en تخصصي Special پژوهشي Research Article <aside style="box-sizing: border-box; font-family: Lato, Arial; word-wrap: break-word; margin-bottom: 10px; font-size: 11px;"> <p style="box-sizing: border-box; word-wrap: break-word; margin: 0px 0px 10px; font-size: 12px; text-align: justify;"><span style="box-sizing: border-box; word-wrap: break-word; font-weight: 700;">Background:</span>&nbsp;The decreased level of somatostatin and increased level of histamine are detected in the Parkinsonian brain. In old Wistar rats, the brain somatostatin deficiency can initiate catalepsy that suggests the pathogenic significance of this abnormality in Parkinson&rsquo;s disease (PD). The ability of histamine to affect the somatostatin deficiency action is not studied.</p> </aside> <aside style="box-sizing: border-box; font-family: Lato, Arial; word-wrap: break-word; margin-bottom: 10px; font-size: 11px;"> <p style="box-sizing: border-box; word-wrap: break-word; margin: 0px 0px 10px; font-size: 12px; text-align: justify;"><span style="box-sizing: border-box; word-wrap: break-word; font-weight: 700;">Objectives:</span>&nbsp;The current study aimed to examine if histamine alters the cataleptogenic activity of the brain somatostatin deficiency in Wistar rats.</p> </aside> <aside style="box-sizing: border-box; font-family: Lato, Arial; word-wrap: break-word; margin-bottom: 10px; font-size: 11px;"> <p style="box-sizing: border-box; word-wrap: break-word; margin: 0px 0px 10px; font-size: 12px; text-align: justify;"><span style="box-sizing: border-box; word-wrap: break-word; font-weight: 700;">Materials and Methods:</span>&nbsp;The animals used in the study were 100 - 110 and 736 - 767 days old. Catalepsy was evaluated by the bar test. The inhibition of the brain somatostatin activity was simulated by I.C.V. administration of cyclosomatostatin (cycloSOM), a somatostatin receptor antagonist.</p> </aside> <aside style="box-sizing: border-box; font-family: Lato, Arial; word-wrap: break-word; margin-bottom: 10px; font-size: 11px;"> <p style="box-sizing: border-box; word-wrap: break-word; margin: 0px 0px 10px; font-size: 12px; text-align: justify;"><span style="box-sizing: border-box; word-wrap: break-word; font-weight: 700;">Results:</span>&nbsp;CycloSOM (0.2, 1.0, and 5.0 &micro;g) and histamine (1.0 and 10.0 &micro;g) alone were ineffective in both young and old animals. In combination, however, cycloSOM and histamine initiated cataleptic response in old rats. Effect of the combination was inhibited by H1 and H2 but not H3 antagonists.</p> </aside> <aside style="box-sizing: border-box; font-family: Lato, Arial; word-wrap: break-word; margin-bottom: 10px; font-size: 11px;"> <p style="box-sizing: border-box; word-wrap: break-word; margin: 0px 0px 10px; font-size: 12px; text-align: justify;"><span style="box-sizing: border-box; word-wrap: break-word; font-weight: 700;">Conclusions:</span>&nbsp;CycloSOM and histamine synergistically exert catalepsy in old rats. In light of these data, the combination of the decreased brain level of somatostatin and increased brain level of histamine may be of pathogenic relevance for extrapyramidal signs in PD.</p> </aside> Histamine, Somatostatin, Aging, Catalepsy, Parkinsonian Disorders 40 43 http://ajnpp.umsha.ac.ir/browse.php?a_code=A-10-2-28&slc_lang=en&sid=1 Ilya D. Ionov newrology@yandex.ru 1003194753284600122 1003194753284600122 Yes Centre on Theoretical Problems in Physical and Chemical Pharmacology, Russian Academy of Sciences, Moscow, Russia Zoya A. Turgeneva 1003194753284600123 1003194753284600123 No Research Group, Timpharm Ltd, Moscow, Russia