Effects of administration of glucocorticoids and feeding status on plasma leptin concentrations in dogs.
OBJECTIVE
To investigate effects of short- and long- term administration of glucocorticoids, feeding status, and serum concentrations of insulin and cortisol on plasma leptin concentrations in dogs.


METHODS
20 nonobese dogs.


METHODS
For experiment 1, plasma leptin concentrations and serum concentrations of insulin and cortisol were monitored for 24 hours in 4 dogs administered dexamethasone (0.1 mg/kg, IV) or saline (0.9% NaCl) solution for fed and nonfed conditions. For experiment 2, 11 dogs were administered prednisolone (1 mg/kg, PO, q 24 h for 56 days [7 dogs] and 2 mg/kg, PO, q 24 h for 28 days [4 dogs]) and 5 dogs served as control dogs. Plasma leptin and serum insulin concentrations were monitored weekly.


RESULTS
For experiment 1, dexamethasone injection with the fed condition drastically increased plasma leptin concentrations. Furthermore, injection of saline solution with the fed condition increased plasma leptin concentrations. These increases in plasma leptin concentrations correlated with increases in serum insulin concentrations. Dexamethasone injection with the nonfed condition increased plasma leptin concentrations slightly but continuously. Injection of saline solution with the nonfed condition did not alter plasma leptin concentrations. For experiment 2, prednisolone administration at either dosage and duration did not alter plasma leptin concentrations in any dogs.


CONCLUSIONS
Dexamethasone injection and feeding increased plasma leptin concentrations in dogs. In addition, dexamethasone administration enhanced the effect of feeding on increases in plasma leptin concentrations. Daily oral administration of prednisolone (1 or 2 mg/kg) did not affect plasma leptin concentrations in dogs.
Nishii
Naohito
N
Department of Clinical Veterinary Medicine, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
Takasu
Masaki
M
Ohba
Yasunori
Y
Maeda
Sadatoshi
S
Kitoh
Katsuya
K
Ohtsuka
Yoshihiko
Y
Honjo
Tsutomu
T
Saito
Masayuki
M
Kitagawa
Hitoshi
H
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule / Q000662:veterinary; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D020738:Leptin / Q000097:blood*; D008297:Male; D011239:Prednisolone / Q000008:administration & dosage / Q000494:pharmacology*
D000893:Anti-Inflammatory Agents; D020738:Leptin; D003907:Dexamethasone; D011239:Prednisolone