ABSTRACT
Background: It has been shown that dietary restriction in the form of every other day fasting [EODF] has neuroprotective effects. The mechanisms of these effects are unknown yet. Recently, it has claimed that dietary restriction can reset circadian and regulate irregular rhythms. Previous studies have demonstrated that dietary restriction can change melatonin production and secretion. Since melatonin has important role in circadian rhythms and its neuroprotective effect has been proved, it is reasonable that at least some dietary restriction effects may be due to the melatonin level changes. To investigate this hypothesis, melatonin receptors antagonist [Luzindole] was used in the rat model of Alzheimer's disease
Material and Methods: Sixty four male rats were assigned into 8 groups which 4 groups had Ad libitum and 4 groups had every other day fasting [EODF] diet. Each group category comprised: 1-control group receiving only solvent of drugs, 2-group which received streptozotocin [STZ] at 3 mg/kg/icv, 3-group which received STZ at 3 mg/kg/icv and luzindole 50 microgr/kg/icv and 4-group which received STZ 3 mg/kg/icv and melatonin 10 mg/kg/ip. Dietary regimen continued for 10 days from the day cannulation was done in lateral ventricles. Spatial memory was evaluated by Morris water maze test. To evaluate the histological changes in the brain tissue, hematoxylin and eosin staining was used
Results: Based on Morris water maze test results, STZ could impair spatial memory in rats while dietary restriction did not improve memory impairment significantly. Likewise, melatonin and luzindole could not restore memory impairment. Histological study indicated that STZ destroyed the brain tissue in different parts including paraventricular zone, fornix, cortex and hippocampus which could be attributed to memory impairment. Counting dead neurons in CA1 part of the hippocampus showed that dietary restriction accompanied by exogenous melatonin with supra physiological dose, could partially improve STZ-induced impact in brain tissue
Conclusion: Melatonin appears not to retain an important role in the effects of dietary restriction on spatial memory impairment. Meanwhile, dietary restriction associated with exogenous melatonin seem to exert neuroprotective effects
ABSTRACT
In addition to genetic and hormonal effect, various environmental influence on hair growth. For instance, stress can release epinephrine in the blood circulation, and epinephrine can effect on various tissues, especially on skin and hair tissue. Many investigators try to find effective drugs for the hair growth. Because most of these drugs are vasodilator agents, we design present study to determine the local effects of epinephrine administration as a vasoconstrictor agent on growth of hair. In this experimental study, 45 Wistar male Rats were divided in three groups, which taking 1.5 ml/kg epinephrine, 1ml/kg epinephrine two times/daily for two months and control group which reciving normal salin with same valume for two months respectively. Following observing the macroscopically findings and segregation of the skin, the slide were prepared and the number of hair follicles were examinated. The epinephrine causes degeneration of hair folicule, sebasus gland, and decreasing number of hair folicule in comping with control group [P<0.05]. This study showed that the subcutaneous adminstration of epinephrine cause the hair lesions, and this significantly is related directly with the dosage of epinephrine