Association of Insulin-Like Growth Factor-I (IGF-I) Gene Polymorphism with Serum IGF-I Concentration and Body Weight in Korean Native Ogol Chicken

ABSTRACT The effects of feed restriction and refeeding on ovarian and hepatic insulin-like growth factor-I (IGF-I) gene expression, systemic and ovarian IGF-I concentrations and on associated metabolic changes were measured in prepubertal gilts. Eleven pairs of littermate gilts (70·7 ± 4·7 kg) were placed on a maintenance level of feeding for 7 days (days 1–7). On day 8, littermates were either fed at a maintenance level of energy or fed to appetite for a further 6 days. Blood samples were taken on day 13 (07.00–16.00 h) to determine plasma insulin and IGF-I, and on day 14 (02.00–06.00 h) to determine plasma GH levels. Following slaughter on day 14, one ovary from each animal was retained to measure follicular fluid IGF-I and oestradiol concentrations. The remaining ovary and a sample of liver were retained for IGF-I mRNA analysis using a ribonuclease protection assay. Six days of refeeding significantly increased plasma IGF-I (P<0·005) and basal insulin (P<0·05) but there was no effect on plasma GH. Ovarian follicular volume and diameter were significantly larger after refeeding (P<0·05), with no effect on follicular fluid oestradiol concentrations. Mean follicular fluid IGF-I concentrations were unaffected by treatment. However, the relationships between individual follicular IGF-I concentrations, absolute follicular fluid IGF-I contents and follicle volume were affected by feeding level (P<0·05). Regression analysis of the same data also revealed that at this stage of maturity, small follicles had greater follicular fluid concentrations of IGF-I than larger follicles. Refeeding increased the amount of IGF-I mRNA in hepatic but not ovarian tissue. We conclude that there is differential regulation of the IGF-I gene in porcine hepatic and ovarian tissues, and that ovarian factors other than, or as well as, IGF-I are involved in the regulation of ovarian responses to refeeding. Journal of Endocrinology (1993) 139, 143–152

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Effects of full-length and truncated insulin-like growth factor-I on nitrogen balance and muscle protein metabolism in nitrogen-restricted rats

Journal of Endocrinology ◽

10.1677/joe.0.1280097 ◽

1991 ◽

Vol 128 (1) ◽

pp. 97-105 ◽

Cited By ~ 51

Author(s):

F. M. Tomas ◽

S. E. Knowles ◽

P. C. Owens ◽

L. C. Read ◽

C. S. Chandler ◽

...

Keyword(s):

Body Weight ◽

Growth Factor ◽

Muscle Protein ◽

Analysis Of Covariance ◽

High Dose ◽

Insulin Like Growth Factor ◽

Body Protein ◽

Factor I ◽

Igf I ◽

Growth Factor I

ABSTRACT The ability of insulin-like growth factor-I (IGF-I) to protect against losses of body protein during periods of dietary nitrogen restriction has been evaluated in young rats. Recombinant human IGF-I was administered by osmotic pumps at dose rates of 0, 1·2 or 2·9 mg/kg per day over a 7-day period beginning with the transfer of animals from an 18% to a 4% protein diet. A fourth group received the potent truncated IGF-I analogue, des(1–3)IGF-I, at a dose of 1·2 mg/kg per day over a comparable 7-day period. Plasma IGF-I levels were reduced by 60% following nitrogen restriction, a reduction that was partly prevented by IGF-I administration, especially at the higher dose, but not measurably by des(1–3)IGF-I. The major IGF-binding protein circulating in blood, IGFBP-3, demonstrated a similar pattern of change. A significant (P<0·05) protection of body weight was achieved in the low dose IGF-I and des(1–3)IGF-I groups, but only after differences in food intake had been eliminated by analysis of covariance. Nitrogen balances were not significantly different unless analysis of covariance was used to adjust for the nitrogen intakes, whereupon all treatment groups showed improved balance, especially the animals treated with the low IGF-I dose and des(1–3)IGF-I (both P<0·01). The rate of muscle protein breakdown calculated from the urinary excretion of 3-methylhistidine was not significantly altered by the treatments, but fell progressively throughout the 7 days. The fractional rate of muscle protein synthesis measured on the final day was increased by 31, 26 and 21% respectively by the low and high doses of IGF-I and by des(1–3)IGF-I. Organ weights (g/kg body weight) showed no effects of IGF-I treatment except for 16% increases in the weight of kidneys in the high dose IGF-I and the des(1–3)IGF-I groups. Carcass analyses demonstrated higher water and lower fat contents (all P< 0·01) in the same groups. These results suggest that exogenous IGF-I and especially des(1–3)IGF-I can partly protect body protein reserves during nitrogen restriction. Journal of Endocrinology (1991) 128, 97–105

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Commentary: A polymorphic CA repeat in the promoter region of the insulin-like growth factor I (IGF-I) gene

European Journal of Epidemiology ◽

10.1023/a:1023309321705 ◽

2002 ◽

Vol 18 (3) ◽

pp. 191-194 ◽

Cited By ~ 7

Author(s):

Ingrid Rietveld ◽

Joop A.M.J.L. Janssen ◽

Cornelia M. Van Duijn ◽

Steven W.J. Lamberts

Keyword(s):

Growth Factor ◽

Promoter Region ◽

Insulin Like Growth Factor ◽

Ca Repeat ◽

Factor I ◽

Igf I ◽

Growth Factor I ◽

I Gene

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Developmental patterns of plasma insulin-like growth factor-I (IGF-I) and body growth in mice from lines divergently selected on the basis of plasma IGF-I

Journal of Endocrinology ◽

10.1677/joe.0.1240151 ◽

1990 ◽

Vol 124 (1) ◽

pp. 151-158 ◽

Cited By ~ 19

Author(s):

R. A. Siddiqui ◽

H. T. Blair ◽

S. N. McCutcheon ◽

D. D. S. Mackenzie ◽

P. D. Gluckman ◽

...

Keyword(s):

Body Composition ◽

Body Weight ◽

Growth Factor ◽

Plasma Concentrations ◽

Body Growth ◽

Insulin Like Growth Factor ◽

Developmental Patterns ◽

Factor I ◽

Igf I ◽

Growth Factor I

ABSTRACT 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<0·05) but not by sex. Significant (P< 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< 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. Nose–anus length was significantly (P<0·01) affected by sex and line from 42 to 105 days of age, but anus–tail length was not affected by sex or line at any age. Effects of sex and line on empty (digesta-free) body weight and wet weights of carcass and skin plus viscera fractions followed a pattern similar to those of liveweights. The effects of sex and line on protein, water and fat content also paralleled their effects on body size. Differences between males and females, and between the lines, in amount of protein, water and fat could be entirely accounted for by the corresponding differences in body weight. It is concluded from these results that divergent selection on the basis of plasma IGF-I at 42 days of age resulted in lines of animals differing in plasma IGF-I from 21 days of age until maturity. These divergent concentrations of IGF-I are associated with differences between the lines in body growth, particularly during the period of accelerated growth at puberty, but not with changes in body composition. Journal of Endocrinology (1990) 124, 151–158

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