SomeDoc is right vsmedic , as receptors are stimulated, second msn AMPc is released. Just to add more info, thats the same reason why you get low urinary AMPc in PseudoHypoparathyroidism (resistance to PTH action in receptors)
There is a good list in the endocrine section of First Aid Step 1, listing the mechanism of most hormones. There is also a similar list for receptor mechanisms of neurotransmitters in the Pharma section of First Aid Step 1.