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New insights into adaptation of adrenal medulla to stress
Author(s) -
Sabban Esther L,
Tillinger Andrej,
Sollas Anne,
Kvetnansky Richard,
Serova Lidia
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.849.5
The adrenal medulla (AM), with rapid release of catecholamines (CA), Epi and NE, plays an key role in the response to stress. Am important question is what mediates the transition from the beneficial responses to acute stress to the detrimental effects of prolonged stress. Single immobilization (IMO) was previously shown to partially deplete rat adrenal CAs, while with chronically repeated daily IMO, there is sustained rise in CA biosynthesis and over compensation of adrenal CA levels beyond unstressed levels. This could be partly mediated by changes in CA uptake and storage. We found that one of the vesicular monoamine transporters (VMAT), VMAT1, is widely expressed in rat AM under basal conditions while VMAT2 is localized to NE chromaffin cells. Repeated IMO elevated VMAT2 gene expression, with more cells expressing VMAT2 and its localization also in Epi synthesizing chromaffin cells. Since VMAT2 can determine quantal size, the findings suggest an adaptive mechanism to enhance Epi storage capacity and prime the adrenal for more efficient utilization of the heightened CA biosynthesis. (supported by NS28869, VEGA2/0133/08)