Chronic Ritalin Administration during Adulthood Increases Serotonin Pool in Rat Medial Frontal Cortex

Background: Ritalin has high tendency to be abused. It has been the main indication to control attention deficit hyperactivity disorder. The college students may seek for it to improve their memory, decrease the need for sleep (especially during exams), which at least partially, can be related to serotonergic system. Therefore, it seems worthy to evaluate the effect of Ritalin intake on mature brain. There are many studies on Ritalin effect on developing brain, but only few studies on adults are available. This study was undertaken to find Ritalin effect on serotonin transporter (SERT) density in medial frontal cortex (MFC) of mature rat. Methods: Thirty male Wistar rats were used in the study. Rats were assigned into five groups (n = 6 per group): one control, two Ritalin and two vehicle groups. Twelve rats received Ritalin (20 mg/kg/twice a day) orally for eleven continuous days. After one week of withdrawal and another two weeks of rest, in order to evaluate short-term effects of Ritalin, six rats were sacrificed. Another six rats were studied to detect the long-term effects of Ritalin; therefore, they were sacrificed 12 weeks after the previous group. The immunohistochemistry was performed to evaluate the results. Results: Immunohistochemistry studies showed a higher density of SERT in both 2 and 12 weeks after withdrawal from Ritalin intake in MFC of rat and there was no significant difference between these two groups. Conclusions: Our findings demonstrated both short- and long-term effects of Ritalin on frontal serotonergic system after withdrawal period.Key Words: Ritalin, Serotonin, Rats     

Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Hypertensive Effect of Protein Hydrolysate from Actinopyga lecanora (Sea Cucumber) in Rats

Food protein hydrolysates are known to exhibit angiotensin converting enzyme (ACE) inhibitory properties and can be used as a novel functional food for prevention of hypertension. This study evaluated the ACE inhibitory potentials of Actinopyga lecanora proteolysate (ALP) in vivo. The pre-fed rats with ALP at various doses (200, 400, 800 mg/kg body weight) exhibited a significant (p ≤ 0.05) suppression effect after inducing hypertension. To determine the optimum effective dose that will produce maximal reduction in blood pressure, ALP at three doses was fed to the rats after inducing hypertension. The results showed that the 800 mg/kg body weight dose significantly reduced blood pressure without noticeable negative physiological effect. In addition, there were no observable changes in the rats’ heart rate after oral administration of the ALP. It was concluded that Actinopyga lecanora proteolysate could potentially be used for the development of functional foods and nutraceuticals for prevention and treatment of hypertension.     

Immunomodulatory effect of cimetidine in common carp (Cyprinus carpio L.)

The main indication of cimetidine is being H₂-receptor antagonist, but studies suggest that cimetidine may also act as a non-specific stimulant of cell-mediated immunity and immunomodulator. In order to determine the immunomodulatory effect of dietary intake of cimetidine in the common carp (100 ± 10 g), subjects were fed diets containing 0 (control), 50, 100 and 200 mg cimetidine kg^?1 of dry diet for a period of 6 weeks. TLC and NBT assays were significantly (P < 0.05) stimulated in cimetidine-supplemented groups displaying the highest value in 200 mg kg^?1 group. A decrease (P < 0.05) in cortisol and ACH50 value was recorded in fish treated with cimetidine. Serum protein, albumin and serum globulin levels were not significantly changed. The findings of the present investigation suggest that the incorporation of cimetidine in the diet of common carp enhances the non-specific immunity.