AJP - Regulatory, Integrative and Comparative Physiology, Vol 262, Issue 6 1000-R1005, Copyright © 1992 by American Physiological Society
Food deprivation and refeeding in the camel (Camelus dromedarius)
K. Dahlborn, S. Benlamlih, R. Zine-Filali, A. Gueroulali, J. Hossaini-Hilali and M. Oukessou
Department of Animal Physiology, Swedish University of Agricultural Sciences, Uppsala.
Camels thrive in arid and semiarid areas, although food and water
frequently are scarce. However, the mechanisms enabling camels to withstand
food deprivation are poorly understood. In this study four female camels
were totally deprived of food for 4 days. Their body weight decreased by
6%. Food deprivation caused no change in total plasma protein concentration
in the camel, indicating that no alterations in plasma volume occurred.
When the first meal was withheld water intake was unchanged. Next day the
camels showed signs of hydration with a decreased plasma Na+ concentration
and an increased excretion of diluted urine. In the afternoon water intake
decreased. Urine K+ excretion fell the first day and urine volume and Na+
excretion from the third day. No activation of the
renin-angiotensin-aldosterone system (RAAS) was observed. Plasma and urine
urea concentration increased during food deprivation. Plasma glucose
concentration and plasma cortisol and thyroxine levels did not change. Body
temperature decreased during food deprivation. After refeeding, total
plasma proteins increased temporarily by 12%, and a threefold increase in
RAAS was seen, implying that both plasma volume and RAAs changed rapidly.
Our results show that fluid balance was only slightly affected in the
food-deprived camel. We suggest that strategies for the camel to endure
food deprivation include maintenance of plasma volume and glucose
concentration and a lowering of the body temperature.
