<Li> Environmental changes, e.g., of light or temperature </Li> <P> One special group of hormones is the tropic hormones that stimulate the hormone production of other endocrine glands . For example, thyroid - stimulating hormone (TSH) causes growth and increased activity of another endocrine gland, the thyroid, which increases output of thyroid hormones . </P> <P> To release active hormones quickly into the circulation, hormone biosynthetic cells may produce and store biologically inactive hormones in the form of pre - or prohormones . These can then be quickly converted into their active hormone form in response to a particular stimulus . </P> <P> Eicosanoids are considered to act as local hormones . They are considered to be "local" because they possess specific effects on target cells close to their site of formation . They also have a rapid degradation cycle, making sure they do not reach distal sites within the body . </P>

Where does the conversion of a prohormone into a hormone take place