Epithelial-Specific and Stage-Specific Functions of Insulin-Like Growth Factor-I during Postnatal Mammary Development

Insulin-like growth factor-I is an important antiapoptotic factor for rat leydig cells during postnatal development.

The present investigation examines the influence of IGF-I and the role of IGF-I receptor (IGF-IR) in the apoptosis/survival of Leydig cells. Immunohistochemical analysis of the rat testis at different ages revealed that the level of the phosphorylated IGF-IR increases from birth to d 20 of postnatal life, remaining high in the adult testis. Western blotting revealed that this level is higher in...

Consequences of postnatal insulin-like growth factor II overexpression in insulin-like growth factor I deficient mice

Insulin-like growth factor I during growth in bulls.

In 10 bulls, changes in blood plasma concentrations of insulin-like growth factor I (IGF1) were studied during rearing and during the ensuing growth period. IGF1 continuously increased from 32 micrograms/l at the age of 15 d to 194 micrograms/l at the age of 307 d together with body weight. However, IGF1 was not related to daily rate of gain, which remained fairly constant during the growth per...

Insulin-like growth factor-I promotes neurogenesis and synaptogenesis in the hippocampal dentate gyrus during postnatal development.

The in vivo actions of insulin-like growth factor-I (IGF-I) on the growth and development of the hippocampal dentate gyrus were investigated in transgenic mice that overexpress IGF-I postnatally in the brain and in normal nontransgenic littermate controls. Stereological analyses of the dentate gyrus were performed by light and electron microscopy on days 7, 14, 21, 28, 35, and 130 to determine ...

Insulin-like growth factor I receptor levels during the lactogenic cycle in rat mammary gland.

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