摘要
The objective of this study was to determine if the addition of zinc (Zn) in combination with zilpaterol HCL (ZH) affected the interaction of ZH with the beta2-adrenergic receptor (<span style="white-space:nowrap;"><i></i></span><i>β<span style="white-space:nowrap;"></span></i>-AR) by altering cAMP production, gene expression, and protein abundance in cultured skeletal muscle cells. Cultures of muscle bovine satellite cells were established and treated at 120 h with: 1) 0 μM Zn/zilpaterol hydrochloride (ZH;<strong>CON</strong>);2) 0 μM Zn/10 μM ZH (<strong>ZH</strong>);3) 1 μM Zn from Zn chloride/0 μM ZH (<strong>Zn</strong>);4) 1 μM Zn from Zn chloride/10 μM ZH (<strong>ZN/ZH</strong>) in differentiation media for an additional 0, 6, 24, 48 and 96 h. Protein and mRNA were isolated and quantified at 24 and 96 h, and cAMP was measured at 0, 6, 24, 48 and 96 h. At 0, 24, 48 and 96 h, no differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in cAMP production. At 6 h, Zn cells had the greatest concentration of cAMP (<span style="white-space:nowrap;"><i></i></span><i>P<span style="white-space:nowrap;"></span></i> < 0.05) compared to ZH treatments. No differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in mRNA abundance at 24 h. At 96 h, 0 μM Zn/10 μM ZH cells had an increased abundance of myosin heavy chain (MHC)-I mRNA (<i><span style="white-space:normal;">P</span></i> < 0.05) compared to CON. Furthermore, ZH had a greater abundance of MHC-IIX mRNA (<i><span style="white-space:normal;">P</span></i> < 0.05) and a tendency for a greater abundance of IGF-1 mRNA (<span style="white-space:normal;"><i></i></span><i><span style="white-space:normal;">P</span><span style="white-space:normal;"></span></i> < 0.15) compared to CON and ZN/ZH. No differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in the protein abundance of <i><span style="white-space:normal;">β</span></i>1AR and the <i><span style="white-space:normal;">β</span></i>2AR. These results indicated Zn and ZH in combination did not have an additive effect on<em> β</em>2-AR function as indicated by cAMP concentrations.
The objective of this study was to determine if the addition of zinc (Zn) in combination with zilpaterol HCL (ZH) affected the interaction of ZH with the beta2-adrenergic receptor (<span style="white-space:nowrap;"><i></i></span><i>β<span style="white-space:nowrap;"></span></i>-AR) by altering cAMP production, gene expression, and protein abundance in cultured skeletal muscle cells. Cultures of muscle bovine satellite cells were established and treated at 120 h with: 1) 0 μM Zn/zilpaterol hydrochloride (ZH;<strong>CON</strong>);2) 0 μM Zn/10 μM ZH (<strong>ZH</strong>);3) 1 μM Zn from Zn chloride/0 μM ZH (<strong>Zn</strong>);4) 1 μM Zn from Zn chloride/10 μM ZH (<strong>ZN/ZH</strong>) in differentiation media for an additional 0, 6, 24, 48 and 96 h. Protein and mRNA were isolated and quantified at 24 and 96 h, and cAMP was measured at 0, 6, 24, 48 and 96 h. At 0, 24, 48 and 96 h, no differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in cAMP production. At 6 h, Zn cells had the greatest concentration of cAMP (<span style="white-space:nowrap;"><i></i></span><i>P<span style="white-space:nowrap;"></span></i> < 0.05) compared to ZH treatments. No differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in mRNA abundance at 24 h. At 96 h, 0 μM Zn/10 μM ZH cells had an increased abundance of myosin heavy chain (MHC)-I mRNA (<i><span style="white-space:normal;">P</span></i> < 0.05) compared to CON. Furthermore, ZH had a greater abundance of MHC-IIX mRNA (<i><span style="white-space:normal;">P</span></i> < 0.05) and a tendency for a greater abundance of IGF-1 mRNA (<span style="white-space:normal;"><i></i></span><i><span style="white-space:normal;">P</span><span style="white-space:normal;"></span></i> < 0.15) compared to CON and ZN/ZH. No differences (<i><span style="white-space:normal;">P</span></i> > 0.05) were detected in the protein abundance of <i><span style="white-space:normal;">β</span></i>1AR and the <i><span style="white-space:normal;">β</span></i>2AR. These results indicated Zn and ZH in combination did not have an additive effect on<em> β</em>2-AR function as indicated by cAMP concentrations.
