Administration of growth hormone ameliorates adverse effects of total sleep deprivation.

Total sleep deprivation (TSD) causes several harmful changes including anxiety, inflammation, and increased expression of extracellular signal-regulated kinase (ERK) and tropomyosin receptor kinase B (TrkB) genes in the hippocampus. The current study was conducted to explain the possible effects of exogenous GH against the above parameters caused by TSD and the possible mechanisms involved. Male Wistar rats were divided into 1) control, 2) TSD and 3) TSD + GH groups. To induce TSD, the rats received a mild repetitive electric shock (2 mA, 3 s) to their paws every 10 min for 21 days. Rats in the third group received GH (1 ml/kg, sc) for 21 days as treatment for TSD. The motor coordination, locomotion, the level of IL-6, and expression of ERK and TrkB genes in hippocampal tissue were measured after TSD. The motor coordination (p < 0.001) and locomotion indices (p < 0.001) were impaired significantly by TSD. The concentrations of serum corticotropin-releasing hormone (CRH) (p < 0.001) and hippocampal interleukin-6 (IL-6) (p < 0.001) increased. However, there was a significant decrease in the interleukin-4 (IL-4) concentration and expression of ERK (p < 0.001) and TrkB (p < 0.001) genes in the hippocampus of rats with TSD. Treatment of TSD rats with GH improved motor balance (p < 0.001) and locomotion (p < 0.001), decreased serum CRH (p < 0.001), IL-6 (p < 0.01) but increased the IL-4 and expression of ERK (p < 0.001) and TrkB (p < 0.001) genes in the hippocampus. Results show that GH plays a key role in modulating the stress hormone, inflammation, and the expression of ERK and TrkB genes in the hippocampus following stress during TSD.