Adiponectin total ELISA

Adiponectin consists of 244 amino acids and has an approximate molecular weight
of 30 kDa. The adiponectin concentration in blood is 5–30µg/ml that accounts for
about 0.01% of the total plasma proteins. Adiponectin has four domains: a signal
peptide, a variable domain, a collagen-like N-terminal domain and a globular Cterminal
domain. Adiponectin exists in different oligomer forms in vivo. Beside the
trimer and ditrimer also high molecular multimers are present. Adiponectin is mainly
expressed by adipocytes, but also muscle cells and hepatocytes can synthesize it.
The only, until now known, natural inductor of the adiponectin synthesis is IGF-I. Two
different adiponectin receptors are known. Both of them are ubiquitary expressed,
though their distribution in the tissues varies: Adiponectin Receptor 1 (AdipoR1) is
synthesized in muscle and AdipoR2 in liver tissue. The adiponectin significance for
the human organism is not completely clear until now. Studies show, that adiponectin
correlates negatively with BMI and could participate at the energy metabolism
through the regulation of fatty acid oxidation. Adiponectin influences further physiological
processes like angiogenesis. It is also associated with glucose and lipid metabolism.
Adiponectin levels are associated with insulin resistance and accordingly
linked with Type II Diabetes. Furthermore, it is involved in inflammatory processes
and therewith of importance for development of arteriosclerosis and coronary artery
diseases. Blüher et al. (2007) showed a correlation of total serum adiponectin to
insulin sensitivity and the ability of total serum adiponectin levels to predict insulin
resistance and impaired glucose tolerance. Low adiponectin concentrations result
in inhibition of fatty acid oxidation and are associated with insulin resistance and
metabolic syndrome as well as arteriosclerosis.