Linked Life Data

1324012

Source:http://linkedlifedata.com/resource/pubmed/id/1324012

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-9-18
pubmed:abstractText
This review addresses some relevant aspects of the aging of the neuroendocrine system, particularly the reproductive and the adrenocortical axis. Deterioration of the reproductive function, one of the most striking endocrine alterations occurring in aging, is related to a complex interplay of factors. They comprise alterations occurring at the level of all the three components of the reproductive axis, the gonads, the pituitary and the brain, acting synergistically to disrupt the normal pulsatile release of gonadotropins. Particular relevance is given to the neurotoxic action of estrogens during the constant estrous phase occurring in aged female rodents, at the level of hypothalamic nuclei regulating gonadotropin secretion. This effect, to be found also in women during the anovulatory period of the perimenopause, would worsen the dysregulation of the central mechanisms controlling the reproductive function. The activity of the adrenocortical (HPA) axis increases with advancing age in rodents but also, although less strikingly, in humans. The main alteration which can be evidenced in both species is a delayed post-stimulus decline in plasma corticosteroid levels, indicating a diminished sensitivity to glucocorticoids of HPA axis feedback regulation in the elderly. Increased exposure to the highly catabolic adrenal glucocorticoids appears to be associated to a loss of cerebral neurons, particularly in the hippocampus, and the emergence of cognitive deficits in the aged rats. The relevance of experimental data performed in rodents to healthy and pathological human aging is extensively discussed. Finally, this chapter considers the age-related impairment in growth hormone secretion, a common finding of all the animal species investigated so far. The etiology of the hyposomatotropism of aging is namely linked to a progressive defect in growth hormone releasing hormone-producing hypothalamic neurons, although alterations of somatostatin-producing neurons have also been described. This background knowledge makes the use of neuroactive compounds aimed at restoring the physiologic function of hypothalamic hypophysiotropic hormones a rational approach to rectify the alterations of the neuroendocrine system occurring in elderly individuals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0394-9532
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Age-related alterations in gonadotropin, adrenocorticotropin and growth hormone secretion.
pubmed:affiliation
Department of Biology and Pharmacology, University of Bari, Italy.
pubmed:publicationType
Journal Article, Review