حسین جنیدی

Ghrelin is a regulatory peptide with endocrine and metabolic effects in mammals and birds.

The aim of this study was to investigate the possible effects of intracerebroventricular (ICV) in-jection of ghrelin on the plasma level of some hormones and biochemical indices involved in the energy balance of neonatal chicks.

Intracerebroventricular injection of 20 or 40 pmol ghrelin/individual was done. Blood samples were collected from the jugular vein 15 and 30 minutes after the ICV injection of ghrelin to measure serum parameters.

The ICV administration of 20 and 40 pmol ghrelin/individual had no effects at 15 min post-injection, but at 30 min post-injection, the triiodothyronine (T3) level significantly decreased in a dose-dependent manner. The leptin level also declined significantly compared to that of the control group. There were no significant changes in other parameters, including insulin, T4, triglyceride, cholesterol, and glucose.

It can be concluded that the changes that occurred in T3 and leptin levels may have been due to the effects of ghrelin on the metabolic rate and food intake (concerning T3) and the parallel action of ghrelin and leptin (concerning leptin).

Benzodiazepines, which act via gama-aminobutyric acid (GABA) chloric channels are among the main drugs used for treatment of anxiety. Lemon Verbena is a herbal medicine, which contains compounds such as flavonoids, which similar to benzodiazepines have affinity to GABA receptors. Lemon verbena is used for treatment of anxiety and insomnia in folk medicine. In this study, we examined possible anti-anxiety and sedative effect of this plant.

Aqueous and alcoholic extracts of Lemon Verbena (1, 10 and 100 mg/kg), distilled water and diazepam (2 mg/kg) were injected intraperitoneally to groups of 7 to 8 mice. For investigating the anxiolytic effects, the animals were tested by elevated plus maze  (EPM) 45min thereafter. For evaluating hypnotic and sedative effects, we used ketamine induced sleeping time test and onset and duration of sleep were recorded.

Aqueous extract of Lemon Verbena (10 mg/kg) increased time spent in open arms and decreased time spent in closed arms compared to control group. Aqueous extract of Lemon Verbena (100 mg/kg) also reduced onset of sleep and increased sleep duration compared to control group. All doses of alcoholic extract reduced onset of sleep and increased sleep duration.

This study shows that lemone verbena possesses anti-anxiety and hypnotic activity in animal model.

Central Nitrergic and GABAergic play several roles in central nervous system. Release and modulation of some neurotransmitters can be affected by nitric oxide. This study was performed to find the effect of intracerebroventricular (ICV) injection of L-arginine as a donor of nitric oxide on the relative mRNA expression of GAD1 and GAD2 in the brain stem of neonatal chicken.

Fifteen Leghorn neonatal chicks were divided into a control group (no injection), sham group (ICV injection of Evans-Blue 0.1%) and test group (ICV injection of 800 nM L-arginine.

ICV injection of L-arginine significantly decreased the relative mRNA expression of GAD1 and GAD2 (p < 0.05). The relative mRNA expression of these two genes in sham group and control group was similar (p > 0.05).

It seems that the effect of nitric oxide on GABAergic system in some physiological behaviors such as food intake is mediated by diminishing of the relative mRNA expression of GAD1 and GAD2.