AJP - Regulatory, Integrative and Comparative Physiology, Vol 253, Issue 3 434-R443, Copyright © 1987 by American Physiological Society
Behavioral and metabolic effects of sucrose-supplemented feeding in hyperactive rats
E. D. Hendley, L. H. Conti, D. J. Wessel, E. S. Horton and R. E. Musty
Two hyperactive rat strains [spontaneously hypertensive rats (SHR) and
SHR-Wistar-Kyoto cross (WK-HA)] and their nonhyperactive genetic control
strain (Wistar-Kyoto) were fed ad libitum sucrose-supplemented rat chow, or
chow alone in controls, to determine the effects of dietary sugar on
behavior. The diets were given either overnight (acute sugar) or for 14-18
days (chronic sugar), and testing was carried out on the morning after each
of the dietary schedules. The metabolic studies revealed significant
strain, sex, and age differences in appetite for sucrose, caloric intake,
postprandial plasma levels of glucose and insulin, and weight gain after
sucrose feeding. The findings indicate that sugar feeding led to increased
plasma glucose and insulin levels; however, total caloric intake was
decreased, and less weight gain was observed than in chow-fed controls,
particularly among the hyperactive strains. In behavioral tests, sugar
feeding did not alter spontaneous activity levels in any of the strains
after either acute or chronic diets. There were also no significant effects
of sucrose consumption on spatial learning and memory in a plus-shaped maze
as determined by use of a shock-avoidance paradigm. The only significant
behavioral effects of sucrose observed were an impairment in habituation
and distractibility among the WK-HA females, the most hyperactive group
among these strains.
