cyclic gmp Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed). 3',5'-cyclic GMP : A 3',5'-cyclic purine nucleotide in which the purine nucleobase is specified as guanidine. | 2.38 | 2 | 0 | 3',5'-cyclic purine nucleotide; guanyl ribonucleotide | Escherichia coli metabolite; human metabolite; mouse metabolite; plant metabolite; Saccharomyces cerevisiae metabolite |