Caffeine administered during pregnancy augments subsequent lactation in mice.

Mice were administered caffeine (500 mg/liter of drinking water) from d 1 until d 18 of pregnancy. Before and after receiving caffeine, mice were given distilled water for drinking, as were controls. Litter size, birth weight, and offspring survival were not affected by caffeine, but litter weight on d 15 of lactation was increased by caffeine 84.0 +/- 3.1 g (n = 8) in controls vs 98.3 +/- 3.7 g (n = 7) in caffeine-treated mice (P less than .05). Mammary gland cell number, measured by the DNA content of mammae, was increased by giving caffeine during pregnancy (P less than .05). On d 18 of pregnancy, mammary DNA was .47 +/- .07 mg (n = 6) in controls vs .71 +/- .11 mg (n = 6) in caffeine-treated mice. On d 15 of lactation, mammary DNA was .96 +/- .12 mg (n = 8) in control vs 1.26 +/- .11 mg (n = 7) in caffeine-treated mice. RNA increased (P less than .05) parallel to DNA. In additional experiments, litters were cross-fostered and standardized to eight pups per litter. Mice were bred and caffeine was administered as described previously. At birth, eight pups from mice treated with caffeine or as controls during the preceding pregnancy were fostered to a control or caffeine-treated mother. In these experiments, litter weight on d 15 of lactation was 82 g for control litters nursing control mothers, 84 g for caffeine litters nursing control mothers, 96 g for control litters nursing caffeine mothers, and 99 g for caffeine litters nursing caffeine mothers (n = 7 per groups, pooled SE = +/- 3.4 g).(ABSTRACT TRUNCATED AT 250 WORDS)