Physical exercise on the rat ventral prostate: steroid hormone receptors, apoptosis and cell proliferation.

Studies have investigated the effect of exercise on prostate cancer risk. However, there are still doubts regarding the correlation between physical activity and the steroid hormones with respect to the reduction of the risk for prostatic lesions. We evaluated the levels of corticosterone, dihydrotestosterone (DHT), testosterone, estradiol, and steroid hormone receptors, and investigated the relationship between apoptosis and cell proliferation in the rat ventral prostate after training. Two groups were included in this study: control and trained. The trained group was submitted to training for 13 weeks (1 week of adaptation). Two days after the last training session, all animals were euthanized, and the intermediate and distal regions of the ventral prostate were collected and processed for immunohistochemistry, Western blotting and hormonal analyses. Physical exercise increased the corticosterone plasma, DHT and testosterone. In addition, androgen receptor expression was lower and estrogen receptor (ER) α and ER ß expression were higher in the trained group. However, the trained group showed disruption of the ratio of apoptotic to proliferating cells, indicating a predominance of apoptosis. We conclude that physical exercise alters the sex hormones and their receptors and is associated with the disruption of the balance between apoptosis and cell proliferation in the rat ventral prostate.

Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat

Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9 percent NaCl + 0.04 mL 95 percent ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2 percent) and estrous cycle remained extensive (26.7 percent), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9 percent) and total antioxidant substances were enhanced within the ovaries (23.9 percent). Additionally, melatonin increased superoxide dismutase (21.3 percent), catalase (23.6 percent) and glutathione-reductase (14.8 percent) activities and the reducing power (10.2 percent GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

Long-term melatonin treatment reduces ovarian mass and enhances tissue antioxidant defenses during ovulation in the rat.

Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight(-1)·day(-1)) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2%) and estrous cycle remained extensive (26.7%), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9%) and total antioxidant substances were enhanced within the ovaries (23.9%). Additionally, melatonin increased superoxide dismutase (21.3%), catalase (23.6%) and glutathione-reductase (14.8%) activities and the reducing power (10.2% GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities.

Chronic haemodialysis for very old patients.

There is in the Western World a progressive ageing of the population, and consequently haemodialysis patients are also getting older. Some ethical questions have been raised as a consequence of the economic issues related to the scarcity of available resources. In this paper we review our experience in the treatment of very old chronic haemodialysis patients. Fifty patients (7.2% of our haemodialysis patients) aged over 80 years at the beginning of dialysis were included (f = 25, m = 26, age = 82.6 +/- 0.3 years). In 42% of the patients the aetiology of renal disease was unknown. In the remainder, the aetiology was: interstitial nephritis 26%, hypertensive nephrosclerosis 14%, chronic glomerulonephritis 8%, diabetes 8% and polycystic disease 2%. There was a great comorbidity: intradialytic hypotension 82%, cardiac disease 74%, gastrointestinal disease 32%, cerebrovascular disease 26%. Vascular access related problems were the main reason for hospitalization. The major cause of death was vascular (cardiac and cerebral disease). Actuarial survival was 89%, 78%, 56% and 48% at 6, 12, 24 and 36 months, respectively. We think that haemodialysis is the best available choice for treating very old chronic renal failure patients. However further studies are needed to improve the quality of life of these patients.

[Chronic hemodialysis with acetate in patients over 70 years old]. / Hemodiálise crónica com acetato em doentes com idade superior a 70 anos.

During the last years there has a significant increase of elderly patients included in chronic dialysis programs. No agreement has been reached about the preferable treatment modality. In this study we analyse our experience in the management of patients over 70 years of age undergoing chronic acetate hemodialysis (HDCA). Sixty four of those patients have initiated HDCA between May 1982 and December 1990 (Mean age 75.9 +/- 4.8). The etiology of renal disease was unknown in a significant number of cases. Morbility was largely due to vascular disease (both cardiac and cerebral). Main causes of death were also vascular disease and infections. Actuarial survival was 79.6% at 12 months and 46.3% after 5 years. Although HDCA is associated with a greater morbility it is the most widely used modality of treatment for chronic renal failure in Portugal and in our experience, it is an acceptable method for elderly patients.

[Chronic hemodialysis: risk factors for intra-dialytic hypotension (IDH)]. / Hemodiálise crónica: factores de risco de hipotensão intradialítica (HID).

Haemodialysis is the most used among the different renal function replacement methods. Although the survival is acceptable the mobility is important; intradialytic hypotension is a main cause of such mobility. In this study which included stable chronic haemodialysis patients, the authors evaluate risk factors for IDH. Advanced age, female sex and autonomic insufficiency are risk factors for IDH. Patients with IDH had more serious ventricular arrhythmias, but a cause-effect relationship was not demonstrated.