st day of gestation (Fairweather-Tait et al 1984) than on the 20th day, as in the present study, possibly because of the exponential nature of the growth which is maximal between days 20 and 21 in the rat (Southgate, 1971). This trend toward increased fetal weight contrasts with the effects of severe Zn deficiency on fetal growth (Hurley & Mutch, 1973), as discussed elsewhere (Fairweather-Tait et al 1985), where it was suggested that the increment in fetal growth, observed in rats given marginal-Zn diets towards term, might be associated with changes in carbohydrate metabolism, hypertrophy being a characteristic feature of offspring of diabetic mothers (Ogata et al 1980).…”

Section: Discussionsupporting

confidence: 69%

Fetal growth, glucose tolerance and plasma insulin concentration in rats given a marginal-zinc diet in the latter stages of pregnancy

1988

View full text Add to dashboard Cite

1.Wistar rats were fed on a control semi-synthetic diet throughout pregnancy, or a control diet in the first 2 weeks and a marginal-zinc diet in the 3rd week of pregnancy. On day 20, after an overnight fast, half the animals in each group were given glucose by gavage and the 0-30 rnin rise in blood glucose measured in tail blood. After 60 rnin blood was taken by cardiac puncture for glucose and insulin assay. Maternal pancreases were removed and the Zn contents measured. Fetuses from each litter were combined for wet/dry weights, protein and DNA determinations.2. Plasma insulin concentration was higher, and glucose concentration and pancreatic Zn content lower, in pregnant v. non-pregnant animals of similar age, fed on the same diet. Pancreatic Zn content was lowest in the marginal-Zn group of pregnant rats. Fetuses from mothers fed on the marginal-Zn diet during the last week of pregnancy were slightly heavier than controls and had a significantly higher protein: DNA ratio. The &30 min rise in blood glucose was significantly greater in the marginal-Zn animals.3. In a second experiment, pregnant rats were given similar diets to those used in the first study, but the marginal-Zn diet was given for a shorter period (days 15-19 of pregnancy). On day 19 the rats were meal-fed and on day 20, after an overnight fast, an oral glucose dose was administered. Tail-blood was taken at timed intervals up to 60 min post-dosing for glucose assay. Both maternal and fetal blood glucose and insulin concentration was measured 70 rnin post-dosing.4. Values for maternal and fetal blood glucose and plasma insulin, measured 70 rnin after the administration of a glucose dose, were similar in the two groups, but the initial rise in blood glucose concentration was again significantly higher in pregnant rats given the marginal-Zn diet towards term.5. It is suggested that the change in growth and composition, observed in fetuses from rats given a marginalZn diet in later pregnancy, is associated with altered maternal carbohydrate metabolism.Rats given a marginal-zinc diet towards the end of pregnancy produce pups which are large for their gestational age. However, rats given a marginal-Zn diet from the start of pregnancy are no different from control-fed animals, and the earlier in pregnancy the marginal-Zn diet is introduced the less is the effect on fetal growth (Fairweather-Tait et al. 1984. This indicates an adaptive response to longer periods of marginal-Zn intake. The reasons for the observed increase in fetal growth are unclear, but the fact that glucose is the major metabolic fuel for the developing fetus (Schwartz, 1968), together with evidence that inadequate dietary Zn results in abnormal carbohydrate metabolism in rats (Reeves & O'Dell, 1983) and man (Baer et al. 1985), suggest that the increased size of pups may be linked to changes in glucose utilization.This possibility was investigated by studying the effect of marginal-Zn intake during the latter stages of pregnancy in the rat on growth, blood glucose and insulin levels ...

show abstract

Section: Discussionsupporting

confidence: 69%

Fetal growth, glucose tolerance and plasma insulin concentration in rats given a marginal-zinc diet in the latter stages of pregnancy

1988

View full text Add to dashboard Cite

show abstract

“…The rest of the amino acids, however, show a downward trend, especially lysine, which decreases by about 40% (Southgate, 1971). The progressive reduction in plasma concentration of amino acids may reflect a considerable amino acid drain by the conceptus.…”

Section: Amino Acid and Protein Metabolismmentioning

confidence: 94%

Nutrition and Pregnancy

Rosso

Cramoy

1979

Nutrition

View full text Add to dashboard Cite

“…Analysis of fetal carcass protein, from the calf (JACOBSEN et al [16]) and rat (SOUTHGATE [34]), has shown that the amino acids are the same, and present in the same proportions, äs in weanling and adult protein (WILLIAMS etal. [37]).…”

mentioning

confidence: 99%