Biomedical subjects

S Lu

Publications and source records attributed to S Lu.

At least 37 records · Page 2Linked to original sources

PubMed2002

Immunocytochemical observation of ghrelin-containing neurons in the rat arcuate nucleus.

Ghrelin is a novel peptide that stimulates the release of growth hormone from the pituitary and is involved in hypothalamic feeding regulation. A pre-embedding immunostaining technique was used to study the ultrastructure and synaptic relationships of ghrelin-containing neurons in the rat arcuate nucleus (ARC). Ghrelin-like immunoreactive (ghrelin-LI) neurons were found in the ARC, and were especially abundant in its ventral part. At the electron microscopic level, ghrelin-LI neurons received afferent synapses from many unknown axon terminals. Ghrelin-LI products in the immunoreactive cell bodies, processes, and axon terminals were detected mainly in dense granular vesicles about 110 nm in diameter. Ghrelin-LI presynaptic axon terminals often made synapses with unknown immunonegative neurons. These results suggest that ghrelin acts to regulate food intake through synaptic connections in hypothalamic neuronal networks.

Animals↗

PubMed2002

DNA prime/protein boost vaccine strategy in neonatal macaques against simian human immunodeficiency virus.

Newborn macaques were vaccinated against a chimeric simian human immunodeficiency (SHIV) virus, SHIV-vpu+, by DNA priming and boosting with homologous HIV-1 gp160. Following SHIV-vpu+ challenge, containment of infection was observed in 4 of 15 animals given DNA priming/protein boost vaccination and in three of four animals given gp160 boosts only. Rechallenge with homologous virus of six animals that contained the first challenge virus resulted in rapid viral clearance or low viral loads. Upon additional rechallenge with heterologous, pathogenic SHIV89.6P, four of these six animals maintained normal CD4+ T-cell counts with no or limited SHIV89.6P infection. Our data suggest that humoral and cellular immune mechanisms may have contributed to the containment of SHIV89.6P; however, viral interference with SHIV-vpu+ could also have played a role. Our results indicate that immunogenicity and efficacy of candidate AIDS vaccines are not affected when vaccination is initiated during infancy as compared with later in life.

AIDS Vaccines↗

PubMed2002

Reciprocal synaptic relationships between orexin- and melanin-concentrating hormone-containing neurons in the rat lateral hypothalamus: a novel circuit implicated in feeding regulation.

OBJECTIVE: Both orexin (ORX)- and melanin-concentrating hormone (MCH) are expressed in different neurons in the lateral hypothalamic area (LH), and are considered to have common effects on stimulating food intake. There are no reports to demonstrate neural interactions between them at the ultrastructural level. We observed these neurons in the LH to evaluate the relationships between them. DESIGN: We used two different types of double immunostaining to reveal the ultrastructure of both the ORX- and MCH-containing neurons. A preembedding double immunostaining technique was used to study the synaptic relationships between the two kinds of neuron. RESULTS: The main new findings are as follows: 1) Both ORX- and MCH-containing neurons received other synaptic input and made synaptic input to other neurons; 2) Reciprocal synaptic relationships were observed between the ORX- and MCH-containing neurons. CONCLUSION: The ORX- and MCH-containing neurons in the lateral hypothalamic area may influence food intake through synapse with each other.

Animals↗

PubMed2002

Extra-articular cartilage affected in collagen-induced, but not pristane-induced, arthritis models.

Rheumatoid arthritis (RA) is a chronic inflammatory disease primarily affecting cartilaginous joints but also extra-articular tissues such as the nose and upper respiratory tract. We have investigated extra-articular cartilage involvement in two commonly used animal models for RA, collagen-induced and pristane-induced arthritis, by immunizing rats with different susceptibility to disease (LEW.1 A, LEW.1F and DA rats). We found that nasal and tracheolaryngeal cartilage is affected in LEW.1 A and DA rats to varying degrees in collagen-induced arthritis but not in any strain in the pristane-induced model. Antibodies to matrilin-1, a cartilage-specific protein expressed mainly in tracheolaryngeal and nasal cartilage but not in joints, were positively associated with the presence of inflammation in nasal cartilage. In contrast, no antibody response to matrilin-1 could be detected in pristane-induced arthritis. In addition, nasal vaccination with collagen type II prior to immunization in DA rats significantly decreased the antibody response to matrilin-1 at day 56, but not at earlier time points, indicating a late protective effect on extra-articular cartilage. We conclude that pristane-induced arthritis is a joint-specific model whereas collagen-induced arthritis affect joints as well as extra-articular cartilage. Furthermore, collagen immunization induces an antibody response to matrilin-1.

Animals↗

PubMed2002

Nontransferrin-bound iron in the plasma of haemodialysis patients after intravenous iron saccharate infusion.

BACKGROUND: Many haemodialysis patients treated with recombinant human erythropoietin (r-HuEPO) receive intravenous iron supplementation on a regular basis. It has been shown previously that this may result in a transient "oversaturation" of transferrin. METHODS: Ten stable haemodialysis patients on r-HuEPO treatment received 100 mg iron saccharate in 60 min, and 1 week later 100 mg in 6 min. Conventional iron metabolism parameters and nontransferrin-bond iron, detected with HPLC after addition of nitrilotriacetate and pretreatment with cobalt, were measured. Also, iron was measured in dialysate. RESULTS: Serum iron increased from 9.6 +/- 6.2 to 213.7 +/- 49.4 micromol L(-1) (P < 0.001) when iron was given in 60 min, and from 11.1 +/- 4.7 to 219.3 +/- 43.7 micromol L(-1) (P < 0.001) when iron was given in 6 min. Transferrin saturation increased from 0.22 +/- 0.18 to 4.75 +/- 1.35 in protocol 1 and 0.26 +/- 0.16 to 4.91 +/- 1.38 in protocol 2. Nontransferrin-bound iron increased from 0.74 +/- 0.69 to 3.79 +/- 1.41 micromol L(-1) in protocol 1, and from 0.90 +/- 0.92 to 2.90 +/- 0.96 micromol L(-1) in protocol 2. No significant iron concentrations were found in dialysate before or during the iron saccharate infusion. CONCLUSION: Nontransferrin-bound iron exists in plasma of dialysis patients after infusion of iron saccharate. There was no difference when 100 mg iron was given in 60 min or in 6 min. Before iron infusion, appreciable concentrations of nontransferrin-bound iron could already be detected. The clinical significance is not clear, but the findings may be important since nontransferrin-bound iron can act as a catalytic agent in the formation of hydroxyl radicals, thus potentially inducing cell damage and atherosclerosis.

Anemia↗

PubMed2001

Ultrastructural and biochemical localization of N-RAP at the interface between myofibrils and intercalated disks in the mouse heart.

N-RAP is a recently discovered muscle-specific protein found at cardiac intercalated disks. Double immunogold labeling of mouse cardiac muscle reveals that vinculin is located immediately adjacent to the fascia adherens region of the intercalated disk membrane, while N-RAP extends approximately 100 nm further toward the interior of the cell. We partially purified cardiac intercalated disks using low- and high-salt extractions followed by density gradient centrifugation. Immunoblots show that this preparation is highly enriched in desmin and junctional proteins, including N-RAP, talin, vinculin, beta1-integrin, N-cadherin, and connexin 43. Electron microscopy and immunolabeling demonstrate that N-RAP and vinculin are associated with the large fragments of intercalated disks that are present in this preparation, which also contains numerous membrane vesicles. Detergent treatment of the partially purified intercalated disks removed the membrane vesicles and extracted vinculin and beta1-integrin. Further separation on a sucrose gradient removed residual actin and myosin and yielded a fraction morphologically similar to fasciae adherentes that was highly enriched in N-RAP, N-cadherin, connexin 43, talin, desmin, and alpha-actinin. The finding that N-RAP copurifies with detergent-extracted intercalated disk fragments even though beta-integrin and vinculin have been completely removed suggests that N-RAP association with the adherens junction region is mediated by the cadherin system. Consistent with this hypothesis, we found that recombinant N-RAP fragments bind alpha-actinin in a gel overlay assay. In addition, immunofluorescence shows that N-RAP remains bound at the ends of isolated, detergent-treated cardiac myofibrils. These results demonstrate that N-RAP remains tightly bound to myofibrils and fasciae adherentes during biochemical purification and may be a key constituent in the mechanical link between these two structures.

Animals↗

PubMed2001

[An epidemiologic study of bowel habit in adult non-patient population in Beijing area].

OBJECTIVE: To determine the bowel habit and its influencing factors in the adult non-patient population in Beijing area. METHODS: A questionnaire survey was conducted among 2486 adult permanent residents in Beijing area by randomized stratified sampling. The bowel habit (defecation frequency, characters of feces, time of defecation, and abnormal defecation) of the 1 952 non-patients among them were further investigated. The non-patient subject should fulfil the following criteria: (1) without gastrointestinal and hepatic organic diseases; (2) without metabolic disease affecting the motility of the gastrointestinal tract, such as diabetes mellitus and thyroid hyperfunction; (3) without irritable bowel syndrome which fits in the Manning criteria; and (4) considering oneself as having normal bowel habits. RESULTS: 84.17% of the non-patient interviewees defecated once per day with the mean defecation frequency of 7.09 times per week. 89.86% of the interviewees had formed or soft stool. 93.08% of the non-patients defecated formed or soft stool 3 to 21 times per week. No evidence showed that the frequency of defecation and character of feces were related to age and sex. 77% of them defecated in the morning. The prevalence rates of constipation, diarrhea, and abdominal pain associated with defecation were 3.74%, 1.08%, and 7.38% respectively. CONCLUSION: The defecation frequency of adult nonpatient population in Beijing area is almost identical to that reported in the west. 93.08% of the non-patient subjects have normal defecation patterns. It is necessary to define the judgement criteria for constipation and diarrhea for Chinese based on their defecation patterns.

Adult↗

PubMed2001

Pooled umbilical cord blood as a possible universal donor for marrow reconstitution and use in nuclear accidents.

Human umbilical cord blood has been shown to be an effective source of stem cells for marrow reconstitution in pediatric patients. Unfortunately, the quantity of stem cells obtained from an individual donor can be quite limited in both the total volume and the numbers of stem cells per ml of cord blood. HLA matching further limits the availability, but recent publications indicate close matching may be unnecessary. Therefore, if cord blood from different donors can be combined, larger numbers of stem cells can be available for clinical use provided pooling does not produce a negative effect. Storage of single cord blood specimens at 4 degrees C for 10-21 days in gas permeable bags produced an apparent increase in the percentage of immature cells (CD34, CD117, GPA) and mitotic activity (S+G2/M cells) over day 1. With similar storage of pooled specimens there was a further increase in the number of immature colonies cultured, CD34, CD117, GPA, S+G2/M cells. In addition, nucleated red blood cells increased over the mean values obtained from single cord blood samples. Our previous studies have indicated that large numbers of human mononuclear cells are necessary to reconstitute an irradiated animal model. By combining multiple samples of human cord blood, adequate numbers of stem cells could be pooled for use in adults and would provide cells for megadose therapy, including those patients that had accidentally received lethal irradiation.

Bone Marrow Transplantation↗

PubMed2001

Bone morphogenetic protein 4 induces efficient hematopoietic differentiation of rhesus monkey embryonic stem cells in vitro.

A cell culture system consisting of mouse S17 stromal cells supplemented with cytokines was developed for hematopoietic differentiation of rhesus monkey embryonic stem (ES) cells. The differentiated colonies that formed contained clusters of hematopoietic-like cells, as well as structures similar in appearance to embryonic blood islands. When this culture system was supplemented with bone morphogenetic protein 4 (BMP-4), the numbers of primary hematopoietic clusters increased by an average of 15 fold. The primary hematopoietic clusters containing clonogenic precursors (expandable hematopoietic clusters) increased by 18 fold. Immunofluorescence analysis showed that a substantial percentage of the hematopoietic-like cells were CD34(+), with morphologic features of undifferentiated blast cells. Enrichment of the CD34(+) cells was associated with enhanced stromal-dependent, cytokine-driven formation of cobblestone colonies on secondary plating. The hematopoietic identity of the precursors was further indicated by their expression of genes associated with hematopoietic differentiation, as well as morphologic assessments that showed erythroid and myeloid lineages among the progeny cells. In addition, reverse transcriptase-polymerase chain reaction analysis of BMP-4-treated rhesus monkey ES cells demonstrated an up-regulation of early-expressed genes responsible for embryonic hematopoiesis and angiogenesis during the first 7 days of culture. These observations suggest that embryonic mesoderm regulatory protein may mimic physiologic signals that are required for the onset of embryonic hematopoiesis and stem cell formation in rhesus monkey ES cells.

Animals↗

PubMed2001

Heterocycle-containing retinoids. Discovery of a novel isoxazole arotinoid possessing potent apoptotic activity in multidrug and drug-induced apoptosis-resistant cells.

In a search for retinoic acid (RA) receptor ligands endowed with potent apoptotic activity, a series of novel arotinoids were prepared. Because the stereochemistry of the C9-alkenyl portion of natural 9-cis-RA and the olefinic moiety of the previously synthesized isoxazole retinoid 4 seems to have particular importance for their apoptotic activity, novel retinoid analogues with a restricted or, vice versa, a larger flexibility in this region were designed and prepared. The new compounds were evaluated in vitro for their ability to activate natural retinoid receptors and for their differentiation-inducing activity. Cytotoxic and apoptotic activities were, in addition, evaluated. In general, these analogues showed low cytotoxicity, with the restricted structures being slightly more active than the more flexible ones. As an exception, however, the isoxazole retinoid 15b proved to be particularly able to induce apoptosis at concentrations <5 microM, showing a higher activity than the classical retinoids such as all-trans-RA, 13-cis-RA, and 9-cis-RA and the previously described synthetic retinoid 4. 15b also exhibited a good affinity for the retinoid receptors. Interestingly, another important property of 15b was its ability to induce apoptosis in the HL60R multidrug-resistant (MDR) cell line, at the same concentration as is effective in HL60. Therefore, 15b represents a new retinoid possessing high apoptotic activity in an MDR cell line. The ability of 15b to act on K562 and HL60R cells suggests that this compound may have important implications in the treatment of different leukemias, and its structure could offer an interesting model for the design of new compounds endowed with apoptotic activity on MDR- and retinoid-resistant malignancies.

Antineoplastic Agents↗

PubMed2001

Targeting of functional antibody-decay-accelerating factor fusion proteins to a cell surface.

Recombinant soluble complement inhibitors hold promise for the treatment of inflammatory disease and disease states associated with transplantation. Targeting complement inhibitors to the site of complement activation and disease may enhance their efficacy and safety. Data presented show that targeting of decay-accelerating factor (DAF, an inhibitor of complement activation) to a cell surface by means of antibody fragments is feasible and that cell-targeted DAF provides significantly enhanced protection from complement deposition and lysis compared with soluble untargeted DAF. An extracellular region of DAF was joined to an antibody combining site with specificity for the hapten dansyl, at the end of either C(H)1 or C(H)3 Ig regions. The recombinant IgG-DAF chimeric proteins retained antigen specificity and bound to dansylated Chinese hamster ovary cells. Both soluble C(H)1-DAF and C(H)3-DAF were effective at inhibiting complement-mediated lysis of untargeted Chinese hamster ovary cells at molar concentrations within the range reported by others for soluble DAF. However, when targeted to a dansyl-labeled cell membrane, C(H)1-DAF was significantly more potent at inhibiting complement deposition and complement-mediated lysis. Cell-bound C(H)1-DAF also provided cells with protection from complement lysis after removal of unbound C(H)1-DAF. Of further importance, the insertion of a nonfunctional protein domain of DAF (the N-terminal short consensus repeat) between C(H)1 and the functional DAF domain increased activity of the fusion protein. In contrast to C(H)1-DAF, C(H)3-DAF was not significantly better at protecting targeted versus untargeted cells from complement, indicating that a small targeting vehicle is preferable to a large one. We have previously shown that for effective functioning of soluble complement inhibitor CD59, binding of CD59 to the cell surface close to the site of complement activation is required. Significantly, such a constraint did not apply for effective DAF function.

Animals↗

PubMed2001

Immune responses and protection obtained with rotavirus VP6 DNA vaccines given by intramuscular injection.

Intramuscular (i.m.) injection of murine VP6 DNA vaccines raised high titers of rotavirus-specific serum IgG and IgA antibodies in BALB/c mice. A Th1-like antibody response was generated based on the ratio of serum IgG2a to IgG1 antibodies. Rotavirus-specific serum IgA but not fecal IgA was detected in mice prior to rotavirus challenge. Partial protection against rotavirus challenge was achieved as measured by reduction of rotavirus antigen shedding in feces. A similar level of protection was found with a bovine rotavirus VP6 DNA vaccine against a murine rotavirus challenge, suggesting that heterologous protection can be obtained by immunizing with VP6 DNA vaccines. We did not directly test for cytotoxic T lymphocyte (CTL) activity, but in vivo depletion of CD8+ T cells in mice immunized with a murine VP6 DNA vaccine did not significantly change the duration of virus shedding or the pattern of protection obtained. This finding suggested that CD8+ CTL activity was not essential for the partial protection we obtained by i.m. immunization of mice with VP6 DNA vaccines.

Animals↗

PubMed2001

Susceptibility of lean and obese Zucker rats to tumorigenesis induced by N-methyl-N-nitrosourea.

To address the possible involvement of hyperinsulinemia in breast cancer development, we have examined the susceptibility of lean and obese Zucker rats to N-methyl-N-nitrosourea (MNU)-induced mammary cancer. Fifty-day-old female lean or obese Zucker rats received intraperitoneal (i.p.) injections of 37.5 or 20 mg/kg MNU, respectively. We showed in separate experiments that these doses produce similar levels of DNA methylation in the mammary epithelial cells of the lean and obese animals. Over the course of 29 weeks following MNU treatment, half of the lean rats developed carcinomas of the mammary gland, demonstrating that they are of intermediate susceptibility to mammary tumorigenesis. During this period, the obese rats developed hyperinsulinemia and insulin resistance as expected. Although palpable tumors developed at a similar rate in the lean and obese rats, only 10% of the obese animals developed mammary carcinomas. The obese rats, however, developed a high incidence (63.3%) of epidermal cysts that occurred mainly in the region of the mammary glands. A 13.3% incidence of colon carcinomas was also found in the obese rats. These results suggest that the development of hyperinsulinemia does not render the obese Zucker rats more susceptible to mammary gland carcinogenesis. Our observation of colon carcinomas in obese, but not lean rats, however, is consistent with evidence that hyperinsulinemia promotes colon cancer in rodents and humans.

Alkylating Agents↗

PubMed2001

Reciprocal synaptic relationships between angiotensin II-containing neurons and enkephalinergic neurons in the rat area postrema.

A preembedding double immunostaining technique was used to study synaptic relationships between angiotensin-II-like immunoreactive and enkephalin-like immunoreactive neurons in the rat area postrema. The angiotensin-II-like immunoreactive neurons were detected by silver-gold intensification of the DAB reaction results while the enkephalin-like immunoreactive neurons were detected by simple ABC-DAB reaction. The synaptic relationships were reciprocal between the two neurons. Most of the synapses found between these two neurons were the presynaptic enkephalin-like immunoreactive axon terminals that made synapses on the angiotensin-II-like immunoreactive perikarya and dendrites. Both the axo-somatic and axo-dendritic synapses were symmetrical. However, although angiotensin-II-like immunoreactive axon terminals also made synapses on enkephalin-like perikarya and dendrites, the axo-somatic synapses were symmetrical, while the axo-dendritic synapses were asymmetrical. The present results confirm the presence of angiotensin-II-like immunoreactive neurons in the area postrema and suggest that these angiotensinergic neurons in the area postrema may play a role in the regulation of blood pressure via coordinated synaptic interactions with enkephalinergic neurons.

Angiotensin II↗

PubMed2001

Yersinia enterocolitica O9 as a possible barrier against Y. pestis in natural plague foci in Ningxia, China.

A survey of Yersinia spp, as related to plague control, was made in Haiyuan of Ganning loess plateau plague focus, Yanchi of Inner Mongolia plateau plague focus, and Yinchuan city, as a control area, in Ningxia, China. In Haiyuan, where the main plague reservoir was Mongolian ground squirrel (Citellus alaschanicus) living in the prairie, Y. enterocolitica O9 was frequently isolated from pigs, dogs, rodents living in and around houses, but only rarely from hare and Mongolian ground squirrel. In Yanchi, where the main plague reservoir was Mongolian gerbil (Meriones unguiculatus) living in the prairie and Y. pestis, which was isolated from rodents up to 1991, Y. enterocolitica O9 was sometimes isolated from pigs and rodents. In all areas, some strains of Y. enterocolitica O3 and Y. pseudotuberculosis serotypes 3 and 4b were also isolated from pigs, dogs, and from rodents. We propose that an epidemiological link exists between the prevalence of Y. pestis and Y. enterocolitica O9 in domestic and rodents living in these areas in China. The residential area in Haiyuan may be protected against Y. pestis by the domestic animals and rodents which acquired cross-protection against Y. pestis by infection with Y. enterocolitica O9, but this is not the case in the Yanchi district.

Animals↗

PubMed2001

VEGF expression in skin warts. Relevance to angiogenesis and vasodilation.

Verrucae vulgaris (skin warts) are benign proliferative lesions which are generally associated with human papillomavirus type 2 (HPV-2) infection. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen able to induce angiogenesis and vasodilation. Our previous findings indicate that these two processes take place during the formation of skin warts. The purpose of this study was to determine whether VEGF expression in these lesions was associated with HPV infection, angiogenesis or vasodilation. To this end, paraffin-embedded specimens of skin warts which were either negative for HPV-1, -2, -3 and -4 (HPV-; n = 18), or positive for HPV-2 (HPV+; n = 21) were compared with histologically normal perilesional skin (n = 13). Serial sections were stained with antibodies to von Willebrand Factor (vWF) and to VEGF. Vascularity was quantified by point counting vWF-positive blood vessels. Small and large vessels were quantified separately, using a cut-off value of 50 microm diameter. VEGF expression in the epidermis was estimated by consensus of two independent observers according to three indices: (1) percentage of cells stained, (2) intensity of the staining, and (3) product of area and intensity (final score). Results were analysed by nonparametric tests. Similar levels of VEGF were found in specimens of normal skin, HPV- and HPV+ warts, irrespective of the index used. There was no significant correlation between VEGF expression and vascularity values for either small or large vessels. These results indicate that, on its own, VEGF expression is not associated with angiogenesis, vasodilation or HPV infection in skin warts. The presence of VEGF in normal skin suggests that it may play a role in tissue homeostasis.

Blood Vessels↗

PubMed2001

Abnormal DNA-binding of transcription factors in minimal change nephrotic syndrome.

The activation of transcription factors such as nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1) plays an important role in regulating the expression of target genes, including those for cytokines involved in pathogenesis of minimal change nephrotic syndrome (MCNS). The therapeutic effects of glucocorticoids depend on the glucocorticoid receptor (GR) acting on gene transcription and interacting with certain transcription factors. To explore the role of transcription factors in the pathogenesis of MCNS and the therapeutic effects of glucocorticoids, we examined the DNA-binding abilities of NF-kappaB, AP-1, and GR in peripheral blood mononuclear cells (PBMC) from 6 children with MCNS and 6 healthy controls by electrophoretic mobility shift assay (EMSA). NF-kappaB and AP-1 DNA-binding abilities were significantly increased both at baseline and after stimulation by phorbol 12-myristate 13-acetate (TPA) in PBMC from MCNS patients compared with controls, but declined to normal levels after treatment with dexamethasone (DEX). GR DNA-binding abilities were significantly reduced at baseline and after treatment with TPA, but were enhanced markedly by DEX. There were strong correlations between urinary protein and the baseline DNA binding ability of NF-kappaB or AP-1, or GR. These results suggested that the abnormal activation of NF-kappaB and AP-1 and the reduction of GR DNA-binding abilities may be involved in the pathogenesis of MCNS. Inhibition of NF-kappaB and AP-1 and enhancement of GR DNA-binding abilities by DEX may form the molecular basis of the effects of glucocorticoids in MCNS.

Child↗

PubMed2001

Regulation of intestinal apolipoprotein A-I synthesis by dietary phosphatidylcholine in newborn swine.

Phospholipid (PL) from both dietary sources and biliary secretions may be important in the regulation of intestinal apolipoprotein (apo) synthesis. We previously demonstrated the up-regulation of apo A-I secretion by phosphatidylcholine (PC) in a newborn piglet intestinal epithelial cell line. We hypothesized that dietary PC increases small intestinal apo A-I synthesis in vivo in the newborn piglet. Two-day-old female swine were fed by gavage for 48 h. Diets consisted of a formula containing 51% of calories as triacylglycerol providing 180 kcal/kg/24 h. The experimental group (+PC, n = 7) received 1 g/L added soybean PC, and the control group (-PC, n = 7) received no added PC. At the end of the study period, jejunal apo A-I, B, and A-IV synthesis was measured, and apo A-I mRNA levels were quantitated. Jejunal mucosal PL content and serum lipids and apo B and A-I levels were measured. Jejunal apo A-I synthesis was almost twice as high in the +PC group as compared to the -PC group with no difference in apo A-I mRNA levels. Jejunal content of PL was higher in the +PC group than in the -PC group. There were no differences in jejunal apo B and A-IV synthesis or serum levels of lipids and apo-lipoproteins between the two groups. Dietary PC supplementation in newborn swine up-regulated jejunal apo A-I synthesis. Apo A-IV synthesis, which is sensitive to fatty acid flux, was not significantly increased, which suggests a specific effect of PC on apo A-I synthesis. Lumenal PC may be important in the regulation of intestinal apo A-I synthesis in the neonate.

Animals↗