And then, there's chief cells, which secrete an enzyme called pepsinogen.

然后，主细胞分泌一种叫做胃蛋白酶原的酶。

Hydrochloric acid and pepsinogen are useful for digestion, but they can be quite aggressive for the delicate mucosa.

盐酸和胃蛋白酶原有助于消化，但它们对脆弱的粘膜很有侵袭性。

And maybe more importantly, when the hydrochloric acid is combined with pepsinogen, an inactive enzyme that's secreted by another kind of stomach cell called chief cells, the mixture creates the protein-digesting enzyme pepsin.

也许更重要的是，当盐酸与胃蛋白酶原结合时，胃蛋白酶原是一种非活性酶，由另一种被称为主细胞的胃细胞分泌，混合物产生蛋白质消化酶胃蛋白酶。