メコリルによる血清ドパミン・β水酸化酵素活性の変動について—健康青年男子例と交感神経機能低下例についての検討

SERUM DOPAMINE-β-HYDROXYLASE ACTIVITY:ITS ELEVATION IN MAN DURING MECHOLYL TEST

I．はじめに

　ドパミン・β水酸化酵素（以下DBHと略す）は，神経伝達物質のひとつであるノルアドレナリンをドパミンから生成する酵素である^10）。この酵素は交感神経終末のカテコールァミン含有小包^19）や副腎髄質のクロマフィン顆粒内^11）に局在すると考えられている。

　動物臓器をもちいての実験では，副腎髄質のアセチルコリンによる刺激^23），脾臓^4,7）や輸精管^27）の神経刺激により，それぞれDBHがカテコールアミンとともに遊出することが報告されている。

In order to clarify the dynamics of the autonomic nervous function, we measured serum dopamine-(3- hydroxylase (DBH) activity in man during mecholyl test in correlation with changes in systolic blood pressure and plethysmogram.

Eleven male volunteers, aged 19 to 25, were examined. Blood samples were obtained via an indwelling intravenous canula before and after intra-muscular injection of mecholyl 10 mg at two minute intervals during 26 minutes.

Blood pressure was measured at the same timeintervals and plethysmogram was determined con-tinuously during 26 minutes.

Results were as follows:

1) First group (4 males): After rising temporarily, the pulse volume fell continuously. The response of blood pressure to mecholyl showed the S type. Serum DBH activity increased markedly.

2) Second group (7 males): After rising tempo-rarily, the pulse volume fell considerably and then returned to the control level. The blood pressure reaction was the N type. Serum DBH activity responded minimally.

These data indicate a close correlation between changes in serum DBH activity, systolic blood pressure and plethysmogram. It is also demon-strated that the changes in serum DBH activity during mecholyl test may represent the functional state of the central sympathetic structure as far as the efferent sympathetic tract is intact.

We also investigated 3 subjects with gross defects in the sympthetic nervous function.