Sexual behavior and serum hormone levels in aging rhesus males: effects of environmental change

Old (N = 9) and middle-aged (N = 9) rhesus males (Macaca mulatta) that were housed in the same type of home cage and the same room for several years were moved to a new location in an adjacent building. Their sexual behavior and hormone levels in the weeks preceding the move were compared to those after the move. The hypothesis that the nonspecific sensory stimulation provided by the move would increase levels of sexual behavior was not supported by the data. To the contrary, the percentages of tests with contacts, mounts, and penile erections, and the rate of contacting the female, decreased significantly for both old and middle-aged males. The intromission rate of middle-aged, but not of old, males also decreased. In consonance with previous findings, middle-aged males displayed significantly higher levels of sexual activity than did old males. The differences were observed both before and after the move. Serum testosterone levels did not differ between middle-aged and old males, and the move did not produce significant changes in testosterone levels. Serum cortisol levels were significantly higher immediately after the move (1 hr) but returned to premove levels the following day.     

Narratives of success among Irish and African Caribbean migrants

This paper compares the narratives of two men in midlife who migrated to the UK from Ireland and from the Caribbean as children, in the middle of the last century. We examine how success is narrated over the life course to show how migrants’ positioning of themselves differs from the ways in which they are positioned by outsiders, including in policy and public discourse. We conclude that while outsider narratives often polarise success and failure, insider understandings of success are dynamic and culturally and historically situated.     

Inhibition of Ca2+-induced cytosolic enzyme efflux from skeletal muscle by vitamin E and related compounds.

1. Efflux of an intracellular enzyme (creatine kinase) from normal rat skeletal muscles was induced by treatment with the Ca2+ ionophore A23187. Addition of alpha-tocopherol (230 microM) to the incubation medium was found to significantly diminish this efflux, and this effect was mimicked by alpha-tocopherol acetate, phytol and isophytol, but not by Trolox C (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). 2. Analysis of muscle cation content has shown that these protective effects of alpha-tocopherol etc. are not due to an inhibition of the Ca2+ accumulating effects of the ionophore. 3. Non-enzymic lipid peroxidation of skeletal-muscle homogenates was found to be inhibited by alpha-tocopherol and Trolox C, partially inhibited by phytol and isophytol, but unaffected by alpha-tocopherol acetate. 4. The activity of lipoxygenase enzymes was partially inhibited by alpha-tocopherol, phytol and isophytol, but not by alpha-tocopherol acetate or Trolox C. 5. Prostaglandin E2 efflux from isolated skeletal muscles was stimulated by treatment with the Ca2+ ionophore, but this was unaffected by alpha-tocopherol treatment.     

Threshold for behavioral response to testosterone in old castrated male rhesus macaques

The sexual behaviors of old, intact (N = 5) and old, castrated (N = 6) rhesus macaque males were compared in six series of pair tests with receptive females. The castrated monkeys were tested when untreated and when given five doses of testosterone propionate (TP; 0.004, 0.016, 0.064, 0.256, and 1.024 mg/kg of body weight) in consecutive months. The serum testosterone (T) level was determined for each male before and after each series of tests. When untreated, none of the castrated males ejaculated, and yawning was significantly less in these monkeys than in intact males-no other behavioral measures differed significantly. Within 2 weeks of daily injections of 0.004 mg of TP/kg, two males ejaculated, and all differences in measures of ejaculation were eliminated. A third male ejaculated after 1 week of treatment with 0.016 mg of TP/kg. Yawning values did not differ during and after treatment with 0.064 mg of TP/kg. Although final mean serum T levels were six times higher in castrated (24.3 ng/ml) than in intact males (4.2 ng/ml), sexual performance levels did not exceed those of intact males.     

The effect of vitamin E analogues and long hydrocarbon chain compounds on calcium-induced muscle damage. A novel role for α-tocopherol?

Previous studies have demonstrated that supplemental α-tocopherol inhibited calcium-induced cytosolic enzyme efflux from normal rat skeletal muscles incubated in vitro and suggested that the protective action was mediated by the phytyl chain of α-tocopherol [1]. In order to investigate this further a number of hydrocarbon chain analogues of tocopherol (7.8-dimethyl tocol, 5,7-dimethyl tocol, tocol, α-tocotrienol, α-tocopherol [10], vitamin K1, vitamin K1 [10], vitamin K1 diacetate, vitamin K2 [20], phytyl ubiquinone and retinol) were tested for any ability to inhibit calcium ionophore, A23187, induced creatine kinase (CK) enzyme efflux. Some compounds were found to be very effective inhibitors and comparison of their structures and ability and to inhibit TBARS production in muscle homogenates revealed that the effects did not appear related to antioxidant capacity or chromanol methyl groups, but rather the length and structure of the hydrocarbon chain was the important mediator of the effects seen.     

Diurnal patterns of testosterone, dihydrotestosterone, estradiol, and cortisol in serum of rhesus males: Relationship to sexual behavior in aging males

This study was carried out to determine differences between old and young rhesus males in levels and diurnal patterns of testosterone, dihydrotestosterone, cortisol, and estradiol, and to determine correlations between these hormones and sexual behavior of the old males. Blood was drawn from old (n = 9) and young (n = 9) rhesus males over 5 consecutive days at 0900, 1300, and 2100 hr. The two groups of males did not differ in mean serum levels of testosterone, dihydrotestosterone, or estradiol at any time. Although the old and young did not differ in cortisol levels at 0900 and 1300 hr, the cortisol levels at 2100 hr were lower in the old males. Diurnal variations in testosterone, dihydrotestosterone, and cortisol were comparable in old and young males. Mean serum levels of estradiol were significantly higher at 0900 hr than at 1300 hr in the old males, whereas in the young males estradiol levels did not differ with time of day. There was a significant positive correlation between testosterone and yawning rate, and cortisol levels were correlated positively with rate of contacting, rate of mounting, and percentage of tests with erections. The decline in sexual performance of old rhesus males cannot be attributed to changes in the levels or diurnal patterns of testosterone, dihydrotestosterone, or estradiol, but lower cortisol levels in old males may contribute to the decline in sexual behavior.     

Sexual behavior of laboratory- and wild-born male Rhesus monkeys.

Rearing method has an important influence on the sexual performance of adult male rhesus monkeys. Testosterone levels and sexual behavior of laboratory-born and -reared adult males were compared with those of males born in the wild and brought to the laboratory as adults. The mean sexual performance level of colony-reared animals was significantly below that of males born in the wild but testosterone levels in the two groups did not differ significantly. Not all laboratory-reared males were sexually inadequate but less than 30% ejaculated in tests of sexual behavior. The sexual behavior and testosterone levels of adult males treated prenatally with testosterone propionate were found not to differ from those of untreated males reared in the same way. Conclusions about sexual adequacy based on 10-mm tests of sexual behavior differed very little from those based on 1-hr tests.