Yukihiko Sugiyama

Measurement of Angiotensin-Converting Enzyme Activity in Intact Human Alveolar Macrophages and Effect of Smoking

Serum angiotensin-converting enzyme (ACE) activity is known to be elevated in various granulomatous conditions such as sarcoidosis, whose characteristic epithelioid cells are thought to belong to the macrophage series. It was recently shown that alveolar macrophages had ACE activity in their sonicated and homogenate forms. We investigated ACE activity of human alveolar macrophages in the intact form using a sensitive radioimmunoassay of generated angiotensin II. We also investigated the effect of smoking on ACE activity of alveolar macrophages using this method. Alveolar macrophages generated angiotensin II (218 +/- 106 pg/20 min/10(5) cells). More angiotensin II was generated in smokers (246 +/- 119 pg/20 min/10(5) cells) than in nonsmokers (160 +/- 50 pg/20 min/10(5) cells) (p less than 0.05). These data showed that ACE activity of macrophages is higher in smokers than nonsmokers.

Increase of Serum Angiotensin-Converting Enzyme Level after Exposure to Cigarette Smoke and Nicotine Infusion in Dogs

Smoking is known to have various effects on metabolic function as well as on the respiratory function in the lung. We report here that exposure to smoke causes a rapid elevation of the level of serum angiotensin-converting enzyme in dogs in vivo. In 7 dogs, the level of serum angiotensin-converting enzyme increased from a basal level of 11.0 +/- 5.0 to 13.9 +/- 4.0 U/ml after 60 min of exposure (mean +/- SD, p less than 0.01). A similar elevation of serum angiotensin-converting enzyme level was noted in dogs that received an intravenous administration of nicotine. The possible mechanism of the change is discussed.

Effect of erythromycin on activated lymphocytes in the peripheral blood of the patient with Sjoegren's syndrome accompanied with lung involvement.

We evaluated the effect of low-dose long-term erythromycin (EM) therapy (600 mg/day) on activated lymphocytes in the peripheral blood of the patient with Sjogrens syndrome accompanied with lung involvement. Before and after EM therapy, we analysed the subsets of peripheral lymphocytes using two-colour analysis by FACScan. Used monoclonal antibodies were Leu 2a, Leu 3a, Leu 4 and Leu HLA-DR. After 9 months of EM therapy, the percentages of activated Leu 2a positive cells, Leu 3a positive cells, and Leu 4 positive cells significantly decreased.These results might be useful to clarify the mechanism of low-dose long-term EM therapy against diffuse panbronchiolitis.