title: LVV-hemorphin-4 modulates Ca2+/calmodulin-dependent pathways in the immune system by the same mechanism as in the brain.
abstract: The effect of synthetic LVV-hemorphin-4 (LVV-H4) on human blood and tonsils lymphocytes total phosphatase activity was studied by a spectrofluorimetric assay using 4-methylumbelliferyl phosphate (4-MUP) as a substrate. It has been established that LVV-H4 at concentrations of 10(-9) to 10(-7) M induces the inhibition of human blood (12-24%) and tonsils (42-45%) lymphocytes total phosphatase activity as 1 mM EGTA. The same peptide at concentrations of 10(-5) to 10(-4) M induces activation of human blood (48-57%) and tonsils (20-25%) lymphocytes total phosphatase activity. LVV-H4 is able to neutralize the inhibitory effect of calmodulin (CaM) antagonist and calcineurin inhibitor trifluoperazine (TFP) on human blood lymphocyte total phosphatase activity. It is suggested that a dose-dependent activation/inhibition of lymphocytes total phosphatase activity is due to activation/inhibition of lymphocyte calcineurin activity. Using enzyme-linked immunosorbentassay (ELISA) it was found that LVV-H4 neutralized the inhibitory effect of cyclosporin A (CsA) and TFP on interleukin-2 (IL-2) synthesis by activated blood lymphocytes. LVV-H4 also affects the lymphocytes proliferation, suppressed in pathophysiological condition, and restores their function by enhancement of DNA synthesis, as determined by measuring of [3H] thymidine incorporation into lymphocytes. It has been proposed that CaM is an essential component in starting up the molecular mechanism of hemorphins action and that calcineurin is a key enzyme underlying the molecular mechanism of hemorphins action on the brain and immune system.
authors.affiliation: H. Buniatian Institute of Biochemistry of the National Academy of Sciences of the Republic of Armenia, Yerevan. nbarkh@ipia.sci.am
authors.forename: Nina
authors.initials: N
authors.lastname: Barkhudaryan
authors.forename: Spartak
authors.initials: S
authors.lastname: Gambarov
authors.forename: Tadevos
authors.initials: T
authors.lastname: Gyulbayazyan
authors.forename: Karine
authors.initials: K
authors.lastname: Nahapetyan
mesh_terms: D000328:Adult; D001773:Blood Cells / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D016572:Cyclosporine / Q000378:metabolism / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007107:Immune System / Q000187:drug effects* / Q000378:metabolism; D007166:Immunosuppressive Agents / Q000378:metabolism / Q000494:pharmacology; D007376:Interleukin-2 / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects*; D008875:Middle Aged; D018847:Opioid Peptides / Q000378:metabolism; D014066:Palatine Tonsil / Q000166:cytology / Q000187:drug effects; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D013270:Stomach / Q000601:surgery; D014268:Trifluoperazine / Q000378:metabolism / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D006454:Hemoglobins; D007166:Immunosuppressive Agents; D007376:Interleukin-2; C471147:LVV-hemorphin-4; D018847:Opioid Peptides; D010446:Peptide Fragments; D014268:Trifluoperazine; D016572:Cyclosporine; D002118:Calcium