Effect of reserpine on 5-hydroxytryptophan (5HTP)-immunoreactive neurons in the rat brain.
By immunohistochemistry of rat brain in conjunction with a specific antibody against 5-hydroxytryptophan (5HTP), we examined immunoreactivity to 5HTP in neurons, from which 5-hydroxytryptamine (5HT; serotonin) was depleted by reserpine treatment. The distribution patterns of 5HTP-positive neurons overlapped with those of 5HT neurons. Treatment with reserpine (5 mg/kg, 90 min before death) caused a complete suppression of 5HT-positive staining, but 5HTP-immunostaining remained in perikarya of the nuclei raphe dorsalis, centralis superior and obscurus. Treatment with reserpine (25 mg/kg, 90 min before death) suppressed the 5HTP-immunoreaction in certain perikarya (e.g. of the nucleus raphe dorsalis) and fibres; however, 5HTP-immunostaining remained in perikarya of the nuclei centralis superior and raphe obscurus. This suggests that these neurons synthesize more 5HTP by a process which appears to be stimulated by reserpine.
Department of Anatomy, Shiga University of Medical Science, Japan.
M
M
Fujimiya
K
K
Okumiya
M
M
Nakazawa
K
K
Kitahama
H
H
Kimura
T
T
Maeda
D006916:5-Hydroxytryptophan / Q000032:analysis* / Q000276:immunology; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects*; D001923:Brain Chemistry; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000276:immunology; D011817:Rabbits; D011903:Raphe Nuclei / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012110:Reserpine / Q000494:pharmacology*; D012701:Serotonin / Q000502:physiology
D012701:Serotonin; D012110:Reserpine; D006916:5-Hydroxytryptophan