Dehydroepiandrosterone (DHEA) 是腎上腺皮質分泌雄性激素時之前
驅物。前人報告提出DHEA對Ｔ淋巴球、巨噬細胞之功能及白血球新生具有
顯著之調節功能。本實驗證明 DHEA 對Ｂ淋巴球分泌Ig之功能也有影響。
DHEA與脂多醣體同時刺激Ｂ淋巴球時，對IgA有促進的作用，IgG及IgM 的
分泌則無影響。DHEA在Ｂ淋巴球受脂多醣體活化24小時後加入，則對 IgA
及IgG 的分泌有促進作用，對IgM分泌卻有明顯的抑制情形。DHEA 對Ｂ淋
巴球功能的調節不受 Anti IL-2 之影響，但受 Anti TGF-.beta.影響。
顯示 TGF-.beta. 參與DHEA對Ｂ淋巴球功能之調節作用。當DHEA與脂多醣
體同時加入時，Anti TGF-.beta. 抑制了DHEA所誘導之IgA分泌 ，但反而
促進IgG與IgM之分泌，顯示DHEA在Ｂ淋巴球活化初期可促進 IgG與 IgM分
泌，但是受TGF-.beta.所抑制，不過DHEA間接利用TGF-.beta.促進了IgA
之分泌。當 DHEA 在Ｂ淋巴球以脂多醣體活化24小時之後加入，則 Anti
TGF-.beta.抑制了DHEA對三種 Ig分泌的調節效應，顯示DHEA對活化後之
Ｂ細胞只藉TGF-.beta.之協助，才能調節Ｂ細胞之功能。 DHEAS為DHEA在
血清中存在的主要形式，但是DHEAS 對Ｂ淋巴球的功能無顯著影響。Dexa
-methasone為 glucocorticoid 之衍生物，對Ｂ淋巴球的增生、存活率及
IgA 分泌皆有顯著抑制作用，而DHEA可以拮抗Dexamethasone 的抑制作用
。DHEA直接或間接對免疫球蛋白分泌之調節作用，為內分泌與免疫系統之
關係提供了重要佐證，而 DHEA 與 glucocorticoid 之間之拮抗作用也顯
示體內，這兩種類固醇荷爾蒙平衡的重要性。

Dehydroepiandrostone(DHEA), a precusor androgen biosynthesis
in adrenal cortex, has been show to regulate the functions of T
lymphocytes and macrophages,and to suppress the lymphopoisis and
myelopoisis. Theresults of this study indicate that DHEA also
has ability to modulateB cell immunoglobulin secretion. DHEA did
enchance IgA secretion buthad no effect on IgG and IgM secretion
when B cells were stimulated by DHEA and lipopolysaccharide(LPS)
at the same time. However, if DHEA was added 24 hours after LPS
induced B cell activation, both the IgA and IgG secretion were
enhanced but IgM secration was suppressed by DHEA.The modulatory
function of DHEA on B cells was not affected by anti-inteleukin2
(IL-2) antibodies but it was significant affected by anti trans-
forming growth factor .beta.( TGF-.beta. ), suggesting that TGF-
.beta.was involved in DHEA-mediated immunoregulation. Anti TGF-
.beta. inhibited DHEA induced IgA secretion but significantly
enhanced IgG and IgMsecretion when B cells were stimulated by
DHEA and LPS at the same time. It implied that DHEA could enhance
IgG and IgM secreation during theearly stage of B cell activation
.However, both IgG and IgM secretionwere suppressed by TGF-.beta.
. On the contrary, TGF-.beta. together with DHEA induced IgA
secretion. Anti-TGF-.beta. completely abrogated the immunoregu-
latory function of DHEA when B cells were stimulated by DHEA 24
hoursafter LPS-induced activiation, suggesting that the presence
of TGF-.beta. is essential for DHEA to regulate the function of
activated B cells, DHEAS , the specific form of DHEA in serum,
showed no effect on immunogloublin secretion. Dexamethasone, a
derivative of glucocorticoid, suppressed B cell growth, reduced
B cell viability and IgA secretion. Results in this study showed
that DHEA significantly antagonized immunosuppresive effect of
dexamethasone. The observation that DHEA directlyor indirectly
regulated immunoglobulin secretion provided an additional evi-
dence to demonstrate the close relationship between endocrine
andimmune system. Furthermere, the counter reaction between DHEA
and glucocorticoid suggested that it is essential to maintance
the properratio between these two important steroid hormone in
body fluid.
Dehydroepiandrostone(DHEA), a precusor androgen biosynthesis