The endocrine system and ageing

Complex changes occur within the endocrine system of ageing individuals. This article explores the changes that occur in the metabolism and production of various hormones and discusses the resulting clinical consequences. As individuals age there is a decline in the peripheral levels of oestrogen and testosterone, with an increase in luteinizing hormone, follicle-stimulating hormone and sex hormone-binding globulin. Additionally there is a decline in serum concentrations of growth hormone, insulin-like growth factor-I and dehydroepiandrosterone and its sulphate-bound form. Even though there are complex changes within the hypothalmo-pituitary-adrenal/thyroid axis, there is minimal change in adrenal and thyroid function with ageing. The clinical significance of these deficiencies with age are variable and include reduced protein synthesis, decrease in lean body mass and bone mass, increased fat mass, insulin resistance, higher cardiovascular disease risk, increase in vasomotor symptoms, fatigue, depression, anaemia, poor libido, erectile deficiency and a decline in immune function. For each endocrine system, studies have been carried out in an attempt to reverse the effects of ageing by altering the serum hormonal levels of older individuals. However, the real benefits of hormonal treatment in older individuals are still being evaluated.     

The endocrine system and immunity

The studies using antinuclear and antideoxyribonucleoprotein immunoglobulins of the G class from hormone-producing cells against specific structures of the adrenals, thyroid gland, and thymus exerting an selective organ-specific effect and an immunomodulator thymaline (a thymus factor) in the structural-functional analysis revealed previously unknown mechanisms of interaction of the endocrine system and immunogenesis organs. These data may facilitate the elucidation of the mechanisms of levelling of disturbed homeostatis.     

Immunohistochemical studies in endocrine carcinoma of the skin

Twenty-two endocrine carcinomas of the skin were examined immunohistochemically for the presence of several polypeptides and serotonin. Eight tumors contained one or more polypeptides. Occasional cells containing calcitonin were found in several tumors. Rare cells with substance P, somatostatin, and ACTH were present in only one tumor each. None of the patients presented a clinical syndrome associated with any of these polypeptides. Met-enkephalin and serotonin were negative in all tumors. The lack of demonstration of met-enkephalin in these tumors makes their relationship to the Merkel cell uncertain.     

Divergent differentiation in endocrine and nonendocrine tumors of the skin

In the skin, endocrine tumors showing areas with nonendocrine features and nonendocrine tumors showing endocrine differentiation are present. (1) Neuroendocrine carcinomas with nonendocrine differentiation: Merkel cell carcinoma (MCC) of the skin has been frequently described in association with squamous cells carcinoma (SCC) which can arise separately (as synchronous or metachronous lesions) from MCC as well as closely intermixed. In the first event the possibility that the lesions are sustained by same causative factors (among which sun exposure is the most probable) is suggested. In cases of lesions closely intermixed the possibility of an origin from a common precursor is suggested. Furthermore, cases of MCC have been described to contain glandular, melanocytic, striated muscle, and lymphoepithelioma-like features. These latter findings further support the hypothesis of tumors showing divergent differentiations. (2) Nonendocrine tumors showing endocrine differentiation: Basal cell carcinoma (BCC) was the first cutaneous nonendocrine tumor described to contain neuroendocrine granules. Presence of endocrine features were subsequently confirmed with immunohistochemical studies. Endocrine features were then described in sweat gland apocrine and eccrine carcinomas. Endocrine elements present in BCC and in sweat gland carcinomas do not show morphological and immunohistochemical features of Merkel cells. Thus the possibility that these tumors develop an immature Merkel cell or a new type of endocrine cell of the skin is suggested. Tumors with follicular differentiation such as trichoblastomas and trichofolliculomas contain a high number of Merkel cells. As Merkel cells are numerous in hair follicles of human fetal skin, the possibility that these tumors recapitulate the human skin embryogenesis is suggested.     

以临床常见病为线索讲解内分泌系统解剖学的方法探讨

正内分泌系统是机体的重要调节系统,它与神经系统相辅相成,共同调节机体的生长发育和各种代谢,维持内环境的稳定等,在人体及临床上是非常重要的一个系统。在中医院校组织学和胚胎学是一门选修课,课时少,学生获得的内分泌系统知识显而易见,因此在解剖学教学活动中,为了使学生更好地理解和掌握内分泌系统知识,摆脱传统的教学法——以老师为中心、填     

The impact of endocrine disrupters on the female reproductive system

Over the last decades, many tonnes of man-made chemicals have been produced and released into the environment. Many of these chemical substances have the ability to modulate the action of hormones and are called endocrine disrupters. Cell receptors that have been pure receptors for thousands of years have (due to industrialization), become susceptible to the action of exogenous chemicals. The balance of the endocrine system is very important in the human body especially in females because the menstrual cycle and fertility are very sensitive to hormone imbalances. This review considers the mode of exposure and action of endocrine disrupters and focuses on their impact on the female reproductive system, including female hormone concentrations, menstrual cycle, fertility, spontaneous abortion and the development of endometriosis. An attempt is made to elucidate the impact of endocrine disrupters on the female reproductive system, while admitting that most scientific data come from experimental animals and the conclusions cannot be applied to humans easily. The aim is to present available information, highlighting the impact of endocrine disrupters on the female reproductive system, in order to stimulate reevaluation in identifying hormone disorders.     

The endocrine system in treated patients with classical galactosemia

Endocrine abnormalities in classical galactosemia, female hypergonadotropic hypogonadism and low thyroxin in neonates, have been reported. Galactosemia is a secondary glycosylation disorder and hypoglycosylation of glycoproteins has a role in this dysfunction. Hypoglycosylation, improves but does not completely disappear with dietary treatment. Our aim was to evaluate the endocrine system in treated patients (n = 37, 25 females, 12 males, age 5-19 years). Endocrine determinations were compared to age and gender matched reference ranges. Sample t-test (to test differences with reference population) and linear regression analysis between hGH (growth hormone), IGF-1 (insulin-like growth factor), IGFBP-3 (insulin growth factor binding protein), FSH (follicle stimulating hormone), LH (luteinizing hormone) and GALT activity, and soy intake, was carried out. Mean IGF-1 Z-score was -0.98 +/- 0.84 (range -2.59 to 1.21) (P < 0.001) in females and 0.03 +/- 0.55 (range -1.0 to 0.89) (P = 0.84) in males. Mean IGFBP-3 Z-score was -0.98 +/- 1.3 (range -3.0 to 2.0) (P < 0.001) in females and 0.26 +/- 0.93 (range -0.94 to 2.0) (P = 0.35) in males. IGF-1 and IGFBP-3 were positively correlated (P < 0.001). IGF-1 or IGFBP-3 Z-scores and age, hGH, estradiol, GALT activity or soy intake were not correlated. FSH was elevated in females, other axes were normal. Besides the hypergonadotropic hypogonadism in females, IGF-1 and IGFBP-3 are in the low to normal ranges in girls. Hypoglycosylation in galactosemia is diet dependent and could worsen when galactose intake increases either because of poor compliance or diet liberalization.