Siddiqui R A, Blair H T, McCutcheon S N, Mackenzie D D, Gluckman P D, Breier B H
Department of Animal Science, Massey University, Palmerston North, New Zealand.
J Endocrinol. 1990 Jan;124(1):151-8. doi: 10.1677/joe.0.1240151.
A study was conducted to investigate developmental patterns of plasma concentrations of insulin-like growth factor-I (IGF-I), body growth and body composition in mice from lines selected for seven generations on the basis of low (L) or high (H) plasma IGF-I, and in a random-bred control (C) line. Litter size was standardized to eight individuals with equal sex ratios (as far as possible) within 48 h of birth. Pups were weaned at an average of 21 days and separated on the basis of sex. Blood samples were collected from one male and one female of each litter on days, 21, 42, 63 and 105 for analysis of plasma concentrations of IGF-I. The animals were then killed and analysed for water, fat and crude protein content. The plasma concentration of IGF-I was influenced by line (P less than 0.05) but not by sex. Significant (P less than 0.001) differences in liveweight between mice from L and H lines were first evident at 21 days of age. From 28 until 105 days of age the H line was significantly (P less than 0.001) heavier than both L and C lines, but differences between C and L lines were inconsistent and mostly non-significant. The growth velocity of the H line was significantly greater than that of C or L lines between 14 and 42 days of age, but differences in growth velocities of C compared with L lines were generally non-significant.(ABSTRACT TRUNCATED AT 250 WORDS)
一项研究旨在调查基于低（L）或高（H）血浆胰岛素样生长因子-I（IGF-I）选择了七代的品系小鼠以及随机繁殖对照（C）品系小鼠的血浆IGF-I浓度、身体生长和身体组成的发育模式。在出生后48小时内，将窝仔数标准化为8只个体，且尽可能保持性别比例相等。幼崽平均在21日龄断奶，并按性别分开。在第21、42、63和105天从每窝中采集一只雄性和一只雌性的血样，用于分析血浆IGF-I浓度。然后处死动物，分析其水分、脂肪和粗蛋白含量。血浆IGF-I浓度受品系影响（P<0.05），但不受性别影响。L系和H系小鼠之间的体重差异在21日龄时首次显著（P<0.001）。从28日龄到105日龄，H系小鼠显著（P<0.001）比L系和C系小鼠重，但C系和L系之间的差异不一致，且大多不显著。在14至42日龄期间，H系小鼠的生长速度显著高于C系或L系小鼠，但C系与L系小鼠生长速度的差异通常不显著。（摘要截断于250字）
