Insulin-like growth factor I and glucagon-like peptide-2 responses to fasting followed by controlled or ad libitum refeeding in rats

2008 ◽  
Vol 294 (4) ◽  
pp. R1175-R1184 ◽  
Author(s):  
David W. Nelson ◽  
Sangita G. Murali ◽  
Xiaowen Liu ◽  
Matthew C. Koopmann ◽  
Jens J. Holst ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Glucose Transporter 1 ◽  
Factor I ◽  
Igf I ◽  
Ad Libitum ◽  
Glucagon Like Peptide ◽  
Growth Factor I ◽  
Mucosal Growth

Luminal nutrients stimulate structural and functional regeneration in the intestine through mechanisms thought to involve insulin-like growth factor I (IGF-I) and glucagon-like peptide-2 (GLP-2). We investigated the relationship between IGF-I and GLP-2 responses and mucosal growth in rats fasted for 48 h and then refed for 2 or 4 days by continuous intravenous or intragastric infusion or ad libitum feeding. Fasting induced significant decreases in body weight, plasma concentrations of IGF-I and bioactive GLP-2, jejunal mucosal cellularity (mass, protein, DNA, and villus height), IGF-I mRNA, and ileal proglucagon mRNA. Plasma IGF-I concentration was restored to fed levels with 2 days of ad libitum refeeding but not with 4 days of intravenous or intragastric refeeding. Administration of an inhibitor of endogenous GLP-2 (rat GLP-23–33) during ad libitum refeeding partially attenuated mucosal growth and prevented the increase in plasma IGF-I to fed levels; however, plasma GLP-2 and jejunal IGF-I mRNA were restored to fed levels. Intragastric refeeding restored intestinal cellularity and functional capacity (sucrase activity and sodium-glucose transporter-1 expression) to fed levels, whereas intravenous refeeding had no effect. Intestinal regeneration after 4 days of intragastric or 2 days of ad libitum refeeding was positively associated with increases in plasma concentrations of GLP-2 and jejunal IGF-I mRNA. These data suggest that luminal nutrients stimulate intestinal growth, in part, by increased expression of both GLP-2 and IGF-I.

Blood Plasma Concentrations of Insulin-like Growth Factor-I (IGF-I) in Resting Standardbred Horses

2002 ◽  
Vol 163 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Z.J. Champion ◽  
B.H. Breier ◽  
W.E. Ewen ◽  
T.T. Tobin ◽  
P.J. Casey
Keyword(s):  
Growth Factor ◽  
Blood Plasma ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

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

1990 ◽  
Vol 124 (1) ◽  
pp. 151-158 ◽  
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

scholarly journals 21. Plasma concentrations of insulin-like growth factor-I (IGF-I) and resumption of cyclicity in pasture-fed dairy cows

2003 ◽  
Vol 15 (9) ◽  
pp. 21
Author(s):  
F. Y. Obese ◽  
T. E. Moyes ◽  
C. S. Pino ◽  
C. R. Stockdale ◽  
K. L. Macmillan ◽  
...  
Keyword(s):  
Growth Factor ◽  
Dairy Cows ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, insulin-like growth factor-I and growth of lambs

1991 ◽  
Vol 128 (2) ◽  
pp. 181-186 ◽  
Author(s):  
J. J. Bass ◽  
J. M. Oldham ◽  
S. C. Hodgkinson ◽  
P. J. Fowke ◽  
H. Sauerwein ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Growth Factor ◽  
Plasma Glucose ◽  
Specific Binding ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

ABSTRACT The effect on young lambs of 0·25 mg recombinant bovine GH (bGH)/kg per day on plasma concentrations of insulin-like growth factor-I (IGF-I), glucose, specific hepatic GH binding and body composition changes was examined at two levels of nutrition (lucerne pellets; 3 and 1·7% of body weight/day). Lambs on low levels of nutrition had low plasma IGF-I (P < 0·001). Plasma concentrations of IGF-I were increased by bGH treatment at both levels of nutrition, with the high nutrition group showing the greatest IGF-I response after 3 and 40 days of bGH treatment. Plasma glucose, after 40 days, was higher overall (P < 0·05) in lambs on high nutrition. bGH treatment increased plasma glucose, with the response being greater in the well-fed lambs. Specific binding of GH to liver membranes was highest in lambs on high nutrition and on bGH treatment; no significant interaction between nutrition and bGH treatment was detected, indicating that specific binding of GH was increased proportionally by bGH at both nutritional levels. The major change in body composition was the reduced level of fatness in lambs treated with bGH. There was no significant effect of bGH on body weight although bGH treatment tended to increase weight gain of well-fed lambs and decreased weight loss of poorly nourished lambs. The results show that, although there was a significant (P < 0·05) bGH/nutrition interaction for IGF-I there was no such interaction for body weight/components or specific GH binding to the liver. The results indicate that an increase in plasma IGF-I does not necessarily result in increases in growth or changes in carcass composition. Journal of Endocrinology (1991) 128, 181–186

Increased secretion of insulin-like growth factor I into milk of cows treated with recombinantly derived bovine growth hormone

1989 ◽  
Vol 56 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Colin G. Prosser ◽  
Ivan R. Fleet ◽  
Anthony N. Corps
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Milk Yield ◽  
Plasma Concentrations ◽  
Significant Proportion ◽  
Bovine Growth Hormone ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

SummarySix lactating, non-pregnant Jersey cows were given subcutaneous injections of recombinantly derived bovine growth hormone for 7 d. Milk yield was increased by 4·5 kg/d on d 7, compared with the average yield of 10·7 ± 0·4 kg/d (mean ± s. e. m.) for the 7d preceding treatment. Concentrations of insulin-like growth factor I (IGF-I) in the milk increased from 0·44 ± 0·04 nmol/1 (mean ± s. e. m.) during the 7 d preceding treatment to 1·6 ± 0·2 nmol/1 on d 7 of treatment. Taking the increase in milk yield into account the total increase in the secretion of IGF-I into milk of one udder half was 6-fold. Plasma concentrations of total IGF-I rose from 15·5 + 1·3 nmol/1 (mean ± s. e. m.) on the day preceding treatment to 56·9 ± 3·6 nmol/1 (mean ± s. e. m.) on d 7 of treatment. Mammary plasma flow increased from 1·6 ± 0·09 to 2·2 ± 0·06 1/min udder half over the same time. Estimates of the amount of IGF-I that reached the mammary gland gave values of 24 and 116 nmol/min udder half before and during treatment respectively. IGF-I in milk of treated cows was associated predominantly with proteins ranging from 40000 to 150000 mol. wt, but a significant proportion (19%) of the total IGF-I was present in the free unbound form. IGF-I crosslinking studies revealed the presence in milk of one specifically labelled band at 31000 mol. wt.

Growth and serum thyroid hormone and insulin-like growth factor I (IGF-I) responses to natural passive immunization against somatostatin in the lamb

1993 ◽  
Vol 73 (3) ◽  
pp. 509-516 ◽  
Author(s):  
A. G. Van Kessel ◽  
R. S. Korchinski ◽  
B. Laarveld
Keyword(s):  
Growth Rate ◽  
Growth Factor ◽  
Thyroid Hormone ◽  
Serum Insulin ◽  
Passive Immunization ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Ad Libitum ◽  
Growth Factor I

The colostral transfer of maternal humoral immunity against somatostatin (SRIF) was examined as a mechanism of improving growth performance of the lamb. Lambs were the offspring of 15 ewes actively immunized against an SRIF-ovalbumin conjugate (SI; 14 male, 7 female) and of 13 ewes actively immunized against ovalbumin (C; 10 male, 5 female). At 5 d of age, lambs were removed from the ewes and received a 50:50 mixture of whole cow's milk and milk replacer ad libitum. At 46 d of age lambs were weaned and provided with an 18% crude protein pelleted grower ration ad libitum. Lamb weight was recorded and blood samples were obtained at regular intervals from 5 to 46 d of age and at 102 d of age. From 5 to 46 d of age, immunization increased growth rate of male (P < 0.001) but not female lambs. Serum thyroxine (T4) was lower (P < 0.001) in male than in female lambs. Serum triiodothyronine (T3) was higher (P < 0.05) in SI male than in C male lambs. SI female lambs initially demonstrated higher serum T3 levels than C female lambs, but this effect reversed after 19 d of age. Serum insulin-like growth factor I (IGF-I) levels were higher (P = 0.08) in SI than in C lambs without significant influence of sex. From 46 to 102 d of age, somatostatin immunization increased growth rate of male (P = 0.08) but not female lambs. Serum levels of T4, T3 and IGF-I at 102 d of age were not affected by immunization. Passive immunization against SRIF through colostral transfer of immunity may improve growth rate of the lamb via an influence on thyroid hormone metabolism. Key words: Sheep, somatostatin, immunoneutralization. growth, thyroid, IGF-I

scholarly journals Metabolic response of sheep skin to a chronic infusion of a variant of insulin-like growth factor I

1995 ◽  
Vol 308 (2) ◽  
pp. 411-418 ◽  
Author(s):  
J E Hocking Edwards ◽  
S K Khalaf ◽  
B R Sinclaire ◽  
J Lee ◽  
C G Prosser ◽  
...  
Keyword(s):  
Amino Acids ◽  
Growth Factor ◽  
Plasma Concentrations ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Wool Production ◽  
Factor I ◽  
Igf I ◽  
Wool Follicle ◽  
Growth Factor I

The effects of a chronic (21-day) skin infusion of a variant of insulin-like growth factor I (IGF-I) (long-Arg3-IGF-I; LR3IGF-I) on short-term (48 h) responses of skin metabolism and 21-day plasma hormone concentration, wool-follicle characteristics and wool production were investigated in well-fed castrated Romney sheep. A bilateral arteriovenous preparation was used to infuse LR3IGF-I continuously into the skin on one abdominal flank and saline into the other abdominal flank of six sheep; a further six sheep had one flank infused with saline (controls). LR3IGF-I caused an initial (4-24 h) reduction in the plasma concentrations of amino acids, especially tyrosine, valine and lysine, and, after 24 h, significant (P < 0.05) reductions in blood oxygen and plasma glucose concentrations. After 4 h of LR3IGF-I infusion, there was a significant increase in blood flow (P < 0.05) and oxygen uptake (P < 0.05), and net uptake of amino acids [which was significant (P < 0.05) for valine and phenylalanine] by the LR3IGF-I-infused skin was increased. Total uptake of phenylalanine for skin protein synthesis, measured using [3H]phenylalanine uptake, was also significantly increased after 4 and 24 h of infusion. After 48 h of infusion all LR3IGF-I-dependent measurements of metabolic parameters had fallen to preinfusion values. By day 7 of the 21-day infusion there was a significant (P < 0.05) decrease in circulating endogenous IGF-I in plasma of treated sheep compared with that of control sheep, followed by a significant (P < 0.05) increase between day 7 and 21. Plasma insulin levels followed a similar pattern. There was no change at any stage of infusion in IGF-binding proteins in the plasma of the two LR3IGF-I-infused sheep tested, and it is concluded that LR3IGF-I caused a down-regulation of the type-I IGF-I receptors followed by a rise in endogenous IGF-I concentration consequent on lack of feedback regulation. After 21 days of infusion there was no effect of LR3IGF-I on wool-follicle-bulb-cell mitotic rate, bulb diameter or wool production.(ABSTRACT TRUNCATED AT 400 WORDS)

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