摘要:

The effects of varied doses of bromocriptine on the growth hormonesomatomedin axis have been studied in 6 acromegalic patients. The study last 9 months and during this time a maximum daily dose of bromocriptine of 60 mg was given to 3, 50 mg to 1 and 20 mg to the remaining 2 patients. In 2 of the 6 there was an excellent reduction in the growth hormone (GH) levels down to the normal range on doses as low as 5 and 10 mg bromocriptine. In these 2 the serum somatomedin activity (SM-act) decreased to 71 and 53% of the basal values and there was an excellent clinical response. A third patient showed moderate clinical improvement, a reduction in the mean GH level but not down to the normal range and a decrease in serum SM-act of 10%. The remaining 3 patients showed no significant changes in GH levels or serum SM-act but all had a good clinical response. We conclude that when the clinical and GH responses to bromocriptine are both excellent there is a significant decrease in serum SM-act. In addition there may be a good clinical response in the absence of any changes in the circulating GH levels or SM-act which suggests that part of the beneficial effects due to bromocriptine are mediated by mechanisms other than changes in the GH-somatomedin axis.

ISSN:1663-2818    

DOI:10.1159/000179113

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The longitudinal change in the percentage binding of testosterone has been studied in 137 serum samplings from 41 pubertal males. Free (unbound) testosterone levels were also calculated and total and free testosterone levels evaluated according to the stage of sexual development and correlated with LH and FSH levels obtained concomitantly. There was a progressive rise of total and free testosterone levels throughout puberty closely correlated with pubic hair staging. Serum LH levels correlated significantly with both total and free testosterone levels while serum FSH correlated with total but not free testosterone levels.

ISSN:1663-2818    

DOI:10.1159/000179114

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Homoplastic anterior pituitaries were transplanted beneath the renal capsule of adult male, Syrian golden hamsters and the effects studied on the gonadal and accessory organ atrophy following bilateral optic enucleation or placement in reduced (L/D = 10/14 h) photoperiods. In all cases, control hamsters, bearing kidney fragments transplanted beneath their renal capsules, showed gonadal atrophy and reduced blood levels of prolactin and LH at 8–10 weeks following light deprivation. On the other hand, hamsters, bearing three or four homoplastic pituitary grafts, showed complete maintenance of gonadal and accessory weights as well as normal or supranormal serum prolactin levels. Prolactin, but not LH, levels were maintained in hypophysectomized male hamsters bearing pituitary homografts. These results point out the significant role played by prolactin, and possibly that of pineal prolactin-regulating factors, in pineal-mediated gonadal atroph

ISSN:1663-2818    

DOI:10.1159/000179115

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Endocrine and behavioral effects of age and aging have been studied in 4 groups of Sprague-Dawley male rats (2, 6, 12, 24 months old). Plasma testosterone decreases after 6 months of age, plasma estradiol decreases from 2 to 6 months, then it increases with age and decreases again with aging (from 12 to 24 months). Aromatization of testosterone in brain tissue is similar in 2-, 12- and 24-month-old rats, but at 6 months a significant increase is observed. Testosterone biosynthesized in the gonad from dehydroepiandrosterone increases from 2 to 6 months, then it decreases, while the other metabolites of dehydroepiandrosterone show an increment with age. Corticosterone and 17α-hydroxyprogesterone biosynthesized in the adrenal decrease with aging. Explorative and loco-motor activity decreases with age and aging, while emotionality decreases from 2 to 12 months, but it increases with aging. These results indicate that endocrine equilibrium is remarkably altered by aging process showing a decrease of plasma sexual hormones and of gonadal activity. The decrement of aromatization of testosterone in the brain, which occurs between 6 and 12 months, is correlated with the decrement of plasma testosterone. It could be hypothesized that the hormones of the brain-pituitary-gonad axis are involved in the control of explorative behavior or that both hormonal and behavioral parameters are controlled by a common factor

ISSN:1663-2818    

DOI:10.1159/000179116

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The stimulatory effect of calcitonin on cerebral acetylcholinesterase activity could not be observed in rats pretreated with p-chlorophenylalanine. The results suggest that the response of the enzyme activity to calcitonin is 5-hydroxytryptamine-mediated.

ISSN:1663-2818    

DOI:10.1159/000179117

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179118

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179119

出版商:S. Karger AG    

年代:1980

数据来源: Karger