title: Chronopharmacological effects of growth hormone on the executive function and oxidative stress response in rats.
abstract: OBJECTIVE
  To investigate the chronopharmacological effects of growth hormone on executive function and the oxidative stress response in rats.
  
  
  METHODS
  Fifty male Wistar rats (36-40 weeks old) had ad libitum access to water and food and were separated into four groups: diurnal control, nocturnal control, diurnal GH-treated, and nocturnal GH-treated animals. Levels of Cu, Zn superoxide dismutase (Cu, Zn-SOD), and superoxide release by spleen macrophages were evaluated. For memory testing, adaptation and walking in an open field platform was used. GH-treated animals demonstrated better performance in exploratory and spatial open-field tests.
  
  
  RESULTS
  The latency time in both GH-treated groups was significantly lower compared with the latency time of the control groups. The diurnal GH treatment did not stimulate superoxide release but increased the CuZn-SOD enzyme levels. The nocturnal GH treatment did not influence the superoxide release and CuZn-SOD concentration. GH treatment also resulted in heart atrophy and lung hypertrophy.
  
  
  CONCLUSIONS
  Growth hormone treatment improved the performance of executive functions at the cost of oxidative stress triggering, and this effect was dependent on the circadian period of hormone administration. However, GH treatment caused damaging effects such as lung hypertrophy and heart atrophy.
authors.affiliation: Federal University of Mato Grosso (UFMT), Mato Grosso, Brazil.
authors.forename: Carlos K B
authors.initials: CK
authors.lastname: Ferrari
authors.affiliation: Federal University of Mato Grosso (UFMT), Mato Grosso, Brazil; São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Eduardo L
authors.initials: EL
authors.lastname: França
authors.affiliation: University Center of Araxá (UNIARAXA), Minas Gerais, Brazil.
authors.forename: Luciane A
authors.initials: LA
authors.lastname: Monteiro
authors.affiliation: University Center of Araxá (UNIARAXA), Minas Gerais, Brazil.
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Santos
authors.affiliation: São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pereira-Junior
authors.affiliation: Federal University of Mato Grosso (UFMT), Mato Grosso, Brazil; São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Adenilda C
authors.initials: AC
authors.lastname: Honorio-França
keywords: Chronopharmacology; Executive function; Growth hormone; Superoxide anion; Superoxide dismutase