You cannot modify any Cart contents. Click here to find out how. These protein regulators play a vital role in regulating FSH, which acts synergistically with luteinizing hormone LH in reproduction. Depending on their subunit composition, they also have an influence in the induction of apoptosis, metabolism, endocrine, homeostasis, bone growth, fibrosis inflammation, neurogenesis, tubulogenesis of endothelial cells, and carcinogenesis in several organs Muenster et al.
The importance of activin to a wide variety of human physiological mechanisms makes it an important drug target Han, When activin is secreted its availability to be active and bind to its receptors can be blocked by other activin-binding proteins such as inhibin and follistatin Gressner, Extracellular regulation of activin is achieved using follistatin and follistatin-related proteins FLRP. Follistatin is also an activin binding protein, it binds directly to activin with high affinity and this stops activin from binding to its own receptors which blocks signaling Bartholin et al.
FLRP also binds to activin but with low reversibility. During development, activin is perhaps best described as acting locally and at many sites during mammalian embryogenesis. Activin has been proposed to be a mesoderm-inducing factor. However, knockout mice have failed to demonstrate this conclusively. These animals show marked cardiovascular positional abnormalities, some of which mimic complex human disorders.
Activin has also been implicated in bone remodeling. During bone formation, a temporal interaction between FS and activin A may be involved in the development and conversion of cartilage to bone. In concert with the BMPs, activin A may also contribute to intramembranous ossification. Blood cell formation also may be influenced by both inhibin A and activin A.
The overall role for activin is considered to be secondary, not primary i.
At the beginning of the menstrual cycle, anterior pituitary gonadotrophic cells release FSH. This FSH travels to the ovary where it binds to immature oocytes, initiating their maturation. Such maturing oocytes or follicles make estrogen, which gives negative feedback to the pituitary to inhibit further FSH release. After about 14 days, one oocyte matures and releases a final burst of estrogen that causes the pituitary gonadotrophs to secrete both FSH and LH luteinizing hormone.
Cells in the ovary that contributed to earlier follicle maturation and now remain following ovulation develop into a structure called the corpus luteum. This structure becomes a center for the synthesis of progesterone, a molecule that both inhibits pituitary LH production, and promotes the growth of the uterus. In the absence of fertilization, the corpus luteum involutes, leading to a period of menses with low circulating estrogen and progesterone levels.
The lack of these two hormones is a positive signal for new FSH release and the start of a new cycle. Although estrogen is the primary stimulus for the "LH spike", gonad-produced inhibin is believed to limit the amount of FSH released during this spike, thus fine-tuning the response.
The above must be viewed as naively simplistic, since there are multiple sites of activin and inhibin production including the pituitary 39 , and multiple combinations of growth factors that affect production at local levels. At these levels, the binding-capacity of FS is likely to be exceeded, making activin available in a true endocrine manner. All Rights Reserved.
Skip to main content. Overview Inhibin is a molecule that was first described over 60 years ago. Structural Information Both activin and inhibin are members of the TGF-beta superfamily of molecules. Vale, W. Mayo, K. Sporn, M. Ling, N. Halvorson, L. DeCherney Fertil.
Muttukrishna, S. Mason, A. Groome, N. Robertson, D. Lambert-Messerlian, G. Krummen, L.
Schneyer, A. Hill, C. Kingsley, D. Knight, P. Burger, H. Igarashi, eds. Fang, J. Hotten, G. Schmitt, J. Oda, S. Hubner, G. Genes Dev, ;28 4 Mol Hum Reprod, ;18 3 Other Available Formats. Learn about Custom Antibody Labeling. Need help? Read the Bioinformatics Tool Guide for instructions on using this tool. Methylation Phosphorylation Deacetylation Cleavage.
View Datasheet. Activin A [Unconjugated] AC PDF Datasheet.
Request CofA. Volume ml ul. Mass mg ug ng. Visit our other sites. Standard Formulation AB Measured by its ability to induce hemoglobin expression in K human chronic myelogenous leukemia cells. Use a manual defrost freezer and avoid repeated freeze-thaw cycles. Regulation of hepcidin expression by inflammation-induced activin B Sci Rep, ;6 0