Faculty of Veterinary Medicine University of Zagreb
Abstract
The effect of dehydration and rehydration was studied during winter and summer on solute loads and transfer function of kidney in healthy adult female dromedary camels. Kidney solute loads (KSLs) which included plasma loads (PL) and tubular loads (TL) were determined for glucose, proteins, urea, creatinine, sodium, potassium, chloride, calcium and phosphorus. The dehydration period was of 24 days in winter and 13 days in summer. Water was provided ad libitum during control and rehydration periods and was restricted
completely during dehydration period. The mean value of TFK during summer control was significantly (P≤0.05) lower than that in winter control. In winter the mean values of TFK during rehydration phases differed significantly (P≤0.05) from control values. A similar trend was observed during summer, except that the calculations for TFK could not be made at hour ½ and at hour 2 of rehydration since animals did not void urine. During dehydration periods in both seasons PL and TL mean values decreased significantly (P≤0.05) from respective control mean values. It was concluded that during dehydration reduction in kidney solute loads was indicative of the water conservation ability of camels because reduced plasma loads and tubular loads resulted in trapping of constituents in the plasma to hold more water.Istražen je učinak dehidracije i rehidracije u tijeku zime i ljeta na opterećenje tekućinom i prijenosnu sposobnost bubrega u zdravih ženki dvogrbe deve. Opterećenje obuhvaća plazmalno (PO) i tubularno (TO) opterećenje, a određivano je za glukozu, bjelančevine, mokraćevinu, kreatinin, natrij, kalij, klor, kalcij i fosfor. Razdoblje dehidracije trajalo je 24 dana zimi i 13 dana ljeti. Životinje su po volji pile vodu tijekom kontrolnoga i rehidracijskoga razdoblja, ali vodu nisu dobivale u tijeku dehidracijskoga razdoblja. Srednja vrijednost
prijenosne sposobnosti bubrega u tijeku ljetnih mjeseci bila je značajno niža (P≤0,05) u odnosu na zimsko kontrolno razdoblje. Zimi su se srednje vrijednosti prijenosne sposobnosti bubrega za vrijeme rehidracije značajno razlikovale u odnosu na kontrolne vrijednosti (P≤0,05). Sličan je trend zabilježen ljeti, osim što izračuni nisu mogli biti učinjeni sat i pol te dva sata nakon rehidracije, jer životinje nisu izlučivale mokraću. Srednje vrijednosti PO i TO bile su značajno manje u odnosu na kontrolu (P≤0,05) u tijeku dehidracijskoga razdoblja u oba godišnja doba. Zaključuje se da je smanjeno opterećenje bubrega u tijeku dehidracije dobar pokazatelj sposobnosti čuvanja vode s obzirom na to da smanjeno plazmalno i tubularno opterećenje dovodi do zadržavanja sastojaka u plazmi koji imaju sposobnost osmotskoga zadržavanja vode
