AJP - Gastrointestinal and Liver Physiology, Vol 244, Issue 4 449-G455, Copyright © 1983 by American Physiological Society
Different effect of starvation on activity of sucrase and lactase in rat jejunoileum
K. Yamada, T. Goda, S. Bustamante and O. Koldovsky
Activities of lactase and sucrase were determined in proximal, middle, and
distal thirds of the jejunoileum of 15-wk-old male rats starved for 1, 2,
and 3 days and in rats fed a high-sucrose diet for 24 h after 3 days of
starvation. Sucrase activity (expressed per tissue protein or DNA as well
as per intestinal segment) showed a progressive decrease during starvation
in proximal and middle segments but not in the distal segment. Lactase
activity expressed per tissue protein or DNA in all segments increased
significantly. This was obviously due to the loss of tissue protein and DNA
because total lactase activity per segment did not change. Refeeding the
sucrose diet produced an increase of sucrase activity without influencing
lactase activity. In serial tissue homogenate of jejunal villus-crypt
columns prepared using cryostat sectioning, it was shown that, during
starvation, activity of lactase (specific and total) increased in the upper
and middle villus. Sucrase activity (specific and total) during starvation
decreased and after refeeding increased in the lower and middle villus.
