title: Distribution and function of recombinant endothelial nitric oxide synthase in transplanted hearts.
abstract: Introducing recombinant genes into donor hearts may offer a therapeutic intervention that could potentially attenuate the complications of heart transplantation, including rejection, infection and accelerated atherosclerosis. In the cardiovascular system, reduced bioactivity of endothelial nitric oxide is a feature of atherosclerosis and vascular injury. Nitric oxide is an arterial vasodilator that also inhibits proliferation of vascular smooth muscle cells and platelet aggregation. Experiments were designed to determine the distribution of adenoviral-mediated transfer of recombinant endothelial nitric oxide synthase gene (eNOS) and the effect of recombinant gene expression on the function of transplanted hearts. Adenoviral vectors for (a) bovine eNOS (AdeNOS) or (b) beta-galactosidase (AdLacZ; control) were infused into two groups (n = 12, per group) of explanted rat hearts. The transduced hearts were then implanted heterotopically into the abdomen of syngeneic recipient rats. After four days, the hearts were excised and examined for distribution and function of the recombinant genes. Polymerase chain reaction (PCR) verified the presence of the recombinant eNOS gene in eNOS-transduced but not in beta-galactosidase-transduced hearts; reverse transcriptase-PCR identified mRNA for eNOS in AdeNOS-transduced hearts. NOS activity (conversion of tritiated L-arginine to citrulline) was greater in homogenates of AdeNOS-compared to AdLacZ-transduced hearts. Positive immunoreactivity for eNOS was present in cardiomyocytes predominantly in eNOS-transduced hearts. Myocardial contractility and coronary blood flow, as determined using a Langendorff preparation, were not different between hearts transduced with AdeNOS or AdLacZ. These results suggest that, up to four days post transplantation, adenoviral-mediated transfer of eNOS into transplanted hearts is possible. However, expression of the recombinant protein did not result in measurable changes in myocardial contractility or coronary perfusion.
authors.affiliation: Department of Surgery, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
authors.forename: J
authors.initials: J
authors.lastname: Yap
authors.forename: T
authors.initials: T
authors.lastname: O'Brien
authors.forename: C
authors.initials: C
authors.lastname: Pellegrini
authors.forename: D A
authors.initials: DA
authors.lastname: Barber
authors.forename: H D
authors.initials: HD
authors.lastname: Tazelaar
authors.forename: S R
authors.initials: SR
authors.lastname: Severson
authors.forename: V M
authors.initials: VM
authors.lastname: Miller
authors.forename: C G
authors.initials: CG
authors.lastname: McGregor
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002417:Cattle; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics; D016027:Heart Transplantation; D008297:Male; D009200:Myocardial Contraction; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D010477:Perfusion; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D001616:beta-Galactosidase