Effects Of Dietary Supplementation Of Conjugated Linoleic Acid (CLA) During Gestation And Lactation On Mammary Gland Development Of Mice Fed With High Fat Diet(HFD)

Mammary gland(MG)is an important lactation organ in mammals,which is great significance for the growth and development of newborn animals.MG development of animals is regulated by multiple factors such as heredity,hormone,nutrition and environment.As one of the three nutrients,fatty acids play an important role in regulating MG development.At present,although there are a few reports on the MG development with fatty acids,the role of linoleic acid(CLA)in the MG development in gestation and lactation period were not known.Therefore,this study investigated the effect of dietary supplement 1.5% CLA during gestation and lactation on MG development of mice fed with HFD.To this end,we analyzed the serum hormone levels of mice on each physiological phases by ELISA.Whole mount and H&E staining were used to observe the morphological structure of MG.Western Blot(WB)was used to detect the expression levels of adipose differentiation related protein(ADRP)and MG development marker protein elf-5 in MG tissue of mice,and QMR was used to analyze the body composition of offspring female mice.The results are as follows:1.Effects of dietary supplementation of CLA during gestation on MG development of mice fed HFD: compared with Control,HFD group significantly inhibited mice food intake,but did not affect energy intake,dietary supplementation CLA compared with HFD,were did not affect food and energy intake;HFD significantly inhibited the expression of elf-5 and ADRP proteins in MG tissues,thereby inhibiting the lipid synthesis of MG,The supplement of CLA could up-regulate the expression of elf-5 and ADRP proteins,thereby reversing this effect.The results of staining showed that HFD could reduce the density of MG parenchyma and ducts,inhibit the development of MG alveolar development,while CLA could increase the density of MG parenchyma and ducts,promote the alveolar development to improve the MG development.E2 concentration was detected by ELISA in maternal mice showed that HFD significantly decreased serum E2 level,while CLA significantly increased serum E2 level,indicating that dietary supplement CLA could up-regulate the concentration of E2,thereby regulating MG development.In short,HFD inhibited MG development,and supplement CLA improved the harmful effects of HFD on MG development.2.Effects of dietary supplementation of CLA during lactation on MG development of mice fed HFD : in lactation,mothers fed with HFD reduced MG ductal and parenchymal density and significantly reduced alveolar area ratio,thereby inhibiting MG development,but dietary supplement CLA can reverse it;At the same time,HFD also inhibited the expression of ADRP proteins,thereby inhibiting the lipids synthesis of MG to inhibiting MG development.The expression of ADRP proteins was significantly up-regulated after CLA addition,thus promoting MG development.And the ELISA results showed that HFD significantly increased the PRL level,resulting in hyperprolactinemia,and dietary supplement CLA could down-regulate the PRL concentration to the normal level,so leads to play its regulatory role on MG development.3.Maternal HFD or supplement CLA feeding during lactation effects on MG development of female offspring : the results showed that Maternal HFD feeding during lactation was significantly reduced TEBs of the female offspring,and the serum IGF-1 level was significantly reduced,thereby inhibiting the MG development of the female offspring;Maternal HFD supplementation of CLA feeding during lactation was significantly increased the TEBs,and the serum IGF-1 level was as same,thereby promoting the MG development of the female offspring.In summary,HFD could inhibit the development of MG during gestation and lactation by reducing the density of duct and parenchyma,decreasing elf-5 and ADRP protein expression.In addition,maternal HFD feeding during lactation inhibit the MG development of female spring.Dietary supplement CLA can promote alveolar development by increasing elf-5 and ADRP protein expression to improve MG development during gestation and lactation.Maternal supplement CLA feeding during lactation improve the MG development of female spring.