Fig. 3.

Zinc retention is higher in the milk of Zip3-null mice. Wild-type and Zip3-null mice [Zip3 KO (knockout)] were removed from their pups for 6 h and were then returned and allowed to nurse for 30 min to eliminate pooled milk from the mammary gland alveoli. Anesthetized dams were given an injection of 0.9% saline ip containing 25 nmol Zn (as ZnCl₂) and 1 μCi ⁶⁵Zn, and milk was then collected 1 h later (10 min collection). The entire mammary glands were dissected and weighed, and the radioactivity in the milk (A) and mammary glands (B) was measured in a gamma scintillation counter. Data represent mean ± SD Zn retained/g (n = 5 or 6 dams/group). *Significant effect of genotype, P < 0.05. Milk was gently collected from wild-type and Zip3-null mice after oxytocin injection, and the Zn concentration was measured by atomic absorption spectroscopy (C). Data represent mean ± SD Zn concentration, n = 6 dams/group. *Significant effect of genotype, P < 0.05.