[ effect of intra-cerebroventricular injection of insulin on nociception of formalin test in non-diabetic and short-term diabetic rat models]

Pain is a complex process in the central nervous system [CNS]. Several factors can alter the pain threshold and insulin is one of them which is produced by the beta cells of pancreas and capable of crossing blood-brain barrier. The aim of this study was to evaluate the effects of intra-cerebroventricular [ICV] injection of insulin on the pain response to formalin in short-term induced diabetic and non-diabetic rats. Sixty-four Sprague-Dawley male rats [280 +/- 30 g] were divided into non-diabetic and diabetic groups. Diabetes was induced with streptozotocin [STZ, 60 mg/kg, i.p] for elimination of peripheral insulin. After proving diabetes, insulin [5 mU/animal, 5 microL] was injected to the left lateral cerebral ventricle while equal volume of normal saline was injected in control groups. After 10 min, formalin test was performed. Present study showed that ICV injection of insulin possessed anti-nociceptive effect in non-diabetic rats in formalin test while in diabetic rats, it did not have this effect and even decreased pain threshold partially. In conclusion we showed that ICV injection of insulin in non-diabetic rats, in contrast with diabetic rats, has an anti-nociceptive effect in formalin test. In short-term diabetic rats, ICV injection of insulin was not able to reduce pain response and partially decreased pain threshold

[Effect of daidzein on the serum glucose level, lipid profile, and paraoxonase activity in diabetic sprague dawley rats]

Diabetes is one of the most prevalent endocrine disorders. Considering the antidiabetic effect of soybean isoflavones, in this study the effect of daidzein, the most important isoflavone in soybean, on the serum glucose level, lipid profile, and paraoxonase activity in diabetic rats was investigted. Thirty six male Sprague Dawley rats were randomly divided into three groups: 1. healthy, 2. diabetic, and 3. diabetic, supplemented with daidzein. Diabetes was induced in rats by a single injection of streptozotocine [60mg/kg body weight, dissolved in 0.05 mol/l citrate buffer]. It was confirmed when the fasting blood glucose level was above 250 mg/dl. For Group 3, the diet was supplemented with 600 mg diazdein/kg basal diet. The groups of rat were fed their respective diets for three weeks. Supplementation with daidzein had no effect on the fasting glucose level, but, as compared to the diabetic [control] group, it brought about a significant decrease in the triglyceride and low-density lipoprotein levels [P=0.0001]. The high-density lipoprotein levels, too, increased in this group [P= 0.001]. Daidzein had no effect on the paraoxonase enzyme activity, as compared to the control values. However, comparison of the initial and final levels of the activity of this enzyme in the daidzein-supplemented group indicated a positive effect of diadzein in preventing reduction of this enzyme's activity [P=0.0001]. Daidzein may have a desirable effect on the lipid profile disorders, one of the most important complications of diabetes. It can also support the antioxidant system

Partial purification and properties of rhodanese from human placenta

The optimum pH of the enzyme rhodanese [thiosulfate: cyanide sulfurtransferase, EC 2.8.1.1.] was found to be 10.5 in glycine-NaOH and 11.5 in borate-NaOH buffers. The K[m] value was found 1.1X10[-1] for cyanide and 4.0 x 10[-3] M for thiosulfate