title: The second messenger.
mesh_terms: D000227:Adenine Nucleotides; D000818:Animals; D002118:Calcium / Q000097:blood; D000242:Cyclic AMP / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D010281:Parathyroid Hormone / Q000378:metabolism / Q000502:physiology; D010758:Phosphorus / Q000097:blood; D051381:Rats; D013972:Thyrotropin / Q000378:metabolism / Q000502:physiology
chemical_list: D000227:Adenine Nucleotides; D010281:Parathyroid Hormone; D010758:Phosphorus; D013972:Thyrotropin; D000242:Cyclic AMP; D002118:Calcium