title: Response of leptin mRNA to 24-h food deprivation and refeeding is influenced by age in rats.
abstract: To obtain an insight into the influence of aging on leptin gene expression, the responses of leptin mRNA in retroperitoneal and epididymal adipose tissues and plasma leptin concentrations to 24-h food deprivation and refeeding were examined in 2-, 10- and 24-month-old normal rats. The basal level of leptin gene expression in retroperitoneal adipose tissue was significantly higher in 10- and 24-month-old rats than that in 2-month-old rats, while the level in epididymal adipose tissue was highest in 10-month-old rats for all three age groups. The basal concentrations of plasma leptin was significantly higher in 10- and 24-month-old rats than those in 2-month-old rats. The 24-h food deprivation was followed by a significant reduction in leptin mRNA expression in both retorperitoneal and epididymal adipose tissues for all three age groups. The leptin gene expression was restored to control levels 24 h following refeeding in the 2- and 10-month-old rats, but failed to be restored in the 24-month-old rats. In addition, the time course of recovery for leptin mRNA expression by refeeding to the control levels differed between the retroperitoneal and the epididymal adipose tissue in 2- and 10-month-old rats. The concentrations of plasma leptin 24 h following refeeding were compatible with the leptin mRNA levels in adipose tissues in three age groups. These results suggest that the expression of the leptin gene in response to food-deprivation and refeeding is influenced by an animal's age and that this expression is different for different regions of white adipose tissue.
authors.affiliation: Department of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603, Tokyo, Japan. shinya@mms.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Shibasaki
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: K
authors.initials: K
authors.lastname: Shima
authors.forename: I
authors.initials: I
authors.lastname: Wakabayashi
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001835:Body Weight; D004435:Eating; D005508:Food Deprivation; D015870:Gene Expression; D020738:Leptin / Q000235:genetics*; D008297:Male; D009929:Organ Size; D012333:RNA, Messenger; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D020738:Leptin; D012333:RNA, Messenger