Tuncay Kuloglu

Protective effects of nanostructures of hydrated C60 fullerene on reproductive function in streptozotocin-diabetic male rats

Diabetes mellitus is a well-recognized cause of male sexual dysfunction and impairments of male fertility. Streptozotocin (STZ) is used for medical treatment of neoplastic islet β-cells of pancreas and producing of animal model of diabetes mellitus type 1 that is characterized by suppression of reproductive activity due to the hyperglycaemia-induced oxidative stress and histopathological alterations in testes. Seeking for the agents that could alleviate diabetes-induced damage to reproductive system is yet the important area of inquiry. The present study was designed to evaluate whether hydrated C(60) fullerene (C(60)HyFn), which is known to be powerful bioantioxidant, eliminate testicular dysfunction induced by STZ-diabetes in rats. Wistar strain male albino rats were divided into four groups of six animals each: (1) control group, (2) C(60)HyFn-treated nondiabetic group, (3) STZ-diabetic group and (4) C(60)HyFn-treated diabetic group. Once hyperglycaemia was induced by STZ, rats in the second and fourth groups were treated with C(60)HyFn (in the form of drinking water) at the dose of 4μg/kg daily for 5 weeks. In diabetic rats, relative weights of right cauda epididymis, seminal vesicles, prostate, sperm motility and epididymal sperm concentration were significantly less than those of control group, but which were restored in the fourth group treated with C(60)HyFn (p<0.001). In hematoxylin and eosin staining, marked histopathological changes including degeneration, desquamation, disorganisation and reduction in germinal cells, interstitial oedema and congestion were evident in the testis of diabetic rats, but C(60)HyFn treatment resulted in recovery of histopathological changes and an increase in Johnsens testicular score significantly (p<0.001). C(60)HyFn treatment restores the increased apoptosis induced by STZ-diabetes. In diabetic rats, levels of serum testosterone, testicular reduced glutathione (GSH) and alpha-tocopherol were significantly reduced and testicular lipid peroxidation level was increased (p<0.001). Nevertheless, treatment of diabetic rats with C(60)HyFn resulted in significant corrective effects on these parameters towards the control levels. C(60)HyFn, applied alone, did not exert any toxic effects in testicular tissues. Furthermore, C(60)HyFn treatment in diabetic and nondiabetic rats resulted in considerable elevations of some important polyunsaturated fatty acids. In conclusion, we have presented for the first time substantial evidence that administration of C(60)HyFn significantly reduces diabetes-induced oxidative stress and associated complications such as testicular dysfunction and spermatogenic disruption.

Cardiac, skeletal muscle and serum irisin responses to with or without water exercise in young and old male rats: cardiac muscle produces more irisin than skeletal muscle.

Irisin converts white adipose tissue (WAT) into brown adipose tissue (BAT), as regulated by energy expenditure. The relationship between irisin concentrations after exercise in rats compared humans after exercise remains controversial. We therefore: (1) measured irisin expression in cardiac and skeletal muscle, liver, kidney, peripheral nerve sheath and skin tissues, as also serum irisin level in 10 week-old rats without exercise, and (2) measured tissue supernatant irisin levels in cardiac and skeletal muscle, and in response to exercise in young and old rats to establishing which tissues produced most irisin. Young (12 months) and old rats (24 months) with or without 10min exercise (water floating) and healthy 10 week-old Sprague-Dawley rats without exercise were used. Irisin was absent from sections of skeletal muscle of unexercised rats, the only part being stained being the perimysium. In contrast, cardiac muscle tissue, peripheral myelin sheath, liver, kidneys, and skin dermis and hypodermis were strongly immunoreactivity. No irisin was seen in skeletal muscle of unexercised young and old rats, but a slight amount was detected after exercise. Strong immunoreactivity occurred in cardiac muscle of young and old rats with or without exercise, notably in pericardial connective tissue. Serum irisin increased after exercise, being higher in younger than older rats. Irisin in tissue supernatants (cardiac and skeletal muscle) was high with or without exercise. High supernatant irisin could come from connective tissues around skeletal muscle, especially nerve sheaths located within it. Skeletal muscle is probably not a main irisin source.

Today's and yesterday's of pathophysiology: Biochemistry of metabolic syndrome and animal models

During the past 20 y, there has been much interest in sugars and especially fructose in relation to human health. Over the past decade, considerable scientific debate and controversy have arisen about the potential health effects of sucrose, high-fructose corn syrup (HFCS), and fructose itself. HFCS increasingly has been used as a sweetener in thousands of food products and soft drinks, leading to the development of obesity, diabetes, dyslipidemia, and metabolic syndrome (MetS) in both rodents and humans, which is associated with an increase in body weight. There is a need for detailed research on the mechanism underlying MetS that could lead to a remedy. This review will first systematically present a definition of MetS, its history, prevalence, and comparative diagnostic criteria. We will then consider fructose and its effects on human health, the diet-induced obesity model (various fat contents), the hypercholesterolemic model, the diabetes model, the hypertensive model, the MetS or insulin resistance model, and biomarkers related to MetS, in light of contemporary data using multiple databases (PubMed, MEDLINE, and OVID).

A comprehensive immunohistochemical examination of the distribution of the fat-burning protein irisin in biological tissues.

Irisin was first identified in skeletal muscle cells, but its precise location has not yet been demonstrated, and there is limited information about irisin protein in other human and rat tissues. The present immunohistochemical study was undertaken to screen skeletal muscle and other tissues for irisin immunoreactivity. İrisin staining was found in the brain (neurons and neuroglia), cardiac and skeletal muscle (fibers) and skin (sebaceous glands) tissues in male rats. In both human adult and fetal skeletal muscle, the most intense immunohistochemical staining was in the perimysium and endomysium, in the peripheral nerve (epineurium) and axon and nerve sheaths spreading among the cells, in the sarcoplasma and subendomysium. Irisin was also demonstrated in the testis (seminiferous tubules, some spermatogenic cells in fetal and Leydig cells in fetal and adult testis, ductus epididymis in fetal human epididymis); pancreas (islets of Langerhans, serous acini cells, intralobular and intralobular ducts cells); liver (hepatocytes; Kupffer cells and sinusoidal endothelial cells); spleen (subcapsular region and periarterial lymphatic sheets); the stomach (gastric parietal cells, tunica muscularis cells). We conclude that the fat-burning protein irisin locally produced in peripheral and central tissues could act as a gatekeeper of metabolic energy regulation in those tissues, since this myokine converts white into brown adipose tissue, enhancing energy expenditure.

Alterations of irisin concentrations in saliva and serum of obese and normal-weight subjects, before and after 45 min of a Turkish bath or running

The purpose of this study was to ascertain (1) whether human saliva contains irisin and whether its level correlates with serum irisin concentration, (2) whether salivary glands, eccrine glands and sebaceous glands in human skin produce irisin, (3) how the changes in saliva and serum irisin concentrations after the Turkish bath at 47 ± 3°C compare with the changes caused by moderate exercise in obese and normal weight subjects. Seven obese male subjects and seven normal weight subjects were enrolled for Turkish bath. Seven obese male subjects and seven normal weight subjects were also enrolled for moderate outdoor exercise, and thirteen male normal weight subjects neither exercised nor showered at the Turkish bath. From each participant, 1.5 ml of saliva and 5 ml blood were collected simultaneously before and after the moderate exercise and Turkish bath. Salivary glands and eccrine and sebaceous glands in the skin were screened immunohistochemically for irisin while serum and saliva irisin were measured with an ELISA. Submandibular glands, eccrine glands and sebaceous glands in the human skin showed strong irisin immunoreactivity. Human saliva contained irisin and its level was significantly higher than the serum levels in both obese and normal weight subjects. However, irisin concentrations were more markedly increased in both saliva and serum samples from subjects who had showered at a Turkish bath than in obese subjects who had exercised or in normal weight subjects. Human submandibular glands, eccrine sweat glands and sebaceous glands synthesize irisin.

Insecticide imidacloprid induces morphological and DNA damage through oxidative toxicity on the reproductive organs of developing male rats

We investigated whether treatment with imidacloprid would induce morphological changes, DNA fragmentation, antioxidant imbalance and apoptosis in the reproductive system of developing male rats. Twenty‐four male rats were included in this 90‐day study, starting at 7 days of age. The rats were divided into four groups. The first group was used as control. The second, third and fourth groups received oral 0.5‐, 2‐ and 8‐mg/kg imidacloprid, respectively. Serum, sperm and testis samples were collected from all groups at the end of the experimental period. The weights of the epididymis, vesicula seminalis, epididymal sperm concentration, body weight gain, testosterone and reduced glutathione values were lower in the imidacloprid‐treated groups than that in the controls. All treated groups had increased lipid peroxidation, fatty acid concentrations and higher rates of abnormal sperm. Apoptosis and fragmentation of seminal DNA were higher in rats treated at the two higher doses of imidacloprid. These results show that this compound has a negative effect on sperm and testis of rats. Copyright

Irisin: a potentially candidate marker for myocardial infarction.

Myocardial infarction (MI) causes energy depletion through imbalance between coronary blood supply and myocardial demand. Irisin produced by the heart reduces ATP production by increasing heat generation. Energy depletion affects irisin concentration in circulation and cardiac tissues, suggesting an association with MI. We examined: (1) irisin expression immunohistochemically in rat heart, skeletal muscle, kidney and liver in isoproterenol (ISO)-induced MI, and (2) serum irisin concentration by ELISA. Rats were randomly allocated into 6 groups (n=6), (i) control, (ii) ISO (1h), (iii) ISO (2h), (iv) ISO (4h), (v) ISO (6h), and (vi) ISO (24h), 200mg ISO in each case. Rats were decapitated and the blood and tissues collected for irisin analysis. Blood was centrifuged at 1792 g for 5 min. Tissues were washed with saline and fixed in 10% formalin for histology. Serum irisin levels gradually decreased from 1h to 24h in MI rats compared with controls, the minimum being at 2h, increasing again after 6h. Cardiac muscle cells, glomerular, peritubular renal cortical interstitial cells, hepatocytes and liver sinusoidal cells and perimysium, endomysium and nucleoi of skeletal muscle were irisin positive, but its synthesis decreased 1-4h after MI. At all time-points, irisin increased near myocardial connective tissue, with production in skeletal muscle, liver and kidney recovering after 6h, although slower than controls. Unique insight into the pathogenesis of MI is shown, and the gradually decrease of serum irisin might be a diagnostic marker for MI.

Copeptin, adropin and irisin concentrations in breast milk and plasma of healthy women and those with gestational diabetes mellitus.

Copeptin, adropin and irisin are polypeptide hormones implicated in energy homostasis and diabetes. The purposes of this study were (1) to compare the copeptin, adropin and irisin concentrations between colostrum, transitional and mature milk and plasma in lactating women with and without GDM and (2) to compare these values with those from non-lactating women. Venous blood samples were obtained before suckling from 15 healthy lactating women aged 26-30 years, 15 lactating women with GDM aged 26-32 years, and 14 age-matched controls aged 25-31 years. Colostrum, transitional milk and mature milk samples were collected just before suckling. The concentration of copeptin was determined by EIA while the concentrations of adropin and irisin were determined by ELISA. The levels of copeptin, adropin and irisin in the colostrum were significantly higher than those in transitional and mature milk samples from healthy women; also, transitional milk had higher copeptin, adropin and irisin concentrations than mature milk. The amounts of copeptin in the colostrum and transitional milk were significantly higher than in mature milk samples from women with GDM, while the amounts of adropin and irisin were significantly lower. The relative concentrations of copeptin, adropin and irisin in the plasma samples from these groups of women were similar to those in the colostrum, transitional and mature milk samples, but the latter concentrations were higher than those in the plasma. These peptides could influence the regulation of metabolic pathways and the postnatal growth and development of different organs in the newborn.

Decreased saliva/serum irisin concentrations in the acute myocardial infarction promising for being a new candidate biomarker for diagnosis of this pathology.

Irisin is a muscle-secreted protein. Cardiac muscle produces more irisin than skeletal muscle in response to acute exercise, and is associated with myocardial infarction (MI) in an experimental model induced by isoproterenol in rats. The timing and significance of its release in patients with acute myocardial infarction (AMI) needs further investigation. We have studied the relationship between serum/saliva irisin concentration and AMI in humans. Serum and saliva samples were taken within 3 days of admission in 11 patients with AMI and in 14 matched controls. Salivary gland irisin was detected immunohistochemically, and serum and saliva levels were measured by ELISA. The three major paired salivary glands (submandibular, sublingual and parotid) produce and release irisin into saliva. Troponin-I, CK, CK-MB concentrations in the AMI group gradually increased from up to 12h, while saliva and serum irisin gradually decreased from up to 48 h, compared with the control group (P<0.05). After 12h, troponin-I, CK, CK-MB started to decrease, while saliva and serum irisin started to increase at 72 h. Serum irisin levels correlated with age, while troponin I, CK-MB, and CK were correlated and with saliva irisin in AMI patients. Besides cardiac troponin and CK-MB, irisin adds new diagnostic information in AMI patients, and the gradual decrease of saliva/serum irisin over 48 h could be a useful biomarker.

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats.

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.