Effects of Essential Amino Acid Deficiency on General Control Nonderepressible 2/Eukaryotic Initiation Factor 2 Signaling and Proteomic Changes in Primary Bovine Mammary Epithelial Cells.

We hypothesized that the general control nonderepressible 2 (GCN2)/eukaryotic initiation factor 2 (eIF2) signaling pathway and intracellular protein synthesis (PS) are regulated to maintain milk PS in primary bovine mammary epithelial cells (MECs) under essential amino acid (EAA) starvation conditions. We cultured MECs with 0%, 2% (depletion), and 100% (control) EAA for two exposure times (8 and 24 h), followed by three refeeding (RF) times with 100% EAA (0, 8, and 24 h). Subsequently, we measured cell viability, total protein concentration, and proliferation.

Amino Acid Metabolomic Profiles in Bovine Mammary Epithelial Cells under Essential Amino Acid Restriction.

Mammary epithelial cells (MECs) in culture are a useful model for elucidating mammary gland metabolism and changes that occur under different nutrient disponibility. MECs were exposed to different treatments: 100% EAA for 8 h and 24 h restriction (R); 2% EAA for 8 h and 24 h R; 2% EAA for 8 h and 24 h + 100% EAA for 8 h and 24 h restriction + re-feeding (R + RF). Western blotting and protein quantification was performed.

Pharmacological overview of galactogogues.

Galactogogues are substances used to induce, maintain, and increase milk production, both in human clinical conditions (like noninfectious agalactias and hypogalactias) and in massification of production in the animal dairy industry. This paper aims to report the state of the art on the possible mechanisms of action, effectiveness, and side effects of galactogogues, including potential uses in veterinary and human medicine. The knowledge gaps in veterinary clinical practice use of galactogogues, especially in the standardization of the lactogenic dose in some pure drugs and herbal preparations, are reviewed.

Association between leptin, LH and its receptor and luteinization and progesterone accumulation (P4) in bovine granulosa cell in vitro.

A full understanding of the cellular events that occur during in vitro luteinization of bovine granulosa cells, stimulated by LH and by leptin, is a complex goal that has not been completely achieved. The aim of this work was to study the effects of leptin, LH and leptin + LH on progesterone accumulation (P4) and on the expression of LH receptors (LHR) in bovine granulosa cells in culture. The results confirm that this in vitro model is representative of functional and morphological luteinization/differentiation.

Estrogen mediates phosphorylation of histone H3 in ovarian follicle and mammary epithelial tumor cells via the mitotic kinase, Aurora B.

Cells of the ovarian follicle undergo extensive proliferation and differentiation from the time that the follicle escapes from the primordial state to its acquisition of ovulatory capacity. We examined the dynamic modification of the phosphorylation state of the histone H3 N-terminal tail in granulosa cells during follicular development. In rodent follicles, the granulosa cell H3 phosphorylation on Ser10 peaks during proestrus.