| دانلود رایگان مقاله انگلیسی + خرید ترجمه فارسی | |
| عنوان فارسی مقاله: | پروتئاز، آمیلاز و لیپاز پانکراس و محتویات روده موش صحرایی عاری از میکروب و متعارف |
| عنوان انگلیسی مقاله: | The proteases, amylase and lipase of the pancreas and intestinal contents of germ-free and conventional rats |
| دانلود مقاله انگلیسی: | برای دانلود رایگان مقاله انگلیسی با فرمت pdf اینجا کلیک نمائید |
| مشخصات مقاله انگلیسی (PDF) و ترجمه مقاله (Word) | |
| سال انتشار مقاله | 1965 |
| تعداد صفحات مقاله انگلیسی | 5 صفحه با فرمت pdf |
| تعداد صفحات ترجمه مقاله | 12 صفحه با فرمت ورد |
| رشته های مرتبط | کشاورزی، علوم دامی، فیزیوژی دام، دامپزشکی و دامپروری |
| دانشگاه تهیه کننده | گروه دامپروری طیور، دانشگاه کالیفرنیا، برکلی، ایالات متحده(Department of Poultry Husbandry, University of California, Berkeley, USA) |
بخشی از ترجمه:
١. اندازه گیری ها از پروتئازها، امیلاز و لیپاز و از پانکراس ها و از همانندی محتوای روده ای، caecal و محتوای روده بزرگ از موش های نطفه آزاد و قراردادی ساخته شده است.
٢. تفاوت کمی بین تجمعی از آنزیم ها در موش های نطفه آزاد و قراردادی یافت می شود.
٣. نتایج نشان می دهد که باکتری روده ای تنها یک بخش کوچکی در تشخیص قسمتی از آنزیم های پانکراسی در محتواهایی از روده، caecum و روده بزرگ است.
۴. تجمع آنزیم کاهش می یابد. پروتئازها، بیشتر مقاوم و ثابت بودند و امیلاز حداقل ثبات را داشت، دوام لیپاز در حد وسط بود یعنی مابین آنچه که پروتئاز و امیلاز بود.
۵. شواهدی از فعالیت باکتریایی در محتوای caecal از موش های قراردادی در درصد بزرگتری از نیتروژن پروتئین دار و در درصد پایین تری از نیتروژن بدون پروتئین دیده شده است.
بخشی از مقاله انگلیسی:
I. Measurements were made of the proteases, amylase and lipase of the pancreas and of the corresponding intestinal, caecal and colonic contents of germ-free and conventional rats. 2. Little difference was found between the concentration of the enzymes in the germ-free and conventional rats. 3. The results indicate that intestinal bacteria had only a minor part in determining the fate of the pancreatic enzymes in the contents of the intestine, caecum and colon. 4. The enzyme concentrations decreased caudally. The proteases were the most stable, and the amylase was the least stable; the stability of lipase was intermediate between that of the proteases and amylase. 5. Evidence of bacterial activity in the caecal contents of conventional rats was seen in the greater percentage of protein nitrogen and in the lower percentage of the non-protein nitrogen. In earlier studies of pancreatic function in rats, measurements were made of the activities of the proteases, amylase and lipase of the pancreas and of the contents of the intestine, caecum and colon (Lepkovsky, unpublished). It was difficult to interpret the values obtained for the contents of the intestine, caecum and colon because the measurements represented the sum of the activity of enzymes entering the duodenum with the pancreatic juice, of the losses due to inactivating mechanisms in the intestinal lumen and of the losses or gains due to the activity of the microflora. Information was needed about the changes brought about by the action of the microflora upon the activities of the proteases, amylase and lipase in the intestinal contents. Accordingly, the activities of these enzymes were measured in the contents of the intestine, caecum and colon of the germ-lree and conventional rat. EXPERIMENTAL Animals and treatment. Female rats of the Lobund germ-free rat colony (twelfth generation) were reared in a Reyniers-type germ-free isolator (Reyniers, Trexler & Ervin, 1946; Reyniers, 1959). Conventional female rats of the same strain (originally derived from Wistar stock) were reared in open wire-mesh cages in the conventional animal house. All rats were fed on the autoclaved L-356 diet (Larner & Gillespie, 1957) with water ad lib. to the age of 127 days. Eight germ-free and seven conventional rats were then anaesthetized and killed by exsanguination through a cardiac puncture. 258 S. LEPKOVSKY AND OTHERS 1966 Collection of the pancreases and intestinal contents from germ-free and conventional rats. Germ-free rats were removed one at a time from the germ-free isolator and killed immediately; the small intestines were divided into three equal parts. Contents from each part and from the caecum, the colon and the faeces were all collected separately in previously sterilized screw-cap vials. The faeces were pellets voided during anaesthesia and exsanguination and may be considered as lower colon contents since the undisturbed animal would probably have retained this material for a longer period of time. The pancreases were also stored in separate screw-capped vials. All specimens were quick-frozen with dry ice immediately after collection from each animal and stored at -25″. The conventional rats were killed and the intestinal contents and pancreases were treated in the same manner. The frozen specimens were refrigerated with dry ice and shipped by air express from Lobund to the University of California for enzyme analysis ; upon arrival the frozen samples were freeze-dried. AnaZytical procedures. Trypsinogen in the pancreas was activated (Kunitz, 1938-9) as follows: 2 ml of sample, 1.0 ml 0.1 M-phosphate buffer pH 5-6, and 2.0 ml enterokinase solution (0.5 % duodenum powder ; VioBin Corporation, Monticello, Ill.) were incubated for 30 min at 37′. The reaction was stopped by the addition of 5.0 ml 0.04 N-HC1. To 0-5 ml of this mixture was added 0.5 ml of a 0-5 yo (w/v) aqueous solution of CaCl, and, after incubation with haemoglobin substrate, the proteases were determined by the method of Anson (1938-9). The ‘ trypsin’ fraction of the proteases was determined as follows : 0.2 mg of a soyabean trypsin inhibitor (Worthington Biochemical Corporation, Freehold, New Jersey) was added to the sample and the residual protease activity was determined. The difference is reported as the percentage of ‘trypsin’. Amylase was determined using a substrate prepared by the method of McCready & Hassid (1943) ; the incubation was carried out by the method of Smith & Roe (1949). The starch-iodide colour was read in a spectrophotometer (Beckman, Model B) at a wave-length of 650 nm after setting the instrument at 100% transmittance with distilled water. Lipase activity was estimated by incubating the sample with Ediol (coconut oil emulsion; Schenley Laboratory, Inc., Lawrenceburg, Indiana) as the substrate using the method of Balls, Matlack & Tucker (1937-8), and the fatty acids released were determined by the Dole (1956) procedure. The incubation mixture consisted of Ediol (50 yo coconut oil emulsion), 01 ml; 5 yo aqueous solution of sodium taurocholate, 0.5 ml; 0.1 M-CaCl,, 0-5 ml; 0.6 M-NH,C~-NH, buffer (pH 8-5), 0.3 ml; water, 0.1 ml; sample, 0.5 ml. The total volume was 2-0 ml. To I ml were added 5-0 ml of the extraction mixture (2-propano1, 40 parts; heptane, 10 parts; N-H,SO,, I part) to prevent lipase action, and this portion served as the control. The remaining I ml was incubated at 37′ for 20 min, after which the extraction mixture was added (Dole, 1956). Whenever sufficient material was available, protein and non-protein nitrogen were determined in the samples as follows. A homogenate containing about 20 mg of dry intestinal contents per ml was prepared. Total nitrogen was determined on the whole VOl. 20 Digestive enzymes in germ-free rats 259 homogenate by the standard micro-Kjeldahl method. One volume of 20 yo (w/v) trichloroacetic acid (TCA) solution was mixed with I volume of homogenate; the mixture was allowed to stand for I h and was then centrifuged. Nitrogen was determined in the TCA filtrate. The protein nitrogen was calculated by subtracting the value for non-protein nitrogen (nitrogen of the TCA filtrate) from that for total nitrogen (nitrogen of the whole homogenate). All values reported are based upon the dry weight.
| دانلود رایگان مقاله انگلیسی + خرید ترجمه فارسی | |
| عنوان فارسی مقاله: | پروتئاز، آمیلاز و لیپاز پانکراس و محتویات روده موش صحرایی عاری از میکروب و متعارف |
| عنوان انگلیسی مقاله: | The proteases, amylase and lipase of the pancreas and intestinal contents of germ-free and conventional rats |
