Pituitary and extrapituitary growth hormone: Pit-1 dependence?
Growth hormone (GH) is primarily produced in pituitary somatotrophs. The synthesis of this hormone is thought to be dependent upon a pituitary-specific transcription factor (Pit-1). However, many extrapituitary tissues are now known to express GH genes. The extrapituitary production of GH may therefore indicate an extrapituitary distribution of the Pit-1 gene. The extrapituitary production of GH may, alternatively, indicate that GH expression occurs independently of Pit-1 in extrapituitary tissues. These possibilities are considered in this brief review.
Harvey
S
S
Department of Physiology, University of Alberta, Edmonton, Canada. steve.harvey@ualberta.ca
Azumaya
Y
Y
Hull
K L
KL
D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000502:physiology*; D004622:Embryo, Mammalian / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D009928:Organ Specificity; D010802:Phylogeny; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; C494187:POU1F1 protein, human; D050817:Transcription Factor Pit-1; D014157:Transcription Factors; D007987:Gonadotropin-Releasing Hormone