Prognostic significance of the chemerin level in coronavirus disease 2019 patients.

Increased serum chemerin levels have been reported in several inflammatory diseases. Few studies have investigated the relationship between chemerin and clinical features of COVID-19. Thus, chemerin may modulate the development and progression of COVID-19. We compared the serum chemerin concentration between patients with and without SARS-CoV-2 infection and its association with the severity and prognosis of COVID-19 pneumonia. This is a prospective, single-center, cross-sectional study. We enrolled COVID-19 patients who presented to our tertiary hospital and healthy controls. The COVID-19 patients were conducted and the dates of symptom onset were recorded. After admission to the hospital and stabilization, blood samples were obtained for routine hemogram, biochemistry, and chemerin. The chemerin level was 37.93 ±â€…17.3 ng/mL in patients followed in the ICU, 29.41 ±â€…12.79 ng/mL in inpatients, 30.48 ±â€…10.86 ng/mL in outpatients, and 25.12 ±â€…9.82 ng/mL in healthy controls. The difference between patients treated in the ICU and healthy controls was significant (P < .001). The high-sensitivity C-reactive protein (hs-CRP), ferritin, procalcitonin (PCT), and D-dimer levels were significantly higher in the intensive care unit (ICU) group (P < .001). Moreover, the chemerin level of patients who died was significantly higher than that of those who survived (P < .001). The chemerin level was increased in COVID-19 patients and also increased with increasing disease severity. The chemerin level was higher in the COVID-19 patients than healthy controls and was significantly higher in patients who died compared to those who did not.

Comparative effects of pravastatin and rosuvastatin on carbohydrate metabolism in an experimental diabetic rat model.

Statin treatment may increase the risk of diabetes; there is insufficient data on how statins affect glucose regulation and glycemic control and the effects of statins on liver enzymes related to carbohydrate metabolism have not been fully studied. Therefore, we aimed to compare the effects of the statin derivatives, pravastatin, and rosuvastatin, on carbohydrate metabolism in an experimental diabetic rat model. Female Wistar albino rats were used and diabetes was induced by intraperitoneal injection of streptozotocin. Thereafter, 10 and 20 mg kg-1 day-1 doses of both pravastatin and rosuvastatin were administered by oral gavage to the diabetic rats for 8 weeks. At the end of the experiment, body masses, the levels of fasting blood glucose, serum insulin, insulin resistance (HOMA-IR), liver glycogen, and liver enzymes related to carbohydrate metabolism were measured. Both doses of pravastatin significantly in creased the body mass in diabetic rats, however, rosuvastatin, especially at the dose of 20 mg kg-1 day-1 reduced the body mass signi ficantly. Pravastatin, especially at a dose of 20 mg kg-1 day-1, caused significant increases in liver glycogen synthase and glucose 6-phosphate dehydrogenase levels but significant decreases in the levels of glycogen phosphorylase, lactate dehydrogenase, and glucose-6-phosphatase. Hence, pravastatin partially ameliorated the adverse changes in liver enzymes caused by diabetes and, especially at the dose of 20 mg kg-1 day-1, reduced the fasting blood glucose level and increased the liver glycogen content. However, rosuvastatin, especially at the dose of 20 mg kg-1 day-1, significantly reduced the liver glycogen synthase and pyruvate kinase levels, but increased the glycogen phosphorylase level in diabetic rats. Rosuvastatin, 20 mg kg-1 day-1 dose, caused significant decreases in the body mass and the liver glycogen content of diabetic rats. It can be concluded that pravastatin, especially at the dose of 20 mg kg-1 day-1 is more effective in ameliorating the negative effects of diabetes by modulating carbohydrate metabolism.

The Effect of Lidocaine on the Experimental Model of Streptozotocin-Induced Alzheimer's Disease.

Introduction: Alzheimer's disease (AD) is a neurodegenerative disease caused by the accumulation of amyloid plaques in the cerebral cortex and hippocampus. In this study, the effects of local anesthetic lidocaine on neurodegeneration markers and memory were investigated for the first time in streptozotocin-induced rat AD model. Methods: Streptozotocin (STZ) was administered intracerebroventricularly (ICV) into Wistar rats to develop AD model. For lidocaine group (n=14), lidocaine (5 mg/kg) was administered intraperitoneally (IP) in addition to STZ injection. Control group animals (n=9) were treated with saline for 21 days. Morris Water Maze (MWM) test was performed to evaluate memory after the injections were completed. Also, the serum levels of TAR DNA-binding protein-43 (TDP-43), amyloid precursor protein (APP), ß-secretase 1, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), response element binding protein (CREB), c-FOS were measured using ELISA test and compared between groups. Results: Lidocaine group animals showed lower escape latency and time in quadrant scores in MWM inferring better memory performance. Furthermore, lidocaine administration caused a significant decline in TDP-43 levels. However, the expression of APP and ß-secretase were significantly higher in AD and lidocaine groups compared to control group. Moreover, lidocaine group markedly had higher serum NGF, BDNF, CREB, and c-FOS levels compared to those in the AD group. Conclusion: In addition to neuroprotective effects in STZ-induced AD model, Lidocaine also appears to improve memory. This effect might be associated with increased levels of several growth factors and associated intracellular molecules. The therapeutic role of lidocaine in the pathophysiology of AD should be studied in the future.

Associations of alveolar bone loss and interleukin-1ß levels in one- and two-stage surgical procedures: a randomized prospective trial.

OBJECTIVE: Dental implants have been widely and successfully used in recent years as an alternative treatment for removable and fixed dental prostheses. The aim of this randomized prospective study was to determine the alveolar bone loss rate (ABLR) and IL-1ß levels in one- and two-stage surgical procedures. MATERIALS AND METHODS: This study included 40 patients with a single missing tooth in the posterior mandible; dental implants were inserted using a one-stage surgical procedure (Group I) or a two-stage surgical procedure (Group II). All clinical periodontal parameters were recorded; peri-implant crevicular fluid (PICF) samples were collected before loading (T0) and during the third (T1) and sixth (T2) months after loading. ABLR values were evaluated at T0 and T2 by using dental tomography. PICF was analysed after T2 samples were collected. The study was registered through clinicaltrials.gov; identifier NCT03045458. RESULTS: This study found that, the probing pocket depth was found to be significantly higher in Group I than Group II at both T1 and T2 (p < .05). There was no significant difference in other clinical parameters between the groups (p > .05). There was a significant difference between Group I ABLR values at T0 and T2 (p < .05). The PICF IL-1ß levels were not significantly different between groups (p > .05). CONCLUSIONS: Within the limitations of the short observational period and small sample size of this study, two-stage implant placement shows comparable clinical outcomes to implants placed using a one-stage placement protocol.

Do 100- and 500-µT ELF magnetic fields alter beta-amyloid protein, protein carbonyl and malondialdehyde in rat brains?

Several studies still state that presently accepted safety standards for extremely low-frequency magnetic fields (ELF-MFs) do not provide adequate protection, and therefore the standards are still open to question. To help resolve this question, the aim of this study was to illuminate the interaction between biomolecules and ELF-MFs by investigating the effect of ELF-MFs on beta-amyloid protein (BAP), protein carbonyl (PC) and malondialdehyde (MDA) in rat brain. For this study, 30 adult male Sprague-Dawley rats were used, which were divided into two experimental groups and a sham exposed group. Rats in two experimental groups were exposed to 100- and 500-µT ELF-MFs (50 Hz) for 2 h/day for 10 months, which are the generally accepted safety standards for public and occupational exposures. The same procedures were applied to the rats in the sham group, but with the generator turned off. The results of this study showed that neither ELF-MFs used in this study altered BAP level significantly (p>0.05). However, PC and MDA levels were increased by the exposure to 100- and 500-µT ELF-MFs (p < 0.0001). In conclusion, both PC and MDA levels were altered by long-term exposure to either 100 or 500 µT ELF-MF. However, many further and more comprehensive studies will be required to elucidate the interaction mechanisms between ELF-MFs exposure and living organisms.

Effect of 900 MHz radio frequency radiation on beta amyloid protein, protein carbonyl, and malondialdehyde in the brain.

Recently, many studies have been carried out in relation to 900 MHz radiofrequency radiation (RF) emitted from a mobile phone on the brain. However, there is little data concerning possible mechanisms between long-term exposure of RF radiation and biomolecules in brain. Therefore, we aimed to investigate long-term effects of 900 MHz radiofrequency radiation on beta amyloid protein, protein carbonyl, and malondialdehyde in the rat brain. The study was carried out on 17 Wistar Albino adult male rats. The rat heads in a carousel were exposed to 900 MHz radiofrequency radiation emitted from a generator, simulating mobile phones. For the study group (n: 10), rats were exposed to the radiation 2 h per day (7 days a week) for 10 months. For the sham group (n: 7), rats were placed into the carousel and the same procedure was applied except that the generator was turned off. In this study, rats were euthanized after 10 months of exposure and their brains were removed. Beta amyloid protein, protein carbonyl, and malondialdehyde levels were found to be higher in the brain of rats exposed to 900 MHz radiofrequency radiation. However, only the increase of protein carbonyl in the brain of rats exposed to 900 MHz radiofrequency radiation was found to be statistically significant (p<0.001). In conclusion, 900 MHz radiation emitted from mobile/cellular phones can be an agent to alter some biomolecules such as protein. However, further studies are necessary.

Identification of interleukin 2, 6, and 8 levels around miniscrews during orthodontic tooth movement.

The aim of this study was to identify the levels of interleukin (IL)-2, IL-6, and IL-8 around miniscrews used for anchorage during canine distalization. Sixteen patients (eight males and eight females; mean age, 16.6 ± 2.4 years) who were treated with bilateral upper first premolar extractions were included in the study. Thirty-two maxillary miniscrew implants were placed bilaterally in the alveolar bone between the maxillary second premolars and first molars as anchorage units for maxillary canine distalization. Three groups were constructed. The treatment, miniscrew, and control groups consisted of upper canines, miniscrew implants, and upper second premolars, respectively. Peri-miniscrew implant crevicular fluid and gingival crevicular fluid (GCF) were obtained at baseline (T1) and at 1 (T2), 24 (T3), and 48 (T4) hours, 7 (T5) and 21 (T6) days, and 3 months (T7) after force application. Paired sample t-tests were used to determine within-group changes and Dunnett's t and Tukey's honestly significant difference tests for between-group multiple comparisons. During the 3 month period, IL-2 levels significantly increased (P < 0.01) but only in the treatment group after 24 hours. IL-6 levels were unchanged at all times points in the three groups. IL-8 levels increased significantly at 1 (P < 0.05), 24 (P < 0.01), and 48 (P < 0.01) hours in the treatment group and at 24 (P < 0.05) and 48 (P < 0.01) hours in the miniscrew group. It appears that miniscrews can be used for anchorage in orthodontics when correct physiological forces are applied.

Alterations of hematological variations in rats exposed to extremely low frequency magnetic fields (50 Hz).

BACKGROUND AND AIMS: The aim of this study was to evaluate the possible effects of in vivo exposure to extremely low frequency electromagnetic fields (ELF-EMF) on whole blood parameters (hematological parameters) in rats. METHODS: Forty eight female Wistar rats, obtained from the Medical Science Application and Research Center, Dicle University, Turkey in 2004 were divided into four separate groups: two exposed groups (0.97 mT, 50 and 100 days, 3h/day) and two controls (sham). RESULTS: Eosinophil, hemoglobin and MPV levels significantly decreased in rats that were exposed to EMF for 50 days. When the data for rats exposed for 50 days and 100 days were compared, it was found that MPV levels in rats exposed for 100 days were significantly lower. There was no significant difference in total leukocyte, neutrofil, lymphocyte, monocyte, eosinophil and basophil counts, or in erythrocyte, Hct, MCH, MCHC, RDW, PLT and PDW levels between the exposed and sham-exposed groups. ELF-EMF exposure had no effect on body weight. Also, liver weight did not show any significant difference between groups. CONCLUSIONS: Our results indicate that the applied ELF-EMF exposure may induce slight but statistically significant alterations in some hematological parameters of rats, within the physiological range.

Extremely low frequency magnetic fields cause oxidative DNA damage in rats.

PURPOSE: To detect the genotoxic effects of extremely low frequency (ELF) -magnetic fields (MF) on oxidative DNA base modifications [8-hydroxyguanine (8-OH-Gua), 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua) and 4,6-diamino-5-formamidopyrimidine (FapyAde)] in rat leucocytes, measured following exposure to ELF-MF. MATERIALS AND METHODS: After exposure to ELF-MF (50 Hz, 100 and 500 microT, for 2 hours/day during 10 months), DNA was extracted, and measurement of DNA lesions was achieved by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS). RESULTS: Levels of FapyAde, FapyGua and 8OHdG in DNA were increased by both 100 microT and 500 microT ELF-MF as compared to a cage-control and a sham group; however, statistical significance was observed only in the group exposed to 100 microT. CONCLUSION: This is the first study to report that ELF-MF exposure generates oxidatively induced DNA base modifications which are mutagenic in mammalian cells, such as FapyGua, FapyAde and 8-OH-Gua, in vivo. This may explain previous studies showing DNA damage and genomic instability. These findings support the hypothesis that chronic exposure to 50-Hz MF may be potentially genotoxic. However, the intensity of ELF-MF has an important influence on the extent of DNA damage.

Effect of ovariectomy and female sex hormones administration upon gastric ulceration induced by cold and immobility restraint stress.

OBJECTIVE: To investigate the protective effects of estrogen and progesterone administrations on gastric mucosal barrier of rats applied ovariectomy, cold and immobility stress. METHODS: Seventy female Wistar rats, obtained from Medical Science Application and Research Center, Dicle University, Turkey on the year 2004, were divided into 10 separate groups (n=7). Nothing was applied to the animals of Group 1 (control); bilateral ovariectomy was performed on the animals of the Groups 2, 4, 5, 6, 7, 8, 9, and 10. Groups 5 and 6 was applied 5 mg/kg 17beta-estradiol and groups 7 and 8 was applied 10 mg/kg progesterone for 7 days. The animals in the Groups 9 and 10 were applied 2.5 mg/kg 17beta-estradiol and 5 mg/kg progesterone during 7 days. The animals in the groups 3, 4, 6, 8 and 10 were exposed to cold and immobility stress for 4 hours at 4degrees celsius. RESULTS: The levels of mucus and phospholipids were decreased in the rats applied ovariectomy and stress as compared to the control groups (p<0.001). The increase determined the mucus and phospholipids levels in estrogen and progesterone administered rats as compared to stress applied group (p<0.001). While the cold and immobility stress causes important damages in gastric mucosa, estrogen and progesterone administrations has protective effects in ovariectomized rats. CONCLUSION: The estrogen and progesterone administration prevents the stress that caused decrease in the levels of mucus and phospholipids, thus females are more resistant to gastric ulcer rather than males due to their sex hormones.

Effect of 50-Hz 1-mT magnetic field on the uterus and ovaries of rats (electron microscopy evaluation).

BACKGROUND: The aim of this study was to investigate the effect of extremely low frequency magnetic fields (ELFMF) on the uterus and ovary of rats. MATERIAL/METHODS: Forty-eight female Wistar albino rats were divided into two groups, one for 50 and the other for 100 days of exposure. Each group was further divided into two groups, one sham exposed (n=12) and the other the experimental group (n=12). The experimental rats were exposed to 50-Hz 1-mT ELFMF for three hours/day for 50 or 100 days. The sham groups of rats were kept under the same circumstances without applying ELFMF. Electron microscopic examination was performed to evaluate the ovaries and uterus. RESULTS: Ultrastructural dissolution, decrease in cell organelles, cavities in cells, heterochromative appearance, and typical structural loss of the nucleus were observed in germinal epithelial cells of the rat ovaries in the 50-days ELFMF exposure group. Ultrastructural alterations in germinal epithelium and tunica albuginea of ovaries, irregularity in nucleus and nucleolus, increase in lipid vacuoles of cell cytoplasm and reduction in organelles were observed in rat ovaries in the 100-days ELFMF exposure group. Similar alterations were observed in uterus. Malondialdehyde concentration (MDA) of the ovaries and uterus increased in rats of the two exposure groups (p<0.001). CONCLUSIONS: The results of the study showed that 50 and 100 days of exposure to a 1-mT ELFMF can cause alterations at the cellular level and in MDA concentration.

Seasonal and physiological variations in serum chemistry and mineral concentrations in cattle.

The present study reports the seasonal and physiological variations of copper, zinc, magnesium, iron, sodium chlorine, potassium, calcium, phosphorus, urea, alkaline phosphatase (ALP), creatinine (CR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, albumin, globulin, lactate dehydrogenase (LDH), and total protein concentrations in cattle. Two groups of mated (n = 14) and nonmated (n = 10) healthy cows were selected for the study. Serum samples were collected at each of four periods: (1) early pregnancy (May), (2) midpregnancy (August), (3) late pregnancy (October), and (4) lactation (February). Physiological variations result in changes of cholesterol, calcium, LDH, and total protein concentrations. Phosphorus varies only with seasonal but not physiological changes, whereas ALP, copper, magnesium, and potassium concentrations change with physiological and seasonal conditions. The copper concentration is increased through the pregnancy. Neither the seasonal nor the physiologic variations affect zinc, iron, sodium, chlorine, calcium, urea, creatinine, albumin, and globulin values in both groups in all periods. Thus, these values can be used as reference for both mated and nonmated bovines. The measured total protein might not reflect its true value because of dehydration during the hot season. These observations suggest that seasonal and physiologic variations have to be taken into consideration for the correct interpretation of serum chemistry and elements status in cattle. Nutritional supplements are required for cattle during certain periods to avoid a decline of their performance, which would then represent consequent economic loses.

N-terminal proBNP plasma levels correlate with severity of mitral stenosis.

BACKGROUND AND AIM OF THE STUDY: Brain natriuretic peptide (BNP), a neurohormone, is secreted predominantly from the ventricular myocardium. Studies investigating BNP secretion in diseases affecting the right side of the heart are scarce. The relationship between N-terminal proBNP (NT-proBNP) and echocardiographic and clinical findings was studied in cases with isolated moderate to severe rheumatic mitral stenosis (MS), and in patients with previous mitral valve replacement (MVR). METHODS: Thirty-two patients with MS (mean age 41.2 +/- 5.7 years), 20 with MVR (mean age 46.0 +/- 4.6 years) and 30 healthy individuals (mean age 40.3 +/- 4.9 years) were included in the study. In addition to NT-proBNP measurements, detailed transthoracic echocardiography was performed in all patients and healthy subjects. RESULTS: Plasma levels of NT-proBNP were significantly higher in patients with MS than in those with MVR or in controls (99.8 +/- 12.7 versus 74.7 +/- 6.9 and 48.5 +/- 10.5 pg/ml, respectively; p <0.0001 all groups). NT-proBNP levels showed a significantly greater increase in severe MS than in moderate MS (109.8 +/- 5.6 versus 88.3 +/- 7.6 pg/ml, p <0.0001). NT-proBNP levels also were higher in MVR patients than in controls (74.7 +/- 6.9 versus 48.5 +/- 10.5 pg/ml; p <0.0001). Although NT-proBNP levels did not correlate with left ventricular ejection fraction (LVEF) in patients with MS (r = -0.33; p >0.05), there was a positive correlation with pulmonary artery pressure (r = 0.87; p <0.001) and a negative correlation with mitral valve area (MVA) (r = -0.89; p <0.0001). However, multivariate analysis identified only MVA as an independent correlate of NT-proBNP (beta = -0.47; p = 0.02). CONCLUSION: In patients with rheumatic MS, NT-proBNP levels correlated positively with MS severity. Moreover, NT-proBNP levels increased significantly in patients with MS, but were significantly lower in those who underwent MVR.

Oxidative DNA damage in rats exposed to extremely low frequency electro magnetic fields.

Extremely low frequency (ELF) electromagnetic field (EMF) is thought to prolong the life of free radicals and can act as a promoter or co-promoter of cancer. 8-hydroxy-2'-deoxyguanosine (8OHdG) is one of the predominant forms of radical-induced lesions to DNA and is a potential tool to asses the cancer risk. We examined the effects of extremely low frequency electro magnetic field (ELF-EMF) (50 Hz, 0.97 mT) on 8OHdG levels in DNA and thiobarbituric acid reactive substances (TBARS) in plasma. To examine the possible time-dependent changes resulting from magnetic field, 8OHdG and TBARS were quantitated at 50 and 100 days. Our results showed that the exposure to ELF-EMF induced oxidative DNA damage and lipid peroxidation (LPO). The 8OHdG levels of exposed group (4.39+/-0.88 and 5.29+/-1.16 8OHdG/dG.10(5), respectively) were significantly higher than sham group at 50 and 100 days (3.02+/-0.63 and 3.46+/-0.38 8OHdG/dG.10(5)) (p<0.001, p<0.001). The higher TBARS levels were also detected in the exposure group both on 50 and 100 days (p<0.001, p<0.001). In addition, the extent of DNA damage and LPO would depend on the exposure time (p<0.05 and p<0.05). Our data may have important implications for the long-term exposure to ELF-EMF which may cause oxidative DNA damage.

Lipid peroxidation, antioxidant defense, status of trace metals and leptin levels in preeclampsia.

OBJECTIVE: To investigate the changes in enzyme activities of erythrocyte superoxide dismutase (SOD), catalase, and placental glutathione peroxidase (GSH-Px), and analyze the levels of serum malondialdehyde (MDA), copper (Cu), zinc (Zn), selenium (Se), leptin and placental MDA and glutathione (GSH). STUDY DESIGN: Cross-sectional prospective study consisting of 32 preeclamptic (PE) pregnant, 25 non-pregnant (NP) women, 28 healthy pregnant (HP) women. Levels of lipid peroxides in serum and placenta, and activities of SOD, catalase in erythrocyte and placental GSH level, placental GSH-Px activity were measured by spectrophotometric methods. Serum levels of Cu, Zn, Se measured by atomic absorption spectrophotometry. Serum levels of leptin was measured by enzyme immunoassay by using the Cayman chemical kit. One-way analysis of variance and post hoc Tukey-HSD test and Pearson correlation test were used for the statistical analyses. RESULTS: Serum levels of MDA, Cu, Leptin were markedly higher (P < 0.001); and serum level of Se was markedly lower (P < 0.001) in PE women compared with HP women and NP women. Also, placental MDA level was higher (P < 0.001) and placental GSH-Px activity was lower in PE women compared with HP women. In preeclamptic women erythrocyte catalase activity was markedly increased (P < 0.001), while erythrocyte SOD activity was markedly decreased (P < 0.001) compared to HP women and NP women. Placental GSH level was decreased compared to HP women (P < 0.001). Serum level of Zn was markedly decreased compared to NP women (P < 0.001) but no significant difference was observed in PE pregnant when compared with HP women (P > 0.05). Placental MDA level in PE women had significant negative correlation with serum Se level (r = -0.353, P < 0.05). A negative correlation was found between erythrocyte catalase activity with birth weight (r = -0.528, P < 0.001). Also, there were a significant negative correlation between serum levels of Cu and Se in the preeclamptic women (r = -0.407, P < 0.05). CONCLUSION: Our data demonstrate that elevation of lipid peroxides together with impaired antioxidant defense mechanisms and status of trace metals and the presence of possible interrelationship and crosstalk between those parameters may be related at least partly to the pathogenesis of preeclampsia. Additionally, lipid peroxides and blood oxidative imbalance could be part of the cytotoxic mechanisms leading to endothelial cell injury.

Effects of seasonal and physiological variations on the serum major and trace element levels in sheep.

The aim of this study was to investigate the possible effects of the seasonal and physiological variations on the Cu, Zn, Mg, Fe, Se, Ca, K, Na, Cl, and P concentrations and their relationships with the estradiol and progesterone levels in Sakiz-Ivesi sheep. For this purpose, 34 healthy Sakiz-Ivesi crossbreed sheep were divided into two groups. The first group (n=22) was mated and the second group (n=12) was not mated. They were raised under pasture conditions and without any dietary supplementation. Their serum samples were collected four times a year at each season and under each physiologic condition. The periods are 1=early pregnancy (October), 2=late pregnancy (January), 3=lactation (April), and 4=dry season (July). The results of this study indicated that (1) Mg concentrations in serum vary with seasonal variations but not physiological variations, (2) Fe and K concentrations in serum vary only with physiological variations, (3) the Cu concentration changes not only pregnancy but also through some other hormonal changes not caused by pregnancy, (4) Ca, P, and Se concentrations could vary with both physiologic and seasonal variations, (5) Zn, Na, and Cl were almost identical for both groups and altered depending on neither season of the year nor the physiologic status, (6) both increased estradiol level and increased progesterone level can raise Cu levels in serum, and (7) increased serum Ca concentrations are related with increased estradiol and decreased P and Mg levels. These observations suggest that seasonal and physiologic variations and sexual cycle have to be taken into consideration for a correct interpretation of elements status. If sheep are maintained at pasture conditions, the nutritional requirements must be supplemented during certain periods. Otherwise, it is apparent that this will cause a decline in the total performance of sheep and, consequently, economic lost.