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.

Tissue remodeling in Guinea pig lateral prostate at different ages after estradiol treatment

Estrogen seems to have an essential role in the fibromuscular growth characteristic of benign prostatic hyperplasia (BPH). This paper describes the effects of chronic estradiol treatment on Guinea pig prostatic stroma at different ages. Tissues from experimental animals were studied by histological and histochemical procedures, morphometric-stereological analysis and transmission electron microscopy (TEM). Marked fibromuscular hypertrophy was observed after estradiol treatment in animals of pre-pubertal and adult ages. Increases in the density and thickness of the collagen and elastic fibers were observed by histochemistry. TEM revealed wide distributions of collagen fibrils and large elastic fibers adjacent to the epithelial basal lamina and between the stromal cells, establishing contacts between them. These results indicate that the Guinea pig prostate simulates the stromal modifications observed in BPH in some aged animals after estrogen treatment at different ages, making it a good model for this disease. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Vascular organization of the hystricomorph placenta: a comparative study in the Agouti, capybara, guinea pig, paca and rock cavy

The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland. (C) 2003 Elsevier Ltd. 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.

Antagonism produced by hypertonic nutrient solutions on the depressive effect of carbofuran on isolated guinea pig atria

The action of hyperosmotic nutrient solutions on the depressive effects of carbofuran was studied on spontaneously contracting guinea pig atria. The force and frequency of contraction were recorded using an isotonic lever. Carbofuran 33.0 mu g ml(-1) produced a gradual depressive effect. The time for stabilization of the depressive effect was 6.0+/-2.3 min. After the depressive effect of carbofuran was established, NaCI, mannitol, or urea were introduced into the organ bath to increase the osmolarity of the nutrient solution to about 100 mosmol kg(-1) of water. This resulted in a reversal of the contraction force and frequency to the initial levels. The addition of the osmotic agents at the same concentrations before the addition of 33.0 mu g ml(-1) carbofuran avoided its depressive effect on guinea pig atria. (C) 1996 the Italian Pharmacological Society.

Investigations on the new free radical scavenger polynitroxyl-albumin to prevent ischemia and reperfusion injury after orthotopic heart transplantation in the pig model

Objective: Nitroxides have strong antioxidant capacity but their effectiveness is limited by their rapid intracellular inactivation. Poly nitroxyl-Albumin (PNA) is capable of regenerating inactivated nitroxide. We tested the effect of PNA against reperfusion injury in heart transplantation. Methods: Pig hearts were transplanted orthotopically. In the control group (n = 9) reperfusion was performed without reperfusion modifications. In the experimental group (n = 10) 1 ml/kg PNA was given before cross-clamp release. Results: Hemodynamic performance was impaired after transplantation in both groups without significant intergroup differences. Plasma malonedialdehyde levels were significantly diminished in the PNA group as compared to the controls. CK-MB levels in both groups were increased within the first 2 h of reperfusion without significant intergroup differences. In contrast, there were found significant higher values of myocardial specific lactate dehydrogenase (LD1) in the controls versus PNA group. Conclusions: PNA was able to reduce lipid peroxidation and attenuate free radical activity. Contractile dysfunction could no be improved, indicating that (a) the radical scavenging effect was to weak or (b) other mechanisms than free oxygen radicals are responsible for myocardial damage in this experimental model. (C) 2001 Elsevier B.V. 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.

Effect of different glycosaminoglycans in a guinea-pig carotid-artery thrombosis model

Heparin is the most frequently used drug for the prevention and treatment of thrombosis. Its use, however, is restricted by its side-effects. To study the efficacy of other glycosaminoglycans that could substitute heparin in the management of arterial thrombosis, 60 guinea-pigs were randomly allocated into 6 groups: G1= control, G2= heparin (150 IU/kg), G3= heparan sulfate from beef pancreas (2.5 mg/kg), G4= heparan sulfate from beef lung (2.5 mg/kg), G5= N-acetylated heparan from beef pancreas, G6= dermatan sulfate from beef intestine (2.5 mg/kg). Ten minutes after intravenous injection of the drugs, thrombosis was induced by the injection of a 50% glucose solution into a segment of the right carotid artery isolated between 2 thread loops during 10 minutes. Three hours later the artery was re-exposed and if a thrombus was present it was measured, withdrawn and weighed. Thrombin time and activated partial thromboplastin time were measured in all animals. Thrombus developed in 90% of the animals in the control group, 0% in G2 and G3, 62.5% in G4, 87.5% in G5 and G6. Only in the animals treated with heparin the coagulation tests were prolonged. In conclusion, in the used dose only the heparan sulfate from beef pancreas presented an antithrombotic effect similar to heparin in this experimental model.

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.