Przemysław Sosnowski

The effect of bradykinin on the oxidative state of rats with acute hyperglycaemia

Many clinical and experimental studies have established the beneficial effect of kinins in hypertension, heart failure and ischaemia-reperfusion syndrome, but little attention has been given to the role of kinins in hyperglycaemic conditions. The purpose of the present study was to determine the influence of bradykinin on the levels of glucose, insulin, malondialdehyde and hydrogen peroxide, as well as antioxidative enzyme activity in rats with streptozotocin (STZ)-induced acute hyperglycaemia. In STZ-induced hyperglycaemic rats the levels of glucose, hydrogen peroxide and malondialdehyde were increased by 256% (from 6.0+/-0.3 to 21.4+/-1.3 mmol/l, P<0.001), 33% (from 1.9+/-0.1 to 5.6+/-0.3 mmol H(2)O(2)/ml, P<0.001) and 19% (from 3.7+/-0.3 to 4.9+/-0.2 nmol/l, P<0.001) respectively. The activity of superoxide dismutase, catalase and glutathione peroxidase and the level of insulin were decreased by 46% (from 1367+/-73 to 737+/-59 U/g Hb, P<0.001), 36% (from 2.3+/-0.3 to 1.4+/-0.1 U Bergmayera/g Hb, P<0.001), 31% (from 236+/-19 to 163+/-24 U/g Hb, P<0.001) and 91% (from 47.5+/-1.7 to 2.4+/-0.5 mU/l, P<0.001) respectively in rats treated with streptozotocin. The administration of bradykinin caused the decrease in glucose, hydrogen peroxide and malondi-aldehyde levels by 38% (from 21.4+/-1.3 to 13.3+/-1.0 mmol/l, P<0.001), 37% (from 5.6+/-0.3 to 4.3+/-0.2 mmol H2O2/ml, P<0.001), 39% (from 4.9+/-0.2 to 3.0+/-0.2 nmol/l, P<0.001) respectively and the increase in insulin level and superoxide dismutase, catalase and glutathione peroxidase activity by 62% (from 2.4+/-0.5 to 4.0+/-0.4 mU/l, P<0.001), 23% (from 736.8+/-58.5 to 906.7+/-47.8 U/g Hb, P<0.001), 23% (from 1.4+/-0.1 to 1.9+/-0.1 U Bergmayera/g Hb, P<0.01) and 19% (from 163.1+/-23.6 to 202.3+/-11.7 U/g Hb, P<0.001) respectively in rats with hyperglycaemia. Thus, bradykinin is able to reduce oxidative stress in hyperglycaemic conditions.

Influence of short-term L-arginine supplementation on carbohydrate balance in rats with ischemia-reperfusion syndrome

BACKGROUND There are studies showing stimulative effect of arginine on insulin secretion. This mechanism is not fully explained. The effects of the impact of arginine on carbohydrate balance under the conditions of ischemia and reperfusion remain to be determined. The aim of this study is the evaluation of the influence of short-term L-arginine supplementation on the concentration of glucose and insulin in blood and insulin binding in rat skeletal muscle under the conditions of ischemia and reperfusion. METHODS The study was conducted on male Wistar rats with average body mass 250 ± 30 g. Animals were divided into four groups: Group I - control, Group II - placebo, Group III - L-arginine 500 mg/kg/24 h for 5 days, Group IV - L-arginine and L-NAME (75 μmol/rat/24 h) for 5 days. Each group was divided into subgroups depending on duration of ischemia and reperfusion. Acute ischemia of hind limb was induced in each group by putting pneumatic tourniquet on the thigh. Blood samples and skeletal muscles were collected from the rats. Plasma concentrations of glucose and insulin were measured. Insulin binding to insulin receptors was determined in skeletal muscle. RESULTS A clear reduction of insulin binding to receptor was found in the group of animals without ischemia and the group supplemented with L-arginine and subjected to 4-h ischemia and 30- and 120-min reperfusion. A significant increase in insulin level was found in groups of animals with L-arginine and/or L-NAME subjected to 4-h ischemia at all times of reperfusion. Supplementation with L-arginine and/or L-NAME decreased levels of glucose in blood serum of animals undergoing ischemia-reperfusion syndrome compared to the control and placebo groups. CONCLUSION Under conditions of ischemia-reperfusion, short-term administration of L-arginine causes a decrease in insulin binding capacity of insulin receptors in skeletal muscle, an increase in insulin level and a decrease in the concentration of glucose in blood serum.

The influence of short-term l-arginine supplementation on rats’ muscular and hepatic cells in ischemia–reperfusion syndrome

Due to the complex mechanisms of l-arginine activity, it is difficult to determine the clinical significance of supplementation with this amino acid. The objective of this study was to determine the influence of short-term supplementation with l-arginine in stress conditions, induced by ischemia–reperfusion syndrome, by assessing the damage to muscular and hepatic cells on the basis of creatine kinase (CK), alanine aminotransferase (ALAT) and aspartic aminotransferase (AspAT) activity in blood and the level of oxygen free radicals in analyzed tissues of rats. We observed that induced ischemia of hind limb caused an increase in CK, ALAT and AspAT activity and an increase in the level of free radicals in liver, but not in skeletal muscle. Supplementation with l-arginine led to a reduction in serum activity of CK and AspAT and reduction of the level of free radicals in analysed tissues. Simultaneous supplementation with l-arginine AND l-NAME resulted in a reversal of changes induced by l-arginine supplementation in the case of AspAT and free radicals in skeletal muscle. The results indicate that under conditions of ischemia–reperfusion, short-term administration of l-arginine has a protective effect on skeletal muscle manifesting itself by reduction of CK in the serum and reduction of free radicals level in THIS tissue.

[Hypothermia--mechanism of action and pathophysiological changes in the human body].

This review focuses on the physiological responses and pathophysiological changes induced by hypothermia. Normal body function depends on its ability to maintain thermal homeostasis. The human body can be divided arbitrarily into two thermal compartments: a core compartment (trunk and head), with precisely regulated temperature around 37°C, and a peripheral compartment (skin and extremities) with less strictly controlled temperature, and lower than the core temperature. Thermoregulatory processes occur in three phases: afferent thermal sensing, central regulation, mainly by the preoptic area of the anterior hypothalamus, and efferent response. Exposure to cold induces thermoregulatory responses including cutaneous vasoconstriction, shivering and non-shivering thermogenesis, and behavioral changes. Alterations of body temperature associated with impaired thermoregulation, decreased heat production or increased heat loss can lead to hypothermia. Hypothermia is defined as a core body temperature below 35ºC, and may be classified according to the origin as accidental (e.g. caused by exposure to a cold environment, drugs, or illness) or intentional (i.e. therapeutic), or by the degree of hypothermia as mild, moderate or severe. Classification by temperature is not universal. Lowering of body temperature disrupts the physiological processes at the molecular, cellular and system level, but hypothermia induced prior to cardiosurgical or neurosurgical procedures, by the decrease in tissue oxygen demand, can reduce the risk of cerebral or cardiac ischemic damage. Therapeutic hypothermia has been recommended as a clinical procedure in situations characterized by ischemia, such as cardiac arrest, stroke and brain injuries.

The assessment of selected factors influencing intent to get pregnant in the Greater Poland Region

INTRODUCTION AND OBJECTIVE Nowadays, people decide to have a baby by first analysing their financial situation. Tradition is no longer a factor which determines the decision whether or not to have a baby. A prognosis of the Polish Central Statistical Office (GUS) shows that the population of Poland will fall from 38 to 36 million by 2035. The aim of this study is to assess the procreation behaviour of women in Greater Poland Region. MATERIALS AND METHODS For the research purpose, 3,120 women of reproductive age were examined by using an author designed questionnaire and a synthetic Family Financial Standard Index. RESULTS 74.6% of the respondents lived in an urban area, 25.4% of women come from a rural area. 49% of examined women did not want to have a bigger family, 45% would like to have another child. Analysis of the reasons why women did not want to have another baby revealed that predominance of the financial factor - 67%, living conditions - 18.4% and health- 13.2%. Only 11.9% of the women declared their high financial status, 4.8% of families received family allowance from the government; 88.4% of the examined families did not receive any social benefits. Bad housing situation was declared by 5% of the respondents, 26.7% of the interviewees lived with family members, i.e. parents or grandparents. Analysis of the data concerning religious bonds showed that 67.6% of women declared their indifference to religion. CONCLUSIONS The economic factor was an important reason limiting procreation. The bad situation on the real estate market combined with an insufficient range of social welfare led to a decrease in the birth-rate in the Greater Poland region. The impact of religion on family planning was less important. The influence of the analysed socio-economic factors on family planning was similar in rural and urban areas.