Allogenic myoblast transplantation in the rat anal sphincter

: To determine the feasibility of injecting rat myoblasts into the intact anal sphincter as a potential treatment for anal incontinence, and to detect transferred myoblast survival and integration.

: A pilot study using nonpregnant female Sprague Dawley rodents of 8 to 10 weeks of age. A biopsy of skeletal muscle was harvested from a study animal and recovered myoblasts were expanded in vitro over 10 days. Myoblasts were then tagged with a cytomegalovirus promoter to transduce green fluorescent protein (GFP) into the myoblasts. The cell aspirate was injected directly into the intact external anal sphincter using an electromyographic guidance. The animals received 1.5 or 4.5 × 10 cells of GFP-labeled myoblasts, dividing the dose between three injection sites. The remaining in vitro myoblasts were still viable 28 days post-harvest. Ten days after transplantation the anal sphincter complex was surgically extracted.

: The presence of GFP-labeled myoblasts was confirmed within the external anal sphincter.

: This demonstrates that myoblasts can be successfully extracted, cultivated in vitro, transplanted and will integrate into the host tissue.