Although it has been reported that hormones or chemicals, which increse in intracellular cAMP, produced Mg2+ release from the heart, it is not well characterized whether a specific Mg2+ exchanger is involved in cAMP-induced Mg2+ efflux in themammalian hearts In this work, we studied the relationship between the increase in intracellular cAMP and ion transport system on Mg2+ regulation in the perfused rat heart and isolated myocytes. The Mg2+ content in the perfusate and supernatant were measured by atomic absorption spectrophotometer. The addition of membrane permeable cAMP analogue to the perfused hearts and myocytes. cAMP-induced Mg2+ efflux was ingibited by H7, benzamil or imipramine in the perfused hearts and myocytes, but not by EIPA. We confirmed that a significant Mg2+ efflux was induced by an increase in intracellular cAMP in the hearts and myocytes. The cAMP-induced increase of Mg2+ efflux in the hearts may be involved in ion transport system(Na+-Ca2+ and Na+-Mg2+ exchanger)

Magnesium (Mg2+) plays an important role in the regulation of a range of intracellular processes. Regulation of extracellular Mg2+ contents was studied in the anesthetized Sprague-Dwley (SD) rats. Animals were injected intraperitoneally with sodium nitrite (NaNO2), and circulating Mg2+([Mg2+]c) was observed in animals injected with NaNO2 at a dose of 10mg/kg or higher. Pretreatment with methylene blue preventd the NaNO2-induced increse in [Mg2+]c.[Mg2+]c displayed an inverse linear correlation with hemoglobin and exponential correlation during NaNO2 injection. Injection of KCN or rotenone also induced an increase in [Mg2+]c. An increase in [Mg2+]c was observed when respiration rate was reduced from 100/min (140ml/min) to 10/min (14ml/min) during 30 min. These results indicate that changes in [Mg2_]c inversely reflect alteration of ATP in a model of metabolic inhibition

Objective: The study was carried out to develop a wet litter model with magnesium chloride to assess the effectiveness of a polyherbal formulation (PHF) on growth performance, litter and cecal moisture (LCM) level, cecal consistency (CC) score, and footpad lesions (FPLs) score in Ross 308 broiler chickens. Materials and Methods: 1,200 one-day-old chicks were assigned into five groups: normal control, negative control [NTC; treated with 1.7% magnesium chloride hexahydrate (MgCl2.6H2O)], and three treatment groups, T1, T2, and T3, where 750, 1,000, and 2,000 gm/ton of PHF, respectively, were supplemented. All the groups were fed a basal diet until day 7. However, the NTC and treat¬ment groups were fed a diet with MgCl2 from days 8 to 42. Results: The addition of MgCl2 for 35 days worsened the growth performance traits in broilers and induced wet litter problems (FPL, high LCM, and poor CC) in the NTC group. However, PHF (750, 1,000, and 2,000 gm/ton) ameliorated the negative effect of a diet with MgCl2 on growth perfor¬mance and wet litter problems, but a better response with respect to LCM and CC was observed in 2,000 gm/ton of PHF group, followed by that in 1,000 gm/ton of PHF group and 750 gm/ton of PHF group on day 42. Conclusion: The wet litter broiler model was developed through excessive feeding of MgCl2, which caused the performance parameters to worsen and the emergence of problems associated with the wet litter. Supplementation with PHF ameliorated these problems and, therefore, it can be used for the management of wet litter in poultry. [J Adv Vet Anim Res 2019; 6(4.000): 536-543]