ABSTRACT
Previous data from our labs and from others have demonstrated that intracerebroventricular (ICV) injection of alarin has orexigenic activity and significantly increases plasma luteinizing hormone (LH) secretion in a gonadotropin-releasing hormone (GnRH) dependent manner. The purpose of the current experiments was to determine if the amino acids at the amino-terminal end of the alarin peptide are critical for alarin's effects on reproductive and feeding systems. First, we injected male mice ICV with full-length alarin (Ala1-25) or peptide fragments missing residues at the amino-terminal end (Ala3-25 or Ala6-25 Cys). Neither peptide fragment alone, significantly increased food intake in male mice compared to controls. Second, ICV injection of Ala1-25, but not Ala3-25, significantly (p < 0.01) increased GnRH-mediated LH secretion. Surprisingly, Ala6-25 Cys significantly (p < 0.05) inhibited plasma LH secretion and inhibited Ala1-25 actions. In conclusion, elimination of the first five amino acids of alarin not only abolishes the biological activity of alarin, but becomes an antagonist to alarin-specific effects. Furthermore, Ala6-25 Cys seems to act as a specific antagonist to putative alarin receptors and therefore may be an important tool in identifying alarin-specific receptors.
Subject(s)
Eating/drug effects , Galanin-Like Peptide/antagonists & inhibitors , Galanin-Like Peptide/pharmacology , Luteinizing Hormone/metabolism , Peptide Fragments/pharmacology , Animals , Body Temperature/drug effects , Body Weight/drug effects , Brain Chemistry/drug effects , Gonadotropin-Releasing Hormone/physiology , Injections, Intraventricular , Male , Mice , Mice, Inbred C57BL , TelemetryABSTRACT
This study determined the relative efficacy of an experimental explicit emergent literacy intervention program for preschoolers experiencing multiple risk factors. Using an alternating treatment research design, children completed two 6-week waves of intervention in small groups; one wave featured the experimental explicit intervention program, whereas the other featured a comparison program. Emergent literacy assessment was conducted at pretest and at the end of each wave. Results indicated significant widespread gains in emergent literacy knowledge over the entire 12-week intervention program; growth was significantly greater during the experimental explicit intervention program compared to the comparison program. An examination of individual differences and intervention outcome showed oral language skills and literacy orientation to predict emergent literacy performance at the end of the program.
