activin


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ac·tiv·in

(ak'ti-vin),
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]

activin

/ac·ti·vin/ (ak´tĭ-vin) a nonsteroidal regulator synthesized in the pituitary glands and gonads that stimulates the secretion of follicle-stimulating hormone.

activin

(ăk′tə-vĭn, ăk-tĭv′ĭn)
n.
A polypeptide growth factor that is synthesized in the pituitary gland and the gonads and stimulates the secretion of follicle-stimulating hormone.

Activin

Either 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.

ac·tiv·in

(ak'ti-vin)
Placental hormone that reaches maximum levels in maternal serum during labor.

activin

a gonadal peptide hormone isolated from follicular fluid; has an unidentified role in stimulating FSH secretion.
References in periodicals archive ?
A second compound in a new class of activin receptor proteins, ACE-536, is under investigation to treat beta-thalassemia, a blood disorder characterized by reduced hemoglobin production.
evaluated a large number of biomarkers and developed a multimarker algorithm combining 4 markers (progesterone, vascular endothelial growth factor, inhibin A, and activin A) that demonstrated improved diagnostic utility (31).
We examined a large random collection of cancer cell lines in vitro, and found that one-third of them secreted large amounts of activin A.
The most frequently studied biochemical markers were human chorionic gonadotropin (hCG, 8 studies), inhibin A, and soluble fms-like tyrosine kinase 1 (sFlt-1) in 6 studies and [alpha]-fetoprotein (AFP), activin A, pregnancy-associated plasma protein A (PAPP-A), and placental growth factor (PlGF) in 5 studies.
In contrast, mRNA levels of interferon gamma receptor 1 (IFNGR1), activin A receptor, type 1 (ACVR1), and activated leukocyte cell adhesion molecule (ALCAM) all exhibited downregulation in study subjects of the high-level arsenic exposure group.
Recent studies by positional cloning approaches identified 2 causative genes of HHT: HHT1 and HHT2,[6] which encode endoglin and activin receptor-like kinase 1 (ALK1), respectively.
Two forms were isolated at Salk -- one named follicle-stimulating hormone releasing protein (FRP) by a group led by Wylie Vale, and the other called activin by a group led by Roger Guillemin.
They found that nicotinamide (vitamin B3, NIC) and Activin A, an important growth factor, promoted differentiation of hESCs towards an RPE fate.
These putative activities and the present data indicate that urocortin--along with CRH, interleukin-11, prostaglandin E2, activin A, and leukemia inhibitory factor--contributes to the implantation process (24).
2-Chloro-s-triazine herbicides induce aromatase (CYP19) activin in H295R human adrenocortical carcinoma cells: a novel mechanism for estrogenicity?
The two poster presentations describe the potential role of activin A as an adverse biomarker for patients with metastatic breast cancer and of BMP9 as a biomarker for the identification and selection of patients with head and neck cancer.