Methyl mercury decreases the eggshell thickness and inhibits the Ca2+ uptake in a homogenate of the eggshell gland mucosa and its subcellular fractions from the domestic fowl.

In the domestic fowl 20 mg of methyl mercuric chloride (MeHg) in a single oral dose given a day before egg-laying reduced the eggshell index by 35% and decreased the Ca content of the eggshell by 31% compared with those in the eggs laid on the previous days. The plasma concentration of Ca was reduced by MeHg by 50% in comparison with controls. The Ca concentration in the shell gland mucosa was not decreased by MeHg in relation to the control value. The rate of ATP-dependent Ca2+ binding by the homogenate of the mucosa was reduced by 33% by MeHg in relation to the control rate. The activity of Ca2+-Mg2+-ATPase was not changed.