No abstract

The biological and psychological significance of oxytocin is increasingly recognized; however, reliable assays of oxytocin in biological samples have not been developed. We raised a new oxytocin polyclonal rabbit antibody against synthetic oxytocin. The affinity of antibodies to oxytocin was examined by a radio-immunoassay and compared with that of a previously validated antibody. One antibody showed affinity for oxytocin in the radio-immunoassay. We developed a solid-phase ELISA for oxytocin using this antibody and compared it with existing methods. The newly developed ELISA showed comparable results using urine samples but not using serum samples. These results indicate that the new ELISA is useful for urinary oxytocin; further modifications, such as different extraction methods, are needed for its application to serum oxytocin.

In humans, tear volume increases in emotional arousal. No studies have investigated the relationship of emotional arousal and tear volume in animals. We measured tear volume in dogs before and after reunion with their owners. Tear volume increased significantly during owner, but not familiar non-owner, reunions but not during reunions with familiar non-owners. When oxytocin instillation was applied to dogs, the tear volume increased, suggesting that oxytocin can mediate the emotion-induced tear secretion in dogs. When the photos of dog's face in which artificial tear was applied to the dog's eyes, the positive impression of these photo increased. These suggest that emotional tear can facilitate human-dog emotional connection.