title: Sleep deprivation increases rat hypothalamic growth hormone-releasing hormone mRNA.
abstract: Much evidence indicates that growth hormone-releasing hormone (GHRH) is involved in sleep regulation. We hypothesized that GHRH mRNA would increase and somatostatin (SRIH) mRNA would decrease during sleep deprivation. With the use of RT-PCR and truncated internal standards, rat hypothalamic GHRH mRNA and SRIH mRNA levels were evaluated after sleep deprivation. After 8 or 12 h of sleep deprivation there was a significant increase in rat hypothalamic GHRH mRNA expression compared with time-matched control samples. Hypothalamic GHRH mRNA levels were not significantly different from control values after 1 or 2 h of recovery after 8 h of sleep deprivation or after 2 h of recovery after 12 h of sleep deprivation. In control animals, variations in hypothalamic GHRH mRNA levels were observed. GHRH mRNA expression was significantly higher in the afternoon than at dark onset or during the dark period. SRIH mRNA levels were significantly suppressed at the termination of an 8-h sleep deprivation period and were significantly higher after dark onset than in the morning. The alterations in GHRH and SRIH mRNA expressions after sleep deprivation and recovery support the notion that GHRH plays an important role in sleep homeostasis and suggest that these neuropeptides may interact reciprocally in modulating sleep as they do in the control of growth hormone secretion.
authors.affiliation: Department of Physiology and Biophysics, University of Tennessee, Memphis, Tennessee 38163, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Taishi
authors.forename: F
authors.initials: F
authors.lastname: Obál
authors.forename: J
authors.initials: J
authors.lastname: Fang
authors.forename: J M
authors.initials: JM
authors.lastname: Krueger
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D013007:Growth Hormone-Releasing Hormone / Q000235:genetics*; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012892:Sleep Deprivation / Q000502:physiology*; D013004:Somatostatin / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone