Effects of litter size on protein, choline acetyltransferase (cat), and dopamine-beta-hydroxylase (DBH) of a mouse sympathetic ganglion.

Litters of 5, 10 and 17 pups were formed at birth. At 7, 14, 21, 28 and 60 days after birth mice were weighed and the cervical superior ganglia were examined for total protein and for CAT and DBH activities. At each age, the parameters examined were fitted into regression lines on the reciprocal of the litter size (L.S.R.); a highly positive correlation was found at each age between body weight and L.S.R., with maximum differences at weaning (day 21) followed by partial recovery after ad libitum feeding until day 60. A positive correlation was also found for total ganglion protein at days 21 and 28, with recovery practically completed at day 60. For CAT activity a positive correlation with L.S.R. appeared at day 14, with increasing coefficient and significance in later periods, until day 60. The temporal pattern of DBH activity for the 5-pup litter showed a peak at day 21, followed by a 35% decrease at day 28, with a steady level until day 60. A similar trend was observed for the 10- and 17-pup litters, but the peak occurred at day 28. Significant differences were found as early as day 7 between the 5- and the 17-pup litters, the maximum differences in the 3 experimental conditions being found at weaning, with a high and significant correlation coefficient, which persisted at day 60. Thus, the biochemical development and maturation of both presynaptic cholinergic nerve terminals and postsynaptic adrenergic neurones was evidently affected by the itter size during the suckling period, with persistent effects.