Cunay Ulku

Protective effect of melatonin against fractionated irradiation-induced epiphyseal injury in a weanling rat model

Abstract: The effects of melatonin, a free‐radical scavenger and a general antioxidant, on radiation‐induced growth plate injury have not been studied previously. The purpose of this study was to determine the potential benefits of sparing longitudinal bone growth by fractionated radiotherapy alone compared with pretreatment with melatonin that provides differential radioprotection of normal cells. Weanling 4‐wk‐old (75–100 g) male Sprague–Dawley rats were randomly assigned to one of three groups: Group R received fractionated radiation alone (n = 8); groups M5 (n = 8) and M15 (n = 7) received 5 or 15 mg/kg melatonin prior to fractionated radiation, respectively. The distal femur and proximal tibia in the right leg of each animal were exposed to a therapeutic X‐irradiation dose (25 Gy total in three fractions) with the contralateral left leg as the non‐irradiated control. Melatonin was administered intraperitoneally to the animals 30 min before radiation exposure. Six weeks after treatment, the rats were killed and the lower limbs disarticulated, skeletonized, radiographed, and bone growth was calculated based on measurement of the bone lengths. Fractionated radiation resulted in a mean percent overall limb growth loss of 41.2 ± 9.5 and a mean percent overall limb discrepancy of 11.2 ± 2.2. The administration of 5 or 15 mg/kg melatonin before each of the three fractions of radiotherapy reduced the mean percent overall limb growth loss to 33.9 ± 5.8 and 32.2 ± 4.5, respectively, and the mean percent overall limb discrepancy to 9.4 ± 1.6 and 8.9 ± 1.1, respectively; these values were significantly different compared with irradiation alone (range: P = 0.01–0.04). When compared with Group R, the growth arrest recovered by 5 or 15 mg/kg melatonin was 19.7 and 24.1% for the tibia, 7 and 18.6% for the femur, and 17.7 and 21.8% for the total limb, respectively. These results support further investigation of melatonin in combination with fractionation for potential use in growing children requiring radiotherapy to the extremity for malignant tumors.

Effect of gender on antinociceptive effect of paroxetine in hot plate test in mice.

PURPOSE Many studies have reported both a gender difference in the rates of depression and its treatment by using any of the widely used antidepressant drug groups. Some studies suggest that females respond more poorly to tricyclic antidepressants than males and appear to respond better to selective serotonin reuptake inhibitors (SSRI). There is no study investigating the analgesic/antinociceptive effects of antidepressant drugs on the basis of gender difference. In this study, we aimed to investigate the antinociceptive effect of paroxetine on the basis of gender difference. METHODS The antinociceptive effect of paroxetine was tested using hot plate test in Balb/c mice (30-40 g). The animals were divided into eight groups on the basis of gender. FINDINGS While paroxetine did not induce an antinociceptive effect in both sex at a dose of 1 mg kg(-1), it showed significant antinociceptive effects in both sex at a dose of 5 or 10 mg kg(-1). None of the doses of paroxetine revealed a gender difference in its antinociceptive action. CONCLUSION There are several studies showing positive or negative evidence on the gender difference of paroxetines antidepressant effect, but in the literature there is no study about the gender difference of paroxetines or any other SSRI drugs antinociceptive effect. In conclusion, our results do not show any gender difference in antinociceptive effect of paroxetine that may be important especially when it would be used as an adjuvant agent in some painful conditions.

Psychotropic drugs in pregnancy: a case-control study

Psychotropic drug exposure during pregnancy is a common problem. Among the 601 cases exposed to drugs during pregnancy, who were followed by our Toxicology Information and Follow-up Service, 124 cases had used psychotropic drugs for depression, anxiety, or psychotic disorders. As the control group, 248 women, who did not use any drugs were selected. Of the 124 cases, 80 (64.5%) had healthy babies, and 17 (13.7%) decided to terminate the pregnancy. Spontaneous abortions, intrauterine death (in the 38th week) and premature deliveries were observed in the 9 (7.3%), 1 (0.8%) and 3 (2.4%) cases, respectively, in the drug exposure group. Pregnancies of the 14 (11.3%) cases were continuing during the preparation of this manuscript. Of the 248 controls, 151 (60.9%) had healthy babies, 9 (3.6%) experienced spontaneous abortion and 3 (1.2%) decided to terminate their pregnancies, 3 (1.2%) had premature deliveries, and we observed one (0.4%) congenital abnormality, 81 (32.7%) cases were still pregnant. Odds Ratio (95% confidence interval) for spontaneous abortion was found to be 1.35 (1.27-11.82) in the cases exposed to psychotropic drugs (P=0.02). No developmental problems were observed in the babies followed for 12 months. These data may give information about the early- but not the late-term effects of psychotropic drugs used in pregnant women.

Acute Alterations in Biochemistry, Morphology and Contractility of Rat Isolated Urinary Bladder via Increased Intra-Abdominal Pressure

Objective: To determine the acute effects of increased intra-abdominal pressure (IAP) on the biochemistry, morphology and contractility of the rat isolated urinary bladder using an experimental laparoscopy model. Methods: We divided 24 adult female Sprague–Dawley rats into three groups. The control group (group I) was not subjected to increased IAP. In groups II and III, IAPs of 10 and 20 mm Hg, respectively, were established by carbon dioxide pneumoperitoneum for 60 min. Thirty minutes after desufflation, the rat urinary bladder dome was removed for in vitro pharmacological investigation, measurement of malondialdehyde (MDA) levels and histopathological examination. Statistical comparisons between groups were performed. Results: Tissue MDA levels in groups II and III were significantly higher than in the control group. In group II, only the lamina propria was significantly damaged. However, the epithelium, lamina propria, and serosa were significantly damaged in group III. Acetylcholine potentiated contractions in both IAP groups. Increased responses to electrical field stimulation in the IAP groups were significant only in group II. Conclusions: In this experimental model, 10 and 20 mm Hg of IAP induced by pneumoperitoneum increased MDA levels and caused important changes in the morphology and contractile response of the urinary bladder.