What is the role of second messenger in hormone action ?

Explanation

In proteinous hormones (e.g. insulin) and amine hormones (e.g. epinephrine), second messengers like C-AMP, IP3 and calcium activate an inactive enzyme system by cascade effect so multiplying the incoming signals.
In steroid hormones (e.g.estrogens) and iodothyronines (e.g. thyroxine), second messenger activates specific gene expression to synthesize specific mRNA to synthesize specific structural or enzymatic proteins.