鉄欠乏状態又は加齢が血漿レプチン濃度と腹腔内脂肪量との関係に及ぼす影響

An investigation on the effects of age and the relationship between plasma leptin concentration and fat weight in iron deficiency anemia was conducted on male Wistar rats, age 3 weeks weighting 40 to 50 g and 15 weeks weighting 330 to 350 g. The rats were fed either an iron deficient diet containing about 3 ppm Fe or a control diet containing about 358 ppm Fe in the form of ferric citrate and distilled water ad libitum for 8 weeks. The animals are divided into 4 groups with their diet intakes and body weights measured weekly. Plasma leptin concentration and blood characteristics were measured in 8 weeks after initial observation were conducted. Body weights, diet intake, RBC, Hb, Hct, MCV and serum Fe of the group kept on the iron deficient diet from 3 weeks old were less than those of the group kept on the control diet of the same aged group. Similarly, body weights, MCV and Fe level of the group kept on an iron deficient diet from 15 weeks old (15w-iron) were less than that of the group kept on the control diet of the same aged group (15w-cont). There was no change in the diet intake, RBC, Hb and Hct between the 15w-iron and 15w-cont groups. However, plasma leptin concentration showed significant correlation with fat weight in both groups (R²=0.804) with a regression line of y=0.59x-1.96, with the slope its line in the group kept from 15 weeks old being sharper than that in the group kept from 3 weeks. Present results suggest that the responsiveness of plasma leptin concentration to fat weight becomes augmented as the rats' age. [Jpn J Physiol 55 Suppl:S217 (2005)]