Localization of sodium-potassium adenosine triphosphatase in sheep myocardium by immunoelectron microscopy

Immunohistochemical localization of sodium and potassium dependent adenosine triphosphatase (Na,K-ATPase) employing polyclonal antibodies was carried out on sheep myocardium. The tissue was fixed with glutaraldehyde or a paraformaldehyde/lysine/periodate combination fixative and embedded in different embedding media. Ultrathin sections were labeled with rabbit anti-sheep Na,K-ATPase antiserum followed by sheep anti-rabbit immunoglobulin complexed with colloidal gold. Glycol methacrylate embedded tissue provided good structural preservation and showed specific immunohistochemical labeling. Analysis of the gold particle distribution showed a significantly higher number of Na,K-ATPase immunoreactive sites associated with cell membrane and T-tubules.