scholarly journals Sexual dimorphism for growth in Muscovy ducks and changes in insulin-like growth factor I (IGF-I), growth hormone (GH) and triiodothyronine (T3) plasma levels

2001 ◽  
Vol 41 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Elisabeth Baéza ◽  
John Williams ◽  
Daniel Guémené ◽  
Michel J. Duclos
Keyword(s):  
Growth Hormone ◽  
Sexual Dimorphism ◽  
Growth Factor ◽  
Plasma Levels ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Muscovy Ducks ◽  
Growth Factor I

Effects of two oral contraceptives on plasma levels of insulin-like growth factor I (IGF-I) and growth hormone (hGH)

Contraception ◽  
2000 ◽  
Vol 62 (5) ◽  
pp. 259-269 ◽  
Author(s):  
A Balogh ◽  
E Kauf ◽  
R Vollanth ◽  
G Gräser ◽  
G Klinger ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Oral Contraceptives ◽  
Plasma Levels ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Progestin treatment in the dog I. Effects on growth hormone, insulin-like growth factor I and glucose homeostasis

1994 ◽  
Vol 131 (4) ◽  
pp. 413-421 ◽  
Author(s):  
PJ Selman ◽  
JA Mol ◽  
GR Rutteman ◽  
A Rijnberk
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Glucose Homeostasis ◽  
Plasma Levels ◽  
Insulin Like Growth Factor ◽  
Treatment Groups ◽  
Factor I ◽  
Igf I ◽  
Progestin Treatment ◽  
Growth Factor I

Selman PJ, Mol JA, Rutteman GR, Rijnberk A. Progestin treatment in the dog. I. Effects on growth hormone, insulin-like growth factor I and glucose homeostasis. Eur J Endocrinol 1994;131:413–21. ISSN 0804–4643 The effects of two synthetic progestins, medroxyprogesterone acetate (MPA) and proligestone (PROL), on the release of growth hormone (GH) and glucose metabolism were studied in two groups of eight ovariohysterectomized dogs. Eight injections of long-acting progestins were administered at 3-week intervals. Recovery was studied in four dogs of each treatment group in the 6 months following cessation of progestin administration. Treatment with both MPA and PROL resulted in similar increases in plasma levels of GH and insulin-like growth factor I (IGF-I). The GH responses to both clonidine and growth hormone-releasing hormone became impaired. In neither treatment group did the elevated plasma GH levels decrease after administration of the synthetic somatostatin analogue SMS 201-995. The size and shape of the pituitary gland were not changed by progestin treatment. After cessation of progestin administration, basal plasma levels of GH and IGF-I did not return to pretreatment values. The GH response to growth hormone-releasing hormone remained impaired for at least 6 months after the last progestin administration. In both treatment groups, glucose homeostasis was sustained initially by increased insulin production. Prolonged treatment with MPA and PROL resulted in glucose intolerance. No amelioration was observed during the recovery period in either group. A small number of dogs developed diabetes mellitus. In more than 50% of the dogs in both treatment groups small mammary tumours developed. The recently discovered local production of GH probably played a role in mammary tumorigenesis. It is concluded that treatment with MPA and PROL results in similar increases in plasma levels of GH and IGF-I and leads to a similar degree of insulin resistance. The elevated GH levels can be neither stimulated nor inhibited, which is a feature compatible with autonomous secretion. These results are consistent with the recent finding of a progestin-induced ectopic production of GH in the mammary gland of the dog. JA Mol, Department of Clinical Sciences of Companion Animals, Utrecht University, PO Box 80. 154, 3508 TD Utrecht, The Netherlands

Effect of insulin-like growth factor I and/or growth hormone on diaphragm of malnourished adolescent rats

1997 ◽  
Vol 82 (4) ◽  
pp. 1064-1070 ◽  
Author(s):  
Michael I. Lewis ◽  
Thomas J. Lorusso ◽  
Mario Fournier
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Fiber Type ◽  
Fatigue Properties ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Fiber Size ◽  
Igf I ◽  
Adolescent Rats ◽  
Growth Factor I

Lewis, Michael I., Thomas J. LoRusso, and Mario Fournier.Effect of insulin-like growth factor I and/or growth hormone on diaphragm of malnourished adolescent rats. J. Appl. Physiol. 82(4): 1064–1070, 1997.—Young growing animals appear to have significantly reduced “nutritional reserve” to short periods of unstressed starvation compared with adults, with resultant growth arrest and/or atrophy of diaphragm (Dia) muscle fibers. The aim of this study was to assess in an adolescent rat model of acute nutritional deprivation (ND; 72 h) the impact of insulin-like growth factor I (IGF-I), with or without added growth hormone (GH), on the cross-sectional areas (CSA) of individual Dia muscle fibers. Five groups were studied: 1) control (Ctr); 2) ND; 3) ND given IGF-I (ND/IGF-I); 4) ND given GH (ND/GH); and 5) ND given a combination of IGF-I and GH (ND/IGF-I/GH). IGF-I was given by a subcutaneously implanted osmotic minipump (200 μg/day), whereas GH was administered twice daily by a subcutaneous injection (250 μg every 12 h). Isometric contractile and fatigue properties of the Dia were determined in vitro. Forces were normalized for muscle CSA (i.e., specific force). Dia fiber type proportions were determined histochemically, and fiber CSA was quantified by using a computer-based image-processing system. Total serum IGF-I concentrations were significantly reduced in ND and ND/GH animals, compared with Ctr, and elevated in the groups receiving IGF-I. The provision of growth factors did not alter the contractile or fatigue properties of ND animals. Dia fiber type proportions were similar among the groups. In ND animals, there was a significant reduction in the CSA of types I, IIa, IIx, and IIc Dia fibers compared with Ctr. The administration of IGF-I alone or in combination with GH to ND animals significantly diminished the reduction in Dia fiber size. GH alone had no effect on Dia fiber size in ND animals. We conclude that with acute ND the peripheral resistance to the action of GH appears to be bypassed by the administration of IGF-I alone or in combination with GH.

Variation in plasma levels of insulin-like growth factor-I (IGF-I) in lingcod: relationships among season, size, and gonadal steroids

2010 ◽  
Vol 158 (2) ◽  
pp. 439-450 ◽  
Author(s):  
Anne H. Beaudreau ◽  
Kelly S. Andrews ◽  
Donald A. Larsen ◽  
Graham Young ◽  
Brian R. Beckman
Keyword(s):  
Growth Factor ◽  
Plasma Levels ◽  
Gonadal Steroids ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Insulin-like growth factor I exerts growth hormone- and insulin-like actions on human muscle protein metabolism

1994 ◽  
Vol 267 (2) ◽  
pp. E331-E336 ◽  
Author(s):  
D. A. Fryburg
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Muscle Protein ◽  
Muscle Metabolism ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Muscle Protein Metabolism ◽  
Growth Factor I ◽  
Forearm Muscle

The effect of a 6-h intra-arterial infusion of recombinant human (rh) insulin-like growth factor I (IGF-I) on forearm muscle metabolism was studied in 19 postabsorptive subjects. Forearm glucose, lactate, and phenylalanine (Phe) balances, as well as estimates of protein degradation (Phe Ra) and synthesis (Phe Rd) were measured before and at 3 and 6 h into an infusion of rhIGF-I at a dose of 1.8 (n = 6), 6.0 (n = 8), or 10.0 (n = 5) micrograms.kg-1.h-1. In response to intra-arterial IGF-I, deep venous IGF-I rose by 55, 141, and 315%, respectively (all P < 0.01), and forearm blood flow accelerated by 75 (1.8 microgram), 213 (6.0 micrograms), and 159% (10.0 micrograms; all P < 0.02). No change in forearm glucose uptake was observed at the lowest dose, whereas four- to sixfold increases were observed at both the 6 and 10 micrograms.kg-1.h-1 doses (both P < 0.02). Forearm Phe balance shifted positively at all three doses by 27 +/- 6, 48 +/- 7, and 51 +/- 9 nmol.min-1 x 100 ml-1, respectively (all P < 0.01). At all three doses, Phe Rd increased comparably by 49-74% (all P < 0.05). At the 6.0 and 10.0 but not the 1.8 microgram.kg-1.h-1 dose, Phe Ra decreased by approximately 45% (P < 0.02). Forearm muscle metabolism was also studied in the contralateral non-IGF-infused arm at these three doses. Despite increases in deep venous IGF-I up to 517 ng/ml due to recirculating IGF-I (10.0 micrograms.kg-1.h-1 dose), contralateral forearm muscle glucose, lactate, or Phe handling did not change. In conclusion, intra-arterial IGF-I exhibits growth hormone-like effects at all doses tested, whereas the insulin-like effects are observed at higher doses; these effects appear dependent on the route of administration.

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