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Active Males (active + male)
Selected AbstractsExposure to Oestrogen Prenatally Does Not Interfere with the Normal Female-Typical Development of Odour PreferencesJOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2007J. Bakker The neural mechanisms controlling mate recognition and heterosexual partner preference are sexually differentiated by perinatal actions of sex steroid hormones. We previously showed that the most important action of oestrogen during prenatal development is to defeminise and, to some extent, masculinise brain and behaviour in mice. Female mice deficient in alpha-foetoprotein (AFP) due to a targeted mutation in the Afp gene (AFP-KO) do not show any female sexual behaviour when paired with an active male because they lack the protective action of AFP against maternal oestrogens. In the present study, we investigated whether odour preferences, another sexually differentiated trait in mice, are also defeminised and/or masculinised in AFP-KO females due to their prenatal exposure to oestrogens. AFP-KO females of two background strains (CD1 and C57Bl/6j) preferred to investigate male over female odours when given the choice between these two odour stimuli in a Y-maze, and thus remained very female-like in this regard. Thus, the absence of lordosis behaviour in these females cannot be explained by a reduced motivation of AFP-KO females to investigate male-derived odours. Furthermore, the presence of a strong male-directed odour preference in AFP-KO females suggests a postnatal contribution of oestrogens to the development of preferences to investigate opposite-sex odours. [source] Human soleus muscle protein synthesis following resistance exerciseACTA PHYSIOLOGICA, Issue 2 2004T. A. Trappe Abstract Aim:, It is generally believed the calf muscles in humans are relatively unresponsive to resistance training when compared with other muscles of the body. The purpose of this investigation was to determine the muscle protein synthesis response of the soleus muscle following a standard high intensity bout of resistance exercise. Methods:, Eight recreationally active males (27 ± 4 years) completed three unilateral calf muscle exercises: standing calf press/heel raise, bent-knee calf press/heel raise, and seated calf press/heel raise. Each exercise consisted of four sets of 15 repetitions (,15 repetition maximum, RM, or ,70% 1RM). Fractional rate of muscle protein synthesis (FSR) was determined with a primed constant infusion of [2H5]phenylalanine coupled with muscle biopsies immediately and 3 h following the exercise in both the exercise and non-exercise (resting control) leg. Results:, FSR was elevated (P < 0.05) in the exercise (0.069 ± 0.010) vs. the control (0.051 ± 0.012) leg. Muscle glycogen concentration was lower (P < 0.05) in the exercise compared with the control leg (Decrease from control; immediate post-exercise: 54 ± 5; 3 h post-exercise: 36 ±4 mmol kg,1 wet wt.). This relatively high amount of glycogen use is comparable with previous studies of resistance exercise of the thigh (i.e. vastus lateralis; ,41,49 mmol kg,1 wet wt.). However, the exercise-induced increase in FSR that has been consistently reported for the vastus lateralis (,0.045,0.060% h,1) is on average ,200% higher than reported here for the soleus (0.019 ± 0.003% h,1). Conclusions:, These results suggest the relatively poor response of soleus muscle protein synthesis to an acute bout of resistance exercise may be the basis for the relative inability of the calf muscles to respond to resistance training programs. [source] DNA damage in peripheral blood leukocytes of physically active individuals as measured by the alkaline single cell gel electrophoresis assayENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2009Gursatej Gandhi Abstract DNA damage induced by physical activity and/or exercise has been reported under different conditions but not for individuals maintaining physical fitness by regular strenuous exercise. Therefore, we compared levels of DNA damage in blood leukocytes of 40 healthy individuals (35 males, 5 females) who regularly exercised in gymnasiums/health clubs and 15 healthy sedentary controls who had never exercised. The former group was selected (after informed consent) on the basis of how long they had been exercising on a regular basis as well as their exercise schedule and regimen. The length of time since starting a regular exercise regimen ranged from 2 months to 9 years, whereas the daily exercise duration ranged from 40 min to 3 hrs and warm-up sessions ranged from none to 90 min. The length of DNA migration (44.66 ± 2.68 ,m in males, 29.62 ± 1.69 ,m in females) and the percentage of cells with tails (79.86 ±1.27% in males, 67.20 ± 0.96% in females) in peripheral blood leukocytes of physically active individuals were increased significantly (P < 0.001) with respect to corresponding values in control males and females (18.85 ± 1.79 ,m, 23.37 ± 3.94 ,m; 24.50 ± 1.98%, 33.00 ± 4.44%, respectively). Highly significant differences for DNA damage were also observed between physically active males and females. These observations, in the absence of any other exposures, indicate a correlation between strenuous exercise to keep fit and increased levels of DNA damage. This finding may have relevance in terms of the ageing process, with diseases associated with aging, and with carcinogenesis. Environ. Mal. Mutagen. 2009. © 2009 Wiley-Liss, Inc. [source] Bourgeois Males of the Peacock Blenny, Salaria pavo, Discriminate Female Mimics from Females?ETHOLOGY, Issue 6 2005David Gonçalves In a Portuguese population of Salaria pavo, two types of reproductively active males occur: large bourgeois males that defend nests and have fully developed secondary sex characters (SSC) and small sneaker males that mimic the females' morphology and behaviour to approach nests and parasitize fertilizations. These two alternative reproductive tactics are sequential, as sneakers develop into bourgeois males. We investigated whether bourgeois males were able to discriminate between sneakers and females of different sizes. In a laboratory experiment bourgeois males were sequentially presented with a female and a sneaker matched for size. Complementary field observations were conducted on the interactions between females and sneakers with bourgeois males. If bourgeois males discriminated females from sneakers, we predicted that they should direct more aggressive behaviours towards sneakers and more courtship acts towards females. In general, bourgeois males courted and attacked small females and sneakers equally. However, large sneakers were courted less and attacked more than large females. Larger sneakers, beginning to develop SSC, were attacked more and courted less by the bourgeois male than smaller sneakers, and larger females were attacked less and courted more than smaller females. These results strongly suggest that only small female-mimicking males were able to deceive bourgeois males. In S. pavo, if the sneakers' fertilization success correlates with their female-mimicking ability, a fitness decrease with an increasing body size can be predicted. [source] The Relationship Between the Presence of Satellite Males and Nest-Holders' Mating Success in the Azorean Rock-Pool Blenny Parablennius sanguinolentus parvicornisETHOLOGY, Issue 3 2002Rui F. Oliveira In the Azorean rock-pool blenny, sexually active males may adopt alternative reproductive tactics. In the present paper the relationship between the presence of satellite males and the reproductive success of nest-holders was investigated by comparing nests with and without an associated satellite male. Males with an associated satellite male suffered more conspecific intrusions but they did not display a higher frequency of attacks towards conspecifics. Nest-holder males were more aggressive towards other conspecifics than towards satellites and the tolerance of nest-holders towards satellites was inversely correlated with the time spent by the satellites in the breeding territory, which suggests control by the nest-holder male of the satellite investment in shared territorial defence. Nest-holders with an associated satellite male had higher condition factors and received more female visits and more spawnings. These results bear two possible interpretations. (1) Nest-holders benefit from the presence of a satellite male by increased attractiveness of their nests to females; satellite males are mutualists helping to defend the nest-owner's territory and to attract females, which is why they are tolerated. (2) Satellite males associate preferentially with more successful nest-holder males which have higher condition factors, and by doing so have more opportunities to achieve parasitic fertilizations. Only experiments will allow these two hypotheses to be distinguished. [source] Inhibition of factor VIII with a partially inhibitory human recombinant monoclonal antibody prevents thrombotic events in a transgenic model of type II HBS antithrombin deficiency in miceJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2004M. Dewerchin Summary., Venous thromboembolic disease is a major cause of morbidity and mortality, necessitating antithrombotic therapy. A human monoclonal anti-factor (F)VIII antibody, LCL-mAb-LE2E9, produced by a lymphoblastoid cell line derived from a hemophilia A patient with inhibitor to wild-type but not mutant self FVIII, was previously reported to achieve efficient inhibition of thrombosis in an experimental vena cava thrombosis model in mice. Here, the antithrombotic efficacy of a recombinant DNA-derived version of this anti-FVIII antibody (rec-mAb-LE2E9) was tested in mice which carry a type II heparin binding site antithrombin deficiency mutation and display spontaneous chronic thrombosis in several sites including the penile vein of sexually active males. The recombinant anti-FVIII antibody (100 µg, repeated after 3 days) prevented thrombotic priapism in all treated males, whereas all control animals treated with saline (group of four animals) developed priapism within 6 days after mating (P < 0.05 for treated vs. saline). The rec-mAb-LE2E9 and the original LCL-mAb-LE2E9 were equally effective (five and seven males/group, respectively). These results confirm that FVIII inhibition represents a potent antithrombotic strategy, and show that both LCL-mAb-LE2E9 and rec-mAb-LE2E9 efficiently prevent thrombosis in a physiological model representative of thrombosis in patients with a severe prothrombotic risk. [source] A meta-analysis of the association of physical activity with reduced risk of colorectal cancerCOLORECTAL DISEASE, Issue 3 2005A. K. A. Samad Abstract Background Physical activity may be associated with reduced risk of colorectal cancer. The main aim of this paper is to review the available evidence for a link between exercise and large bowel cancer. Methods A Cochrane-type methodology was performed. Data extracted included, type of study, type of physical activity measured and the numerical results. The risk ratios (RR) of the studies have been pooled according to the type of study, type of exercise, type of cancer and sex. Pooling was undertaken using fixed effect meta-analysis. A random effect meta-analysis was used where substantial heterogeneity existed. Result Data from 19 cohort studies showed a statistically significant reduction in the risk of colon cancer in physically active males, RR being 0.79 (95% CI 0.72,0.87) and 0.78 (95% CI 0.68,0.91) for occupational and recreational activities, respectively. In women only recreational activities are protective against colon cancer (RR = 0.71, 95%CI 0.57,0.88). Case-control studies showed significantly reduced risks of colon cancer in both sexes irrespective of the type of activity. No protection against rectal cancer is seen in either sex. Conclusion There is considerable evidence that physical activity is associated with reduced risk of colon cancer in both males and females. [source] | |||||||||||||