Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.

Micropropagação e aclimatização de gerânio (Pelargonium graveolens L. ) / Micropropagation and acclimatization of geranium (Pelargonium graveolens L. )

O gerânio (Pelargonium graveolens L.) é uma planta medicinal e aromática nativa do sul da África, cujo óleo essencial é amplamente empregado nas indústrias de perfumaria e cosmético, além de ser usado como terapêutico. Avaliou-se o efeito da luminosidade e dos reguladores de crescimento BAP e ANA na multiplicação in vitro e o uso de diferentes substratos na aclimatização de mudas micropropagadas. Foram avaliadas as concentrações 0; 0,5; 1,0 e 2,0 mg L-1 de BAP, 0; 0,1 e 0,5 mg L-1 de ANA e duas condições de luminosidade (ausência e presença de luz), em esquema fatorial 4x3x2; para a aclimatização foram utilizados quatro substratos, pó de coco + Biosafra® (3-12-6) (12 g L-1) + calcário (1 g L-1) (PCBC); pó de coco + Biosafra® (3-12-6) (12 g L-1) + calcário (1 g L-1) + vermiculita (1:1) (PCBCV 1:1); pó de coco + Biosafra® (3-12-6) (12 g L­-1) + calcário (1 g L-1) + vermiculita (PCBCV 2:1) e vermiculita e adição semanal de sais MS (VS). Para a micropropagação de P. graveolens a utilização de 1,3 mg L-1 de BAP e 0,5 mg L-1 de ANA é eficiente na regeneração direta de plantas de gerânio, sendo a condição de escuro a mais indicada por proporcionar o maior número de brotos por explante. Para a aclimatização das mudas de gerânio, os melhores resultados foram obtidos em mudas aclimatizadas no substrato vermiculita com adição semanal de sais de MS seguido do substrato PCBCV 1:1.

Geranium (Pelargonium graveolens L.) is a medicinal and aromatic plant native to the south of Africa and whose essential oil is widely used by perfume and cosmetic industries, as well as in therapeutics. The effect of luminosity and growth regulators BAP and NAA on in vitro multiplication was evaluated, together with the use of different substrates on the acclimatization of micropropagated seedlings. The evaluated concentrations were 0, 0.5, 1.0 and 2.0 mg L-1 BAP; 0, 0.1 and 0.5 mg L-1 NAA; and two luminosity conditions (absence and presence of light), in a 4 x 3 x 2 factorial arrangement. For acclimatization, four substrates were tested: coconut dust + Biosafra® (3-12-6) (12 g L-1) + limestone (1 g L-1) (CDBL); coconut dust + Biosafra® (3-12-6) (12 g L-1) + limestone (1 g L-1) + vermiculite (1:1) (CDBLV 1:1); coconut dust + Biosafra® (3-12-6) (12 g L-1) + limestone (1 g L-1) + vermiculite (CDBLV 2:1); and vermiculite with weekly addition of MS salts (VS). For P. graveolens micropropagation, the use of 1.3 mg L-1 BAP and 0.5 mg L-1 NAA is efficient for the direct regeneration of geranium plants, and the dark condition is the most suitable since it provides a larger number of shoots per explant. For the acclimatization of geranium seedlings, the best results were obtained with seedlings acclimatized in the substrate vermiculite with weekly addition of MS salts, followed by the substrate CDBLV 1:1.

Investigaçöes epidemiológicas sobre demência nos países em desenvolvimento / Epidemiological research on dementia in developing countries

Na medida em que a populaçäo mundial está envelhecendo, a demência está se constituindo em importante problema de saúde pública, particularmente nos países em desenvolvimento. Investigaçöes epidemiológicas nestes países säo escassas e apresentam dificuldades metodológicas adicionais, principalmente no que se refere à adequaçäo sociocultural dos instrumentos utilizados para a definiçäo de casos. Tendo em vista estas preocupaçöes, foi fundado o "Grupo de Pesquisa em Demência 10/66", que é constituído por uma rede internacional de pesquisadores, predominantemente de países em desenvolvimento. O nome do grupo tem como referência o paradoxo de que menos de 10 por cento dos estudos populacionais sobre demência säo dirigidos aos 2/3 ou mais de casos de pessoas com demência que vivem em países em desenvolvimento. O objetivo do artigo é atualizar informaçöes da literatura sobre as diferenças de prevalência e incidência de demência encontradas em países desenvolvidos e em desenvolvimento

Sexual behavior and fertility of male rats submitted to prolonged immobilization-induced stress

In order to investigate whether prolonged stress interferes with the onset of sexual behavior at puberty and with fertility at adulthood, prepubertal male Wistar rats (40 days of age) were immobilized 6 h a day for 15 days (up to early puberty) or for 60 days (until sexual maturity). Pubertal stressed rats showed a two-fold increase in the latency for the first mount (probably due to repeated aversive experience in which a change of environment was always followed by immobilization) and a 2.5-fold increase in the frequency of thrusting (indicative of enhanced sexual performance). The apparently stimulatory effect of prolonged stress on the onset of sexual behavior is discussed in terms of increased testosterone level and interference with the complex interchanges between the neurotransmitters/neuropeptides involved in the central control of male sexual activity. Adult stressed animals were mated with normal females, which became pregnant but exhibited a more than two-fold increase in both pre-implantation and post-implantation loss, probably due to a smaller rate of fertilization and/or fertilization with damaged spermatozoa

Decreased spermatogenic and androgenic testicular functions in adult rats submitted to immobilization-induced stress from prepuberty

We investigated whether chronic stress applied from prepuberty to full sexual maturity interferes with spermatogenic and androgenic testicular functions. Male Wistar rats (40 days old) were immobilized 6 h a day for 60 days. Following immobilization, plasma concentrations of corticosterone and prolactin increased 135 per cent and 48 per cent, respectively, while plasma luteinizing hormone and testosterone presented a significant decrease of 29 per cent and 37 per cent, respectively. Plasma concentration of follicle-stimulating hormone was not altered in stressed rats. Chronic stress reduced the amount of mature spermatids in the testis by 16 per cent and the spermatozoon concentration in the cauda epididymidis by 32 per cent. A 17 per cent reduction in weight and a 42 per cent decrease in DNA content were observed in the seminal vesicle of immobilized rats but not in its fructose content. The growth and secretory activity of the ventral prostate were not altered by chronic stress.

Sexual development of hypernatriophilic male rats up to puberty

The sexual development of normonatriophilic (Normo) and hypemrntriophilic (Hyper) male Wistar rats was compared from 30 to 60 days of age (N = 8-10 per group) with emphasis on the onset of puberty. Hyper rats (more than 5 ml of saline a day in a situation of free access to tap water and 1.5 per cent NaCl) had a 20-39 per cent body weight reduction and a 22-29 per cent testicular growth rate decrease compared to Normo rats. Plasma testosterone (ng/ml) of Normoo rats increased from 0.29 ñ 0.02 at 30 days to 1.42 ñ 0.18 at 50 days, decreasing to 0.87 ñ 0.15 at 60 days of age, with no significant difference compared to Hyper animals. Plasma concentration (ng/ml) of luteinizing hormone (LH) was significantly lower in Hyper (0.21 ñ 0.03) than in Normo (0.43 ñ 0.06) rats at 40 days. At 30 days, plasma follicle stimulating hormone (FSH) levels (ng/ml) were significantly higher in Hyper (18.9 ñ 1.3) than in Normo (15.6 ñ 0.5) rats. It is possible that increased levels of FSH compensated for a reduced amount of LH, thus allowing similar testosterone production by Hyper and Normo rats. At 30 days, testis maturation was higher in Hyper rats, as indicated by a 22 per cent increase in tubular cross-sections with young spermatids. At 50 days, spermatogenesis progressed to the production of mature spermatids (onset of puberty) and Hyper rats exhibited an 18.7 per cent lower rate of testis maturation. Testis maturation was similar in Hyper and Normo rats at 60 days.