| Metabolic and endocrine changes have been documented in canine patients with critical illness and neoplasia. The first part of the study investigated endogenous protein synthesis (PSR), urinary loss of nitrogen, glucose flux, resting energy expenditure (REE), and respiratory quotient (RQ) in fifteen dogs with osteosarcoma (OSA) and 11 healthy female beagle dogs using stable isotope tracer (15N-glycine, 6,6-deuterium-glucose) and indirect calorimetry techniques. Endogenous protein synthesis (PSR), urinary loss of nitrogen, and glucose flux were calculated using lean body mass values obtained from a dual energy x-ray absorptiometry examination performed on each patient while under general anesthesia. Dogs with OSA had statistically higher REE in the pre-, but not post-operative time periods. There was no significant difference in RQ from dogs with OSA before or after surgery and control dogs. Post-operatively, dogs with OSA had significantly lower rates of PSR, higher urinary loss of nitrogen, and greater glucose flux than the control dogs, indicating alterations in nitrogen balance and carbohydrate flux.; Thirty-six dogs with a variety of critical illnesses and neoplasia (6 sepsis, 5 trauma, 12 surgery, 13 neoplasia) before and after 48 hours of supplemental enteral feeding with or without additional supplemental L-glutamine powder (0.24 g/kg/day) were entered into the second part of the study. Endogenous thyroid stimulating hormone (eTSH), total thyroxine (T4) and ACTH stimlulation tests using 0.25 mg/patient IV Cosyntropin® were measured before and after feeding. Stable isotope tracer analyses were performed before and after 48 hours of enteral feeding. A p-value of p < 0.05 was set as a level of significance. Euthyroid sick syndrome was observed in 41.6% of patients before feeding, and 60% of patients after feeding. No significant difference in adrenocortical function was observed in any disease category. Endogenous protein synthesis was not statistically lower in any disease category pre- or post-feeding. Patients with sepsis had higher PSR after supplemental feeding. Overall, urinary nitrogen loss statistically decreased post-feeding. No significant difference was observed in glucose flux in any disease pre- or post-feeding. Glutamine supplementation had no significant effect on PSR, urinary loss of nitrogen, glucose flux, or hormonal axes in any disease category. |
