吸收動態的探討是藥物動力學中極為重要但又屬於比較困難的部分。作者曾報告CPK於肌注後之絕對可用率，並以統計學的moment解析法求得其平均吸收時間。然而解析之結果顯示CPK在體內滯留時間之分佈並非對數常態分佈型式，而是偏左的非對稱分佈，使求得之平均吸收時間之意義變成不明確。本報告針對CPK之吸收相以三種不同之數值解纏法(numerical deconvolutioo method)分別解析肌肉注射後CPK之吸收速率過程。CPK之肌肉吸收動態呈二相性零階次動力學特性。0-4h約為53.0土17.0U/b (mean土 S.D., n=5)，而4-12h約為18.1土7.4U /h。傳統上常用之area-area解纏法之結果比數學上較正確之poiot-area解纏法之結果有意的偏高(P<0.05)，而簡化近似值計算法之iostantaneous midpoint-input法之解析結果則顯著地偏低(P<0.05)。CPK之吸收速率在吸收過程中有由快而慢之變化，主要是因為CPK之吸收是經由淋巴系故受到淋巴流速的管制;而淋巴流速是受到組織絀胞間壓及淋巴泵之支配。在肌注後之初期，組織細胞間壓及淋巴泵之活性皆很高，經過一段時間後才能恢復正常，這種變化正反映於CPK之吸收速率之變化。CPK肌注後之平均吸收時間為12h，此結果和前以統計學的moment解析法所得之結果完全相同。然而decoavolution解析法較能闡明吸收過程之變化動態同時只須要較短時間之測定資料，其繁雜之計算可由電子計算機代勞。 The absorption rate of rabbit muscle creatine phosphokinase (CPK) and the mean absorption time for the injected CPK after intramuscular administration (860 U/kg bodyweigt, n = 5, male rabbits) were investigated with deconvolution method. The absorption of the injected CPK from the muscle depot into the circulation appeared to be a biphasic zero-order kinetic process determined by the point-area deconvolution. A fast initial phase with a rate of 53.0 +- 17.9 U/h (mean +- S.D., n = 5, 0-4 h) was follwed by a slow phase with a rate of 18.1 +- 7.4 U/h (4.0-12.0 h) after the administration. The result obtained with the popular area-area deconvolution method showed a positive deviation and the instantaneous midpoint-input method showed a negative deviation to that with the point-area method. The change of the absorption rate of CPK may be resulted from the alteration of the rate of lymph flow which is governed by the interstitial fluid pressure and the activity of the lymphatic pump. It was estimated that the mean absorption time for the injected CPK was 12.0 h after the administration and the result was consistent with that with the statistical moment analysis.
