Changes in insulin-like growth factor-1 and IGF-binding protein-3 in camel plasma during dehydration in the presence and absence of losartan

In the present study, the effect of 20 days of dehydration in the presence or absence of losartan (angiotensin II AT1 receptor antagonist) on insulin-like growth factor-1(IGF-1) and insulin-like growth factor-binding protein-3(IGFBP-3) in plasma of the one-humped camel was studied. Eighteen male camels, 3-4 years of age, were divided into three equal groups: control, dehydrated, and dehydrated-losartan-treated groups. The control camels were given food and water ad libitum. The two dehydrated groups underwent 20 days of water deprivation but were given food ad libitum. The dehydrated-losartan-treated camels were given losartan injection (Merck, USA), intravenously at a dose of 5 mg/kg body weight daily for 20 days. Our results demonstrated a progressive decrease in the circulating levels of IGF-1 and IGFBP-3 in the dehydrated and dehydrated-losartan-treated animals across dehydration compared to their basal levels and time-matched control. On day 5 of dehydration, the IGF-1 level in the losartan-treated group showed a decrease of 60 % and the dehydrated group showed 45 % decrease from their baseline levels and time-matched control. On day 10 the decrease in the losartan-treated animals reached 74 % and for the dehydrated was 62 %. On day 20 the decrease in the losartan-treated was 89 % and for the dehydrated reached 80 % from their baseline levels and time-matched control. Dehydration in the presence or absence of losartan caused a decrease in the circulating level of IGFBP-3. The decrement reached 26 % on day 10 and 20 for the treated camels, while the decrease for the dehydrated was 22 % on day 10 of dehydration and reached 29 % on day 20 compared to their baseline levels and time-matched control. In conclusion, dehydration alone, or in presence of Angiotensin II AT1 receptor blocker caused significant decrease in the circulating levels of IGF-1 and IGFBP-3 compared to their basal values and to time-matched controls. Losartan enhanced the effect of dehydration mainly in the early phase of dehydration for both parameters; albeit, no significant differences between the two dehydrated groups was observed. Finally, these findings suggest an essential role of IGF-1and IGFBP-3 in the dehydration state of these dromedarian camels.