title: Synthetic peptide octarphin (TPLVTLFK) inhibits the activity of the hypothalamus-pituitary-adrenal axis through nonopioid β-endorphin receptor.
abstract: The synthetic peptide octarphin (TPLVTLFK) corresponding to the sequence 12-19 of β-endorphin, a selective agonist of nonopioid β-endorphin receptor, was labeled with tritium to specific activity of 29 Ci/mmol. The analysis of [(3)H]octarphin binding to rat pituitary and adrenal cortex membranes revealed the existence of one type of binding sites (receptors): Kd 5.9 and 35.6 nM, respectively. Octarphin at concentrations of 1-1000 nМ was shown to inhibit the adenylate cyclase activity of rat adrenocortical membranes, while its intramuscular injection at doses of 10-100 μg/kg was found to reduce the secretion of corticosterone from the adrenals to the bloodstream. Thus, the nonopioid receptor of β-endorphin may be involved in the regulation of the activity of the pituitary and adrenal glands.
authors.affiliation: Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Science Avenue, 6, Pushchino, Moscow Region 142290, Russia. Electronic address: nekr-jul@mail.ru.
authors.forename: Yuliia N
authors.initials: YN
authors.lastname: Nekrasova
authors.affiliation: Institute of Molecular Genetics of the Russian Academy of Sciences, Kurchatov Square, 2, Moscow 123182, Russia. Electronic address: zolya@img.ras.ru.
authors.forename: Yury A
authors.initials: YA
authors.lastname: Zolotarev
authors.affiliation: Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Science Avenue, 6, Pushchino, Moscow Region 142290, Russia. Electronic address: navolotskaya@fibkh.serpukhov.su.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Navolotskaya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism*; D007273:Injections, Intramuscular; D008297:Male; D009842:Oligopeptides / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013329:Structure-Activity Relationship; D001615:beta-Endorphin / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; C555005:octarphin; D001615:beta-Endorphin