Distribution of the 1,25 dihydroxy-vitamin D3 receptor in the bursa of Fabricius of chicken

The vitamin D₃ metabolite 1,25(OH)₂D₃ is probably involved in B lymphocyte ontogeny. We therefore determined the distribution of the 1,25(OH)₂D₃ receptor in the bursa of Fabricius and spleen cells of 7-day-old chicks, by immunohistochemistry using a monoclonal antibody against the chick intestinal cell 1,25(OH)₂D₃ receptor. The bursa cells of young (7-day-old) chicks contained large amounts of receptor while the spleen cells did not. The bursa cells of older (35-day-old) chicks contained fewer receptors, but the number of receptors in the spleen increased.     

Tubuloreticular structures in chicken bursa Fabricii lymphocytes

Summary Tubuloreticular structures were observed in bursal lymphocytes of a 12-day-old male chicken. These structures are often observed in mammalian lymphocytes and endothelial cells. Their presence in bursal lymphocytes confirm their association with B-lymphocytes.We are grateful to Dr. J.L.F. Cristina Afonso for material support, to Mrs M. Lapão and J.P. Cristina Afonso for thier technical help, and to the Freixial Poultry Industry for providing the chickens.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution.

The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the post-involution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.     

Suppressive effects of graft versus host reaction on humoral immunity: consequences of homograft of chicken spleen on differentiation of the bursa of Fabricius

By engrafting the chorio-allanto?s of Chick embryos with spleen fragments from homologous adult donors, one elicits a graft-versus-host disease. When the graft is performed before the bursa of Fabricius has reached the lymphoid differentiation state, the final follicular organization is greatly reduced. It seems that this suppression effect cannot be related to a diminution of the stem cell compartment available in the anlage but is a result of a direct impact on the mesenchyme and/or the epithelium of the bursa.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution

Summary The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the postinvolution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.Supported by the University Grants Commission, Govt of India under the scheme Support to Research.     

Role of 1,25-dihydroxyvitamin D3 in the generation of the acute-phase response in rats with talc-induced granulomatosis

Subcutaneous injection of nonspecific irritants such as magnesium silicate (talc) provokes granulomatous inflammation in the rat. Part of the acute phase response (APR) in these animals is the loss of trabecular bone at sites distant from the site of inflammation. To assess the possible involvement of vitamin D in the bone loss, we studied the development of the acute phase response in vitamin D-deprived rats. The serum APR provoked by subcutaneous inflammation in rachitic rats consisted of hypozincemia, hypercupremia, increased, alkaline phosphatase activity and adrenocorticotropic hormone (ACTH) concentration, and was similar to that in control animals except for the absence of hypoferremia. Control rats with talc-induced subcutaneous inflammation also had splenomegaly and decreased total and mononuclear peripheral blood cell counts, while subcutaneous inflammation did not induce spleen changes in rachitic rats. Subcutaneous inflammation induced the loss of trabecular bone and decreased the osteoblastic cell count in tibial metaphyses in control animals. Rachitic rats had abundant osteoid on trabecular surfaces, and the number of osteoblasts and osteoclasts was comparable to that of the controls. Subcutaneous inflammation did not affect any of the bone parameters in rachitic rats. These results indicate that vitamin D plays an important role in the generation of the acute phase response during inflammation, particularly in the induction of spleen and bone cell changes. The discrepancy of the blood on one hand and bone and spleen indices of the APR on the other, indicate that there may be divergent pathways in the generation of the inflammatory response, some of which may be dependent on vitamin D.     

The Bursa of Fabricius isolated from intestinal flow in chicken at hatching: The surgical technique

Summary A proposed operational technique is described whereby the intestinal flow from the Bursa of Fabricius in chickens at hatching is excluded.     

Distribution of vitamin D3: Evidence of accumulation in renal proximal tubuli and thyroid parafollicular cells

Zusammenfassung Mit Hilfe der Ganzkörper-Autoradiographietechnik konnte nach Zufuhr von Vitamin D₃-4-¹⁴C an Mäusen der Nachweis einer radioaktiven Ansammlung in gewissen Gebieten (Labyrinth) der Nierenrinde sowie der Thyroidea erbracht werden, die möglicherweise mit parafollikulären Zellen identisch ist.     

The action of the cholecystokinin-A receptor antagonist,devazepide, on the digestive system of the chicken

The influence of the cholecystokinin (CCK)-A receptor antagonist, devazepide (DVZ), on the chicken digestive tract was investigated. The passage of food from the crops of birds treated with DVZ was not significantly different from that of the control. DVZ treatment did not inhibit the biliary flow stimulated by the CCK analogue, caerulein. Dispersed chicken pancreatic acini stimulated with CCK were treated with various concentrations of DVZ. At 10^–5 M, DVZ completely inhibited amylase release; this concentration was much higher than those reported to have similar effects in mammals. The results suggest that the action DVZ as a CCK antagonist in the chicken is very weak.     

Y-organ of the crab,Varuna litterata (Fabricius)

Résumé Dans l'«organe Y» du crabeV. litterata, deux types de cellules ont été observés et leurs caractères morphologiques sont décrits.     

Endocrine regulation of the bursa copulatrix and receptacle gland ofDanaus plexippus L. (Lepidoptera: Danaidae)

Summary Significant growth occurs in the bursa copulatrix and receptacle glands of female Monarch butterflies held in summer conditions after adult emergence. Removal of the corpora allata prevents this growth, but normal development occurs if juvenile hormone is injected into females lacking corpora allata.     

Somatostatin and 3-oxy-methyl-D-glucose (3-OMG) uptake in isolated chicken intestinal epithelial cells

The direct effect of somatostatin on the absorption of 3-oxymethylglucose in epithelial cells isolated from the small intestine of chicken was studied. The presence of somatostatin in the incubation medium at concentrations of 3.5 X 10(-8) M and 7 X 10(-8) M produced significant dose-dependent increases in the accumulation of sugar in the enterocytes. This effect might be due to an increase in the cell membrane permeability caused by hormone action.     

Somatostatin and 3-oxy-methyl-D-glucose (3-OMG) uptake in isolated chicken intestinal epithelial cells

Summary The direct effect of somatostatin on the absorption of 3-oxymethylglucose in epithelial cells isolated from the small intestine of chicken was studied. The presence of somatostatin in the incubation medium at concentrations of 3.5×10^–8 M and 7×10^–8 M produced significant dose-dependent increases in the accumulation of sugar in the enterocytes. This effect might be due to an increase in the cell membrane permeability caused by hormone action.     

The ontogeny ofa-foetoprotein in the chicken

Summary The ontogeny ofa-foetoprotein (AFP) has been studied in the chicken using polyacrylamide gel gradient electrophoresis and electroimmunoassay from 7 days of incubation until after hatching. The results are discussed in the light of previous on the ontogeny of AFP in mammals.     

In vitro stimulation of chicken pituitary growth hormone and prolactin secretion by chicken hypothalamic extract.

The effect of an acid extract of chicken hypothalami on the in vitro secretion of prolactin and growth hormone (GH) by dispersed chicken pituitary cells has been investigated. Both prolactin and GH release were stimulated in a dose related manner in the presence of the hypothalamic extract (HE). Somatostatin had no effect on the basal or HE stimulated release of prolactin although it did inhibit the HE induced release of GH.