activin(redirected from Activin A)
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Placental hormone that reaches maximum levels in maternal serum during labor; helps to regulate production of gonadotropin-releasing hormones, human chorionic gonadotropin, and steroids by the placenta.
[active + -in]
Farlex Partner Medical Dictionary © Farlex 2012
A polypeptide growth factor that is synthesized in the pituitary gland and the gonads and stimulates the secretion of follicle-stimulating hormone.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
ActivinEither of two dimeric proteins belonging to the TGF-beta superfamily (as do inhibin and bone morphogenic protein) which act primarily through SMADs, a class of signal transducers, which are involved in DNA-binding and signal transduction. Activins are involved in all stages of the cell cycle: proliferation, differentiation, metabolism, homeostasis, and death (apoptosis), as well as immune response and tissue repair—activins A and B are highly expressed during wound repair and healing, and have yin-yang relationship with inhibin. Activins are involved in differentiation of erythroid precursors and erythroleukemia cell lines, neuronal survival, stimulation of insulin and anterior pituitary hormone secretion, regulation of the menstrual cycle, increasing FSH production and granulosa cell differentiation by binding to follistatin, an FSH release inhibitor.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
Placental hormone that reaches maximum levels in maternal serum during labor.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012