Low-Protein Diet during Lactation and Maternal Metabolism in Rats

Abstract

Some metabolic alterations were evaluated in Wistar rats which received control or low-protein (17%; 6%) diets, from the pregnancy until the end of lactation: control non-lactating (CNL), lactating (CL), low-protein non-lactating (LPNL) and lactating (LPL) groups. Despite the increased food intake by LPL dams, both LP groups reduced protein intake and final body mass was lower in LPL. Higher serum glucose occurred in both LP groups. Lactation induced lower insulin and glucagon levels, but these were reduced by LP diet. Prolactin levels rose in lactating, but were impaired in LPL, followed by losses of mammary gland (MAG) mass and, a fall in serum leptin in lactating dams. Lipid content also reduced in MAG and gonadal white adipose tissue of lactating and, in LPL, contributed to a decreased daily milk production, and consequent impairment of body mass gain by LPL pups. Liver mass, lipid content and ATP-citrate enzyme activity were increased by lactation, but malic enzyme and lipid: glycogen ratio elevated only in LPL. Conclusion. LP diet reduced the development of MAG and prolactin secretion which compromised milk production and pups growth. Moreover, this diet enhanced the store of lipid to glycogen ratio and suggests a higher risk of fatty liver development.

Prolactin and the dietary protein/carbohydrate ratio regulate the expression of SNAT2 amino acid transporter in the mammary gland during lactation

“…It has been explored whether the amount of dietary protein could affect the levels of circulating prolactin. Moretto et al clearly demonstrated that in fact when rats consumed a low protein diet, the concentration of serum prolactin was significantly reduced [22]. Our results also demonstrated that the dietary protein/carbohydrate ratio influences the serum prolactin concentration.…”

“…The lower the amount of protein, the lower the concentration of serum prolactin [22]. As a result there is a decrease in milk production that is reflected in the growth pattern of the pups.…”

Nutritional epigenetics with a focus on amino acids: implications for the development and treatment of metabolic syndrome

“…Second, maternal protein restriction alters hepatic lipid content in male offspring rats [124] and promotes the hepatic accumulation of lipids, leading to a high incidence of fatty liver [125].…”

Experimental diet based on the foods listed in the Family Budget Survey is more detrimental to growth than to the reflex development of rats

“…Low-protein diets reduce serum prolactin by 70%, evidenced by less suckling and milk production, which in turn does not promote leptin resistance, characteristic of this phase 27 . Shaw et al 25 stated that the third week of pregnancy is characterized by continuous hyperinsulinemia and insulin resistance.…”