The release of secretory products from the corticotrophic cells of Salmo gairdneri in vitro

1974 ◽  
Vol 151 (4) ◽  
Author(s):  
BridgetI. Baker ◽  
JohnL. Leatherland ◽  
A.P. Scott
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Christopher C. Evans ◽  
Katherine M. Day ◽  
Yi Chu ◽  
Bridget Garner ◽  
Kaori Sakamoto ◽  
...  

Abstract Background The Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.


1976 ◽  
Vol 33 (4) ◽  
pp. 974-988 ◽  
Author(s):  
Bernard Jalabert

The endocrine processes which control oocyte maturation (resumption of meiosis) and ovulation have been studied in vitro in the trout Salmo gairdneri. Follicular maturation is ultimately under the control of a pituitary gonadotropin which induces the follicle to synthesize specific steroids; these steroids act in turn directly on the oocyte to promote maturation. The systematic study of the in vitro efficiency of various steroids have shown that 17α-hydroxy-20β-dihydroprogesterone plays a preferential role in initiating maturation; this steroid has a high affinity for a plasma protein system. The efficiency of this steroid, similarly to the efficiency of the gonadotropin, can be modulated by other circulating steroids. The precise chronology of some events of follicle maturation have been defined using inhibitors of protein and RNA synthesis.The ovulatory process (sensu stricto: expulsion of matured oocyte from the follicular envelopes) has been experimentally dissociated from oocyte maturation, and some mediators likely to act on ovulation have been identified.These data permit the consideration of novel means of intervention at the ovarian level to synchronize maturation and ovulation in fish, in order to give new tools for progress in aquaculture.


Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 371-378 ◽  
Author(s):  
D. CARMENA ◽  
J. MARTÍNEZ ◽  
A. BENITO ◽  
J. A. GUISANTES

This study describes, for the first time, the characterization of excretory–secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, evaluating their usefulness in the immunodiagnosis of human cystic echinococcosis. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. This preparation contained over 20 major protein components which could be distinguished by 1-dimensional SDS–PAGE with apparent masses between 9 and 300 kDa. The culture of of protoscoleces from liver produced a greater variety of excretory–secretory protein components than those from lung. Determination of enzymatic activities of secreted proteins revealed the presence of phosphatases, lipases and glucosidases, but no proteases. These findings were compared to those obtained from somatic extracts of protoscoleces and hydatid cyst fluid products. Immunochemical characterization was performed by immunoblotting with sera from individuals infected by cystic echinococcosis (n=15), non-hydatidic parasitoses (n=19), various liver diseases (n=24), lung neoplasia (n=16), and healthy donors (n=18). Antigens with apparent masses of 89, 74, 47/50, 32, and 20 kDa showed specificity for immunodiagnosis of human hydatidosis. The 89 and 74 kDa components corresponded to antigens not yet described in E. granulosus, whereas proteins of 41–43 kDa and 91–95 kDa were recognized by the majority of the non-hydatid sera studied.


1978 ◽  
Vol 35 (4) ◽  
pp. 477-479 ◽  
Author(s):  
P. Payan ◽  
P. Pic ◽  
G. De Renzis
Keyword(s):  

The Cl− influxes are identical in vivo and in vitro providing that the gills are externally irrigated during the preparation of the isolated head. A net uptake of Cl− is observed. When no irrigation is used the Cl− influx is reduced by 66% and Cl− is lost by the preparation.


1998 ◽  
Vol 332 (3) ◽  
pp. 593-610 ◽  
Author(s):  
Peter ARVAN ◽  
David CASTLE

Secretory granules are specialized intracellular organelles that serve as a storage pool for selected secretory products. The exocytosis of secretory granules is markedly amplified under physiologically stimulated conditions. While granules have been recognized as post-Golgi carriers for almost 40 years, the molecular mechanisms involved in their formation from the trans-Golgi network are only beginning to be defined. This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel. In the first half of the review, the emerging role of immature secretory granules in protein sorting is highlighted. The second half of the review summarizes what is known about the composition of granule membranes. The numerous similarities and relatively limited differences identified between granule membranes and other vesicular carriers that convey products to and from the plasmalemma, serve as a basis for examining how granule membrane composition might be established and how its unique functions interface with general post-Golgi membrane traffic. Studies of granule formation in vitro offer additional new insights, but also important challenges for future efforts to understand how regulated secretory pathways are constructed and maintained.


2012 ◽  
Vol 246 (1-2) ◽  
pp. 85-95 ◽  
Author(s):  
Robert P. Lisak ◽  
Joyce A. Benjamins ◽  
Liljana Nedelkoska ◽  
Jennifer L. Barger ◽  
Samia Ragheb ◽  
...  

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