Use of Ozone Therapy and Thymoquinone in the Prevention of Formaldehyde Toxicity by Inhalation: An Experimental Study.

INTRODUCTION: The study determined the damage caused by formaldehyde (FA) exposure in blood and liver samples using biochemical markers. Histopathological analysis was performed using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method and measurement of CD68 cell density. To what extent the antioxidant molecules thymoquinone (TQ) and ozone (O3) reversed the damage caused by FA exposure was investigated, both when used alone and combined. METHODS: Fifty-six Sprague-Dawley male rats of eight to ten weeks of age were used in the experiment. The rats were divided into eight groups, with seven rats in each group: the untreated control group, the group treated with TQ (10 mg/kg/day), the group treated with O3 (150 µg/kg/day), the group treated with TQ+O3, the group exposed to FA (10 ppm 8 h/day), the group receiving FA+TQ, the group receiving FA+O3, and the group receiving FA+TQ+O3. Serum aspartate transaminase (AST), alanine transaminase (ALT), total antioxidant (TAS, U/mL), and total oxidant (TOS, nmol/mL) levels were analyzed. TAS and TOS levels, CD68 cell density, and apoptotic cells were determined in liver tissues. RESULTS: FA exposure caused an increase in serum AST and ALT levels of (p<0.05) experimental animals, a decrease in TAS levels in serum (p=0.03) and liver (p>0.05) and an increase in TOS levels (p>0.05), TUNEL positivity (p<0.001), and CD68 cell density (p=0.004). Administration of TQ and O3 as antioxidants significantly reversed biochemical and histopathological alterations in the serum and liver. CONCLUSION: TQ and ozone therapy suppressed oxidative stress caused by FA exposure and reversed the emerging histopathological deteriorations. Ozone therapy did not suppress the effects of TQ. Therefore, ozone therapy can be given as a supportive therapy along with the main therapeutic agents. We think TQ and ozone therapy may be useful to protect individuals exposed to FA.

Evaluation of major coronary artery Bifurcation angles with digital angiography: A detailed study of prevalence in the Upper Euphrates Basin.

Objectives: To investigate the diversity and average values of bifurcation angles in a large population to help develop new methods. Methods: One thousand five individuals (504 females, 501 male) who visited the Cardiology Polyclinic of Firat University Hospital with the complaint of chest pain between 2010 and 2015 were evaluated retrospectively. Bifurcation angle measurements between LMCA-CX, CX-LAD, LMCA-LAD, CX-OM1, CX-OM2, LAD-D1, LAD-D2, RCA-RMD, RCA-RVD and PDA-PL were evaluated in all cases. Results: Bifurcation angles between LMCA-LAD, LMCA-Cx and LAD-Cx branches with "> 90 wide angle bifurcations", and Cx-OM1, Cx-OM2, LAD-D1, LAD-D2, RCA-RMD and PDA-PL with "<70 Y type bifurcation angle" were found to be high in male and female individuals. The RCA-RVD in female individuals was "<70 Y-type bifurcation" in 14 (2.8%) people, "> 70-90 T-type bifurcation" in 209 (41.5%) people, and "> 90 wide angle bifurcation" in 281 (55.8%) people. Results for male subjects were compatible with this. The correlations of all angles were examined. Robust positive correlations (p≤0.001) were found for the angular measurements between the main branches and the side branches (Cx-OM1, Cx-OM2, LAD-D1, LAD-D2 and RCA-RMD, PDA-PL). Conclusion: With the help of developing technology, we believe that all this coronary angiography data will guide bifurcation stent techniques, which are essential alternatives to bypass.

The effect of the platelet-rich plasma and ozone therapy on tendon-to-bone healing in the rabbit rotator cuff repair model.

BACKGROUND: The aim of this study is to histologically and biomechanically investigate the effects of local PRP and ozone therapy (O2O3) on tendon-to-bone healing in a rabbit model of the supraspinatus tendon tear. METHODS: Four groups were formed to have seven rabbits in each group: repair, R; repair + PRP, RP; repair + ozone, RO; and repair + PRP + ozone, RPO. The supraspinatus tendon was detached by sharp dissection from the footprint and an acute tear pattern was created. Thereafter, tendon repair was performed with the transosseous technique. In the RP group, PRP, and in the RPO group, PRP + O2O3 mixture was injected to the tendon repair site. In the RO group, O2O3 gas mixture was injected into subacromial space three times a week for a total of 4 weeks. The study was ended at postoperative 6th week. RESULTS: When compared with the R group, a statistically significant increase was observed in the biomechanical strength of the RP and RPO groups. The highest increase in biomechanical strength was detected in the RPO group. The histology of the RO and RPO groups showed better collagen fiber continuity and orientation than the R and RP groups. CONCLUSIONS: The results obtained from this study show that the ozonized PRP can be used as biological support to increase tendon-to-bone healing. However, these results need to be supported by clinical studies.

The Evaluation of Radiologic Angular Measurements in Patients with Foot Pain.

BACKGROUND: The aim of this study was to investigate the relationship between foot deformities by comparing foot radiographs of patients with complaints of foot pain with those of healthy individuals. METHODS: The study included 30 patients with pes cavus, 30 patients with pes planus, 30 patients with calcaneal spur, and 30 controls aged 30 to 60 years. All participants underwent measurement of right and left foot length; metatarsophalangeal width; and calcaneal pitch (CA), talohorizontal (TA), talometatarsal (TM), and lateral talocalcaneal (LTC) angles from lateral radiographs. RESULTS: There were no statistically significant differences between all participants regarding sex, age, weight, and body mass index (P > .05). Among patients with clinically diagnosed pes cavus, the diagnostic rate of CA was 100% in both feet, and 83.3% in the right foot and 96.7% in the left foot according to the TM angle. The diagnostic rates of angular measurements in patients with pes planus were as follows: 20% in the right foot and 30% in the left foot depending on the CA angle, 100% in both feet depending on the TM angle, and 66.7% in the right foot and 46.7% in the left foot depending on the LTC angle. A very strong positive correlation was found between the CA and LTC angles in patients with calcaneal spur and pes planus (P < .001); also, statistically significant positive correlation was found between the CA and TA angles (P < .05). The angular measurements in patients with calcaneal spur were found to be consistent with pes planus with a high rate. CONCLUSIONS: Angular changes caused by deterioration of foot biomechanics lead to various deformities. Pes planus ranks first among these. Therefore, we believe that radiographic angular measurements in patients presenting with foot pain in addition to clinical evaluation would be useful in considering associated deformities and planning treatments.

Impact of Hard Palate Angulation Caused by Septal Deviation on Maxillary Sinus Volume.

OBJECTIVE: To investigate the effect of hard palate angulation caused by septal deviation on the volume of the maxillary sinus. METHODS: Coronal computed tomographic (CT) scans of 1568 patients aged from 18 to 60 were examined. CT scans of 402 patients were included in the study. On these scans, the maxillary sinus volume, the angle of the nasal septal deviation, and the angulation of the hard palate were calculated using the ImageJ software. Each maxillary sinus volume was statistically compared with each other and with those in the control group. Correlations between palatal angulation and septal deviation were determined. RESULTS: Deviated nasal septum whether with or without deflection of the hard palate was noted to have caused changes in the volume of the maxillary sinus in both female and male patients. The volume of the maxillary sinus on the deviated side was less than that of the opposite side, and the differences between the volumes of both sinuses were statistically significant (p<0.05). No significant differences were noted when compared with the control group. A positive correlation was observed between the nasal septal deviation angle and the angulation of the hard palate. CONCLUSION: Regardless of whether or not it affects the hard palate, nasal septal deviation reduces the volume of the maxillary sinus on the deviated side but does not affect the total volume of the maxillary sinuses. Significant differences between the volumes on the two sides can lead to facial asymmetry.

Effect of carnosine supplementation on apoptosis and irisin, total oxidant and antioxidants levels in the serum, liver and lung tissues in rats exposed to formaldehyde inhalation.

The main objective of the study has been to show whether carnosine has positive effects on liver and lung tissues of rats exposed to a range of formaldehyde concentrations, and to explore how irisin expression and antioxidant capacity are altered in these tissues by carnosine supplementation. Sprague-Dawley type male rats were divided into 8 groups with 6 animals in each: (I) Control; no chemical supplementation); (II) sham (100mg/kg/day carnosine); (III) low dose formaldehyde (LDFA) for 5 days/week; (IV) LDFA for 5 days/week and carnosine); (V) moderate dose formaldehyde (MDFA) for 5 days/week); (VI) MDFA for 5 days/week and carnosine; (VII) high dose formaldehyde (HDFA) for 5 days/week; (VIII) and HDFA for 5 days/week and carnosine. Sham and control groups were exposed to normal air. Irisin levels of the serum, liver and lung tissue supernatants were analyzed by ELISA, while the REL method was used to determine total oxidant/antioxidant capacity. Irisin production by the tissues was detected immunohistochemically. Increasing doses of FA decreased serum/tissue irisin and total antioxidant levels relative to the controls, as also to increases in TUNEL expressions, total oxidant level, oxidant and apoptosis index. Irisin expression was detected in hepatocyte and sinusoidal cells of the liver and parenchymal cells of the lung. In conclusion, while FA exposure reduces irisin and total oxidant in the serum, liver and lung tissues in a dose-dependent manner and increases the total antioxidant capacity, carnosine supplementation reduces the oxidative stress and restores the histopathological and biochemical signs.

Postoperative pain and respiratory function in patients treated with electroacupuncture following coronary surgery.

OBJECTIVES: To evaluate respiratory function and pain score in patients undergoing coronary bypass procedures during the first 7 postoperative days. METHODS: The study was carried out as a case-control study between April 2008 and April 2009 in the Department of Cardiovascular Surgery, Firat University Faculty of Medicine, Elazig, Turkey. Thirty patients, who had undergone a median sternotomy (MS) for coronary artery bypass graft, were randomized to either the electroacupuncture and pharmacologic analgesia (acupuncture) group, or the pharmacologic analgesia alone (control) group. In each group, severity of pain, analgesic intake, respiratory function, and pulmonary complications were recorded. Pethidine hydrochloride and metamizole sodium were administered. RESULTS: Of the 30 subjects, 15 were in the control group and 15 in the acupuncture group. There were no statistically significant differences between the 2 groups in terms of age and gender. Statistically significant differences in metamizole, pethidine, days 3, 5, 6, and 7 visual analogue scale scores were observed between the acupuncture and control groups. Postoperative complications (atelectasia) were observed in 2 (13.3%) patients, one (6.6%) in each group. The postoperative forced expiratory volume in one second/forced vital capacity value was higher than the preoperative value in the acupuncture group. CONCLUSIONS: Electroacupuncture was more effective than control treatments in decreasing pain and limiting opioid and non-opioid medication intake during the first 7 postoperative days following MS.

Efects of melatonin and octreotide on peridural fibrosis in an animal model of laminectomy.

AIM: To investigate the effects of melatonin and octreotide in the prevention of peridural fibrosis in an experimental rat model. MATERIAL AND METHODS: A total of 36 rats were divided into three groups: Group I was laminectomized and not given any treatment. Group II received an intraperitoneal 30 microg/kg/day dose of octreotide for six weeks after the laminectomy. Group III rats were injected with melatonin 7.5 mg/kg/day for six weeks after the laminectomy. At the end of six weeks, plasma transforming growth factor beta-1 levels and peridural fibrous tissue hydroxyproline concentrations were determined and histopathological examinations was performed. RESULTS: Serum TGF-Beta1 levels of the octreotide and melatonin groups were found to be lower than the control group. The lower levels of TGF-Beta1 was statistically significant in both of the groups. Hydroxyproline levels of the octreotide and melatonin groups were found to be lower than that of the control group. The decrease was statistically significant only in the melatonin group. Peridural fibrosis scores of the octreotide and melatonin groups were lower than the control group. This histopathological improvement was statistically significant only in the melatonin group. CONCLUSION: Melatonin and octreotide prevented TGF-Beta1 increase in peridural fibrosis, but only melatonin significantly improved hyroxyproline levels and fibrosis scores as demonstrated.

The effects of acupuncture on rats with brain ischemia-reperfusion.

OBJECTIVE: To investigate the damage of brain ischemia-reperfusion (I/R) caused by occlusion of the middle cerebral artery (MCA), and the effects of acupuncture on this damage. METHODS: This investigation took place in the Experimental Research Unit of Firat University, Elazig, Turkey in January-February 2007. For this aim, 14 rats were divided into 2 groups: I/R (control) and I/R+acupuncture (experiment). In the I/R group, the MCA was occluded for 60 minutes, after this reperfusion was applied. In the I/R+acupuncture group, dry needle acupuncture was applied after reperfusion for 10 days. At the end of the experiment, all rats were sacrificed. The brain tissues were examined after staining with hematoxylin and eosin. RESULTS: In the samples belonging to the I/R group, widespread necrotic areas, red neurons, vacuolization, congestion, and edema were observed. In the I/R+ acupuncture group, the findings of ischemia were significantly decreased when compared with the I/R group. CONCLUSION: The damage caused by I/R was decreased by manual acupuncture therapy, however, further clinical studies are needed to determine the mechanism of acupuncture treatment, the optimal timing, and duration of acupuncture treatment in such disorders.

Protective effect of omega-3 fatty acids in a rat focal cerebral ischemia-reperfusion model.

OBJECTIVE: To investigate possible neuroprotective effects of dietary supplementation of fish oil in brain ischemia-reperfusion (I/R). METHODS: This investigation took place in the Experimental Research Unit, Firat University, Elazig, Turkey, from January-February 2006. The study was carried out on 12 male Wistar rats; divided into 2 groups: I/R (control) and I/R + omega-3 essential fatty acids (EFA) (experiment). The rats in the I/R group received only ordinary rat food before middle cerebral artery (MCA) occlusion. The I/R + omega-3 EFA group received omega-3 fatty acid daily via intragastric gavage (300 mg/kg Marincap capsule) with normal food before MCA occlusion for 30 days. Structural alterations in the brain tissues were semi-quantitatively analyzed (0: absent, +: slight, ++: moderate, +++: severe). RESULTS: There was evident severe (+++) edema, vacuolization, and eosinophilic degeneration in the I/R group, while only slight (+) edema and eosinophilic degeneration in the I/R + omega-3 EFA group in which no vacuolization was determined. These findings are consistent with the available studies in this field. CONCLUSION: Results from this study indicate the beneficial effects of omega-3 EFA supplementation in prevention of I/R - induced damage in rats.

Effects of omega-3 essential fatty acids against formaldehyde-induced nephropathy in rats.

The aim of this study was to examine the toxicity of formaldehyde (FA) on the kidney and the protective effects of omega-3 essential fatty acids against these toxic effects. Twenty-one male Wistar rats were divided into three groups. Rats in Group I comprised the controls, while the rats in Group II were injected every other day with FA. Rats in Group III received omega-3 fatty acids daily while exposed to FA. At the end of the 14-day experimental period, all rats were killed by decapitation and the kidneys removed. Some of the kidney tissue specimens were used for determination of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities, and malondialdehyde (MDA) levels. The remaining kidney tissue specimens were used for light microscopic evaluation. The levels of SOD and GSH-Px were significantly decreased, and MDA levels were significantly increased in rats treated with FA compared with those of the controls. Furthermore, in the microscopic examination of this group, glomerular and tubular degeneration, vascular congestion and tubular dilatation were observed. However, increased SOD and GSH-Px enzyme activities, and decreased MDA levels were detected in the rats administered omega-3 fatty acids while exposed to FA. Additionally, kidney damage caused by FA was decreased and structural appearance was similar to that of the control rats in this group. In conclusion, it was determined that FA-induced kidney damage was prevented by administration of omega-3 essential fatty acids.

Jugular foramen syndrome caused by choleastatoma.

Unilateral paresis of 9th-11th cranial nerves together is defined as jugular foramen (Vernet's) syndrome. A cholesteatoma case that penetrated into intracranial area after eroding temporal bone and led to jugular foramen syndrome is presented here, since such a case has not been reported in the literature hitherto. A 46-year-old male patient was evaluated for hoarseness. It was learnt from his anamnesis that he had been operated for otitis media nearly 20 years ago. Uvula deviated towards right. Loss of gag reflex was remarkable on the left. Paresis was found on the left vocal cord. There was weakness in rotation of the head to the right. Computerized tomography (CT) scan revealed that the temporal bone lost its integrity and that there was an extra-axial hypodense mass neighboring pontocerebellum. Post-contrast magnetic resonance imaging showed that the mass, which showed thin, regular circular contrasting and which was hypointense in T1-weighted MR and hyperintense in T2-weighted MR, extended to the left jugular foramen. The mass was totally removed with left sub-occipital approach in the treatment. After the treatment, hoarseness, weakness in the rotation movement of the head and loss of gag reflex recovered totally, while deviation in the uvula was permanent. Cholesteatomas can extend to posterior fossa and cause jugular foramen syndrome. Early surgery is important to completely reverse the lost nerve functions in treatment.

Morphometric examination of the paranasal sinuses and mastoid air cells using computed tomography.

BACKGROUND: The paranasal sinuses and mastoid air cells vary considerably in size and shape from person to person. The main structures are pneumatic. In this study, we investigated the relationship between right and left sides and evaluated the volume changes according to age and sex. METHODS: Of all patients attending the radiology department, 91 cases without paranasal sinuses and mastoid air cells pathology (i.e., inflammation, operation or trauma) were selected for evaluation. Axial computed tomography (CT) scans were obtained for both paranasal sinuses and temporal bones. In all scans, the volumes of each area (maxillary sinus, frontal sinus, sphenoid sinus and mastoid air cell) were calculated and analyzed statistically. RESULTS: The volumes of paranasal sinuses and mastoid air cells increased with age and women had a lower mean volume. There was a positive correlation between right-left and ipsilateral structures (paranasal sinuses and mastoid air cells). CONCLUSIONS: These results are helpful in understanding the normal and pathological conditions of the paranasal sinuses and the mastoid air cells.

Reduction of carbon tetrachloride-induced nephropathy by melatonin administration.

The aim of this study was to investigate possible protective effects of melatonin on carbon tetrachloride (CCl4)-induced renal damage in rats. A total of 24 animals were divided into three equal groups: the control rats received pure olive oil subcutaneously, rats in the second group were injected with CCl4 (0.5 ml kg-1, s.c. in olive oil) and rats in the third group were injected with CCl4 (0.5 ml kg-1) plus melatonin (25 mg kg-1, s.c. in 10% ethanol) every other day for 1 month. At the end of the experimental period, the animals were sacrificed and blood samples were collected. The kidneys were removed and weighed. Urea and creatinine levels were determined in blood samples. Histopathological examination of the kidney was performed using light microscopic methods. Administration of CCl4 significantly increased relative kidney weight (g per 100 g body weight) and decreased serum urea levels compared to controls (p<0.01). Melatonin treatment significantly (p<0.01) reduced relative kidney weight, and it produced a statistically equal (p=0.268) relative weight with the kidneys of control rats. CCl4 administration alone also caused histopathologically prominent damage in the kidney compared to the control group. Glomerular and tubular degeneration, interstitial mononuclear cell infiltration and fibrosis, vascular congestion around the tubules, and interstitial haemorrhage in perivascular areas were observed in the renal cortex and cortico-medullary border. However, the affect of CCl4 on the medulla was limited. Melatonin provided protection against CCl4-induced renal toxicity as was evident by histopathological evaluation. In view of the present findings, it is suggested that melatonin protects kidneys against CCl4 toxicity.

Volume assessment of age-related conversion of the tympanic cavity by helical computerized tomography scanning.

OBJECTIVE: To investigate the right-left asymmetry, and gender and age groups differences of the tympanic cavities (TC) using the Cavalieri principle for volume calculation on temporal bone computerized tomography (CT) scans. METHODS: This study was carried out over a 4-year period from 2000 to 2004 at Firat University, School of Medicine, Elazig, Turkey. The areas of the cavities were measured using trace and area measurement functions of CT scanner, and by multiplying the area by slice thickness (0.2 cm) and the volume of each slice was calculated. By summing all volumes of every slice based on the Cavalieri principle for volume calculation, the total volumes were obtained and analyzed. RESULTS: The mean (SD) volumes of right and left tympanic cavities in males were 0.52 (0.15) versus 0.55 (0.14) cm3 and in females were 0.45 (0.16) versus 0.49 (0.14) cm3, and there were statistically significant differences between males and females in both right and left sides (p=0.028 and p=0.043). There was a statistically significant difference in left TC volumes between age groups (p=0.019). However, no differences by age were noted for right TC volumes (p=0.065). A strong correlation was found between right and left volumes. However, there were no strong correlations between age and volumes of right and left cavities in both males and females, although the volumes increased by aging. CONCLUSION: These results should help surgeons and radiologists to update their knowledge for evaluation of the middle ear region.

Variants and deformities of atlas vertebrae in Eastern Anatolian people.

OBJECTIVE: At the craniocervical junction, developmental anomalies of the atlas may produce clinical symptoms by compressing on the vertebral artery, particularly during extreme rotational movements of the cervical spine. The aim of the present study was to investigate several varieties and deformities of the atlas vertebra from the skeletal specimens of Eastern Anatolian people. METHODS: This study was carried out over a 3-year period, 2000 through to 2002 in the Department of Anatomy, Firat, Yuzuncu Yil and Ataturk University, Turkey. Developmental anomalies and the variants of the first vertebrae were investigated on 86 atlas. RESULTS: Ponticulus posterior was observed with a low frequency on right as 2.3%. The bilateral localization was 10.5% and the left-side localization was 9.3%. Ponticulus lateralis showed an equal localization as 1.2% on the right, 1.2% on the left and 1.2% bilateral. In the present study, a complete subdivision of the joint surface was observed in 11 atlases (12.8%). Processus infratransversarius atlantis with a frequency between 1.2-7%, arthrotic formation and corona atlantis peridentals in 8 cases (9.3%) were also found. CONCLUSION: The low frequency for fonticulus posterior might be peculiar to the population living in this area.

[Radiologic and morphologic evaluation of the lateral sacral mass]. / Lateral sakral kitlenin morfolojik ve radyolojik degerlendirilmesi.

OBJECTIVES: Morphologic measurements of the lateral sacral mass (LSM) and adjacent bone structures were made on dried sacrum specimens, together with radiologic evaluations on computed tomography (CT) scans in order to assess the appropriateness of this area in iliosacral screw applications. METHODS: On thirty dried human sacral bone specimens, morphologic measurements of the LSM were made by a compass sensitive to millimeters. Computed tomographic views of S1 and S2 pedicle-bodies and intervertebral foramina were obtained to make radiologic measurements by a millimeter-sensitive ruler to examine the relationship between LSM and the neural canal and intervertebral foramina. RESULTS: The average widths of the LSM on the posterior and anterior surfaces of the sacrum were as follows. Posterior aspect: 24.1 mm on S1, 18.4 mm on S2 levels on the right; 24.5 mm on S1 and 18.8 mm on S2 levels on the left. Anterior aspect: 28.9 mm on S1, 22.6 mm on S2 levels on the right; 29.1 mm on S1 and 23 mm on S2 levels on the left. The average (oblique) heights of LSM on the postero-lateral surface were 39 mm on S1, 28.6 mm on S2 levels on the right; 37.4 mm on S1, 27.6 mm on S2 levels on the left. The average depth of the sacral ala was 50.6 mm on the right, 50.7 mm on the left. The average posterior alar height was 26 mm on both sides. On CT scans, the average widths of pedicle+sacral ala were measured as 37.6 mm (right) and 36.3 mm (left) at the S1 pedicle-body level. The average widths of LSM were 22 mm (right) and 22.3 mm (left) at the S1 intervertebral foramina level. The average widths of pedicle+LSM were 27.8 mm (right) and 26.4 mm (left) at the S2 pedicle-body level. The average widths of LSM at the S2 intervertebral foramina level were 15.9 mm (right) and 16.3 mm (left). CONCLUSION: Our results suggest that iliosacral screw fixation may be more safely performed, especially at the S1 pedicle-body level and lateral to the sacral neural canal and intervertebral foramina. Injury to the neural tissues and surrounding structures is more unlikely if preoperative measurements of LSM are made on CT scans.

Effects of melatonin on Leydig cells in pinealectomized rat: an immunohistochemical study.

We have investigated immunohistochemically the effects of melatonin on Leydig cells in rat. Three groups of Wistar rats were used. Rats in group I and II were sham-pinealectomized (control) and pinealectomized, respectively, whereas rats in group III were pinealectomized and injected daily with melatonin for 2 months. At the end of the experiment, all animals were killed by decapitation and blood samples were obtained. Serum testosterone levels were determined with the use of a chemiluminescent enzyme immunoassay. Testicular tissue was collected and processed for semiquantitative evaluation of immunohistochemical testosterone staining. Intensity of immunostaining was determined on a scale between 0 (no staining) and 5 (heavy staining). In pinealectomized rats, serum testosterone levels were significantly increased as compared to sham-pinealectomized rats. Daily administration of melatonin after pinealectomy resulted in significant decreased serum testosterone levels as compared to levels in control and pinealectomized rats. Immunostaining of testosterone was moderate (3+) in sham-pinealectomized rats, heavy (5+) in pinealectomized rats and low (1+) in pinealectomized rats that were treated with melatonin, respectively. The results of our study indicate that pinealectomy induces increased testosterone secretion in Leydig cells and this increased secretion can be prevented by administration of melatonin.