Identification of haptoglobin as an endogenous inhibitor of prostaglandin H synthetase in the cytosol of sheep vesicular gland cells

: It was shown that sheep vesicular gland cytosol inhibits the peroxidase activity of prostaglandin H synthetase (PGHS). The degree of enzyme inactivation depends on cytosol concentration and incubation time. It was found that cytosol contains a glycoprotein, haptoglobin, which is one of the cytosolic basic components responsible for its ability to inhibit PGHS. Haptoglobin is supposed to participate in endogenous regulation of the PGHS activity in sheep vesicular glands.