Is persistent mucus hypersecretion a feature of horses with heaves?
Horses with the disease heaves (equine COPD) have airway obstruction, which is a result of bronchospasm, thickening of the wall of the airway, and mucus accumulation. This project addresses the issue of mucus secretion. Mucus consists of a core protein to which is attached carbohydrate sidechains. We are determining if mucus hypersecretion continues even between bouts of acute airway obstruction that are induced by stabling. We are using a combination of morphometry, molecular biology, and immunological methods to quantify stored mucins, to examine gene expression, and to quantify secreted mucins. In horses with heaves, there is increased expression of genes that encode the mucin core protein and there are persistent alterations in mucus glycoproteins (the carbohydrates sidechains). The viscoelasticity of mucus is altered during acute bouts of heaves so that the mucus has a much reduced clearability 6-24 hours after heaves susceptible horses are stabled. These studies have been support
