Growth hormone administration produces a biphasic cellular muscle growth in weaning mice.
J Physiol Biochem
; 57(3): 255-63, 2001 Sep.
Article
em En
| MEDLINE
| ID: mdl-11800288
ABSTRACT
The present study was undertaken to elucidate the effect of the exogenous administration of rhGH on the time course of the cellular muscle growth in male and female BALB/c mice fed 20% dietary protein between weaning and 50 days of age. Also, the efficiency of utilization of protein and energy intake to muscle DNA content and protein per cell (protein to DNA ratio) storage were studied. 120 weaned mice (21 d) were assigned to four groups based on rhGH-treatment (rhGH-treated 7.4 ng x g(-1) BW and control saline vehicle; via s.c. every two days) and gender. Feed intake was measured daily. At 25, 30, 35, 40, 45 and 50 days of age twenty mice were killed by cervical dislocation and the samples of gastrocnemius muscles were isolated, weighed and protein and DNA contents were measured. The rhGH administration caused a biphasic response altering the muscle cellular growth as a consequence of age-specific feed intake changes. The GH-induced fall of feed intake between 25 and 30 days of age caused decreases in muscle weight and myonuclei number (DNA), whereas muscle cell size was maintained. Later on, the self-controlled increase of feed intake led to the muscle weight recovery to control level, in spite of the irreversible DNA fall, as a consequence of the increase of cellular protein deposition and an enhancement of utilization of protein and energy intakes to deposit protein per cell. These results demonstrate that in spite of the initial (25-30 d of age) muscle DNA fall, rhGH-administration from weaning ensures the recovery of cellular muscle growth to control level through a compensatory muscle hypertrophy.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA
/
Hormônio do Crescimento
/
Músculo Esquelético
/
Ingestão de Alimentos
/
Proteínas Musculares
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Physiol Biochem
Assunto da revista:
BIOQUIMICA
/
FISIOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Espanha
País de publicação:
ES
/
ESPANHA
/
ESPAÑA
/
SPAIN