abnormal kidney collecting duct morphology abnormal kidney collecting duct epithelium morphology 2012-11-30T03:40:18Z MP:0011843 MPheno.ontology any structural anomaly of the simple cuboidal epithelium lining the lumen of kidney collecting ducts; the mature and differentiated CD epithelium comprises two unique cells types with principal cells responsible for vasopressin-regulated water reabsorption, and intercalated cells regulating acid-base homeostasis; injury to the epithelium is believed to cause epithelial cells to acquire mesenchymal characteristics via epithelial-mesenchymal transition (EMT), a process through which tubular epithelial cells may transform into interstitial fibroblasts and promote renal fibrosis csmith