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The aims of this study were to evaluate the doxorubicin concentration that induces toxic effects on in vitro culture of isolated mouse secondary follicles and to investigate whether resveratrol can inhibit or reduce this toxicity. Secondary follicles were isolated and cultured for 12 days in control medium (α-MEM+) or in α-MEM+ supplemented with doxorubicin (0.1 µg/ml) or different concentrations of resveratrol (0.5, 2, or 5 µM) associated with doxorubicin (0.1 µg/ml) (experiment 1). For experiment 2, follicles were cultured in α-MEM+ alone or supplemented with doxorubicin (0.3 µg/ml) or different concentrations of resveratrol (5 or 10 µM) associated or not with doxorubicin (0.3 µg/ml) (experiment 2). The endpoints analyzed were morphology (survival), antrum formation, follicular diameter, mitochondrial activity, glutathione (GSH) levels and DNA fragmentation. In the first experiment, doxorubicin (0.1 µg/ml) maintained survival and antrum formation similar to the control, while 5 µM resveratrol showed increased parameters, maintained mitochondrial activity and increased GSH levels compared to the control. In the second experiment, doxorubicin (0.3 µg/ml) reduced survival, antrum formation and follicular diameter compared to the control. Resveratrol at a concentration of 10 µM attenuated the damage caused by doxorubicin by improving follicular survival and did not present DNA fragmentation. In conclusion, supplementation of the in vitro culture medium with 0.3 µg/ml doxorubicin reduced the survival and impaired the development of mouse-isolated preantral follicles. Resveratrol at 10 µM reduced doxorubicin-induced follicular atresia, without DNA fragmentation in the follicles.

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The flavonoid kaempferol has attracted research attention as a potential adjuvant during chemotherapy. This study aimed to evaluate the protective effects of kaempferol against ovarian damage in cisplatin-treated mice. Two groups of mice received saline solution (intraperitoneal injection [i.p.]; control) or a single dose of cisplatin (5 mg/kg body weight, i.p.). Moreover, two other mice groups were pretreated with kaempferol (1 or 10 mg/kg body weight, i.p.) 30 min before of the cisplatin administration. Thereafter, their ovaries were harvested and subjected to histological (follicular morphology and activation) and fluorescence (reactive oxygen species [ROS] production, glutathione [GSH] concentration, and mitochondrial activity) analyses. Compared with cisplatin treatment alone, pretreatment with 1 mg/kg kaempferol maintained normal follicular morphology, reduced ROS production and mitochondrial damage, and enhanced GSH concentration. However, pretreatment with 10 mg/kg kaempferol did not prevent cisplatin-induced damage. The rate of primordial follicle activation was greater in mice pretreated with 1 mg/kg kaempferol than in the other treatment groups. In conclusion, pretreatment with 1 mg/kg kaempferol prevents cisplatin-induced ovarian damage and stimulates primordial follicle activation in mice.

O flavonoide kaempferol tem atraído a atenção como um potencial adjuvante durante a quimioterapia. O presente estudo objetivou avaliar os efeitos do kaempferol contra os danos ovarianos em camundongos tratados com cisplatina. Fêmeas de camundongos receberam solução salina (injeção intraperitoneal [ip]; controle) ou uma dose única de cisplatina (5 mg/kg, ip) ou foram pré-tratadas com kaempferol (1 ou 10 mg/kg, ip) 30 min antes da administração de cisplatina. Os ovários foram recuperados e destinados para as análises histológicas (morfologia e ativação folicular) e de fluorescência (produção de espécies reativas de oxigênio [ERO], concentração de glutationa [GSH] e atividade mitocondrial). Em comparação ao tratamento apenas com cisplatina, o pré-tratamento com 1 mg/kg de kaempferol manteve a morfologia folicular normal, reduziu a produção de ERO, bem como os danos mitocondriais, e aumentou a concentração de GSH. Entretanto, o pré-tratamento com 10 mg/kg de kaempferol não preveniu os danos induzidos pela cisplatina. A taxa de ativação do folículo primordial foi maior em camundongos pré-tratados com 1 mg/kg de kaempferol do que nos outros grupos experimentais. Em conclusão, o pré-tratamento com 1 mg/kg de kaempferol previne o dano ovariano induzido pela cisplatina e estimula a ativação do folículo primordial em camundongos.

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Changes in physiological parameters that are induced by acute exercise on a treadmill in healthy military dogs have not been thoroughly investigated, especially with regard to age. This study investigated the effects of acute exercise on a treadmill on cardiovascular function, biochemical parameters and gastric antral motility in military dogs. Thermography was used to assess variations in superficial hindlimb muscle temperature. Nine healthy dogs were distributed into three groups according to their age (Group I: 25 ± 7 months; Group II: 51 ± 12 months; Group III: 95 ± 10 months) and sequentially subjected to running exercise on a treadmill for 12 min (3.2 km/h at 0° incline for 4 min, 6.4 km/h at 0° incline for 4 min and 6.4 km/h at 10° incline for 4 min). Heart rate, systolic and diastolic arterial pressure (DAP), gastric motility, haematocrit and biochemical analyses were performed at rest and after each session of treadmill exercise. Infrared thermographic images of muscles in the pelvic member were taken. Exercise decreased DAP in Group I, increased systolic arterial pressure in Groups II and III and increased mean arterial pressure in Group III (all p < 0.05). After the exercise protocol, plasma creatine kinase and aspartate aminotransferase levels increased only in Group I (p < 0.05). Exercise increased heart rate and decreased the gastric motility of a solid meal at 180 min in all groups (all p < 0.05). Exercise also elevated temperature in the femoral biceps muscles in Group I compared with the older dogs. The results indicate that acute exercise decreased gastric motility in dogs, regardless of age, and caused more pronounced cardiovascular changes in older dogs than in younger dogs. Acute exercise also altered biochemical parameters and superficial hindlimb muscle temperature in younger military dogs.

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Local tissue reactions provoked by Bothrops venoms are characterized by edema, hemorrhage, pain, and inflammation; however, the mechanisms of tissue damage vary depending upon the species of snake. Here, we investigated the mechanisms involved in the local inflammatory response induced by the Bothrops jararacussu venom (BjcuV). Female Swiss mice were injected with either saline, BjcuV (0.125-8 µg/paw) or loratadine (an H1 receptor antagonist), compound 48/80 (for mast cell depletion), capsaicin (for C-fiber desensitization), infliximab (an anti-TNF-α antibody), indomethacin (a non-specific COX inhibitor), celecoxib (a selective COX-2 inhibitor) or fucoidan (a P- and L-selectins modulator) given before BjcuV injection. Paw edema was measured by plethysmography. In addition, paw tissues were collected for the measurement of myeloperoxidase activity, TNF-α and IL-1 levels, and COX-2 immunoexpression. The direct chemotactic effect of BjcuV and the in vitro calcium dynamic in neutrophils were also investigated. BjcuV caused an edematogenic response with increased local production of TNF-α and IL-1ß as well as COX-2 expression. Both edema and neutrophil migration were prevented by pretreatment with indomethacin, celecoxib or fucoidan. Furthermore, BjcuV induced a direct in vitro neutrophil chemotaxis by increasing intracellular calcium. Therefore, BjcuV induces an early onset edema dependent upon prostanoid production and neutrophil migration.

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Sildenafil slows down the gastric emptying of a liquid test meal in awake rats and inhibits the contractility of intestinal tissue strips. We studied the acute effects of sildenafil on in vivo intestinal transit in rats. Fasted, male albino rats (180-220 g, N = 44) were treated (0.2 mL, iv) with sildenafil (4 mg/kg) or vehicle (0.01 N HCl). Ten minutes later they were fed a liquid test meal (99m technetium-labeled saline) injected directly into the duodenum. Twenty, 30 or 40 min after feeding, the rats were killed and transit throughout the gastrointestinal tract was evaluated by progression of the radiotracer using the geometric center method. The effect of sildenafil on mean arterial pressure (MAP) was monitored in a separate group of rats (N = 14). Data (medians within interquartile ranges) were compared by the Mann-Whitney U-test. The location of the geometric center was significantly more distal in vehicle-treated than in sildenafil-treated rats at 20, 30, and 40 min after test meal instillation (3.3 (3.0-3.6) vs 2.9 (2.7-3.1); 3.8 (3.4-4.0) vs 2.9 (2.5-3.1), and 4.3 (3.9-4.5) vs 3.4 (3.2-3.7), respectively; P < 0.05). MAP was unchanged in vehicle-treated rats but decreased by 25 percent (P < 0.05) within 10 min after sildenafil injection. In conclusion, besides transiently decreasing MAP, sildenafil delays the intestinal transit of a liquid test meal in awake rats.

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We evaluated the effects of cyclooxygenase-2 (COX-2) selective inhibitors, COX-1 selective inhibitor, or COX non-selective inhibitor on gastric emptying and intestinal transit of liquids, and evaluated the effect of a COX-2 selective inhibitor on gastric tonus (GT). Male Wistar rats were treated per os with saline (control), rofecoxib, celecoxib, ketorolac, rofecoxib + ketorolac, celecoxib + ketorolac, or indomethacin. After 1 h, rats were gavage-fed (1.5 mL) with the test meal (5% glucose solution with 0.05 g mL(-1) phenol red) and killed 10, 20 or 30 min later. Gastric, proximal, medial or distal small intestine dye recovery (GDR and IDR, respectively) were measured by spectrophotometry. The animals of the other group were treated with i.v. valdecoxib or saline, and GT was continuously observed for 120 min using a pletismomether system. Compared with the control group, treatment with COX-2 inhibitors, alone or with ketocolac, as well as with indomethacin increased GDR (P < 0.05) at 10-, 20- or 30-min postprandial intervals. Ketorolac alone did not change the GDR, but increased the proximal IDR (P < 0.05) at 10 min, and decreased medial IDR (P < 0.05) at 10 and 20 min. Valdecoxib increased (P < 0.01) GT 60, 80 and 100 min after administration. In conclusion, COX-2 inhibition delayed the gastric emptying of liquids and increased GT in rats.

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