Lipolytic effect of in vivo leptin administration on adipocytes of lean and ob/ob mice, but not db/db mice.
The present study has examined the effect of a single in vivo intraperitoneal injection of the adipocyte-derived hormone, leptin, on the in vitro lipolysis of fat cells of different types of mice. Administration of 1 and 10 mg leptin per kg body weight to ob/ob mice significantly increased (P < 0.0001) the basal lipolytic activity compared to ob/ob mice receiving vehicle solution (phosphate-buffered saline, PBS). The highest leptin dose tested (10 mg/kg body weight) produced a threefold increase in basal lipolysis. In lean mice administration of 10 mg leptin per kilogram of body weight produced an increase in basal lipolysis of 52.7% (P < 0.01). However, in db/db mice none of the three leptin doses injected had a significant effect on the lipolytic activity of adipocytes relative to basal lipolysis observed in db/db mice injected with PBS only. These data provide evidence for a lipolytic effect of leptin on white adipose tissue, which operates independently from changes in food intake, body weight, and the size of the fat stores.
Frühbeck
G
G
Department of Physiology and Nutrition, University of Navarra, Pamplona, 31080-, Spain.
Aguado
M
M
Gómez-Ambrosi
J
J
Martínez
J A
JA
D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D020738:Leptin; D008066:Lipolysis / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D009765:Obesity / Q000378:metabolism*; D011506:Proteins / Q000008:administration & dosage / Q000494:pharmacology*
D020738:Leptin; D011506:Proteins