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412. The hypothalamo-pituitary gonadal axis in elderly males
394
Abstracts
cessing is required, especially in handling an emergency. Constitutionally more masculine boys and less feminine girls learn driving faster and do it better than their opposite groups in the opinion of 34 driving instructors. (2) A surgeon’s job more often demands speedy information processing compared to that of a physician. Forty-two surgeons’ voices, compared to those of 38 internists were found to be low-pitched (p < 0.01). (3) The court-room performance of a lawyer should be considerably influenced by his speed of information processing. A striking negative correlation was noted between the success in practice and the voice pitch of all the 20 senior lawyers in an area. (4) Empirically. verbally humorous comedians are found to be more masculine if they are men and less feminine if they are women. (5) Masculinity ratings were arbitrarily done from their pictures of all the 34 U.S. Presidents up to 1963 and all of the 47 German Nobel Laureates in science up to 1967; the presidents were found to be more masculine (p < 0.01). Fast information processing ability is a great asset to a president but not necessarily to a scientist. The different indices of androgenicity are hardly seen in equal proportions in a given individual: this should have many implications at the psychic level. the exploration of which is a promising field for future research. 412. The hypothalamctpituitary-gonadal axis in elderly males VERMEL~LEN.A., RUBENS. R. and VERDONCK, L.. Department of Endocrinology and Metabolism, Medical Clinic, Akademisch Ziekenhuis. Ghent, Belgium Plasma testosterone levels(T) and apparent free testosterone concentration (AFTC) are significantly decreased in elderly males. Pathophysiological mechanisms leading to this decreased Leydig cell function were studied. LH (fi = 24.1 mIU/ml) and FSH (fi = 15.8 mIU/ml/2 IRP.HMG) were significantly higher in elderly (> 65 yr) than in younger (< 50 yr) males (LH I% 13.0 mIU/ml. FSH fi 5.6 mIU/ml, p z 0,001) indicating a primary testicular origin of decreased T secretion. HCG stimulation produced a significantly lower absolute (p < 0.02) but a similar relative increase in T levels in elderly males. The LH-RH test showed a hyperresponsiveness of the gonadotrophs in elderly males (p < 0.01) when compared to younger adults. These data (low plasma T, notwithstanding an important reserve secretory capacity of both Leydig cells and gonadotrophs) suggests a resetting of the hypothalamic feed-back center. Estradiol levels were slightly but significantly increased in elderly males. The free estrogen fraction, as percent of total estradiol, decreases in old age, but whereas in younger males it .is lower than the free testosterone fraction. in elderly males it is higher than the free testosterone fraction. The free estradiol concentration in elderly males is not significantly different from the concentration in younger males. Thereexistsa highly significantly correlation between *the AFTC and both LH and FSH levels (p -C 0.001) suggesting that the feed back is regulated via the free rather than via total testosterone levels. 413. Efiects of ovariectomy and estradiol intake and body weight in rats hypothalamic lesions BEATTY. W. W. and O’BRIANT. D. Psychology, North Dakota State North Dakota. U.S.A. Female
rats
bearing
ventromedial
injections on food with ventromedial A.. Department of University, Fargo,
hypothalamic
(VMH)
lesions were ovariectomized during the static stage 01 rhc VMH syndrome when body weight levels had stabili/rd. Following ovariectomy the rats with VMH Icsions g:rined less weight than surgical controls ovarlcctomircd at the \amc time, and they also exhibited smaller increases in food intake than controls after ovariectomy. Thirty to 60 days following ovariectomy when body weight levels had again stabilized. all subjects received 28 daily injectiona of eqtradiol bcnloatc (/lpg/kg). Animals with VMH lesions lost levs weight than controls during estradiol treatment and they hhowcd \omewhat smaller reductions in food intahc than controls consequent to estrogen injections. Thcsc results support earlier conclusions. based on central implants of cstrogcn. that the VMH is a focal area through which estrogen acts to suppress food intake and body weight. At the sdme time it is clear that VMH lesions attenuate. but do not abolish responsiveness to estrogen. 414. Dependence of the gonadotrophic surge on circadian rhythms of methionine incorporation into brain proteins MACKINNON. P. C. B.. TER HAAK, M. B. and BURNET, F. R., Department of Human i\natomy. South Parks Road. Oxford, OX1 3QX. England Circadian rhythms in the uptake of S’” methionine into protein have been found in discrete areas of the rat brain. These rhythms are sexually differentiated and can bc transformed to that characteristic of the opposite sex by the administration or deprivation of the relevant steroids in neonatal life. In adult life the circadian rhythm can bc altered either by changes in hormone levels or by change\ in the photoperiod. The concept that this rhythm in methionine incorporation integrates stirnull arising in both the external and internal environments and thus enables crucial events of the oestrous cycle to he titned. has been tested. Ovariectomized rats kept under regulated lighting conditions and which showed a random pattern of LH release were given serial injections of oestradiol benzoate. Bqftire the animals regained the capacity to show timed LH surges a “female type” of circadian rhythm of methionine incorporation into cerebral proteins had returned. 415. Aggressive and exploratory behaviour and their relation to steroid hormones and gonadal steroidogenesis in mice LLJPO DI PRISCO.C. and DESSI’-FULC;HERI. F.. Institute of Zoology. University of Camerino. Camermo (MC) Italy The relationship between behavioral variability and cndocrine function has been investigated in two experiments. A group (26 males of heterogeneous strain) was observed in :I “hole in the wall” like test and in an “open field” like test; another group (14 albino males) was kept in isolation for 15 days and then tested in a fighting situation to determme a dominance rank. Plasma and fresh organs were collected after decapitation: Testosterone and estradiol were detrrmined in plasma by RIA; testicular tissue was used for irr vitro incubations with pregnenolonr-7-H’. Plasma testosterone was significantly correlated with some behavioral traits(central squares crossed: r = -0.33, p = 0.05. df = 24: time of freezing and grooming: r = 0.33. p = 0.05, df = df: rearingson hind legs: r = -0.34. p = 0.05. df = 24). The amount of testosterone formed from pregnenolone \\:I\ significantly correlated with the holes in the wall cross& (r = 0.45. p = 0.01. df = 24, time of freezing and grooming (r = -0.44. p = 0.025. df = 24) and dominance rank
Abstracts
cessing is required, especially in handling an emergency. Constitutionally more masculine boys and less feminine girls learn driving faster and do it better than their opposite groups in the opinion of 34 driving instructors. (2) A surgeon’s job more often demands speedy information processing compared to that of a physician. Forty-two surgeons’ voices, compared to those of 38 internists were found to be low-pitched (p < 0.01). (3) The court-room performance of a lawyer should be considerably influenced by his speed of information processing. A striking negative correlation was noted between the success in practice and the voice pitch of all the 20 senior lawyers in an area. (4) Empirically. verbally humorous comedians are found to be more masculine if they are men and less feminine if they are women. (5) Masculinity ratings were arbitrarily done from their pictures of all the 34 U.S. Presidents up to 1963 and all of the 47 German Nobel Laureates in science up to 1967; the presidents were found to be more masculine (p < 0.01). Fast information processing ability is a great asset to a president but not necessarily to a scientist. The different indices of androgenicity are hardly seen in equal proportions in a given individual: this should have many implications at the psychic level. the exploration of which is a promising field for future research. 412. The hypothalamctpituitary-gonadal axis in elderly males VERMEL~LEN.A., RUBENS. R. and VERDONCK, L.. Department of Endocrinology and Metabolism, Medical Clinic, Akademisch Ziekenhuis. Ghent, Belgium Plasma testosterone levels(T) and apparent free testosterone concentration (AFTC) are significantly decreased in elderly males. Pathophysiological mechanisms leading to this decreased Leydig cell function were studied. LH (fi = 24.1 mIU/ml) and FSH (fi = 15.8 mIU/ml/2 IRP.HMG) were significantly higher in elderly (> 65 yr) than in younger (< 50 yr) males (LH I% 13.0 mIU/ml. FSH fi 5.6 mIU/ml, p z 0,001) indicating a primary testicular origin of decreased T secretion. HCG stimulation produced a significantly lower absolute (p < 0.02) but a similar relative increase in T levels in elderly males. The LH-RH test showed a hyperresponsiveness of the gonadotrophs in elderly males (p < 0.01) when compared to younger adults. These data (low plasma T, notwithstanding an important reserve secretory capacity of both Leydig cells and gonadotrophs) suggests a resetting of the hypothalamic feed-back center. Estradiol levels were slightly but significantly increased in elderly males. The free estrogen fraction, as percent of total estradiol, decreases in old age, but whereas in younger males it .is lower than the free testosterone fraction. in elderly males it is higher than the free testosterone fraction. The free estradiol concentration in elderly males is not significantly different from the concentration in younger males. Thereexistsa highly significantly correlation between *the AFTC and both LH and FSH levels (p -C 0.001) suggesting that the feed back is regulated via the free rather than via total testosterone levels. 413. Efiects of ovariectomy and estradiol intake and body weight in rats hypothalamic lesions BEATTY. W. W. and O’BRIANT. D. Psychology, North Dakota State North Dakota. U.S.A. Female
rats
bearing
ventromedial
injections on food with ventromedial A.. Department of University, Fargo,
hypothalamic
(VMH)
lesions were ovariectomized during the static stage 01 rhc VMH syndrome when body weight levels had stabili/rd. Following ovariectomy the rats with VMH Icsions g:rined less weight than surgical controls ovarlcctomircd at the \amc time, and they also exhibited smaller increases in food intake than controls after ovariectomy. Thirty to 60 days following ovariectomy when body weight levels had again stabilized. all subjects received 28 daily injectiona of eqtradiol bcnloatc (/lpg/kg). Animals with VMH lesions lost levs weight than controls during estradiol treatment and they hhowcd \omewhat smaller reductions in food intahc than controls consequent to estrogen injections. Thcsc results support earlier conclusions. based on central implants of cstrogcn. that the VMH is a focal area through which estrogen acts to suppress food intake and body weight. At the sdme time it is clear that VMH lesions attenuate. but do not abolish responsiveness to estrogen. 414. Dependence of the gonadotrophic surge on circadian rhythms of methionine incorporation into brain proteins MACKINNON. P. C. B.. TER HAAK, M. B. and BURNET, F. R., Department of Human i\natomy. South Parks Road. Oxford, OX1 3QX. England Circadian rhythms in the uptake of S’” methionine into protein have been found in discrete areas of the rat brain. These rhythms are sexually differentiated and can bc transformed to that characteristic of the opposite sex by the administration or deprivation of the relevant steroids in neonatal life. In adult life the circadian rhythm can bc altered either by changes in hormone levels or by change\ in the photoperiod. The concept that this rhythm in methionine incorporation integrates stirnull arising in both the external and internal environments and thus enables crucial events of the oestrous cycle to he titned. has been tested. Ovariectomized rats kept under regulated lighting conditions and which showed a random pattern of LH release were given serial injections of oestradiol benzoate. Bqftire the animals regained the capacity to show timed LH surges a “female type” of circadian rhythm of methionine incorporation into cerebral proteins had returned. 415. Aggressive and exploratory behaviour and their relation to steroid hormones and gonadal steroidogenesis in mice LLJPO DI PRISCO.C. and DESSI’-FULC;HERI. F.. Institute of Zoology. University of Camerino. Camermo (MC) Italy The relationship between behavioral variability and cndocrine function has been investigated in two experiments. A group (26 males of heterogeneous strain) was observed in :I “hole in the wall” like test and in an “open field” like test; another group (14 albino males) was kept in isolation for 15 days and then tested in a fighting situation to determme a dominance rank. Plasma and fresh organs were collected after decapitation: Testosterone and estradiol were detrrmined in plasma by RIA; testicular tissue was used for irr vitro incubations with pregnenolonr-7-H’. Plasma testosterone was significantly correlated with some behavioral traits(central squares crossed: r = -0.33, p = 0.05. df = 24: time of freezing and grooming: r = 0.33. p = 0.05, df = df: rearingson hind legs: r = -0.34. p = 0.05. df = 24). The amount of testosterone formed from pregnenolone \\:I\ significantly correlated with the holes in the wall cross& (r = 0.45. p = 0.01. df = 24, time of freezing and grooming (r = -0.44. p = 0.025. df = 24) and dominance rank