Avaliação da absorção de ocitocina sintética aplicada em diferentes formulações pela via vaginal em novilhas girolando

Abstract

The aim of this study was to test the feasibility of vaginal route in order to apply oxytocin in female bovines using specific formulations. The oxytocin was used in both its injectable form (as a comparison standard) and associated with absorption enhancers. Seven formulations were produced: oxytocin plus water; oxytocin plus polyvinyl alcohol 4% W/V; oxytocin plus carboxy methyl cellulose 2% W/V; oxytocin plus glycerin 2% V/V; oxytocin plus dimethyl sulfoxide 10% V/V; oxytocin plus propylene glycol 25% V/V and oxytocin plus tween80 10% V/V, containing all 5 IU/ml of oxytocin. The experimental design was made in an 8x8 latin square (eight days, eight treatments and eight cycling heifers). The formulations were delivered in vaginal route and the injectable oxytocin was applied intravenously, all of them having 10 IU of oxytocin. Blood samples (n=7) were collected from each animal, the first at time 0, prior to the administration of the treatment, and the following every three minutes until 18 minutes. Oxytocin was extracted from plasma and measured using the commercial kit Oxytocin EIA. The responses were evaluated using the non-parametric statistic test method by Kruskal Wallis. A statistical difference was observed between times 0 and 12 (p<0,05) for the oxytocin plus glycerin formulation, showing that absorption did occur. Therefore, the outcomes revealed that this formulation had been absorbed, even though it does not suppress the need for further research before it can be effectively used in female bovine management.