Effect of maternal ethanol consumption during pregnancy and lactation on kinetic parameters of folic acid intestinal transport in suckling rats.

Ethanol ingestion is known to interfere with folate absorption and metabolism. A fostering/crossfostering analysis of maternal ethanol exposure effects on jejunum and ileum kinetic parameters in vivo of offspring rat folic acid absorption at 21 days postpartum was carried out. The rats were divided into four groups: CP, control pups; GP, pups exposed to ethanol only during gestation; LP, pups exposed to ethanol only during lactation; GLP, pups exposed to ethanol during gestation and lactation. Jejunal and ileal loop transport studies were performed using in vivo perfusion at a flow rate of 3 ml/min for 5 min. Folic acid concentrations of 0.25, 0.5, 1, 1.5 and 2.5 microM: were used. Jejunal and ileal absorption values were determined by the difference between the initial and the final amounts of substrate in the perfusate and expressed as picomoles per square centimeter of intestinal surface every 5 min. The results indicated that ethanol consumption by the dams during gestation and/or lactation led to significant changes in V(max), with no significant changes in apparent K(m). These findings suggest that exposure to ethanol during gestational and suckling periods leads to a general delay in postnatal body weight and that intestinal folate absorption appears to be upregulated in suckling rats, this effect being higher in the LP group.

Effects of prenatal or postnatal ethanol consumption on zinc intestinal absorption and excretion in rats.

AIMS: The effect of ethanol consumption, either during the pregnancy or lactation period, on the altered metabolism of zinc is not well-defined; consequently, this study was performed to analyze the effect of chronic ethanol exposure on milk consumption, serum, milk, duodenal absorption, fecal and urinary excretion of zinc in dams and offspring during either gestation or lactation in the rat. A complementary study was performed regarding pregnancy outcome. We evaluated testosterone values, the offspring born/litter and several indices such as fertility, viable gestations and the survival index. METHODS: To study the effect of chronic alcoholism during gestation or lactation separately, at birth control newborns were cross-fostered to ethanol dams (ED), and the offspring issued from the ethanol treated mothers were cross-fostered to control dams (CD). Thus, three experimental groups of offspring were formed: (i) control offspring receiving no treatment (CO); (ii) offspring exposed to ethanol only during gestation (GO); and (iii) offspring exposed to ethanol only during lactation (LO). All the results were compared with offspring pair-fed groups (PFO) born of the pair-fed dams (PFD). RESULTS: Duodenal absorption of zinc increased significantly in LO offspring when the substrate concentrations in the perfusion medium were 25, 75, and 150 microM. A higher faecal excretion in GO pups compared with those with LO exposure and control groups (CO and PFO). The urine excretion of zinc was higher for LO offspring with respect to the other three experimental groups (CO, GO, and PFO). CONCLUSIONS: Maternal adaptation resulted in zinc retention, adequate to meet the demands of pup's growth in the face of a lower diet intake. The zinc status in pups is regulated by a higher absorption of zinc and intestinal conservation of endogenous fecal zinc after postnatal ethanol consumption. The increase in urinary zinc excretion could be responsible for decreased serum zinc. However, we found an increase in serum zinc probably due to an increase in the zinc absorption values.

Effects of maternal ethanol consumption during pregnancy or lactation on intestinal absorption of folic acid in suckling rats.

A fostering/crossfostering analysis of the effects of maternal ethanol exposure on jejunal and ileal folate absorption was performed. Male and female rats were randomized into two groups. In the first group, ethanol-treated rats received ad libitum 5, 10 and 15% ethanol in the drinking fluid during three successive weeks. A consumption of 20% was maintained in this group for 5 additional weeks. Ethanol-treated rats were mated. Group 2 served as the control. To study the effect of chronic alcoholism during lactation or gestation separately, at birth (2nd day postpartum) control newborns were cross-fostered to ethanol dams (EG), and the pups issued from the ethanol treated mothers were cross-fostered to control dams (CG). Thus, three experimental groups of pups were formed: (1) control pups receiving no treatment during gestation and lactation (CG); (2) pups exposed to ethanol only during gestation (GG); and (3) pups exposed to ethanol only during lactation (LG). At 21 days postpartum the jejunal and distal ileum folate absorption was determined in the offspring rats by a perfusion technique. Milk folic acid levels were determined by an immunoluminometric assay. The results showed an increase in jejunal folic acid absorption in offsprings exposed to ethanol only during the lactation period (LG). However, in pups exposed to ethanol only during the gestation period (GG), the jejunal folic acid absorption was significantly increased only at concentrations of 0.25, 0.5 and 2.5 microM. No free folic acid absorption occurred in the distal ileum of control pups (CG) at day 21 at all assayed concentrations but in offsprings exposed to ethanol only during the gestation or lactation periods absorption did take place. Pups exposed to ethanol during the gestation period (GG) showed decreased values in ileum folic acid absorption at the lowest assayed concentration (0.25 microM) compared to values obtained for pups exposed to ethanol only during lactation (LG). Milk folic acid levels were significantly decreased in the ethanol-fed dams on day 21 of lactation. These results indicate that exposure of rats to ethanol during the lactation period affects more severely postnatal development of intestinal functions than ethanol exposure only during gestation. In summary, both the exposure to ethanol itself and the decrease in folic acid intake caused alterations in the function of the intestinal mucosa in the offspring, which in turn altered absorption time and development. However, the present results do not explain how ethanol stimulated intestinal absorption of folic acid in pups exposed to ethanol during the gestation or lactation periods. Further studies are needed.