Linked Life Data

8583833

Source:http://linkedlifedata.com/resource/pubmed/id/8583833

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1996-3-19
pubmed:abstractText
There is substantial evidence that growth hormone (GH) is particularly important in the control of the age-related decline of thymus function. It was therefore of interest: (a) to assess the overall capacity of tissue extracts from mediobasal hypothalamus (MBH), anterior pituitary (AP) and testis, obtained from young (3 months, Yc), middle-aged (13 months, MAc) and old (18 months, Oc) intact C57BL/6 mice to stimulate in vitro the release of thymulin, a Zn-bound immunoregulatory thymic peptide, from pure cultures of mouse thymic epithelial cells (TEC); (b) to perform the same evaluation utilizing MBH, AP and testicular extracts from mice of the same age-range but treated for 45 days with a sc dose of ovine GH (2 micrograms/g body wt) known to stimulate thymulin secretion in vivo. Pituitary hormones were measured by heterologous rat RIAs, whereas thymulin release was estimated by a rosette assay. Untreated animals showed a significant age-dependent increase in the AP content of follicle stimulating hormone but not in other AP hormones. In both control and treated animals, pituitary GH content decreased significantly with age. MBH extracts from C57BL/6 males evidenced thymulin-releasing activity on mouse TEC lines. This activity was maximal in the MBH from young animals and declined with the age of the MBH donors. The thymulin-releasing activity of MBHs from GH-treated mice was higher than that of the control animals and showed a less pronounced decline with age. AP extracts from the same animals showed a higher thymulin-releasing activity than did MBH preparations. This activity showed a progressive age-associated reduction in the APs from untreated mice, whereas in the GH-treated group, an age-related decline was only seen in the old donors. Control testicular extracts had little effect on thymulin release whereas GH treatment induced a definite thymulin-release inhibiting activity in the testicular homogenates of our animals which increased progressively with the age of the testis donors. We conclude that the MBH, AP and testis of the young mouse contain factors able to affect directly the endocrine activity of the thymic epithelium. The amount of these substances declines with age and seems to be modulated by GH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0047-6374
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
143-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Reduced ability of hypothalamic and pituitary extracts from old mice to stimulate thymulin secretion in vitro.
pubmed:affiliation
INIBIOLP, La Plata, Argentina.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't