title: Uniform scale-independent gene transfer to striated muscle after transvenular extravasation of vector.
abstract: BACKGROUND
  The muscular dystrophies exemplify a class of systemic disorders for which widespread protein replacement in situ is essential for treatment of the underlying genetic disorder. Somatic gene therapy will require efficient, scale-independent transport of DNA-containing macromolecular complexes too large to cross the continuous endothelia under physiological conditions. Previous studies in large-animal models have revealed a trade-off between the efficiency of gene transfer and the inherent safety of the required surgical and pharmacological interventions to achieve this.
  
  
  RESULTS
  Rats and dogs underwent limb or hemibody isolation via atraumatic tourniquet placement or myocardial isolation via heterotopic transplantation. Recombinant adenovirus (10(13) particles per kilogram) or recombinant adeno-associated virus (10(14) genome copies/kg) encoding the lacZ transgene was delivered through pressurized venous infusion without pharmacological mediators. Muscle exhibited almost 100% myofiber transduction in rats and dogs by X-galactosidase staining and significantly higher beta-galactosidase levels compared with nonpressurized delivery. No significant difference was seen in beta-galactosidase levels between 100- or 400-mm Hg groups. The <50-mm Hg group yielded inhomogeneous and significantly lower transgene expression.
  
  
  CONCLUSIONS
  Uniform scale- and vector-independent skeletal and cardiac myofiber transduction is facilitated by pressurized venous infusion in anatomic domains isolated from the central circulation without pharmacological interference with cardiovascular homeostasis. We provide the first demonstration of uniform gene transfer to muscle fibers of an entire extremity in the dog, providing a firm foundation for further translational studies of efficacy in canine models for human diseases.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Leonard T
authors.initials: LT
authors.lastname: Su
authors.forename: Kapil
authors.initials: K
authors.lastname: Gopal
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Yin
authors.forename: Anthony
authors.initials: A
authors.lastname: Nelson
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Kozyak
authors.forename: James M
authors.initials: JM
authors.lastname: Burkman
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Mitchell
authors.forename: David W
authors.initials: DW
authors.lastname: Low
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bridges
authors.forename: Hansell H
authors.initials: HH
authors.lastname: Stedman
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics*; D004285:Dogs; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006321:Heart; D016027:Heart Transplantation / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D001616:beta-Galactosidase