Effects of prolactin on sleep in cyclic rats.
We previously demonstrated that pregnancy-associated sleep enhancement is correlated with the daily surges of prolactin (PRL). However, in spite of a surge of PRL in the proestrous night, a reduction of nocturnal sleep occurs in phase with proestrus. Therefore, to clarify the physiological role of PRL in sleep regulation during the estrous cycle, time-course changes in sleep were analyzed in bromocriptine (CB-154)-treated and/or PRL-supplemented female rats. Sleep patterns characteristic of proestrus-to-estrus were not affected by the CB-154 treatment. In contrast, nocturnal rapid eye movement sleep (REMS) was significantly increased after the PRL supplementation. The CB-154 treatment diminished the REMS-enhancing effect of PRL. Thus, the results suggest that the endogenous PRL is not crucial for the regulation of sleep during the estrous cycle, while exogenous PRL can enhance REMS.
Zhang
S Q
SQ
Division of Biocybernetics, Institute for Medical and Dental Engineering, Tokyo Medical and Dental University, Japan.
Kimura
M
M
Inoué
S
S
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology*; D004971:Estrus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012894:Sleep Stages / Q000187:drug effects / Q000502:physiology*; D012895:Sleep, REM / Q000187:drug effects / Q000502:physiology
D006727:Hormone Antagonists; D001971:Bromocriptine; D011388:Prolactin