Nerve growth factor in mouse milk during early lactation: lack of dependency on submandibular salivary glands.

Using a specific and sensitive nerve growth factor radioimmunoassay we show measurable quantities of beta nerve growth factor in mouse milk during the period of early lactation. Partial purification by cationic exchange resin yielded a preparation which exhibited biological activity in a PC-12 cell bioassay system. Submandibular-sublingual sialoadenectomy had no influence on the breast milk NGF concentrations. These results support the presence of bioactive NGF in mouse milk during early lactation, but do not clarify the source.