[The effect of tyrosine-containing dipeptide on neuroglycopenia-induced changes in the activities of the sympathetic nervous system and of the systemic hemodynamics in waking rats].
A modulatory role of the precursor of catecholamines--tyrosine (TYR)--in 2-deoxyglucose (2DG)-induced changes in blood pressure (BP), renal sympathetic nerve activity (renSNA), plasma levels of epinephrine (EPI) and norepinephrine (NE), total spillover of NE (TSO), and sensitivity of baroreceptor reflex (SBR) is studied. Chronically instrumented male Wistar rats were injected with 2DG (125 - 500 mg/kg iv), and BP, heart rate (HR), renSNA, TSO, EPI, NE, plasma clearance NE (CINE) and SBR were monitored before and after 2DG administration. The responses to 2 DG in control rats were compared with those in rats pretreated with tyrosile-tyrosine dipeptide (TYR-TYR). SBR was estimated by bolus i.v. sodium nitroprusside injection. 2DG evoked an increase in renSNA by 23%, 40-fold and 2.5-fold increases in EPI and NE concentrations, 2,7-fold increase in TSO, a decrease in HR by 5% in 45 min without reliable changes in BP and CINE. TYR-TYR administration did not affect 2DG-induced changes in HR, TSO, EPI and NE concentrations, but potentiated changes in renSNA by 53% and significantly increased BP by 10%. 2DG produced an increase in the chronotropic (by 87%) and sympathetic (by 72%) components of SBR. TYR-TYR restored the normal values of SBR in 2DG-treated rats. Thus, tyrosine modulates 2DG-induced changes in hemodynamic parameters and renSNA and normalizes SBR via central mechanisms.
Tiurmina
O A
OA
Kuz'min
A I
AI
Medvedev
O S
OS
D000704:Analysis of Variance; D000818:Animals; D003847:Deoxyglucose; D004151:Dipeptides / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D007003:Hypoglycemia / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects* / Q000502:physiology
D004151:Dipeptides; C042696:tyrosyltyrosine; D003847:Deoxyglucose
Vliianie tirozinsoderzhashchego dipeptida na vyzvannye neĭroglikopenieĭ izmeneniia aktivnosti simpaticheskoĭ nervnoĭ sistemy i sistemnoĭ hemodinamiki u bodrstvuiushchikh krys.