Figure 2. Schematic diagram depicting the different physiological roles of IRS-1
and IRS-2 as realized by animal and human studies. Note the prevalent
action of IRS-1 in regulating muscle glucose transport, brown adipocyte
differentiation, and insulin-induced ß cell insulin secretion; a role
in bone turnover is demonstrated. IRS-2 appears to play a crucial role
in regulation of pancreatic ß cell development and differentiation,
fat lipolysis, hepatic glucose production, and pituitary–ovarian axis
function.
