scholarly journals Intestinal absorption of linoleic acid in experimental renal failure

1991 ◽  
Vol 66 (3) ◽  
pp. 467-477
Author(s):  
M. V. Pahl ◽  
A. Barbari ◽  
N. D. Vaziri ◽  
D. Hollander ◽  
M. Yazdani ◽  
...  
Keyword(s):  
Renal Failure ◽  
Linoleic Acid ◽  
Water Layer ◽  
Short Term ◽  
Unstirred Water Layer ◽  
Wide Range ◽  
Significant Difference

Linoleic acid (LA) transport in rats with experimental short-term and long-term renal failure (RF) was compared with that of sham-operated normal animals on liberal food intake and pair-fed animals. The perfusions in vivo and incubations in vitro were conducted using a micellar solution containing a wide range of LA concentrations. Both absorption in vivo and uptake in vitro of LA were significantly reduced in animals with short-term RF. Lipid extraction and separation by thin-layer chromatography revealed a marked LA trapping as trilinolein (TL) in the perfused intestinal tissue in the short-term RF group. The esterification process, as defined by the rate of LA incorporation into TL, was moderately reduced in short-term RF animals. The thickness of the unstirred water layer showed no significant difference among the groups studied. In contrast, animals with long-term RF exhibited normal absorption of LA in vivo at all concentrations tested. In conclusion, LA absorption is reduced in short-term RF and restored in long-term RF. Several steps including LA transport into and TL transport out of the enterocyte and the esterification process were impaired in short-term RF. These changes are not due to alteration in the unstirred water layer, anorexia, weight loss or a rapid effect of uraemic chemical environment or circulatory factors.

Correlation between magnesium and potassium contents in muscle: role of Na(+)-K+ pump

1993 ◽  
Vol 264 (2) ◽  
pp. C457-C463 ◽  
Author(s):  
I. Dorup ◽  
T. Clausen
Keyword(s):  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Deficient Diet ◽  
Young Rats ◽  
Wide Range ◽  
86Rb Influx

In young rats fed a Mg(2+)-deficient diet for 3 wk, Mg2+ and K+ contents in soleus and extensor digitorum longus muscles were significantly reduced and closely correlated. In isolated soleus muscles, Mg2+ depletion induced an even more pronounced loss of K+, and Mg2+ and K+ contents were correlated over a wide range (r = 0.95, P < 0.001). Extracellular Mg2+ (0-1.2 mM) caused no change in total or ouabain-suppressible 86Rb influx. After long-term incubation in Ca(2+)-Mg(2+)-free buffer with EDTA and EGTA, cellular Mg2+ and K+ contents were reduced by 35 and 15%, respectively, without any reduction in ATP and total or ouabain-suppressible 86Rb influx. In Mg(2+)-depleted muscles 42K efflux was increased by up to 42%, and repletion with Mg2+ produced a graded decrease. We conclude that Mg2+ and K+ contents are closely correlated in muscles Mg2+ depleted in vivo or in vitro and that neither extracellular nor moderate intracellular Mg2+ depletion affects total or Na(+)-K+ pump-mediated K+ influx. The reduced K+ content may rather be related to increased K+ efflux from the muscles.

Short-term effect of aldosterone on NEM-sensitive ATPase in rat collecting tubule

1989 ◽  
Vol 257 (2) ◽  
pp. F177-F181 ◽  
Author(s):  
C. Khadouri ◽  
S. Marsy ◽  
C. Barlet-Bas ◽  
A. Doucet
Keyword(s):  
Atpase Activity ◽  
Affinity Constant ◽  
Short Term ◽  
Collecting Tubule ◽  
Lag Period ◽  
In Vitro Effects ◽  
Collecting Tubules

Because previous studies indicated that in the collecting tubule, N-ethylmaleimide (NEM)-sensitive ATPase, the biochemical equivalent of the proton pump, is controlled by mineralocorticoids in the long term, the present study was designed to investigate whether such control also exists in the short term. Therefore we investigated the in vivo and in vitro effects of aldosterone on the enzyme activity in cortical and outer medullary collecting tubules (CCT and MCT, respectively) from adrenalectomized rats. Administration of aldosterone (10 micrograms/kg body wt) markedly stimulated NEM-sensitive ATPase activity in the CCT and MCT within 3 h. Similarly, incubating CCT or MCT for 3 h in the presence of 10(-8) M aldosterone enhanced NEM-sensitive ATPase activity up to values similar to those previously measured in the corresponding nephron segments of normal rats. In vitro stimulation of NEM-sensitive ATPase was dose dependent in regard to aldosterone (apparent affinity constant approximately 10(-9) M), appeared after a 30-min lag period, and reached its maximum after 2-2.5 h. Finally, actinomycin D and cycloheximide totally abolished the in vitro action of aldosterone, demonstrating the involvement of protein synthesis in this process.

scholarly journals Cleaved CD31 as a target for in vivo molecular imaging of inflammation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jonathan Vigne ◽  
Sylvie Bay ◽  
Rachida Aid-Launais ◽  
Guillaume Pariscoat ◽  
Guillaume Rucher ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Molecular Form ◽  
Positive Control ◽  
Negative Control ◽  
Stability Study ◽  
Biodistribution Studies ◽  
Wide Range ◽  
Significant Difference

AbstractThere is a need for new targets to specifically localize inflammatory foci, usable in a wide range of organs. Here, we hypothesized that the cleaved molecular form of CD31 is a suitable target for molecular imaging of inflammation. We evaluated a bioconjugate of D-P8RI, a synthetic peptide that binds all cells with cleaved CD31, in an experimental rat model of sterile acute inflammation. Male Wistar rats were injected with turpentine oil into the gastrocnemius muscle two days before 99mTc-HYNIC-D-P8RI (or its analogue with L-Proline) SPECT/CT or [18F]FDG PET/MRI. Biodistribution, stability study, histology, imaging and autoradiography of 99mTc-HYNIC-D-P8RI were further performed. Biodistribution studies revealed rapid elimination of 99mTc-HYNIC-D-P8RI through renal excretion with almost no uptake from most organs and excellent in vitro and in vivo stability were observed. SPECT/CT imaging showed a significant higher 99mTc-HYNIC-D-P8RI uptake compared with its analogue with L-Proline (negative control) and no significant difference compared with [18F]FDG (positive control). Moreover, autoradiography and histology revealed a co-localization between 99mTc-HYNIC-D-P8RI uptake and inflammatory cell infiltration. 99mTc-HYNIC-D-P8RI constitutes a new tool for the detection and localization of inflammatory sites. Our work suggests that targeting cleaved CD31 is an attractive strategy for the specific in vivo imaging of inflammatory processes.

Development and population dynamics of Steinernema yirgalemense (Rhabditida: Steinernematidae) and growth characteristics of its associated Xenorhabdusindica symbiont in liquid culture

2015 ◽  
Vol 90 (3) ◽  
pp. 364-371 ◽  
Author(s):  
T. Ferreira ◽  
M.F. Addison ◽  
A.P. Malan
Keyword(s):  
Population Density ◽  
Liquid Culture ◽  
Commercial Application ◽  
Adult Density ◽  
Developmental Phase ◽  
Male Density ◽  
Wide Range ◽  
Significant Difference

AbstractEntomopathogenic nematodes have become a valuable addition to the range of biological control agents available for insect control. An endemic nematode, Steinernemayirgalemense, has been found to be effective against a wide range of key insect pests. The next step would be the mass production this nematode for commercial application. This requires the establishment of monoxenic cultures of both the nematode and the symbiotic bacterium Xenorhabdus indica. First-stage juveniles of S. yirgalemense were obtained from eggs, while X. indica was isolated from nematode-infected wax moth larvae. The population density of the various life stages of S. yirgalemense during the developmental phase in liquid culture was determined. The recovery of infective juveniles (IJs) to the third-stage feeding juveniles, was 67 ± 10%, reaching a maximum population density of 75,000 IJs ml− 1 on day 13 after inoculation. Adult density increased after 8 days, with the maximum female density being 4600 ml− 1 on day 15, whereas the maximum male density was 4300 ml− 1 on day 12. Growth curves for X. indica showed that the exponential phase was reached 15 h after inoculation to the liquid medium. The stationary phase was reached after 42 h, with an average of 51 × 107 colony-forming units ml− 1. Virulence tests showed a significant difference in insect mortality between in vitro- and in vivo-produced nematodes. The success obtained with the production of S. yirgalemense in liquid culture can serve as the first step in the optimizing and upscaling of the commercial production of nematodes in fermenters.

In vitro pituitary GH secretion after GHRH, forskolin, dibutyryl cyclic-adenosine 3′,5′-monophosphate and phorbol 12-myristate 13-acetate stimulation in long-term orchidectomized rats

1996 ◽  
Vol 16 (1) ◽  
pp. 81-88 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
E Aguilar
Keyword(s):  
Male Rats ◽  
Short Term ◽  
Compensatory Mechanisms ◽  
Gh Secretion ◽  
Camp Pathway ◽  
Kinase C ◽  
High Doses

ABSTRACT In the present work in vitro GH pituitary responsiveness to GHRH in short-term (STO) and long-term orchidectomized (LTO) male rats was compared. In agreement with previous data obtained in vivo, pituitaries from STO rats showed reduced GH release after GHRH stimulation while LTO male pituitaries presented responses similar to those from control animals after maximal GHRH (10-6 m) stimulation. This suggests that compensatory mechanisms have taken place, probably at the pituitary level, in order to restore GH pituitary responsiveness to high doses of GHRH. However, LTO male rats showed a reduced sensitivity to GHRH relative to intact males, as indicated by a higher EC50 vs controls (40·82 ± 12·03 nm vs 0·35 ± 0·09 nm in intact males). We aimed to investigate further the events involved in the compensatory mechanisms that take place in LTO rats. For this purpose, we compared in vitro GH secretion by pituitaries from intact and LTO male rats after stimulation with specific activators of the signal transduction pathways related to GH release. Forskolin and dibutyryl cyclic-adenosine 3′,5′-monophosphate were more effective in eliciting GH secretion (expressed in terms of percent increment over basal GH release) in LTO males, whereas phorbol 12-myristate 13-acetate was completely ineffective in stimulating GH release in this group. Thus, our results clearly showed that long-term orchidectomy enhances the effectiveness of the cAMP pathway in inducing GH release while it completely blunts that of the protein kinase C pathway. In conclusion, orchidectomy decreased the effectiveness of GHRH in eliciting GH release in vitro. However, long-term orchidectomy activated compensatory mechanisms that restored complete GH pituitary responsiveness to maximal GHRH stimulation. These mechanisms seem not to operate in STO rats. An increased effectiveness of the cAMP pathway in eliciting GH release in LTO rats is probably involved in the aforementioned compensatory mechanisms.

Lymphoid-Restricted Development From Multipotent Candidate Murine Stem Cells: Distinct and Complimentary Functions of the c-kit and flt3-Ligands

Blood ◽  
1999 ◽  
Vol 94 (11) ◽  
pp. 3781-3790 ◽  
Author(s):  
Ole Johan Borge ◽  
Jörgen Adolfsson ◽  
Annica Mårtensson, Inga-Lill Mårtensson, and Sten E.W. Jacobsen
Keyword(s):  
Stem Cells ◽  
Cell Formation ◽  
Stem Cell Population ◽  
Tyrosine Kinase Receptors ◽  
Short Term ◽  
Interleukin 7 ◽  
Potential Interactions

Abstract The two tyrosine kinase receptors, c-kit and flt3, and their respective ligands KL and FL, have been demonstrated to play key and nonredundant roles in regulating the earliest events in hematopoiesis. However, their precise roles and potential interactions in promoting early lymphoid commitment and development remain unclear. Here we show that most if not all murine Lin−/loSca1+c-kit+ bone marrow (BM) cells generating B220+CD19+proB-cells in response to FL and interleukin-7 (IL-7) also have a myeloid potential. In contrast to FL + IL-7, KL + IL-7 could not promote proB-cell formation from Lin−/loSca1+c-kit+ cells. However, KL potently enhanced FL + IL-7–stimulated proB-cell formation, in part through enhanced recruitment of FL + IL-7–unresponsive Lin−/loSca1+c-kit+progenitors, and in part by enhancing the growth of proB-cells. The enhanced recruitment (4-fold) in response to KL occurred exclusively from the Lin−/loSca1+c-kit+flt3−long-term repopulating stem cell population, whereas KL had no effect on FL + IL-7–stimulated recruitment of Lin−/loSca1+c-kit+flt3+short-term repopulating cells. The progeny of FL + IL-7–stimulated Lin−/loSca1+c-kit+ cells lacked in vitro and in vivo myeloid potential, but efficiently reconstituted both B and T lymphopoiesis. In agreement with this FL, but not KL, efficiently induced expression of B220 and IL-7 receptor- on Lin−/loSca1+c-kit+flt3+cells. Thus, whereas KL appears crucial for recruitment of FL + IL-7–unresponsive candidate (c-kit+flt3−) murine stem cells, FL is essential and sufficient for development toward lymphoid restricted progenitors from a population of (c-kit+flt3+) multipotent short-term reconstituting progenitors.

Lymphoid-Restricted Development From Multipotent Candidate Murine Stem Cells: Distinct and Complimentary Functions of the c-kit and flt3-Ligands

Blood ◽  
1999 ◽  
Vol 94 (11) ◽  
pp. 3781-3790 ◽  
Author(s):  
Ole Johan Borge ◽  
Jörgen Adolfsson ◽  
Annica Mårtensson, Inga-Lill Mårtensson, and Sten E.W. Jacobsen
Keyword(s):  
Stem Cells ◽  
Cell Formation ◽  
Stem Cell Population ◽  
Tyrosine Kinase Receptors ◽  
Short Term ◽  
Interleukin 7 ◽  
Potential Interactions

The two tyrosine kinase receptors, c-kit and flt3, and their respective ligands KL and FL, have been demonstrated to play key and nonredundant roles in regulating the earliest events in hematopoiesis. However, their precise roles and potential interactions in promoting early lymphoid commitment and development remain unclear. Here we show that most if not all murine Lin−/loSca1+c-kit+ bone marrow (BM) cells generating B220+CD19+proB-cells in response to FL and interleukin-7 (IL-7) also have a myeloid potential. In contrast to FL + IL-7, KL + IL-7 could not promote proB-cell formation from Lin−/loSca1+c-kit+ cells. However, KL potently enhanced FL + IL-7–stimulated proB-cell formation, in part through enhanced recruitment of FL + IL-7–unresponsive Lin−/loSca1+c-kit+progenitors, and in part by enhancing the growth of proB-cells. The enhanced recruitment (4-fold) in response to KL occurred exclusively from the Lin−/loSca1+c-kit+flt3−long-term repopulating stem cell population, whereas KL had no effect on FL + IL-7–stimulated recruitment of Lin−/loSca1+c-kit+flt3+short-term repopulating cells. The progeny of FL + IL-7–stimulated Lin−/loSca1+c-kit+ cells lacked in vitro and in vivo myeloid potential, but efficiently reconstituted both B and T lymphopoiesis. In agreement with this FL, but not KL, efficiently induced expression of B220 and IL-7 receptor- on Lin−/loSca1+c-kit+flt3+cells. Thus, whereas KL appears crucial for recruitment of FL + IL-7–unresponsive candidate (c-kit+flt3−) murine stem cells, FL is essential and sufficient for development toward lymphoid restricted progenitors from a population of (c-kit+flt3+) multipotent short-term reconstituting progenitors.

scholarly journals Triggering DTH and CTL Activity by fd Filamentous Bacteriophages: Role of CD4+ T Cells in Memory Responses

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Giovanna Del Pozzo ◽  
Dina Mascolo ◽  
Rossella Sartorius ◽  
Alessandra Citro ◽  
Pasquale Barba ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Long Term Memory ◽  
Short Term ◽  
Filamentous Bacteriophages ◽  
Ctl Responses

The ability of fd bacteriophage particles to trigger different arms of the immune system has been previously shown by us with particular emphasis on the ability of phages to raise CTL responses in vitro and in vivo. Here we show that fd virions in the absence of adjuvants are able to evoke a DTH reaction mediated by antigen specific CD8+ T cells. In addition, we analyzed the induction of CTL responses in mice depleted of CD4+ T cells, and we observed that short-term secondary CTL responses were induced in the absence of CD4+ T cells while induction of long-term memory CTLs required the presence of CD4+ T lymphocytes. These results examine the cellular mechanism at the basis of fd efficiency and provide new elements to further validate the use of fd particles for eliciting and monitoring antigen-specific CTLs.

scholarly journals Optimization of Degradation Profile for New Scaffold in Cartilage Repair

Cartilage ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 438-449 ◽  
Author(s):  
Sarav S. Shah ◽  
Haixiang Liang ◽  
Sandeep Pandit ◽  
Zalak Parikh ◽  
John A. Schwartz ◽  
...  
Keyword(s):  
Cartilage Repair ◽  
Subchondral Bone ◽  
Rat Model ◽  
Articular Chondrocytes ◽  
Short Term ◽  
Morphological Studies ◽  
Biomaterial Scaffold

Objective To establish whether a novel biomaterial scaffold with tunable degradation profile will aid in cartilage repair of chondral defects versus microfracture alone in vitro and in a rat model in vivo. Design In vitro—Short- and long-term degradation scaffolds were seeded with culture expanded articular chondrocytes or bone marrow mesenchymal stem cells. Cell growth and differentiation were evaluated with cell morphological studies and gene expression studies. In vivo—A microfracture rat model was used in this study to evaluate the repair of cartilage and subchondral bone with the contralateral knee serving as the empty control. The treatment groups include (1) empty osteochondral defect, (2) polycaprolactone copolymer–based polyester polyurethane–urea (PSPU-U) caffold short-term degradative profile, and (3) PSPU-U scaffold long-term degradative profile. After placement of the scaffold, the rats were then allowed unrestricted activity as tolerated, and histological analyses were performed at 4, 8, and 16 weeks. The cartilage defect was measured and compared with the contralateral control side. Results In vitro—Long-term scaffolds showed statistically significant higher levels of aggrecan and type II collagen expression compared with short-term scaffolds. In vivo—Within 16 weeks postimplantation, there was new subchondral bone formation in both scaffolds. Short-term scaffolds had a statistically significant increase in defect filling and better qualitative histologic fill compared to control. Conclusions The PSPU short-term degradation scaffold may aid in cartilage repair by ultimately incorporating the scaffold into the microfracture procedure.

scholarly journals Studies on drug absorption from oral cavity. II Influence of the unstirred water layer on absorption from hamster cheek pouch in vitro and in vivo.

1987 ◽  
Vol 10 (4) ◽  
pp. 180-187 ◽  
Author(s):  
YUJI KUROSAKI ◽  
SHINICHI HISAICHI ◽  
CHIEKO HAMADA ◽  
TAIJI NAKAYAMA ◽  
TOSHIKIRO KIMURA
Keyword(s):  
Oral Cavity ◽  
Drug Absorption ◽  
Water Layer ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Unstirred Water Layer
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