title: Injection of melatonin into cisterna magna increases concentration of 3', 5' cyclic guanosine monophosphate in cerebrospinal fluid.
abstract: Rabbits were anesthetized with urethane and were given intracisternal injections of the following substances: adrenocorticotropin, beta-melanocyte stimulating hormone, choroid plexus peptide IIF, epinephrine, serotonin, histamine, oxytocin, lysine and a arginine vasopressins, acetylcholine and melatonin. The effects on the concentration of 3', 5' cyclic guanosine monophosphate (cGMP) in cerebrospinal fluid were then measured. Only melatonin and acetylcholine caused a significant (p less than 0.05) effect on cGMP concentration. Both agents increased the nucleotide's concentration within 30 min. Melatonin was about 1,000 times more potent than acetylcholine; the mininal effective doses were 1 mug and 1,000 mug, respectively.
mesh_terms: D000818:Animals; D002946:Cisterna Magna; D000242:Cyclic AMP / Q000134:cerebrospinal fluid*; D006152:Cyclic GMP / Q000134:cerebrospinal fluid*; D007278:Injections, Spinal; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits
chemical_list: D000242:Cyclic AMP; D006152:Cyclic GMP; D008550:Melatonin