The effect of hetero- and homosexual experience and long-term treatment with fluoxetine on homosexual behavior in male rats

Introduction the selective serotonin reuptake inhibitors have become the most frequently prescribed drugs for the treatment of depression. Sexual side effects have been noted to occur with this treatment on heterosexual behavior in rats. Heterosexual experience facilitates sexual orientation of male rats and decreases the latencies to first mount and first intromission. on the other hand, homosexual behavior in male rats induced by female hormones has not been evaluated.Aim the objective of this work is to evaluate the effects of heterosexual and homosexual experience in male rats long-term treated with fluoxetine (FLX) on homosexual hormone-induced behavior.Materials and Methods Male rats were treated with FLX or saline solution (10 mg/kg for 65 days). At days 36, 50, and 65 of the treatment, the rats were evaluated for homosexual behavior. Other rats treated with FLX or saline solution for 60 consecutive days were submitted to heterosexual behavior at 14, 21, and 28 days of the treatment. After this, they were orquiectomized and homosexual hormone-induced behavior was observed at 45 and 60 days of the treatment.Results (1) Only treatment with FLX did not affect the homosexual behavior. (2) the homosexual experience facilitated the homosexual behavior mainly on the animals from the control group. (3) the heterosexual experience facilitated the homosexual behavior on both groups.Conclusions Only long-term administration of FLX does not interfere with the homosexual behavior in male rats. The homosexual and the heterosexual experience facilitated the homosexual behavior on the control and experimental groups. We suggested that learning aspects related to sexual behavior are responsible by these results.

Comparative genomic hybridization analysis of benign and invasive male breast neoplasms

Comparative genomic hybridization (CGH) analysis was performed for the identification of chromosomal imbalances in two benign gynecomastias and one malignant breast carcinoma derived from patients with male breast disease and compared with cytogenetic analysis in two of the three cases. CGH analysis demonstrated overrepresentation of 8q in all three cases. One case of gynecomastia presented gain of 1p34.3similar topter. 11p14similar toq12. and 17p11.2similar toqter, and loss of 1q41similar toqter and 4q33similar toqter. The other gynecomastia presented del(1)(q41) as detected by both cytogenetic and CGH analysis. CGH analysis of the invasive ductal carcinoma confirmed a gain of 17p11.2similar toqter previously detected by cytogenetic analysis. These regions showed some similarity in their pattern of imbalance to the chromosomal alterations described in female and male breast cancer. (C) 2002 Elsevier B.V. All rights reserved.

CYTOGENETIC REPORT OF A MALE BREAST-CANCER

The cytogenetic findings on G-banding in an infiltrating ductal breast carcinoma in a 69-year-old man are reported. The main abnormalities observed were trisomy of chromosomes 8 and 9 and structural rearrangement in the long arm of chromosome 17 (add(17)(q25)). Our results confirm the trisomy of chromosome 8 in the characterization of the subtype of ductal breast carcinomas and demonstrate that chromosome 17, which is frequently involved in female breast cancers, is also responsible for the development or progression of primary breast cancers in males.

Evaluation of transformation growth factor beta(1), interleukin-10, and interferon-gamma in male symptomatic and asymptomatic dogs naturally infected by Leishmania (Leishmania) chagasi

The aims of this study were to evaluate the immunomodulatory role of TGF-beta(1), 1L-10, and INF-gamma in spleen and liver extracts and supernatant cultures of white spleen cells from male symptomatic and asymptomatic dogs, naturally infected by Leishmania (Leishmania) chagasi. Thirty dogs from Aracatuba, São Paulo, Brazil, an endemic leishmaniosis area, were selected by positive ELISA serological reaction for Leishmania sp. and divided into two groups: asymptomatic (n=15) and symptomatic (n=15) consisting of animals with at least three characteristic signs (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachex a, locomotion problems, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy). After euthanasia, spleen and liver fragments were collected for ex vivo quantification of TGF-beta(1), IL-10, and INF-gamma. Naturally active in vitro produced TGF-beta(1) was also evaluated in spleen cell culture supernatant. Spleen and liver extract of asymptomatic dogs had higher mean TGF-beta(1) levels than symptomatic dogs. High concentrations of IL-10 were found in spleen, and mainly in liver extract of both groups. Higher INF-gamma concentrations were found in spleen extracts of symptomatic dogs, and in liver extracts of asymptomatic dogs. Extract of this cytokire was lower in spleen extract. Although INF-gamma is being produced in canine infection, mean levels of TGF-beta(1) and IL-10 from spleen and liver extracts were quantitatively much higher; suggesting that immune response in both asymptomatic and symptomatic dogs A as predominantly type Th2. (c) 2006 Elsevier B.V. All rights reserved.

Effect of calcitonin on bone regeneration in male rats: a histomorphometric analysis

The aim of this study was to evaluate the effectiveness of calcitonin in promoting bone growth in surgical bone defects in rat mandibles. Fifty male rats were divided into two groups: bone defect (control) and bone defect with calcitonin (experimental). A circular bone defect 4 mm in diameter was made in the mandibular bone of the rats in the angle region, and covered with a polytetrafluoroethylene barrier. The experimental group received 2 IU/kg of synthetic salmon calcitonin intramuscularly three times a week, with treatment starting immediately after surgery. The animals were killed 3, 7, 14, 21 and 28 days after the surgical procedure. The bone defects were examined histologically and by histomorphometric analysis. The Student t-test was applied to the histomorphometric data, with the level of significance set at 5%. The animals of the experimental group showed a lower level of bone formation at almost all time points than the control group, but no difference between groups was observed 28 days after surgery. The volume of newly formed bone matrix was significantly greater in the control than the experimental group at 7, 14 and 21 days, as determined by both morphologic and histomorphometric analysis. Bone repair in the calcitonin-treated animals was delayed in comparison to controls, indicating the need for further studies on male rats.

Testosterone, androstenedione, cortisol, triiodothyronine and thyroxine hormonal profile in neonate male buffaloes

Basic aspects of the hormonal profile of five hormones were studied in neonate male buffaloes. The level of testosterone (T), androstenedione (A), cortisol (C), triiodothyronine (T3) and thyroxine (T4) were determined during the period of 1-6, 7-8, - 9-12, 24, 48, 72 and 96 hours after parturition, using RIA solid phase technique. All hormones studied presented high levels in the neonate animals. The T and A levels were high in the first 1-6 hours post-partum, being 99.6+/-66.6 and 1,301.4+/-887.7 pg/ml, respectively. The T decreased sharply to basal levels (below the analysis limit of detection) within 24 hours while the A reached the basal level within 48 hours with 348.0+/-279.4pg/ml. The C and T4 levels were also high in the first 24-48 hours, which levels were 5.0+/-3.2 and 11.1+/-2.6 mu g/ml, respectively, decreasing gradually and significantly (P<0.01) until 96 hours post-partum, when they approached the basal levels (1.2+/-1.5 and 7.2+/-2.7 mu g/ml, respectively). The concentration of T3 remained elevated during the entire period of sample collection with little variation (P>0.05), with levels of 328.6+/-130.8 and 294.5+/-134.9ng/dl, respectively during 1-6 hours and 96 hours after parturition.

Effects of Short-term Hyper- and Hypoprolactinaemia on Hormones of the Pituitary, Gonad and -Thyroid Axis and on Semen Quality in Male Beagles

Effects of a short-term hyper- and hypoprolactinaemia on serum concentrations of LH, testosterone and semen quality in six male Beagles were investigated. Blood samples were collected at 3-day intervals for 12 weeks. The time span was divided into five 3-week periods: pre-treatment, metoclopramide (MCP) treatment (0.2 mg/kg orally three times daily), cabergoline (CAB) treatment (5 mu g/kg orally once daily), post-treatment 1 and post-treatment 2. In the latter, only semen characteristics were evaluated. Semen parameters were analyzed once per week during the whole 15-week investigation time. At the end of each period, the effects of a single intravenous injection of thyrotropin-releasing hormone (TRH; 10 mu g/kg) on the secretion of prolactin (PRL), LH, testosterone, thyroid-stimulating hormone and thyroxine (T4) were investigated. Pre-treatment serum PRL concentration increased under MCP (p < 0.05), followed by a decrease under CAB administration (p < 0.05). Luteinizing hormone and testosterone concentrations were not affected. Except for straight-line sperm velocity, semen quality did not differ between collection periods. A single iv TRH injection induced a significant PRL increase at 20 min in all experimental periods except during CAB treatment. Luteinizing hormone and testosterone did not show clear TRH-related changes. Basic T4 levels were significantly reduced after CAB treatment ( p < 0.05). The results of the present study demonstrate that MCP-induced short-term hyperprolactinaemia in male beagles does not seriously affect the hypothalamo-pituitary axis and semen quality.

Effects of nandrolone decanoate and resistance exercise on skeletal muscle in adult male rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of histone hyperacetylation on the preimplantation development of male and female bovine embryos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of prenatal exposure to deltamethrin on forced swimming behavior, motor activity, and striatal dopamine levels in male and female rats

The effects of prenatal exposure of rat pups to 0.08 mg/kg deltamethrin (DTM) on physical, reflex and behavioral developmental parameters, on forced swimming and open-field behaviors, and on striatal monoamine levels at 60 days of age were observed. Maternal and offspring body weight, physical and reflex development were unaffected by the exposure to the pesticide. At 21 days of age, open-field locomotion frequency and immobility duration of male and female offspring were not different between control and exposed animals. However, male rearing frequency was increased in experimental animals. A decreased immobility latency to float and in general activity after the swimming test in male offspring was observed at adult age; no interference was detected in the float duration during the swimming test. In addition, these animals presented higher striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels without modification in dopamine (DA) levels and an increased DOPAC/DA ratio. These data indicate a higher activity of the dopaminergic system in these animals. Noradrenaline (NA) levels were increased, while MHPG levels were not detectable in the system studied. Serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as well as the homovanillic acid (HVA)/DA ratio, were not modified by the exposure to the pesticide. No changes were observed in swimming and open-field behaviors nor were there any changes in striatal monoamines or their metabolites in the female experimental group. In relation to the pesticide formula, the present data showing that prenatal exposure to DTM alters latency to float and the activity of striatal dopaminergic system might reflect a persistent effect of the pesticide on animal motor activity, mainly in males. on the other hand, the decrease in general activity observed in experimental male rats suggests higher levels of emotionality induced by previous exposure to the swimming behavior test in relation to control animals. Data gathered in the present study may be important for the assessment of the safety of pyrethroid insecticides. (C) 2001 Elsevier B.V. All rights reserved.