Browsing by Author "Viñas, O."

Chronic and acute ethanol treat nents increased th,: 3-hydroxybutyrate uptake by lactating rat mammary gland as :1 consequence of its high afferent concentration, without changing its relative extraction. The uptake of glucose was inhibited in the ethanol treated animals due to int ·insic alterations in the mammary gland metabolism as indicated by the decreased relative extrac1 ion and unchanged afferent concentration. These results would suggest that the ek:vated uptake of ketone bodies in ethanol-treated rats can be respcnsible, at least in part, for the decrease in glucose uptake by lactating rat mammary gland, although other direct effects of ethanol may be implied.

The effects of chronic ethanol consumption on lactational performance were studied in the rat on day 15 after delivery by determining mammary gland and milk composition, while growth rate and metabolic parameters were studied in pups coming from untreated mothers but being suckled by ethanol-treated mothers. Alcohol treatment increases the dry weight and lipoprotein lipase activity in the mammary gland, and decreases both absolute and relative mammary gland weight and mammary tissue protein content. The triacylglycerol concentration of milk from treated dams is increased, whereas lactose concentration is decreased in comparison to milk from controls, although the total energy content of milk from alcohol-treated dams is higher than that from controls. Ethanol treatment produces a reduction of daily milk production. Pups nursed by alcoholic mothers show a retarded growth with respect to pups nursed by untreated mothers. Furthermore, they present a reduction in the levels of circulating glucose, insulin, glycerol and free fatty acids, whereas an increase in acetoacetate and in urea levels is observed. Pups from alcoholic mothers show reduced glycogen concentration in the liver while the protein content is increased. Plasma free amino acids in pups nursed by alcoholic mothers are lower than in control pups, the differences in Ala, Glu +Gin, Gly, Pro, 4-OH-Pro, citrulline, Cys, Tyr, Phe and the combined total values being statistically significant. We may therefore draw the conclusion that chronic ethanol treatment impairs lactational performance affecting mammary gland function as shown by the decline in milk production and altered milk composition. All these changes result in evident notable malnutrition in suckling young, which may be added to the negative effects of foetal development produced by maternal alcohol ingestion during pregnancy.

I. A model of chronic ethanol administration has been used to study the effects of chronic ethanol consumption on the general metabolism of lactating rats on day 15 after delivery. 2. We have studied the effects of ethanol on calorics, food and fluid intake. body weight, circulating parameters such as glucose, glycerol, free fatty acids (FFA). triacylglyccrots (TAG), amino ncids (AA), ketone bodies, insulin and ethanol levels and liver composition. 3. Chronic ethanol consumption markedly incrr.ascs the levels of circulating D-OH-butyrate (B-OB-B), glycerol and FFA, while those of acetoacetate (AcAc), glucose, insulin and TAG remain constant. With the only exception of an increase in Glu + Gin levels, plasma AA dccre;1se in the alcohol-treated rats, the change being significant for Ala, Pro, Lys, Alg, Val, Phe and 4-OH-poline. 4. In the liver ethanol treatment causes an increment in TAG concentration and a decrease in glycogen content. 5. In conclusion, chronic ethanol consumption produces notable alterations in the metabolism of lactating rats, which may diminish the efficiency (1f lactation, influencir g milk production and, therefore, the pups' development.

The 1,ffects of chronic ethanol consumption on mammary gland amino acid uptake at the 15th day of lactation in the rat have been studied. Ethanol treatment decreased the arterial levels of Ala, Asp, Gly, Pro, Lys and Met, and increased those of Gln and ct-amino-butyrate. Chronic ethanol treatment produced a decrease in the arteriovenous differences of Asp, Thr, Arg, Met and Phe, and increased those of Ala, Gln, Gly, Pro and Tyr. The combination of the calculated values of relative extraction and the arteriovenous differences indicate that these alterations in amino acid uptake are related to changes in the transport process for Ala, Asp, Thr, Pro, Arg, Asn, Gly, Tyr, and Phe, and that the alterations in the arteriovenous differences of Gln, Lys and Met are due to the affected arterial levels of these amino acidE. Measurements of enzymatic activities in the mammary gland show that these alterations in the amino acid transport process cannot be ascribed to chan€eS in the ¥"-glutamyl cycle.