Previous studies have demonstrated that central injection of L-carnosine (β-alynyl-L-histidine), dipeptide synthesized in mammalian muscles, affects renal sympathetic nerve activity (RSNA) and blood pressure (BP) in anesthetized rats. In the present study, using urethane-anesthetized rats, we examined the dose-dependent effects of intravenous (IV) injection of various doses of anserine, dipeptide of similar structure to L-carnosine, on RSNA, BP and heart rate (HR). We found that injection of a low dose of anserine (1 μg) significantly suppressed RSNA, BP and HR. Conversely, a high dose (1000 μg) of anserine significantly elevated RSNA, BP and HR. Pretreatment with lateral cerebral ventricular (LCV) injection of thioperamide, a histaminergic H3-receptor antagonist, eliminated the effects of a low dose of anserine on RSNA, BP and HR. LCV injection of diphenhydramine, a histaminergic H1-receptor antagonist, abolished the effects of a high dose of anserine on RSNA, BP and HR. These findings suggest that anserine affects RSNA, BP and HR in a dose-dependent manner, and that the histaminergic nerve may be involved in the dose-different effects of anserine in rats., M. Tanida ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Beneficial effects of sesame lignans, especially antioxidative
effects, have been widely reported; however, its potential effects
on autonomic nerves have not yet been investigated. Therefore,
the current study aimed to investigate the effect of sesame
lignans on the autonomic nervous system. The sympathetic nerve
activity in rat skeletal muscle was measured using
electrophysiological approaches, with blood flow determined
using the laser Doppler method. Sesame lignans were
administered intragastrically at 2 and 20 mg/kg, and after
60 min, the sympathetic nerve activity was observed to increase
by 45.2 % and 66.1 %, respectively. A significant increase in
blood flow (39.6 %) was also observed for the 20-mg/kg dose
when measured at 55 min after administration. These
sympathomimetic effects were completely prevented by
subdiaphragmatic vagotomy, and the increase in blood flow was
eliminated in the presence of the β2-adrenergic receptor inhibitor
butoxamine. Thus, it is proposed that sesame lignans can
increase the blood flow of skeletal muscle, possibly by exciting
sympathetic nerve activity through the afferent vagal nerve.