The Functional Differentiation of the Small Intestine

Development ◽  
1960 ◽  
Vol 8 (2) ◽  
pp. 182-197
Author(s):  
Florence Moog ◽  
Evelina Ortiz

The epithelium of the duodenal mucosa of vertebrates is strikingly uniform. In all but the cyclostomes and a few fishes, the epithelium is made up of tall columnar absorbing cells, with mucus-producing goblet cells interspersed. The columnar cells have a high cytoplasmic/nuclear ratio, with the cytoplasm arranged into an apical zone containing a prominent Golgi apparatus, and a basal zone. The apical surface is featured by a sheet of microvilli that are extremely rich in alkaline phosphatase. The attainment of these characteristics has been shown to take place in a brief critical period, just before hatching in the chick embryo (Moog, 1950) and just before birth in the mouse (Moog, 1951), although in the latter animal a second period of phosphatase accumulation precedes weaning. The guinea-pig has now been added to this comparative series, because the protracted gestation period (about 67 days) might permit some further insight into the problems of duodenal differentiation.

2017 ◽  
Vol 119 (1) ◽  
pp. 71-77 ◽  
Author(s):  
José Rosa Gomes ◽  
Laís Costa Ayub ◽  
Camila Audrey dos Reis ◽  
Miriam Joice Machado ◽  
Jéssica da Silva ◽  
...  

Author(s):  
А.А. Коваленко ◽  
Г.П. Титова ◽  
В.К. Хугаева

Оперативное лечение различных заболеваний кишечника сопровождается осложнениями в виде нарушений микроциркуляции в области анастомоза кишки. Ранее нами показана способность лимфостимуляторов пептидной природы восстанавливать нарушенную микроциркуляцию, что послужило основой для настоящего исследования. Цель работы - оценка влияния стимуляции лимфотока в стенке кишки на процессы восстановления микроциркуляции, структуры и функции тонкой кишки в области оперативного вмешательства. Методика. В экспериментах на наркотизированных крысах (хлоралгидрат в дозе 0,6 г/кг в 0,9% растворе NaCl) моделировали различные поражения тонкой кишки (наложение лигатуры, перевязка 1-3 брыжеечных артерий, перекрут петли кишки вокруг оси брыжейки, сочетание нескольких видов повреждений). Резекция поврежденного участка через 1 сут. с последующим созданием тонкокишечного анастомоза завершалась орошением операционного поля раствором пептида-стимулятора лимфотока (40 мкг/кг массы животного в 1 мл 0,9% раствора NaCl). На 7-е сут. после операции проводили гистологическое исследование фрагмента кишки в области анастомоза. Результаты. На 7-е сут. после резекции у выживших животных (летальность вследствие кишечной непроходимости составляла 30%) имеют место морфологические признаки острых сосудистых нарушений стенки кишки, изменений кровеносных и лимфатических микрососудов, интерстициальный отек всех слоев стенки кишки, дилатация просвета кишки, повреждение всасывающего эпителия ворсин с истончением щеточной каемки клеток, морфологические признаки гиперфункции бокаловидных клеток. Использование лимфостимулятора пептидной природы после операции увеличивало выживаемость животных на 24%. У части животных отмечалось уменьшение расширения просвета кишки, у других практически полная его нормализация. Восстанавливалась форма кишечных ворсин и распределение бокаловидных клеток. Отсутствовали признаки внутриклеточного и межмышечного отека. Отмечено умеренное полнокровие венул. Заключение. Использование лимфостимулятора при хирургическом лечении кишечной непроходимости увеличивает выживаемость животных на 24% по сравнению с контролем, способствует более раннему восстановлению структуры и функции тонкой кишки. Полученные результаты свидетельствуют о перспективности использования стимуляции лимфотока при операциях на кишечнике. Surgical treatment of bowel diseases is associated with complications that cause microcirculatory disturbances in the anastomosis area and may lead to a fatal outcome. This study was based on our previous finding that peptide-type lymphatic stimulators are able to restore impaired microcirculation. The aim of this work was stimulating the lymph flow in the intestinal wall to facilitate recovery of microcirculation, structure and function of the small intestine in the area of surgical intervention. Methods. In experiments on anesthetized rats (0.6 g/kg chloral hydrate in 0.9% NaCl), various small bowel lesions were modeled (bowel ligation, ligation of 1-3 mesenteric arteries, gut torsion, combination of several lesion types). In 24 h, the damaged area was resected, and a small intestine anastomosis was creased. The surgery was completed with irrigation of the operative field with a solution of lymph flow stimulating peptide (40 мg/kg body weight in 1 ml of 0.9% NaCl). A gut fragment from the anastomosis area was examined histologically on day 7 after the surgery. Results. On the 7th day after removing the intestinal obstruction, the surviving animals (lethality 30%) had morphological signs of acute vascular disorders in the intestinal wall; changes in blood and lymphatic microvessels; interstitial edema of all intestinal wall layers; dilatation of the intestinal lumen; damage to the absorptive epithelium of villi with thinning of the brush border, and hyperfunction of mucous (goblet) cells. The use of the peptide after surgery increased the survival rate of animals by 24% and provided a smaller dilatation of the intestinal lumen in some animals. In other animals, the lumen recovered. The shape of intestinal villi and distribution of goblet cells were restored. Signs of intracellular and intermuscular edema were absent. Moderate venular congestion was noticed. Conclusion. Using the lymphatic stimulator in surgical treatment of intestinal obstruction increases the survival rate of animals by 24% compared to the control, facilitates earlier restoration of the small intestine structure and function. The obtained results indicated the effectiveness of lymphatic stimulation in intestinal surgery.


Author(s):  
Jacob Bamaiyi ◽  
Omajali ◽  
Sanni Momoh

This study investigates the effects of kanwa on rat gastrointestinal phosphatases. The rats were administered 7% w/v concentration of  trona (Kanwa) orally for a period of two weeks in order to investigate how this compound is being used as food additive in some homes in Nigeria. The Kanwa used in this study was the handpicked variety obtained from sellers from Anyigba market in eastern part of Kogi State, Nigeria. Kanwa, a hydrated sodium carbonate (Na2CO3NaHCO3.2H2O) was obtained as a dried lake salt. Acid phosphatase has the ability to dephosphorylate molecules containing phosphate group. The decreased and elevated level in serum or plasma acid and alkaline phosphatases serves as diagnostic indices for various diseases. Results showed that there was increase and decrease of acid phosphatase (ACP) activities in both the stomach and small intestine. The activities of alkaline phosphatase (ALP) fluctuated in the small intestine. However, in the stomach, an increase activity of ALP was noticed throughout the period of ‘Kanwa’ administration. We concluded that although the level of ‘Kanwa’ consumed in most homes may not be toxic if not taken continuously or repeatedly. Thus, continuous consumption should be discouraged as accumulation of high level of ‘Kanwa’ may cause damages or injuries to the various organs/tissues and may disrupt normal body function.


2015 ◽  
Vol 129 (7) ◽  
pp. 529-531 ◽  
Author(s):  
Neil A. Mabbott

A new study by Man and colleagues provides further insight into the effects of aging on small intestinal barrier function in humans. Here, their findings are briefly summarised and the wider implications discussed.


Parasitology ◽  
1973 ◽  
Vol 67 (3) ◽  
pp. 307-314 ◽  
Author(s):  
I. K. Barker

Duodenal mucosae of uninfected lambs and lambs inoculated at least 16 days earlier with 85000–140000 Trichostrongylus colubriformis larvae were examined with the scanning electron microscope. Normal duodenum had tall spatulate villi with surface folds upon which goblet cells and a regular pattern of hexagonal enterocytes were seen. Micro villi on normal enterocytes were closely packed and imparted a granular surface texture. In heavily infected areas of gut the villi were atrophic, the mucosa sometimes being composed of irregular masses and ridges, with crypt mouths, often surrounded by collars of cells, opening into the surface. More severely affected mucosae were flat, with protuberant collars of cells surrounding crypt mouths. There were rounded bodies, interpreted as sloughing enterocytes, or inflammatory cells, on the mucosal surface. Apices of enterocytes were domed and microvilli were sparse and irregular. Micro-organisms were numerous on cell surfaces. Nematodes were located in sinuous thin-walled tunnels in the epithelium. The mucosal microtopography is compared with that of coeliac disease of humans, nippostrongylosis in rats and with villus atrophy in pigs.


1998 ◽  
Vol 275 (2) ◽  
pp. G296-G304 ◽  
Author(s):  
Catherine S. Chew ◽  
Bengt Säfsten ◽  
Gunnar Flemström

Vagal stimuli increase duodenal mucosal[Formula: see text] secretion and may provide anticipatory protection against acid injury, but duodenal enterocyte (duodenocyte) responses and cholinoceptor selectivity have not been defined. We therefore developed a stable primary culture model of duodenocytes from rats and humans. Brief digestion of scraped rat duodenal mucosa or human biopsies with collagenase/dispase yielded cells that attached to the extracellular matrix Matrigel within a few hours of plating. Columnar cells with villus enterocyte morphology that exhibited spontaneous active movement were evident between 1 and 3 days of culture. Rat duodenocytes loaded with fura 2 responded to carbachol with a transient increase in intracellular calcium concentration ([Ca2+]i), with an apparent EC50 of ∼3 μM. In a first type of signaling pattern, [Ca2+]ireturned to basal or near basal values within 3–5 min. In a second type, observed in cells with enlarged vacuoles characteristic of crypt cell morphology, the initial transient increase was followed by rhythmic oscillations. Human duodenocytes responded with a more sustained increase in [Ca2+]i, and oscillations were not observed. Rat as well as human duodenocytes also responded to CCK-octapeptide but not to vasoactive intestinal polypeptide. Equimolar concentrations (100 nM) of the subtype-independent muscarinic antagonist atropine and the M3 antagonist 4-diphenylacetoxy- N-methylpiperidine methiodide prevented the response to 10 μM carbachol, whereas the M1 antagonist pirenzepine and the M2 antagonists methoctramine and AF-DX 116BS had no effect at similar concentrations. Responses in rat and human duodenocytes were similar. A new agonist-sensitive primary culture model for rat and human duodenocytes has thus been established and the presence of enterocyte CCK and muscarinic M3 receptors demonstrated.


2021 ◽  
Vol 58 (1) ◽  
pp. 68-73
Author(s):  
O. C. Iacob

SummaryThe present study was carried out on 10 frogs, Pelophylax ridibundus (Pallas, 1771), captured near the river Bahlui, Iasi, between April and May, 2019, for the study of digestive helminths and their effect on the digestive tract. Macroscopic examination of the general cavity revealed distension of the small intestine. The sectioning of the intestinal wall revealed a variable number of parasites (1 – 12) with a whitish cylindrical body, anchored in the duodenal mucosa. The morphological study of the parasites confirmed the species as Acantocephalus ranae. The prevalence of the infection was 60 % and the average intensity was 4.83 ± 4.15. Lesions of the small intestine were characterized by catarrhal enteritis, hemorrhagic spots and ulcers on the mucosa, occlusion and obstruction of the intestinal lumen. Histologically, eosinophilic inflammatory infiltrate in the glandular crypts, mucosal and submucosal edema, fibrosis and conjunctival hyperplasia, total mucosal atrophy, were found. The infection with Acanthocephalus ranae in Pelophylax ridibundus caused severe pathological changes, conditioned by the intensity of the infection, aspects revealed for the first time in Romania.


1978 ◽  
Vol 39 (2) ◽  
pp. 307-316 ◽  
Author(s):  
N. T. Davies ◽  
A. A. Flett

1. The activities of alkaline phosphatase (EC 3.1.3.1) and phytase (EC3.1.3.8) were similarly distributed in the small intestine of rats. Regional differences in activity were reflected by similar differences in the capacity of ligated intestinal segments to hydrolyse phytate in vivo. Activities were greatest in the duodenum and lowest in the terminal ileum.2. Specific activities of both enzymes were tenfold greater in the brush border fraction of duodenal mucosa compared with entire mucosal homogenates.3. Brush-border alkaline phosphatase and phytase activities required both magnesium and zinc ions for maximal activity.4. Zn deficiency induced by feeding a diet low in Zn (0.5 mg Zn/kg) caused similar reductions in activity of both enzymes.5. Zn deficiency induced by feeding diets marginally adequate in Zn (12 mg/kg) and phytate (10g/kg) caused reductions in alkaline phosphatase, phytase activities and phytate hydrolysis in vivo.6. It is suggested that phytase activity is a manifestation of alkaline phosphatase and the significance of this in relation to phytate-induced Zn deficiency is discussed.


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