The morphometric parameters of adrenal cortex in sows: in normal condition and after prolactin infusion

The aim of this study was to examine the effect of experimental hyperprolactinemia on the sterological parameters of porcine adrenal cortex. In cyclic sows, after preovulatory luteinizing hormone (LH) peak, porcine prolactin (PRL, 0.3 mg) or saline were administered iv. for 48 h at 2 h intervals. Next sows were slaughtered and adrenal glands were dissected. Stereological analysis of the left adrenal gland did not reveal any significant differences between control and PRL-treated sows. Experimental hyperprolactinemia did not affect the volume of particular cortical zones, the number and the volume of adrenocortical cells or the average volume of their cell nuclei. Moreover, we present for the first time a detailed stereological description of adrenal cortex in sows

Phytoestrogens alter cortisol and and rostenedione secretion by porcine adrenocortical cells

The effect of plant-derived, nonsteroidal estrogens (genistein, daidzein and biochanin A) on cortisol and androstenedione secretion by porcine adrenocortical cells was examined. Adrenals were harvested from locally slaughtered mature gilts on days 5–9 of the oestrous cycle. Adrenocortical cells were incubated with or without genistein, daidzein, biochanin A (0.5, 5, 10 or 50 μM), oestradiol (10, 50, 100 or 500 pg/mL) and ACTH (5 nM — positive control). All incubations were performed for 8 h (95% air and 5% CO 2 , 37°C). ACTH increased cortisol and androstenedione secretion. Genistein, daidzein and biochanin A suppressed cortisol output, whereas androstenedione secretion was enhanced by these phytoestrogens. In contrast, oestradiol did not alter steroid secretion by porcine adrenocortical cells, which may suggest that phytoestrogens have a non-oestrogenic mechanism of action. Therefore, phytoestrogens present in commercial forage may influence adrenocortical function in pigs by decreasing cortisol and increasing androstenedione secretion

Are oestrogen receptors and protein tyrosine kinases involved in phytoestrogen-modulated steroid secretion by porcine adrenocortical cells?

The phytoestrogens genistein and daidzein had been found to affect the function of some tissues via oestrogen receptors (ER). In addition, genistein, but not daidzein, is considered to be a protein tyrosine kinase (PTK) inhibitor. Thus, the involvement of oestrogen receptors and PTK in phytoestrogen action on adrenocortical porcine steroidogenesis was examined in this study. The aims of the experiment were to test the effects of (i) ICI 182, 780 (ICI), an ER antagonist, on genistein- and daidzein-modulated cortisol and androstenedione (A4) secretion by adrenocortical cells isolated during the luteal and follicular phases of the porcine oestrous cycle; (ii) tyrphostin AG 957 (TAG), a nonsteroidal PTK inhibitor, on cortisol and A4 secretion by the cells and (iii) the phase of the porcine oestrous cycle on the mechanism of phytoestrogen action. Adrenals were harvested during the luteal (n = 5 animals) and follicular (n = 5 animals) phases of the oestrous cycle from locally slaughtered crossbred gilts. The isolated adrenocortical cells were incubated for 8 h (37 °C, 95% air, 5% CO2) with genistein (5 or 10 μM) or daidzein (5 or 10 μM) in the presence or absence of ICI (0.5 μM) or TAG (5 or 10 μM). Genistein and daidzein inhibited cortisol secretion and stimulated A4 secretion by porcine adrenocortical cells harvested during both the luteal and follicular phases of the oestrous cycle. The ER antagonist ICI did not eliminate phytoestrogen-induced changes in steroidogenesis. In contrast to genistein, TAG reduced the secretion of A4 and did not affect cortisol secretion. There was no observable effect due to the phase of the cycle. It is suggested that the mechanism of genistein and daidzein action in the adrenocortical cells of pigs is independent of ER and PTK. It is possible that PTK are involved in A4 secretion by porcine adrenocortical cells

Effects of dietary meals containing different levels of phytoestrogens on reproductive function in Bilgoraj ganders

The aim of this study was to investigate how long-term feeding of ganders with diets containing different levels of phytoestrogens affects the morphometry of testes, plasma steroid levels, sperm parameters and reproductive performance. Male Bilgoraj geese were fed diets containing grass meal (with low phytoestrogen levels) and those containing alfalfa meal and soybean meal (with higher levels of phytoestrogens). Testes were obtained from ganders at the peak of mating and the ongoing laying period as well as at the beginning of photorefractoriness. The morphometric parameters were measured in frozen testicular sections. Blood was collected monthly from December to June, and plasma testosterone, androstenedione and corticosterone concentrations were determined. During the mating season, semen was collected and its quantity and quality were investigated. In the flocks (ganders with geese) reproductive output was noted. Seasonal changes were observed in the morphology of testes and in plasma testosterone, androstenedione and corticosterone concentrations in ganders. The feeding of ganders with dietary meals containing higher levels of phytoestrogens did not affect the plasma steroid contents or the majority of the morphometric parameters of testes, except for the height of the seminiferous epithelium, which was lowered. Moreover, diets with higher levels of phytoestrogens decreased the volume of ejaculates and the percentage of normal spermatozoa. However, these changes were not reflected in the fertilisation rates

Self-reporting versus parental reporting of physical activity in adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study Auto-relato de atividade física na adolescência comparado ao relato dos pais: a visita de 11 anos da coorte de nascimentos de Pelotas, Rio Grande do Sul, Brasil, 1993

The aim of this study was to verify the agreement between different approaches for estimating levels of physical activity in adolescents. One questionnaire was administered to parents and two were administered to the adolescents. This was a cross-sectional analysis of data collected in the 2004-2005 follow-up of the 1993 Pelotas (Brazil) birth cohort study. Parents or guardians answered the following question: "Compared to most children the same age, would you say that your child exercises more, less, or the same amount?" A similar question was addressed to adolescents, as was a detailed questionnaire on physical activity. Agreement between the questionnaires was measured by the weighted kappa statistic. A total of 4,254 adolescents and parents/guardians answered the questionnaires. Kappa values indicated low agreement for all comparisons (kappa < 0.33 for all analyses). Measurement of physical activity in adolescents is complex, and available instruments should be validated prior to their use.<br>O objetivo deste estudo foi verificar a concordância entre diferentes formas de se estimar o nível de atividade física de adolescentes. Um questionário foi aplicado aos pais e outros dois aos adolescentes. O estudo foi transversal aninhado ao acompanhamento de 2004-2005 da coorte de nascimentos de 1993 em Pelotas, Rio Grande do Sul, Brasil. Pais ou responsáveis responderam à questão: "Comparando com a maioria das crianças da mesma idade, o(a) Sr(a). diria que o seu filho faz mais exercícios que elas, menos exercícios que elas ou a mesma quantidade que elas?". Questão análoga foi aplicada aos adolescentes. Os adolescentes também responderam a um questionário mais detalhado sobre a prática de atividades físicas. A concordância entre os questionários foi avaliada pelo teste kappa ponderado. Um total de 4.254 adolescentes e responsáveis responderam aos questionários. Os valores de kappa indicaram concordância baixa para quaisquer das comparações (kappa < 0,33 para todas as análises). A mensuração de atividade física em adolescentes é complexa e os instrumentos disponíveis devem ser validados antes do uso