Intermittent fasting was previously reported to exert beneficial effects in sand rats, an animal model of diabetes. The present report complements recent comparable findings recorded in streptozotocin-induced diabetic rats (STZ rats). Intermittent fasting minimized the increase in pancreatic, hepatic and renal weight otherwise observed in the STZ rats. The glycogen content of the liver was higher in the STZ rats than in the control animals. It was positively correlated, at the individual level, with the hepatic glucose content. Significant positive correlations also prevailed between the plasma glucose concentration at sacrifice, which was lower in intermittently fasting or calorie-restricted STZ rats than in non- fasting STZ rats, and either the liver glucose content or liver total carbohydrate content. The kidney PCNA (proliferating cell nuclear antigen) index, as well as the plasma creatinine and urea concentrations, were also lower in intermittently fast- ing or calorie-restricted STZ rats than in non-fasting diabetic animals. These findings reinforce the view that intermittent fasting may exert a favourable effect, in terms of glucose homeostasis and the undesirable consequences of its perturba- tion, in diabetic animals.

The present report complements recent publications on the occurrence of a metabolic syndrome in rats deprived of a dietary supply of long-chain polyunsaturated � 3 fatty acids and on the attempt to correct the resulting metabolic and hormonal defects by exposure of the � 3-depleted rats to a diet enriched with flaxseed oil rich in � -linolenic acid (C18:3� 3). Emphasis is placed (i) on the much slower time course for the depletion in docosahexaenoic acid (C22:6� 3) and accumulation of docosapentaenoic acid (C22:5� 6) and their reversal during dietary deprivation and replenishment of � 3 fatty acids in brain phospholipids, as opposed to liver or intestinal phospholipids, (ii) on the role of circulating phos- pholipids in the transfer of C22:6� 3, synthesized from C18:3� 3 in hepatocytes, from the liver to the brain in the rats de- prived of a dietary supply of � 3 fatty acids, and (iii) on the unfavorable effect of an increase in the total lipid content of the diet from 5 to 10% (w/w) in the perspective of the correction of liver steatosis and visceral obesity in the � 3-depleted rats.

Residual Ca 2+ can accumulate in the nerve terminal during repetitive stimulation; thus, the basis for short-term facilitation (STF). The plasmalemmal Na + /Ca 2+ exchanger (NCX), the Ca 2+ -ATPase (PMCA) and the sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase (SERCA) on the endoplasmic reticulum are three important Ca 2+ regulatory processes in controlling (Ca 2+ )i. The role of these (Ca 2+ )i regulators in the development and maintenance of STF was addressed at the neuromuscular junction. When the NCX is compromised by reduced (Na + )o, the EPSP amplitudes decrease, but with KB-R7943 (a reverse blocker of NCX) the amplitude increases. Compromising the PMCA with pH 8.8 produces an increase in EPSP amplitudes, but treatments with carboxyeosin (a blocker of PMCA) produced mixed results. Blocking the SERCA increases EPSP amplitudes. Facilitation was only slighted altered in some conditions with these manipulations. The results support the view that release is not saturated during a plateau phase of STF since the terminal is able to reach a new plateau with higher stimulation frequency or an altered (Ca 2+ )i. Multiple approaches in compromising the NCX and PMCA are presented. These findings are significant because there is a rapid alteration in transmission when compromising Ca 2+ extrusion mechanisms during STF.

Objectives: In this study the effects of different Leptin concentrations on the blood pressure and heart rate in vivo in anesthetized rabbits were studied. Methods: Sixty Rabbits were divided into two groups, first group received Leptin intra-venously and other group received Leptin intra-arterially. Blood pressure and heart rate in were recorded before and after administration of Leptin. Results: A significant increase in mean arterial blood pressure (MABP) was seen after an intra-arterial injection of 3, 5 and 7 � g/kg of Leptin. This increase in MABP was monitored for different durations 10, 20 and 30 minutes after the infu- sion of each Leptin concentrations. The trend of the increase in MABP with time was demonstrated with all three concen- trations. Intra-venous infusion of Leptin caused a significant decrease in MABP after 10 minutes as well as after 20 and 30 minutes, with all three concentrations (3, 5, and 7 μg/Kg). Heart rate (HR) was not changed significantly at the end of 30 min of infusion. Conclusion: this in vivo study demonstrated that intra-venous Leptin infusion has a different effect on the MABP com- pared with intra-arterial infusion and this difference might be due to the site of action of Leptin.

Grape seed procyanidins (GSPCs) are bioflavonoid polymers that have been shown to have health benefits. We assessed the antidiabetic effect of GSPC in mice. Mice with streptozotocin(STZ)-induced diabetes were orally or intrape- ritoneally administered saline or 40-100 mg GSPC/kg BW daily for 7-10 d. We monitored body weight, blood glucose levels, amounts of food and water consumed, and amounts of urine and feces excreted. On the final day, we analyzed plasma chemistry and found that GSPC, but not structurally related monomers (e.g., catechin and epicatechin), reduced the glucose levels, food and water intake, and urine and feces excreted, all of which had increased due to STZ administra- tion. This suggests a procyanidin-dependent effect of grape seed polyphenols on diabetes. Oral administration of GSPC was less effective within 9 d than was intraperitoneal administration of GSPC, suggesting that the effect is route- dependent. The decrease in diabetic blood glucose levels was reversible; when GSPC administration was stopped, glucose levels rose. However, although pretreatment with GSPC for 7 d did not completely prevent STZ-induced diabetic effects, it rapidly reduced them. Treatment with GSPC reduced fasting glucose levels and improved glucose tolerance in STZ- treated mice, in addition to decreasing STZ-stimulated levels of plasma triglyceride and cholesterol, creatinine, uric acid, and alkaline phosphatase activity. Moreover, GSPC suppressed the reduction in pancreatic islets and the decrease in plasma insulin hormone levels caused by STZ. Our findings indicate that GSPC improves hyperglycemia, polydipsia, polyuria, and polyphagia in mice with STZ-induced diabetes.

Ginsenoside Rg1, the main active ingredient of Ginseng Radix which is a famous Chinese medicine, is widely used as an anti-stress, anti-aging and neurological performance improving agent. In this study, we used calcium imaging and whole-cell patch clamp techniques to investigate the effect of Ginsenoside Rg1 on spontaneous and synchronous Ca 2+ oscillations and the possible mechanisms in primarily cultured hippocampal neuronal networks. We found that Ginse- noside Rg1 could decrease the frequencies of spontaneous and synchronous Ca 2+ oscillations and inhibit the amplitude of high-voltage activated calcium channel currents. These results provided the experimental evidence for the clinical applica- tion of Rg1 as a neuroprotector on the cellular level, and enriched the theoretical system of Chinese medicine.

Progressive evolution of retinal vascular in diabetic retinopathy leads to blindness in up to 8,000 patients yearly. The major purpose of this investigation was to determine proton radiation dose response of the eye's retinal vascu- lature in the hypergalactosemia induced rat model of diabetic-like retinopathy and gain insight of possible role of proton radiotherapy in controlling diabetic retinopathy. A single dose range of proton radiation (8, 14, and 20 Gy) was delivered to one eye of each rat at 4 months following induction of hypergalactosemia. The opposite eye of each rat, which was not irradiated, showed normal progression of retinopathy. Stereologic techniques were used to quantify tissue parameters in situ in a retinal digest preparation that allowed unobstructed access to the vasculature. 15 months following 50% galactose diet, characteristic histopathological lesions of retinopathy such as capillary endothelial cell proliferation, capillary clo- sure, capillary microaneurysms, pericyte loss developed in non-irradiated eyes. The endothelial cell densities for rat re- ceiving 50% galactose diet were significantly higher than that of control (p<0.05). Proton irradiation inhibited significant endothelial cell proliferation at dose from 14Gy to 20Gy (p<0.05), yet not diminished pericyte loss at current dose sched- ule. These findings indicated beneficial effects of proton radiation on hypergalactosemia induced diabetic-like retinopa- thy. Our study should have an impact on further studies to optimize radiation treatment strategies for diabetic retinopathy.

Shift work is associated with alterations in physiological circadian patterns resulting in chronic diseases, e.g. cardiovascular disorders or major depression. The intensity and spectral composition of light is known to affect the 24 h- rhythm of our body. We investigated the effects of two different lighting environments on parameters of circadian rhythm and performance in healthy volunteers during an experimental night shift. Test light with a low color temperature was compared to normal light with a higher color temperature. Melatonin synthesis, red and white blood count, blood pressure, heart rate and indicators of performance were analyzed. Nocturnal increases in melatonin were more pronounced under low color temperature lighting conditions. This was not associated with limited degrees of arousal or vigilance. Mainte- nance of a normal nocturnal rhythm of melatonin with adapted illumination may provide a benefit for employees well- being without affecting their productivity.