| It is important to improve the survival rate by reinforcing thediagnosis and therapy of earlier colorectal cancer, as which is a familiarmalignant tumor. It is a new diagnostic method that laser inducingfluorescent technique can discover earlier colorectal carcinoma, whichhas utterly predominance than other methods. 5-ALA can inducecumulation of protoporphysinⅨin tumor tissue. Because itself has nophotoallergy character, refraining from directs application protophotosensitizer producing phototoxic side effect during photodynamicsdiagnosis, and more that have extensive application prospect indrug-fluorescence diagnosis. This task approach the character ofcumulation of protoporphysinⅨin colorectal carcinoma tissue inducedby DFO+5-ALA, and undertake the fundamently empirical study offeasibility of earlier colorectal carcinoma being diagnosised byfluorescence induced by DFO+5-ALA.Objective: (1) To explore the dynamical variation regularity,drugcentration,PH value of cumulation of protoporphysinⅨin colorectal gland cancer tissue combine induced by DFO+5-ALA, and to providereference to empirical study of cumulation of protoporphysinⅨin color-ectal carcinoma tissue induced by drug; (2)To establish the animal modelof empirical study of cumulation of protoporphysinⅨcombine inducedby DFO+5-ALA; (3) To quantitative analysis the character of cumulationof protoporphysinⅨinduced by 5-ALA, or DFO+5-ALA in intestinenormal tissue,earlier cancer tissue,progression cancer tissue ofcolorectal carcinoma rats, and to observe the difference of fluorescencedistribution and intensity of protoporphysinⅨof different tissue;(4) Toexplore the effect of cumulation of protoporphysinⅨof intestine tissueof colorectal carcinoma rats induced by 5-ALA through variousmedication pathway, to provide gist of application of fluorescencediagnosis on earlier colorectal carcinoma induced by DFO+5-ALA.Empirical method: The SW480 cells of large intestine glandcancer have been cultivated for 2 hr, with DFO+5-ALA culture solutionin vitro, stopping cultivation at various time points. The content ofprotoporphysinⅨof cell were determined at various time point by highperformance liquid chromatography and fluorescence detection method,and which has been contrast analysised on different cultivating-time,PHvalue,drug level combine induced by DFO+5-ALA. 60 young Sprague-Dawley rats were given injections of 1,2-dimethylhydraxine (DMH)solution in abdominal cavity once a week, observed on the dynamic state of the internal change and tumour-forming by micro choleochoscope. TheSD rat(include all stage of colorectal carcinoma) successfully inducedwere given injections of physiological saline solution,5-ALA,DFO+5-ALA, after having been induced for 4 hr, which were dissectedand taken out of the suspect canceration and normal tissue sample ofintestine. Extacted the protoporphysinⅨfrom intestine normal tissue,earlier cancer tissue,progression cancer tissue sample definitely diagn-osised by pathological section, the content of protoporphysinⅨdetectedby HPLC-fluorescence detection, which from three kinds of tissue sampleinduced by DFO+5-ALA for different time were contrast analysised, thefluorescene distribution and intensity from three kinds of tissue samplewere detected by laser confocal microscopy. After cancer-forming rat hasbeen given injection through abdominal cavity for 0.5 hr, the cumulationof protoporphysinⅨof intestine tissue of rat induced by three kindsadministration such as 5-ALA intravenous injection,oral administer-ation,retention enema, It is contrast analysised that the induced effect ofcumulation of protoporphysinⅨof canceration tissue by three kindsdifferent administration pathway, through quantitative analysis andfluorescence distribution observing and intensity detecting of intestinenormal tissue,earlier cancer tissue,progression cancer tissue.Experimental result: The cytology experiement display that thecontent of protoporphysinⅨof intestinal gland cancer obviously stepped up after drug having acted cell for 40 min, which achieved peak afterhaving been cultivated for 4 hr (drug having been stopped effect for 2 hr),then fall-off, which achieved the max of cancer cell, with PH 6.5-7.0,DFO 10-20moml/ml, 5-ALA 1.5-2.0moml/ml. The carcinogenesis of SDrat intestine major assume as the developing procedure: inflammation—depauperation—accrementition—canceration, the con-inductivity ofcolorectal carcinoma is 85%, the multiple tumour occupy 94% of the total.The three group rats induced by different drug, the content of protop-orphysinⅨof intestine tissue of colorectal carcinoma rats of variousgroup from little to great one by one: intestine normal tissue,earliercancer,progression cancer. The content of protoporphysinⅨis thehighest combine-induced by DFO+5-ALA, which of earlier cancer andprogression cancer tissue achieved max after having been induced for 4 hr,which of normal tissue achieved the peak after having been induced for 2hr, which has obvious difference of canceration tissue,normal intestinaltissue after having been induced for 4 hr. The red fluorescence ofprotoporphysinⅨexpress the poorest of normal tissue in three kindstissue, which of mucous membrane proper of earlier cancer assumedpunctiform distribution in canceration tissue cell, which of the infectionfocus of progression colorectal carcinoma assumed a great quantityhighlight lumping form fluorescence. That fluorescence intensity analysisnormal tissue,earlier colorectal carcinoma tissue,progression cancer tissue. In the three different 5-ALA administration pathway, the contentof protoporphysinⅨof canceration tissue with intravenous injection isthe highest, retention enema administration gain good induced effect, andthe fluorescence intensity of surface layer of canceration tissue is great,the content of protoporphysinⅨof canceration tissue with oraladministration is minimum.Conclusion: (1) It is 2 hr after having been stopped drug action thatthe optimal time of cumulation of protoporphysinⅨin intestinal glandcancer cell induced by DFO and 5-ALA for detection, and the shortestinduction time of which must not less than 40 min; (2) To apply theabdominal cavity injection with 1,2-dimethylhydraxine (DMH) solutionand endoscopic views inducing SD rat, then successfully establishing thecolorectal carcinoma animal model including all stage canceration; (3)The combine application with 5-ALA+DFO can significantly elevatingthe cumulation of protoporphysinⅨin cancer tissue induced by 5-ALA.The red fluorescence of protoporphysinⅨmajor centralize in cancer-ation tissue cell, the optimal time for dectecting is after medication 4～6hr; (4) Retention enema administration with 5-ALA can gain betterinducing effect.
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