Differences in isoproterenol-stimulated melatonin production by perifused rat pineal glands: time dependent effects and role of enantiomeric forms.
The perifusion of rat pineal glands removed at different times of the light-dark cycle showed a greater beta adrenergic-stimulated production of melatonin in glands obtained at the beginning of either the light or the dark stage. The effect of isoproterenol was found dependent upon its enantiomeric forms (-, +/-, +). The relative order of potency was (-) > (+/-) > (+) enantiomer. These results show that the response of pineal beta-adrenergic receptors to isoproterenol is stereospecific and circadian stage dependent.
Zhao
Z Y
ZY
Department of Biochemistry, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
Touitou
Y
Y
D000704:Analysis of Variance; D000818:Animals; D066298:In Vitro Techniques; D007536:Isomerism; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008550:Melatonin / Q000096:biosynthesis*; D010477:Perfusion; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013329:Structure-Activity Relationship; D013997:Time Factors
D008550:Melatonin; D007545:Isoproterenol