Anabolic effects of insulin-like growth factor-I (IGF-I) and an IGF-I variant in normal female rats.

Tomas FM, Knowles SE, Chandler CS, Francis GL, Owens PC, Ballard FJ

The Journal of endocrinology1 Jun 1993Cited by 39 (Europe PMC)

PMID8371075DOI10.1677/joe.0.1370413PepBankPUB-08371075

Publisher page PubMedAsk about this study

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study6

3 results from studies that gave the peptide. No result from this study comes from people.

01AnimalAnimal study (in vivo)Efficacy outcome
In growing female rats, LR3IGF-I at 44 micrograms/day increased body weight gain to a similar extent as the highest IGF-I dose tested (278 micrograms/day), so it was substantially more potent than IGF-I.
In plain wordsIn growing female rats, a small dose of LR3IGF-I raised weight gain about as much as a much larger dose of IGF-I.
Peptide
IGF-1 LR3
Outcome
IncreaseBody weight gain
Study
ratn: not reported in source
Normal growing female rats
Comparator
IGF-I
Outcome group
Body weight · Metabolic and weight
Studied dose
44 micrograms/day · subcutaneous osmotic pump · 14 daysAs given in this study (rat).
Source sentences
Summary
LR3IGF-I, a variant of human IGF-I that contains an amino terminal extension peptide as well as glutamate-3 replaced by arginine and exhibits very weak binding to IGF-binding proteins, was substantially more potent than the natural growth factor, in the 44 micrograms/day of this peptide produced sim…
2 context sentences(design, population, supporting numbers)
Summary · context
The effects were dose-dependent, with the highest daily dose tested, 278 micrograms/day, producing 18-26% increases in these measurements.
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
Report a problemFND-0837107501
02AnimalAnimal study (in vivo)Efficacy outcome
In growing female rats, LR3IGF-I at 44 micrograms/day improved nitrogen retention similarly to the high IGF-I dose, so it was substantially more potent than IGF-I.
In plain wordsIn growing female rats, a small dose of LR3IGF-I improved nitrogen retention about as much as a much larger dose of IGF-I.
Peptide
IGF-1 LR3
Outcome
IncreaseNitrogen retention
Study
ratn: not reported in source
Normal growing female rats
Comparator
IGF-I
Outcome group
Body weight · Metabolic and weight
Studied dose
44 micrograms/day · subcutaneous osmotic pump · 14 daysAs given in this study (rat).
Source sentences
Summary
LR3IGF-I, a variant of human IGF-I that contains an amino terminal extension peptide as well as glutamate-3 replaced by arginine and exhibits very weak binding to IGF-binding proteins, was substantially more potent than the natural growth factor, in the 44 micrograms/day of this peptide produced sim…
2 context sentences(design, population, supporting numbers)
Summary · context
The effects were dose-dependent, with the highest daily dose tested, 278 micrograms/day, producing 18-26% increases in these measurements.
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
Report a problemFND-0837107502
03AnimalAnimal study (in vivo)Efficacy outcome
In growing female rats, LR3IGF-I at 44 micrograms/day improved food conversion efficiency similarly to the high IGF-I dose, so it was substantially more potent than IGF-I.
In plain wordsIn growing female rats, a small dose of LR3IGF-I improved food conversion about as much as a much larger dose of IGF-I.
Peptide
IGF-1 LR3
Outcome
IncreaseFood conversion efficiency
Study
ratn: not reported in source
Normal growing female rats
Comparator
IGF-I
Outcome group
Body weight · Metabolic and weight
Studied dose
44 micrograms/day · subcutaneous osmotic pump · 14 daysAs given in this study (rat).
Source sentences
Summary
LR3IGF-I, a variant of human IGF-I that contains an amino terminal extension peptide as well as glutamate-3 replaced by arginine and exhibits very weak binding to IGF-binding proteins, was substantially more potent than the natural growth factor, in the 44 micrograms/day of this peptide produced sim…
2 context sentences(design, population, supporting numbers)
Summary · context
The effects were dose-dependent, with the highest daily dose tested, 278 micrograms/day, producing 18-26% increases in these measurements.
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
Report a problemFND-0837107503

Studies that did not test the peptide alone3

In this study, IGF-1 LR3 was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking IGF-1 LR3.

04AnimalNot a test of IGF-1 LR3 aloneAnimal study (in vivo)Efficacy outcome
In growing female rats, IGF-I and LR3IGF-I together generally maintained body proportions at those existing when the experiment began.
In plain wordsIn growing female rats, the two IGF peptides together generally kept body proportions the same as at the start.
Peptide
IGF-1 LR3
Outcome
No significant changeOrgan weight and carcass composition
Study
ratn: not reported in source
Normal growing female rats
Outcome group
Body weight · Metabolic and weight
Source sentences
Summary
Organ weight and carcass composition measurements showed that the two IGF peptides generally maintained body proportions at those existing when the experiment began.
1 context sentence(design, population, supporting numbers)
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
In this study, IGF-1 LR3 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking IGF-1 LR3.
Report a problemFND-0837107504
05AnimalNot a test of IGF-1 LR3 aloneAnimal study (in vivo)Efficacy outcome
In growing female rats, IGF treatment (IGF-I and LR3IGF-I) slightly increased muscle protein synthesis.
In plain wordsIn growing female rats, IGF treatment slightly increased muscle protein synthesis.
Peptide
IGF-1 LR3
Outcome
IncreaseMuscle protein synthesis
Study
ratn: not reported in source
Normal growing female rats
Outcome group
Body weight · Musculoskeletal
Source sentences
Summary
Muscle protein synthesis and myofibrillar protein breakdown were both slightly increased by IGF treatment, so that the observed improvement in N retention could not be explained through protein accretion rates calculated from these measures.
1 context sentence(design, population, supporting numbers)
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
In this study, IGF-1 LR3 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking IGF-1 LR3.
Report a problemFND-0837107505
06AnimalNot a test of IGF-1 LR3 aloneAnimal study (in vivo)Efficacy outcome
In growing female rats, IGF treatment (IGF-I and LR3IGF-I) slightly increased myofibrillar protein breakdown.
In plain wordsIn growing female rats, IGF treatment slightly increased muscle protein breakdown.
Peptide
IGF-1 LR3
Outcome
IncreaseMyofibrillar protein breakdown
Study
ratn: not reported in source
Normal growing female rats
Outcome group
Body weight · Musculoskeletal
Source sentences
Summary
Muscle protein synthesis and myofibrillar protein breakdown were both slightly increased by IGF treatment, so that the observed improvement in N retention could not be explained through protein accretion rates calculated from these measures.
1 context sentence(design, population, supporting numbers)
Summary · context
Administration of IGF-I over a 14-day period to growing female rats via s.c. implanted osmotic pumps led to an increased body weight gain, an improved N retention and a greater food conversion efficiency.
In this study, IGF-1 LR3 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking IGF-1 LR3.
Report a problemFND-0837107506

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
13 Oct 2026, 21:44 UTC
Study results updated
Version 1
13 Oct 2026, 16:31 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

MeSH terms

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