RESUMO
BACKGROUND: In humans with pheochromocytomas (PCCs), targeted metabolomics is used to determine the catecholamine phenotype or to uncover underlying pathogenic variants in tricarboxylic acid (TCA) cycle genes such as succinate dehydrogenase subunits (SDHx). HYPOTHESIS/OBJECTIVES: To analyze catecholamine contents and TCA cycle metabolites of PCCs and normal adrenals (NAs). ANIMALS: Ten healthy dogs, 21 dogs with PCC. METHODS: Prospective observational study. Dogs diagnosed with PCC based on histopathological and immunohistochemical confirmation were included. Tissue catecholamine contents and TCA metabolites in PCCs and NAs were measured by liquid chromatography with mass spectrometry or electrochemical detection. RESULTS: Compared to NAs, PCCs had significantly higher tissue proportion of norepinephrine (88% [median: range, 38%-98%] vs 14% [11%-26%]; P < .001), and significantly lower tissue proportion of epinephrine (12% [1%-62%] vs 86% [74%-89%]; P < .001). Pheochromocytomas exhibited significantly lower fumarate (0.4-fold; P < .001), and malate (0.5-fold; P = .008) contents than NAs. Citrate was significantly higher in PCCs than in NAs (1.6-fold; P = .015). One dog in the PCC group had an aberrant succinate : fumarate ratio that was 25-fold higher than in the other PCCs, suggesting an SDHx mutation. CONCLUSIONS AND CLINICAL IMPORTANCE: This study reveals a distinct catecholamine content and TCA cycle metabolite profile in PCCs. Metabolite profiling might be used to uncover underlying pathogenic variants in TCA cycle genes in dogs.
RESUMO
BACKGROUND: Options for treatment of diabetes mellitus in cats are limited to insulin injections and monitoring for hypoglycemia. HYPOTHESIS: Once daily sodium-glucose cotransporter-2 inhibitor velagliflozin PO is noninferior to insulin injections. ANIMALS: Client-owned diabetic cats (127 safety; 116 efficacy assessment). METHODS: Prospective, randomized (1 mg/kg velagliflozin), positive controlled (titrated Caninsulin), open label, noninferiority field trial, comparing number of cats with treatment success in ≥1 clinical variable and ≥1 glycemic variable (margin Δ: 15%) on Day 45; secondary endpoints included glycemic and clinical assessments during 91 days. RESULTS: On Day 45, 29/54 (54%) velagliflozin-treated cats and 26/62 (42%) Caninsulin-treated cats showed treatment success, demonstrating noninferiority (difference -11.8%; upper 1-sided 97.5% confidence interval, -∞ to 6.3%). By Day 91, quality of life (QoL), polyuria, and polydipsia had improved in 81%, 54% and 61% (velagliflozin); on blood glucose (BG) curves, mean BG was <252 mg/dL in 42/54 (78%; velagliflozin) and 37/62 (60%; Caninsulin); minimum BG was <162 mg/dL in 41/54 (76%; velagliflozin) and 41/62 (66%; Caninsulin); serum fructosamine was <450 µmol/L in 41/54 (76%; velagliflozin) and 38/62 (61%; Caninsulin). Velagliflozin's most frequent adverse events were loose feces/diarrhea (n = 23/61, 38%), positive urine culture (n = 19/61, 31%), and nonclinical hypoglycemia (BG <63 mg/dL; n = 8/61, 13%); Caninsulin's: clinical and nonclinical hypoglycemia (n = 35/66, 53%), positive urine culture (n = 18/66, 27%), and loose feces/diarrhea (n = 10/66, 15%). Diabetic ketoacidosis occurred in 4/61 (7%; velagliflozin) and 0/66 (Caninsulin). CONCLUSIONS AND CLINICAL IMPORTANCE: Once daily oral administration of velagliflozin was noninferior to insulin injections, showed good QoL and glycemia without clinical hypoglycemia.