Surfactant Proteins A and D in the Seminal Plasma of Stallions

We have previously shown that surfactant protein (SP)-A and SP-D are present in the stallion's genital system. The aim of the present study was to evaluate the expression and presence of SP-A and SP-D in the seminal plasma and accessory sex glands of stallions. We characterized further the SP-A and SP-D in the seminal plasma of stallions by western blotting and immunohistochemically in accessory sex glands. On one-dimensional SDS-PAGE electrophoresis and western blots, bands for SP-A (34 kDa) and SP-D (43 kDa) in seminal plasma and accessory sex gland tissue extracts were detected. The similarity between biochemical properties (relative molecular masses) of SP- A and SP-D in accessory sex glands and seminal plasma imply that SP-A and SP-D proteins are also present in the seminal plasma and accessory sex glands of stallions.