AJP - Regulatory, Integrative and Comparative Physiology, Vol 248, Issue 2 181-R189, Copyright © 1985 by American Physiological Society
Differential effects of food restriction on pituitary-testicular function in mice
J. L. Blank and C. Desjardins
The reproductive responses of two species of wild rodents, house mice and
deer mice, were evaluated following a 30% reduction in food intake for 5
wk. These animal models were chosen as prototypes of other rodent species
because each employs unique functional adjustments when confronted with
reduced resources in their natural habitats. Modest inanition failed to
alter pituitary-testicular function in house mice; neither spermatogenesis
nor plasma concentrations of luteinizing hormone (LH) and testosterone were
modified. In sharp distinction, deer mice exposed to restricted food intake
showed significant reductions in plasma LH and testosterone and an
accompanying loss in spermatogenesis. Reduced food intake also caused
pronounced shifts in the temporal organization and amount of wheel-running
activity in both animal models, albeit in a dichotomous fashion. House mice
exhibited the same amount of wheel-running activity throughout inanition,
but the diel periodicity of locomotor behavior was shifted from the dark to
the light period. Deer mice, in comparison, significantly curtailed
wheel-running activity during the dark hours but ran in precise phase
relationship with the light-dark cycle. Taken together, our results
establish that the male reproductive system and its supporting
neuroendocrine and behavioral correlates can be disrupted by modest levels
of food restriction in certain animal models.
