title: Growth hormone upregulates intestinal trefoil factor expression in the ileum of rats after γ-radiation.
abstract: Growth hormone (GH) and intestinal trefoil factor (ITF) have been involved in intestinal protection and repair. This study investigates the effects of GH administration on ITF expression and histological changes associated with tissue injury in an intestinal rat model of radiation. Adult male rats were divided into four groups: control, GH, radiation and radiation + GH (GHyRAD). Ileum samples were obtained at 2 or 72 h after radiation and processed to determine ITF levels (mRNA and protein) by quantitative polymerase chain reaction, Western blot and immunohistochemistry. In addition, goblet ITF-positive cells were identified by immunohistochemistry at 72 h. Our results showed an upregulation of mRNA and protein production of ITF in ileum samples after GH and radiation + GH compared with control and irradiated samples. Irradiation alone affected ITF protein expression. However, irradiation after GH pretreatment produced the highest ITF mRNA and protein levels at both the tested time points. ITF-producing goblet cells were identified in intestinal villi (apical location). GH treatment increased the number of ITF-producing goblet cells, and radiation after GH treatment displayed further increase in the number of ITF-positive goblet cells. GH upregulates ITF in normal intestinal tissue. This upregulation is higher when radiation is given after GH treatment. Nevertheless, the mechanism by which GH regulates ITF expression remains unclear and is still under investigation. These results could open up new avenues in the therapeutic reparative and protective effects of GH during radiotherapy and chemotherapy.
authors.affiliation: Experimental Surgery Department, La Paz Hospital, Paseo de la Castellana 261, 28046, Madrid, Spain. spos1970@hotmail.com
authors.forename: Sinforiano J
authors.initials: SJ
authors.lastname: Posadas
authors.forename: Carlota
authors.initials: C
authors.lastname: Largo
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Merino
authors.forename: Marcos
authors.initials: M
authors.lastname: Elvira
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Gonzalez
authors.forename: Victor
authors.initials: V
authors.lastname: Caz
authors.forename: Isabel
authors.initials: I
authors.lastname: Caballero
authors.forename: Enrique
authors.initials: E
authors.lastname: De Miguel
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005720:Gamma Rays; D015870:Gene Expression; D020869:Gene Expression Profiling; D013006:Growth Hormone / Q000378:metabolism*; D007082:Ileum / Q000528:radiation effects*; D007150:Immunohistochemistry; D008297:Male; D010455:Peptides / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011832:Radiation Injuries / Q000473:pathology*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D000071164:Trefoil Factor-2
chemical_list: D010455:Peptides; D012333:RNA, Messenger; D000071164:Trefoil Factor-2; D013006:Growth Hormone