title: Daily variation in 5-hydroxytryptamine in rat spleen and the effect of stimuli on the rhythm.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D005260:Female; D005470:Fluorometry; D007103:Immobilization; D008027:Light; D008297:Male; D009929:Organ Size; D010775:Photic Stimulation; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D012737:Sex Factors; D013154:Spleen / Q000378:metabolism*
chemical_list: D012701:Serotonin