Cutaneous anaphylactoid reaction to polyoxyethylene hydrogenated castor oil in dogs.

BACKGROUND: Polyoxyethylene hydrogenated castor oil (HCO ethoxylates) is a nonionic surfactant used as an excipient for ointments and injections in human and veterinary drugs. Several polyethylene glycol (PEG) derivatives can be obtained depending on the number of moles of ethylene oxide (EO). HCO ethoxylates have the potential to cause anaphylactoid reactions. There is little published information about these types of reactions in dogs. OBJECTIVE: To determine the potential for HCO-ethoxylate-containing drugs to cause anaphylactoid reactions in dogs, employing intradermal testing (IDT) with various concentrations of HCO ethoxylates (HCO-25, -40, -60 and -80). ANIMALS: Four healthy male laboratory dogs. MATERIALS AND METHODS: We performed IDT with drugs containing HCO ethoxylates and HCO ethoxylates alone to determine threshold concentrations. The IDT scores and threshold concentrations were compared. Analysis of skin biopsies from IDT sites was used to measure the percentage of degranulated mast cells. The effect of histamine at IDT sites was investigated by pre-treatment with an antihistamine. RESULTS: All HCO-ethoxylate-containing drugs caused a wheal-and-flare reaction. The threshold concentrations (0.001% and 0.00001%) of each HCO-ethoxylate depended on the number of moles of EO (p < 0.05). Mast cell degranulation was enhanced by all HCO ethoxylates. The HCO-60-induced reaction was suppressed by an oral antihistamine. CONCLUSIONS AND CLINICAL RELEVANCE: The threshold concentration can serve as a consideration for developing safe new drug formulations and for clinical decision-making around using drugs containing PEG derivatives. IDT is useful to predict the risk of adverse effects. Antihistamines could demonstrate a prophylactic effect.

Relationships between the expression of adipose genes and profiles of hospitalized dogs.

Obesity is one of the risk factors for the onset of various metabolic diseases in dogs. Energy expenditure in brown/beige adipocytes, which is partially regulated by the bone morphogenetic protein (BMP) pathway, is a key factor determining systemic energy balance. Here, we examined gene expression in the fat depots of 129 hospitalized dogs, and the relationship between the relative levels of gene expression and profiles of dogs. We evaluated the expression levels of 23 genes such as regulatory genes of adipocyte differentiation and function, adipokines, genes related to brown adipogenesis and uncoupling protein (Ucp), and genes involved in BMP signaling. A reliable equation of multiple regression was not obtained to explain the body condition score (BCS), which is an index of adiposity. Positive relationships were detected between the expression levels of many genes, except for Ucp1 or Ucp3. BCS was found to increase with age. BCS was negatively correlated to the expression levels of Pparγ and Fasn, and positively correlated to Leptin and Opn3 expression. Aging decreased the expression levels of genes related to adipocyte differentiation and function (Pparγ, Fabp4, Fasn, Hsl, and Insr) and Adipoq. In addition, age was negatively correlated with the expression of genes involved in brown adipogenesis and BMP signaling components (Prdm16, Bmp4, Alk3, Actr2a, and Actr2b). In contrast, the expression levels of Leptin and Ucp2 were found to increase with age. The present study clarifies BCS- and age-related gene expressions in the adipose tissue, which potentially contribute to elucidating the etiology of canine obesity.