Complement activation within the coeliac small intestine is localised to Brunner's glands.
(41/55)Complement activation may play an important role in the pathogenesis of coeliac disease. In the present study immunohistochemical localisation of C3 and of a neoantigen exposed only on the terminal C5b-9 complement complex has been performed on small intestinal biopsy sections from newly diagnosed untreated coeliac patients, from coeliac patients on long-term gluten-free diet and from disease controls. Levels of C3 were markedly increased in treated coeliac patients compared with controls. Staining of C3 was concentrated subepithelially and within the centre of the lamina propria. No staining was detected at these sites using antibody to the neoantigen, however, strongly suggesting that the increased levels of C3 seen in the coeliac patients was the result of increased extravasation of serum proteins rather than complement activation. Surprisingly, complement activation was detected within the glands of Brunner. Positive staining using anti-C5b-9 neoantigen was found in all coeliac patients, both treated and untreated. Three of the 13 disease controls also showed reactivity with this antibody. This novel finding suggests that Brunner's glands, hitherto largely neglected structures, may play an important role in the development of coeliac disease. (+info)
Adrenergic effects on secretion of epidermal growth factor from Brunner's glands.
(42/55)The influence of the sympathetic nervous system and adrenergic agonists on flow rate and secretion of epidermal growth factor (EGF) from Brunner's glands has been investigated in the rat. Chemical sympathectomy by administration of 6-hydroxydopamine increased volume secretion and output of EGF from Brunner's glands but depleted the glands of EGF. Infusion of noradrenaline, an alpha-adrenergic agonist, inhibited basal and vasoactive intestinal polypeptide (VIP) stimulated flow rate and output of EGF from Brunner's glands and increased the amount of EGF in the tissue. Vasoactive intestinal polypeptide also increased the amount of EGF in Brunner's gland tissue and this was unchanged after simultaneous infusion of VIP and noradrenaline as well as VIP and isoproterenol, a beta-adrenergic agonist. Isoproterenol had no effect on basal and VIP stimulated secretion of EGF from Brunner's glands. The presence of PAS-positive mucus in Brunner's glands was unchanged during infusion of noradrenaline whereas VIP induced a depletion of Brunner's gland mucus which in turn was prevented by simultaneous infusion of noradrenaline. This study indicates that the sympathetic nervous system influence the volume secretion, output of EGF and mucus content in Brunner's glands probably by activation of alpha-adrenergic pathways. (+info)
Immunohistochemical localisation of urogastrone to human duodenal and submandibular glands.
(43/55)Urogastrone has been localised by immunostaining to granules of the cells of human duodenal (Brunner's) glands and their ducts and of acinar cells in the human submandibular gland. The immunoreactive peptide is present in large quantities in duodenal glands and their secretory ducts. Urogastrone or human epidermal growth factor promotes cellular proliferation in vivo as well as in vitro and inhibits gastric acid secretion and may, therefore, be one of the duodenal factors inhibiting gastric activity. Thus it may have an important regulatory and protective function for the intestinal mucosa and may possibly become a useful therapeutic agent. (+info)
Relation between serum group II pepsinogen concentration and the degree of Brunner's gland hyperplasia in patients with chronic renal failure.
(44/55)Serum concentrations of group I and II pepsinogens (PG I and PG II) were determined in 15 patients with chronic renal failure. Gastroduodenoscopy with biopsy and acid secretion tests were also performed. Five patients had histologically confirmed severe Brunner's gland hyperplasia manifesting as multiple polyps in the duodenal bulb. Five patients had a mild form of Brunner's gland hyperplasia which was evident only by histological analysis. Five had no signs of such alterations. The three groups of patients were comparable in age, sex, mean level of serum creatinine, mean duration of dialysis treatment, distribution of non-dialysed and dialysed patients, and gastric histology. In patients with severe Brunner's gland hyperplasia the mean serum PG II concentration was significantly higher than in the other patients. Both the serum PG I and the serum PG II concentrations decreased after receiving a well functioning renal transplant in the two patients who underwent transplantation. (+info)
Mucosubstances in Brunner's glands of the mouse.
(45/55)The mucins of Brunner's glands in the mouse have been studied by histochemical methods. The secretion droplets in both acinar cells and the cells lining the ducts are PAS-positive and diazyme-resistant. The latter cells are alcianophilic at pH 2.5, react positively with Hale's colloidal iron method and exhibit metachromasia with azure A. The reaction to Hale's colloidal iron method is lost after digestion with neuraminidase. These results suggest that an acid as well as a neutral mucopolysaccharide is present in the secretion of Brunner's glands of the mouse, the acid mucosubstance being a sialomucin. The possible significance of this finding is discussed. This work was performed in partial fulfilment of work for the degree of Doctor of Philosophy of the University of Sheffield. It was supported by a Research Fellowship from the World Health Organisation (W.H.O.) during a study leave granted by the University of Lagos, Nigeria. (+info)
Postnatal growth of Brunner's glands in the mouse.
(46/55)In the newborn mouse the glands of Brunner consist of a few tubular downgrowths from the proximal duodenal crypts. Within three weeks the characteristic 'comma' shape of the gland is established by later downgrowths from more distal growths. The gland cells, although specialized from birth, show a high mitotic index, and a high labelling index with 3H-T, during the first three weeks, and particularly during the first two weeks. Nevertheless, the daily mitotic rate during this period is insufficient to account for the daily addition of glandular cells, suggesting that there is a continuing contribution of cells from the crypts. After this time, however, the mitotic activity of the mature gland cells is sufficient to account for the continuing increase in cell population. After the fourth postnatal week the mitotic and labelling indices decline markedly, and although mitoses are rarely seen in individual sections from older animals, cellular addition at a very slow rate is sufficient to account for the gradual expansion in size of the gland, and the process continues long after the adult body weight has been established. (+info)
Effect of vasoactive intestinal polypeptide and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands.
(47/55)The effect of VIP and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands was investigated in the rat. Vasoactive intestinal polypeptide infused in doses of 10 and 100 ng/kg/h significantly increased epidermal growth factor and bicarbonate output, but the concentrations did not change. Somatostatin infused at doses of 1, 10, 100 and 1000 ng/kg/h against a background of VIP 100 ng/kg/h inhibited in dose-dependent fashion the stimulated epidermal growth factor and bicarbonate outputs from rat Brunner's gland pouches. Also basal secretion was inhibited by somatostatin. Infusion of antisomatostatin serum stimulated Brunner's gland secretion. By immunohistochemical studies of rat duodena, it was found that epidermal growth factor, is almost exclusively present in the secretory cells of Brunner's glands. It is concluded that VIP stimulates secretion of epidermal growth factor and bicarbonate from Brunner's glands, an effect which is inhibited by somatostatin. A possible role for somatostatin in the control of Brunner's gland secretion is suggested. (+info)
Multiple duodenal polyps in uraemia: a little known clinical entity.
(48/55)Multiple duodenal polyps were found by endoscopy in five out of 33 patients with chronic renal failure and in one of 300 controls. In the uraemic cases the polyps were caused by circumscribed nodular hyperplasia of Brunner's glands. One of these five patients later underwent surgery for duodenal obstruction caused by the polyps; the other patients were asymptomatic. One of the controls had multiple duodenal polyps. The recorded incidence of multiple duodenal polyps was significantly higher among patients with chronic renal failure than in patients without renal disease. Patients with chronic renal failure and polyps did not differ significantly from the other renal patients in the comparison of variables such as gastric acid secretion, serum concentrations of gastrin and group I pepsinogens or mean length of dialysis treatment. The mean pH of gastric resting juice was significantly higher, however, in uraemic patients with polyps than in those without. Uraemic patients displayed a gastric acid secretion capacity within normal range, and significantly raised serum gastrin and group I pepsinogen concentrations. (+info)