Direct infusion of a variant of insulin-like growth factor-I into the skin of sheep and effects on local blood flow, amino acid utilization and cell replication

1993 ◽  
Vol 139 (3) ◽  
pp. 463-472 ◽  
Author(s):  
P. M. Harris ◽  
B. W. McBride ◽  
M. P. Gurnsey ◽  
B. R. Sinclair ◽  
J. Lee
Keyword(s):  
Blood Flow ◽  
Amino Acid ◽  
Growth Factor ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Amino Acid Utilization ◽  
Igf I ◽  
Growth Factor I

ABSTRACT In vivo effects of local infusion of a variant of insulin-like growth factor-I (IGF-I), long-R3-IGF-I, into the skin were investigated using six conscious sheep with food available ad libitum. An artery and vein on the abdominal flank of each animal, as well as the saphenous artery, were catheterized so that infusion of isotopically labelled amino acids, with or without IGF-I, could be used to determine amino acid uptake by arteriovenous difference in combination with blood flow determined by dye dilution. Measurements were made on each animal prior to IGF-I infusion, at hourly intervals for the 4 h of IGF-I infusion into the skin artery, then 2 and 4 h after IGF-I infusion ceased. Numbers of cells replicating in the bulbs of wool follicles in the IGF-I-infused area and in the skin on the contralateral side of each animal were measured after labelling with 5-bromo-2′-deoxyuridine. IGF-I caused a significant increase in the skin blood flow (P<0·05), utilization of oxygen (P<0·05), uptake of cysteine (P<0·05) and phenylalanine (P<0·001), and the rate of utilization of cysteine (P<0·05) for protein synthesis. IGF-I increased amino acid uptake regardless of whether the skin was in negative or positive amino acid balance prior to infusion. During the recovery period amino acid utilization by skin returned towards preinfusion levels. No effects of IGF-I were found on replicating cell numbers in the bulbs of wool follicles. Journal of Endocrinology (1993) 139, 463–472

Effects of insulin, insulin-like growth factor-I (IGF-I) and progesterone on glucose and amino acid uptake in Xenopus laevis oocytes

1991 ◽  
Vol 75 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Pierre Hainaut ◽  
Aline Kowalski ◽  
Yannick Le Marchand-Brustel ◽  
Sophie Giorgetti ◽  
Nadine Gautier ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Xenopus Laevis ◽  
Amino Acid Uptake ◽  
Xenopus Laevis Oocytes ◽  
Acid Uptake ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Insulin-like growth factor I (IGF-I) stimulates glucose and amino acid uptake in cultured glomerular mesangial cells

1991 ◽  
Vol 5 (2-3) ◽  
pp. 184-185 ◽  
Author(s):  
Masaki Togawa ◽  
Ryuichi Kikkawa ◽  
Masakazu Haneda ◽  
Daisuke Koya ◽  
Naoki Horide ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Mesangial Cells ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Insulin Like Growth Factor ◽  
Glomerular Mesangial Cells ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Effect of insulin-like growth factor-I (IGF-I) on transplacental transfer of amino acid to fetus

Placenta ◽  
1994 ◽  
Vol 15 (7) ◽  
pp. A48
Author(s):  
T. Mimuro ◽  
M. Iwashita ◽  
M. Kudo ◽  
Y. Takeda
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Transplacental Transfer ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Increase in milk secretion and mammary blood flow by intra-arterial infusion of insulin-like growth factor-I into the mammary gland of the goat

1990 ◽  
Vol 126 (3) ◽  
pp. 437-443 ◽  
Author(s):  
C. G. Prosser ◽  
I. R. Fleet ◽  
A. N. Corps ◽  
E. R. Froesch ◽  
R. B. Heap
Keyword(s):  
Blood Flow ◽  
Mammary Gland ◽  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Milk Secretion ◽  
Arterial Infusion ◽  
Factor I ◽  
Lactating Goats ◽  
Igf I ◽  
Growth Factor I

ABSTRACT The close-arterial infusion of free insulin-like growth factor-I (IGF-I; 1·1 nmol/min) for 6 h into the pudic artery supplying one mammary gland of lactating goats caused a 25±6% (mean ± s.e.m., n = 6) increase in the rate of milk secretion of that gland. The increase in the rate of milk secretion in the adjacent non-infused gland (14±4%) was not significantly different from that observed during saline infusion (4±5%). Blood flow to the infused gland was increased from 378±26 ml/min 1 h before to 487±56 ml/min approximately 5 h after the start of the infusion of IGF-I, declining to 420±44 ml/min approximately 2 h after the end of the infusion. The total concentration of IGF-I (free and bound) in milk of the infused gland was significantly higher than that of the non-infused gland. The concentrations of IGF-I in carotid arterial plasma samples increased during IGF-I infusion from a mean value of 32±2 nmol/l before to a maximum of 49±3 nmol/l 5 h after the infusion commenced. Circulating concentrations of total IGF-I declined slowly after the infusion with an estimated half-life of 5 h. Infusion of saline alone did not alter mammary blood flow or the concentration of total IGF-I in milk or plasma. The results indicate that the infusion of free IGF-I into the mammary arterial supply enhances milk secretion and mammary blood flow in intact, conscious goats. The more pronounced effect in the infused compared with the non-infused gland suggests that free IGF-I acts directly on the mammary gland. The response in the non-infused gland was attenuated presumably due to association of IGF-I with plasma binding proteins during recirculation. Journal of Endocrinology (1990) 126, 437–443

scholarly journals dl-Methionine supplementation in a low-fishmeal diet affects the TOR/S6K pathway by stimulating ASCT2 amino acid transporter and insulin-like growth factor-I in the dorsal muscle of juvenile cobia (Rachycentron canadum)

2019 ◽  
Vol 122 (07) ◽  
pp. 734-744 ◽  
Author(s):  
Yuanfa He ◽  
Shuyan Chi ◽  
Beiping Tan ◽  
Xiaohui Dong ◽  
Qihui Yang ◽  
...  
Keyword(s):  
Weight Gain ◽  
Amino Acid ◽  
Growth Factor ◽  
Mrna Levels ◽  
Insulin Like Growth Factor ◽  
Rachycentron Canadum ◽  
Dorsal Muscle ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

AbstractAn 8-week feeding experiment was conducted to investigate the effects of dl-methionine (Met) supplementation in a low-fishmeal diet on growth, key gene expressions of amino acid transporters and target of rapamycin (TOR) pathway in juvenile cobia, Rachycentron canadum. Seven isonitrogenous and isolipidic diets were formulated, containing 0·72, 0·90, 1·00, 1·24, 1·41, 1·63 and 1·86 % Met. Weight gain and specific growth rates increased gradually with Met levels of up to 1·24 % and then decreased gradually. In dorsal muscle, mRNA levels of ASCT2 in the 1·00 % Met group were significantly up-regulated compared with 0·72, 1·63, and 1·86 %. The insulin-like growth factor-I (IGF-I) mRNA levels in the dorsal muscle of fish fed 1·00 and 1·24 % Met were higher than those in fish fed other Met levels. In addition, fish fed 1·24 % Met showed the highest mRNA levels of TOR and phosphorylation of TOR on Ser2448. The phosphorylation of ribosomal p70-S6 kinase (S6K) on Ser371 in the dorsal muscle of fish fed 1·86 % Met was higher than those in the 0·72 % group. In conclusion, straight broken-line analysis of weight gain rate against dietary Met level indicates that the optimal Met requirement for juvenile cobia is 1·24 % (of DM, or 2·71 % dietary protein). Met supplementation in a low-fishmeal diet increased cobia growth via a mechanism that can partly be attributed to Met’s ability to affect the TOR/S6K signalling pathway by enhancing ASCT2 and IGF-I transcription in cobia dorsal muscle.

Several insulin-like growth factor-I analogues and complexes of insulin-like growth factors-I and -II with insulin-like growth factor-binding protein-3 fail to mimic the effect of growth hormone upon lactation in the rat

1994 ◽  
Vol 140 (2) ◽  
pp. 211-216 ◽  
Author(s):  
D J Flint ◽  
E Tonner ◽  
J Beattie ◽  
M Gardner
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Milk Production ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Litter Weight ◽  
Igf I ◽  
Growth Factor I ◽  
Igfbp 3

Abstract Lactation was suppressed in rats using a combined treatment of bromocriptine (to reduce prolactin concentrations) and a specific antiserum to rat GH administered twice daily for 2 days. When milk production had ceased, as determined by litter weight loss and the absence of milk in the stomachs of pups, attempts were made to reinitiate lactation using prolactin, GH, insulin-like growth factor-I (IGF-I) precomplexed to recombinant human IGF-binding protein-3 (hIGFBP-3) or IGF-I plus IGF-II precomplexed to hIGFBP-3. Despite the fact that all treatments except prolactin led to increases in serum IGFs and IGFBP-3, only prolactin and GH provoked the reinitiation of milk production as determined by increased litter weight gain, milk in the stomach of pups and a significant increase in the weight of the mammary glands. Since the mammary gland has been shown to produce IGFBPs which may inhibit IGF action we also tested three IGF-I analogues, R3-IGF-I, Long-IGF-I and Long-R3-IGF-I. R3-IGF-I has a single amino acid substitution (Glu to Arg) at position 3 whereas Long-IGF-I has a 13 amino acid N-terminal extension. These modifications dramatically reduce the ability of these analogues to bind to IGFBPs although they remain active at the IGF-I receptor. Such IGF analogues would therefore be expected to be active irrespective of the production of inhibitory IGFBPs. However, none was effective in reinitiating lactation, even at doses which have been shown to be biologically effective in terms of nitrogen retention. We therefore conclude that, despite the fact that GH induces increases in serum IGF-I, IGF-II and IGFBP-3 when administered to lactating rats, the combination of all of these factors fails to reinitiate lactation. The biological significance of these changes and the mechanism by which GH stimulates milk secretion, when there appear to be no GH receptors on mammary epithelial cells, remain unclear, although the fact that both GH and prolactin were able to prevent reductions in DNA content of the gland suggest that regulation of apoptosis may be involved. Journal of Endocrinology (1994) 140, 211–216

Purification, amino acid sequences and assay cross-reactivities of porcine insulin-like growth factor-I and -II

1989 ◽  
Vol 122 (3) ◽  
pp. 681-687 ◽  
Author(s):  
G. L. Francis ◽  
P. C. Owens ◽  
K. A. McNeil ◽  
J. C. Wallace ◽  
F. J. Ballard
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Mammalian Species ◽  
Cross Reactivity ◽  
Porcine Insulin ◽  
Amino Acid Sequences ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

ABSTRACT Porcine insulin-like growth factor-I (IGF-I) and IGF-II have been characterized to help define the roles of these peptides in the growth process. The amino acid sequence of porcine IGF-I was found to be identical to the human and bovine peptides. Porcine IGF-II was more similar to human IGF-II than to forms of this growth factor in other mammalian species, differing only in the replacement of asparagine for serine at residue 36. In a biological assay that measures the stimulation of protein synthesis in rat L6 myoblasts, porcine IGF-I was approximately ninefold more potent than porcine IGF-II or bovine IGF-II, while recombinant human IGF-I and IGF-II had half the potency of the respective natural peptides. Porcine and recombinant human IGF-I showed essentially equal competition for binding in a human IGF-I radioimmunoassay while between 0·6 and 1·5% cross-reactivity was observed with human, bovine or porcine IGF-II. A receptor assay for IGF-II demonstrated similar potencies for the three IGF-II peptides, while the cross-reactivity of recombinant human IGF-I was only 0·05%. Porcine IGF-I exhibited a higher cross-reactivity, presumably due to very slight contamination with IGF-II. Journal of Endocrinology (1989) 122, 681–687

Sign in / Sign up

Export Citation Format

Share Document