Intracellular magnesium concentrations in dogs with gastric dilatation-volvulus

Objective-To quantify and compare intracellular magnesium concentrations (M g-i) in clinically normal dogs (control dogs) and dogs that have gastric di latation-volvulus (GDV dogs) and to determine whether there is a difference in Mg-i and serum magnesium concentrations (Mg-s) between GDV dogs with an d without cardiac arrhythmias. Animals-41 control dogs and 21 GDV dogs. Procedure-Rectus abdominis muscle specimens were obtained from control and GDV dogs for determination of Mg-i. Blood samples were obtained from GDV do gs for determination of Mg-s, and dogs were monitored for 48 hours for card iac arrhythmias. Muscle specimens were frozen at -40 C, oven dried at 95 C, and digested with concentrated nitric acid. Multielemental analyses were p erformed by simultaneous/sequential inductively coupled plasma-atomic emiss ion spectroscopy with fixed-cross flow nebulization. The Mg-i was standardi zed to sulfur content to correct for the amount of fat and fascia in the mu scle specimen. Mean (+/- SEM) values were recorded in parts per million (pp m). Results-There were no significant differences in Mg-i between control (627 +/- 11.1 ppm) and GDV (597 +/- 20.5 ppm) dogs, in Mg-i between GDV dogs wit h (590 +/- 34 ppm) and without (584 +/- 29 ppm) cardiac arrhythmias, and in Mg-s between GDV dogs with (1.77 +/- 0.26 ppm) and without (1.51 +/- 0.09 ppm) cardiac arrhythmias. There was no correlation between Mg-s and Mg-i (R -2=0.0001). Conclusions and Clinical Relevance-Results indicate that Mg depletion is no t pathophysiologically important in dogs with GDV and does not play a role in the cardiac arrhythmias detected in these patients.