Abstract:The relation of the reproductive endocrine system to impotence in older men was examined by measuring the concentrations of testosterone (T), bioavailable testosterone (BT), LH, and PRL and body mass index (BMI) in 57 young controls (YC), 50 healthy potent older controls attending a health fair (HF), and 267 impotent patients (SD). The SD and HF had markedly reduced mean T and BT values compared to YC. When adjusted for age and BMI there was no difference in BT between potent and impotent older men. The percen… Show more
“…Although some follow-up studies failed to detect age-related decline in plasma testosterone levels in older men [99][100][101][102][103][104], subsequent population-based cross-sectional and longitudinal studies have confirmed progressive loss of testosterone with aging in healthy men [96,[105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121][122]. Mirroring this decline in plasma testosterone concentration is an age associated increase in sex-hormonebinding globulin (SHBG) level [117], a major plasma carrier of testosterone, resulting in even more dramatic decreases in unbound free testosterone [110,[123][124][125], and weakly bound bioavailable testosterone [126,127]. [In healthy male adults, circulating testosterone exists in three forms: testosterone strongly bound to SHBG, testosterone weakly bound to albumin and free testosterone].…”
Steroid hormones are lipophilic, low-molecular weight organic compounds all of which are derived from cholesterol. They are primarily synthesized by steroidogenic glands such as gonads (ovary and testis), the adrenal gland and, during pregnancy, by the placental trophoblasts. Limited steroid synthesis also takes place in the brain. Steroid hormones are crucial for the proper functioning of the body. They mediate a wide variety of vital physiological functions, ranging from maintaining normal reproductive function and secondary sexual characteristics, to regulating virtually every metabolic process in the body. Like many age-related endocrine disorders, aging also progressively impacts the tissue-specific synthesis and secretion of steroid hormones. The goal of this review is to summarize the effects of aging on steroid hormone synthesis and secretion by the adrenal gland and gonads of both human and experimental animal models, to describe the potential involvement of excessive oxidative stress in mediating age-related alterations in steroidogenesis, and to discuss the possible underlying mechanisms involved.
“…Although some follow-up studies failed to detect age-related decline in plasma testosterone levels in older men [99][100][101][102][103][104], subsequent population-based cross-sectional and longitudinal studies have confirmed progressive loss of testosterone with aging in healthy men [96,[105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121][122]. Mirroring this decline in plasma testosterone concentration is an age associated increase in sex-hormonebinding globulin (SHBG) level [117], a major plasma carrier of testosterone, resulting in even more dramatic decreases in unbound free testosterone [110,[123][124][125], and weakly bound bioavailable testosterone [126,127]. [In healthy male adults, circulating testosterone exists in three forms: testosterone strongly bound to SHBG, testosterone weakly bound to albumin and free testosterone].…”
Steroid hormones are lipophilic, low-molecular weight organic compounds all of which are derived from cholesterol. They are primarily synthesized by steroidogenic glands such as gonads (ovary and testis), the adrenal gland and, during pregnancy, by the placental trophoblasts. Limited steroid synthesis also takes place in the brain. Steroid hormones are crucial for the proper functioning of the body. They mediate a wide variety of vital physiological functions, ranging from maintaining normal reproductive function and secondary sexual characteristics, to regulating virtually every metabolic process in the body. Like many age-related endocrine disorders, aging also progressively impacts the tissue-specific synthesis and secretion of steroid hormones. The goal of this review is to summarize the effects of aging on steroid hormone synthesis and secretion by the adrenal gland and gonads of both human and experimental animal models, to describe the potential involvement of excessive oxidative stress in mediating age-related alterations in steroidogenesis, and to discuss the possible underlying mechanisms involved.
“…Já a resposta ao Clomifeno é normal e o seu uso em baixas doses por longo prazo leva à normalização androgênica (5). O conjunto destes achados laboratoriais indica uma possível deficiência na liberação de LHRH (3-5), cuja causa poderia ser qualquer uma das que levam a uma redução dos níveis de testosterona, tais como stress (6,7), abuso de álcool (8), doenças sistêmicas crônicas ou agudas (9), idade avançada e outras (8,10,11).…”
There is a group of middle-aged men with sexual dysfunction that presents reduced serum testosterone levels and normal to low levels of prolactin and gonadotropins, but without any dermonstrable hypothalamicpituitary anatomic abnormality. This condition is considered a form of idiopathic hypogonadotropic hypogonadism, probably of hypothalamic origin. We present and discuss two patients with similar features in whom sexual dysfunction preceded actual hypoandrogenism. We conclude that in these two patients hypoandrogenism was the consequence of a psychoneuroendocrine disturbance due to the sexual dysfunction. 1,2). No entanto, têm sido descritos casos de pacientes não idosos com DS e hipoandrogenismo secundário na ausên-cia de lesão orgânica hipotálamo-hipofisária, nos quais a origem destes achados permanece obscura. Estamos apresentando os casos de dois destes pacientes, e discutindo as possíveis causas do hipoandrogenismo e sua relação com a DS.
Caso lPaciente de 46 anos, casado e com um filho de 5 anos, visto em abril de 1997 com libido normal e queixas de disfunção erétil e ejaculação precoce. Sendo professor universitário em fase de doutoramento, encontrava-se sob stress intenso (sic), que era agravado pela própria DS. Não fumava, mas referia ingestão diária de bebidas alcoólicas. Seu IMC era 21 kg/m 2 . Os exames clínico e da genitália resultaram normais. A capacidade erétil era normal, comprovada por um teste de injeção intracavernosa de prostaglandina.
“…There appear to be age related changes in the Leydig cells and elevated LH levels have been found in association with elevated FSH (Nieschlag et al, 1982;Gray et al, 1991) and reduced sperm production . Others have found unchanged LH levels (Zumoff et al, 1982;Korenman et al, 1990) or reduction in LH pulse amplitude (Veldhuis et al, 1992) consistent with hypogonadotropic hypogonadism. Further evidence for declining pituitary function is a reduced and delayed response to gonadotrophin releasing hormone (GnRH) .…”
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