Effects of serotonin on the release of thyrotropin-releasing hormone from the rat retina in vitro.
Effects of serotonin on the release of thyrotropin-releasing hormone (TRH) from the rat retina were studied in vitro. The retina was incubated in medium 199 (pH 7.4) with 1.0 mg/ml of bacitracin and 100 micrograms/ml of ascorbic acid (medium) for 20 min. The amount of TRH release into the medium was measured by radioimmunoassay. The TRH release from the rat retina was inhibited significantly in a dose-related manner with the addition of serotonin and enhanced with cyproheptadine. The inhibitory effect of serotonin on TRH release from the retina was blocked with the addition of cyproheptadine. The elution profile of methanol extract of the rat retina was identical to that of synthetic TRH. The findings suggest that the serotonergic system inhibits TRH release from the rat retina in vitro.
Mitsuma
T
T
Fourth Department of Internal Medicine, Aichi Medical University, Japan.
Kayama
M
M
Yokoi
Y
Y
Rhue
N
N
Izumi
M
M
Takatsu
S
S
Adachi
K
K
Hirooka
Y
Y
Nogimori
T
T
D000818:Animals; D003533:Cyproheptadine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D066298:In Vitro Techniques; D007201:Indicator Dilution Techniques; D008297:Male; D000432:Methanol; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000187:drug effects* / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*
D003533:Cyproheptadine; D012701:Serotonin; D013973:Thyrotropin-Releasing Hormone; D000432:Methanol