• Title/Summary/Keyword: G Proteins

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$\beta$-Subunit 94~96 Residues of Tethered Recombinant Equine Chorionic Gonadotropin are Important Sites for Luteinizing Hormone and Follicle Stimulating Hormone like Activities

  • Park, Jong-Ju;JarGal, Naidansuren;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.34 no.1
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    • pp.33-40
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    • 2010
  • Equine chorionic gonadotropin (eCG) is a heavily glycosylated glycoprotein composed of non-covalently linked $\alpha$- and $\beta$-subunits. To study the function and signal transduction of tethered recombinant-eCG (rec-eCG), a single chain eCG molecule was constructed, and the rec-eCG protein was prepared. In this study, we constructed 5 mutants (${\Delta}1$, ${\Delta}2$, ${\Delta}3$, ${\Delta}4$, and ${\Delta}5$) of rec-eCG using data about known glycoprotein hormones to analyze the role of specific follicle stimulating homone (FSH)-like activity. Three amino acids of certain specific sites were replaced with alanine. The expression vectors were transfected into CHO cells and subjected to G418 selection for 2~3 weeks. The media were collected and the quantity of secreted tethered rec-eCGs was quantified by ELISA. The LH- and FSH-like activities were assayed in terms of cAMP production by rat LH/CG and rat FSH receptors. Then, the metabolic clearance rate analyzed by the injection of rec-eCG (5 IU) into the tail vein was analyzed. The mutant eCGs (${\Delta}l$, ${\Delta}4$, and ${\Delta}5$) were transcripted, but not translated into proteins. Rec-eCG A2 was secreted in much lower amounts than the wild type. Only the rec-eCG ${\Delta}3$ ($\beta$-subunit: $Gln^{94}-Ile^{95}-Lys^{96}{\rightarrow}Ala^{94}-Ala^{95}-Ala^{96}$) was efficiently secreted. Although activity is low, its LH-like activity was similar to that of tethered $eCG{\beta\alpha}$. However, the FSH-like activity of rec-$eCG{\beta\alpha\Delta}3$ was completely flat. The result of the analysis of the metabolic clearance rate shoed the persistence of the mutant in the blood until 4 hours after the injection. After then, it almost disappeared at 8 hours. Taken together, these data suggest that 94~96 amino acid sequences in eCG $\beta$-subunit appear to be of utmost importance for signal transduction of the FSH receptor.

Biological Functions of the COOH-Terminal Amino Acids of the $\alpha$-Subunit of Tethered Equine Chorionic Gonadotropin

  • Jeoung, Youn-Hee;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.34 no.1
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    • pp.47-53
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    • 2010
  • Glycoprotein hormones have a common $\alpha$-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the $\alpha$-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the $NH_2$-terminus of the $\alpha$-subunit to the COOH-terminus of the $\beta$-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form ${\Delta}96$, Lys was substituted at position 95 to form ${\Delta}95$, His was inserted at position 93 to form ${\Delta}93$ and Tyr was substituted at position 87 to form ${\Delta}87$. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and ${\Delta}96$, ${\Delta}95$, and ${\Delta}93$ mutants were efficiently secreted into the medium but the ${\Delta}87$ mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the ${\Delta}87$ mutant. However, the ${\Delta}87$ mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The ${\Delta}95$ and ${\Delta}93$ mutants were completely inactive in both the LH- and FSH-like activity assays. The ${\Delta}96$ mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the ${\Delta}96$ mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the a-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the $\alpha$-subunit is very important for the secretion and functioning of this hormone.

Gleditsia Spina Extract Protects Hepatocytes from Oxidative Stress through Nrf2 Activation (皂角刺 추출물의 Nrf2 활성화를 통한 간세포 보호 효과)

  • Kim, Jae Kwang;Park, Sang Mi;Jegal, Kyung Hwan;Kim, Young Woo;Byun, Sung Hui;Kim, Sang Chan;Cho, Il Je
    • The Korea Journal of Herbology
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    • v.30 no.4
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    • pp.57-64
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    • 2015
  • Objectives : Oxidative stress is one of the most causes of hepatocyte injury. Gleditsia spina, the thorns ofGleditsia sinensisLam., has been known for its anti-cancer and anti-inflammatory effects in Korean medicine. The present study investigated hepatoprotective effect of Gleditsia spina water extract (GSE) against oxidative stress induced by arachidonic acid (AA) + iron in HepG2 cells.Methods : To investigate cytoprotective effect of GSE, cells were pretreated with GSE and then subsequently exposed to 10 μM AA for 12 h, followed by 5 μM iron. Cell viability was monitored by MTT assay, and expression of apoptosis-related proteins was examined by immunoblot analysis. To identify responsible molecular mechanisms, reactive oxygen species (ROS) production, GSH contents, and mitochondrial membrane potential were measured. In addition, effect of GSE on nuclear factor erythroid 2-related factor 2 (Nrf2) activation was determined by immunoblot and antioxidant response element (ARE)-driven reporter gene assays.Results : GSE pretreatment prevented AA + iron-mediated cytotoxicity in concentration dependent manner. In addition, ROS production, glutathione depletion, and mitochondrial impairment by AA + iron were significantly inhibited by GSE. Furthermore, GSE promoted translocation of Nrf2 to nucleus, which acts as essential transcription factor for induction of antioxidant genes. Increased nuclear Nrf2 that caused by GSE treatment promoted transcriptional activity of ARE. Finally, GSE up-regulated sestrin-2 which was widely recognized as target gene of Nrf2.Conclusions : This study demonstrates that GSE protects hepatocytes from oxidative stress via activation of Nrf2 signaling pathway.

ADHESION OF CANDIDA ALBICANS ISOLATES TO ACRYLIC RESIN IN RELATION TO SALIVARY GLYCOPROTEINS IN DENTURE STOMATITIS PATIENTS (의치 구내염 환자에서 분리한 Candida albicans의 아크릴 수지에 대한 부착성과 타액 단백질과의 상호 관계)

  • Oh, Jung-Hwan;Choi, Boo-Byung;Choi, Dae-Gyun;Woo, Yi-Hyung;Lee, Sung-Bok;Kwon, Kung-Rock
    • The Journal of Korean Academy of Prosthodontics
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    • v.37 no.5
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    • pp.698-713
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    • 1999
  • Adherence of Candida albicans(C. albicans) to the surface of a denture is believed to be an initial and essential step in the formation of denture-induced stematitis. Previous studies have provided enormous infomation on the relationship between composition of palatine gland/parotid saliva and upper denture stomatitis. Relatively little information is available on the correlation between lower denture stomatitis and sublingual-submandibular ( SLSM ) saliva. The plaque samples were collected from the two sites($100mm^2$) on the inner surface of lower partial denture corresponding to the stematitis and healthy region of the lower partial dentures of 12 denture stomatitis patients and 6 nor-mal persons who wore lower partial dentures. The samples were plated to isolate C. albicans on a selective Saboraud's dextrose agar plate and the isolates were identified by germ tube test and gram staining. The subjects were divided into group I (stomatitis with C. albican), group II (lesion without C. albicans), group III (no lesion but C. albicans), and group IV (normal and healthy denture wearer). Individual SLSM saliva($20{\mu}g$ of protein) was analyzed by SDS-PAGE (SDS -poly-acrylamide gel electrophoresis) with Coomassie brilliant blue and PAS(Periodic Acid Schinff) stain-ing. The salivary proteins separated in the polyacryamide gels were subjected to immunoblot anaysis using anti-lactoferrin, anti-sIgA, and anti-secretory component of sIgA. In this study using custom made acrylic denture resin beads(5mm in diameter) coated with stimulated individual SLSM saliva, the binding ability of individual C. albicans strains to the beads was observed. Levels of C, albicans adhered to the acrylic resin beads were determined by measuring the optical density of the bound C. albicans to the beads at 580nm. The results showed that a higher number of C. albicans was observed in the lesion site than healthy site. The saliva of group I contained more high molecular weight glycoprotein(mucin, MGI) as compared to group II, III and IV. And lactoferrin and sIgA affected to the binding ability of C. albicans to acylic resin beads. Binding ability of individual C. albicans to the acrylic resin coated with respective individual saliva was found to be greater in group I than the other 3 groups. And when bound cells of C. albicans isolated from individual subject #2 to the saliva coated beads were used binding ability of subject #2 saliva coated beads was founed to be greater than the other sutjects. These results suggested that denture induced stomatitis is related to individual patient's salivary protein composition, especially MG-1. Future studies will be directed toward saliva exam-ination of patients who have general disease and analysis of pellicles formed on prosthesis with respect to oral disease.

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ANTIBODY PRODUCTION BY PARENTERAL ADMINISTRATION OF STREPTOCOCCUS MUTANS AND GLUCOSYLTRANSFERASE IN MICE (비경구 투여한 Streptococcus mutans 균체 및 Glucosyltransferase에 대한 마우스의 면역항체반응)

  • Yang, Kyu-Ho;Chung, Mee;Chung, Jin;Chang, Mee-Young;Oh, Jong-Suk;Nah, Hee-Sam;Kang, In-Chol;Lee, Hyun-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.1
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    • pp.61-68
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    • 2003
  • Streptococcus mutans is known to be a major causative organism of human dental caries. The development of a vaccine against dental caries involves identification of appropriate antigens of mutans streptococci against which protective immune responses can be mounted, and the selection of a method of immunization that will generate sustained levels of protective antibodies. Antigens receiving most attention include streptococcal surface proteins that are involved in attachment to tooth surfaces and glucosyltransferases (GTF) that synthesize adhesive glucans from sucrose. The induction of antibody responses to orally administered antigens is often difficult due to digestive destruction of antigens and immune tolerance. Here we report the induction of antibody responses to an anti-caries vaccine containing retinoic acid (RA). Subcutaneous immunization with formalin-fixed bacteria or GTF supplemented with RA induced higher serum IgM and IgA responses to GTF compaired to oral adminstration. Antisera induced by Ingbritt strain showed partial cross-reaction with LM-7 strain, but not with OMZ175. These results suggest that subcutaneous immunization with GTF combined with an immunomodulator, RA, may be applied to anti-caries vaccine.

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Phosphorylation of Transcriptional Factor by Mitogen-activated Protein (MAP) Kinase Purified from Nucleus (핵 내에서 분리한 Mitogen-Activated Protein (MAP) Kinase의 Transcription Factor에 대한 인산화)

  • 김윤석;김소영;김태우
    • Biomedical Science Letters
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    • v.2 no.2
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    • pp.175-185
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    • 1996
  • The mitogen-activated protein(MAP) kinase signal transduction pathway represents an important mechanism by which mitogen, such as serum and PMA, regulate cell proliferation and differentiation. Target substrates of the MAP kinase are located within several compartments containing plasma membranes and nucleus. We now report that serum addition induces proliferation of the P388 murine leukemia cell, but PMA does not, while both serum and PMA treatment cause translocation of the MAP kinase, mainly p42$^{mapk}$ isoform, from cytosol into the nucleus, which was monitored by immunoblot analysis using polyclonal anti-ERK1 antibodies. We investigated whether the MAP kinase was capable of phosphorylating c-Jun protein and GST-fusion proteins, the P562$^{kk}$N-terminal peptides (1-77 or 1-123 domain) of the T cell tyrosine kinase, using the partially purified MAP kinase by SP-sephadex C-50, phenyl superose and Mono Q column chromatography. We found that the partially purified MAP kinase was able to phosphorylate c-Jun protein and the GST-fusion protein expressed using E.coli DH5$\alpha$ which is transformed with pGEX-3Xb plasmid vector carrying of p562$^{kk}$N-terminal peptide-encoding DNA. These results imply that tyrosine kinase receptor/Ras/Raf/MAP kinase pathway is a major mechanism for mitogen-induced cell proliferation in P388 murine leukemia cell and that the various MAP kinase isoforms may have their own target substrates located in distinct subcellular compartments.

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Odorant Receptors Containing Conserved Amino Acid Sequences in Transmembrane Domain 7 Display Distinct Expression Patterns in Mammalian Tissues

  • Ryu, Sang Eun;Shim, Tammy;Yi, Ju-Yeon;Kim, So Yeun;Park, Sun Hwa;Kim, Sung Won;Ronnett, Gabriele V.;Moon, Cheil
    • Molecules and Cells
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    • v.40 no.12
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    • pp.954-965
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    • 2017
  • Mammalian genomes are well established, and highly conserved regions within odorant receptors that are unique from other G-protein coupled receptors have been identified. Numerous functional studies have focused on specific conserved amino acids motifs; however, not all conserved motifs have been sufficiently characterized. Here, we identified a highly conserved 18 amino acid sequence motif within transmembrane domain seven (CAS-TM7) which was identified by aligning odorant receptor sequences. Next, we investigated the expression pattern and distribution of this conserved amino acid motif among a broad range of odorant receptors. To examine the localization of odorant receptor proteins, we used a sequence-specific peptide antibody against CAS-TM7 which is specific to odorant receptors across species. The specificity of this peptide antibody in recognizing odorant receptors has been confirmed in a heterologous in vitro system and a rat-based in vivo system. The CAS-TM7 odorant receptors localized with distinct patterns at each region of the olfactory epithelium; septum, endoturbinate and ectoturbinate. To our great interests, we found that the CAS-TM7 odorant receptors are primarily localized to the dorsal region of the olfactory bulb, coinciding with olfactory epithelium-based patterns. Also, these odorant receptors were ectopically expressed in the various non-olfactory tissues in an evolutionary constrained manner between human and rats. This study has characterized the expression patterns of odorant receptors containing particular amino acid motif in transmembrane domain 7, and which led to an intriguing possibility that the conserved motif of odorant receptors can play critical roles in other physiological functions as well as olfaction.

Analysis of Immunomodulating Gene Expression by cDNA Microarray in $\beta$-Glucan-treated Murine Macrophage

  • Sung, Su-Kyong;Kim, Ha-Won
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.98-98
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    • 2003
  • ${\beta}$-(1,3)-D-Glucans have been known to exhibit antitumor and antimicrobial activities. The presence of dectin-1,${\alpha}$, ${\beta}$-glucan receptor of dendritic cell, on macrophage has been controvertial. RT-PCR analysis led to the detection of dectin-1${\alpha}$ and ${\beta}$ in murine macrophage Raw264.7 cell line. Among the various organs of mouse, dectin-1${\alpha}$ and ${\beta}$ were detected in the thymus, lung, spleen, stomach and intestine. To analyze gene expression modulated by ${\beta}$-glucan treated murine Raw264.7 macrophage, total mRNA was applied to cDNA microarray to interrogate the expression of 7,000 known genes. cDNA chip analysis showed that ${\beta}$-glucan of P. osteatus increased gene expressions of immunomodulating genes, membrane antigenic proteins, chemokine ligands, complements, cytokines, various kinases, lectin associated genes and oncogenes in Raw 264.7 cell line. When treated with ${\beta}$-glucan of P. osteatus and LPS, induction of gene expression of TNF-${\alpha}$ and IFN-R1 was confirmed by RT-PCR analysis. Induction of TNF-R type II expression was confirmed by FACS analysis. IL-6 expression was abolished by EDTA in ${\beta}$-glucan and LPS treated Raw264.7 cell line, indicating that ${\beta}$-glucan binds to dectin-l in a Ca$\^$++/ -dependent manner. To increase antitumor efficacy of ${\beta}$-glucan, ginsenoside Rh2 (GRh2) was co-treated with ${\beta}$-glucan in vivo and in vitro tests. IC$\sub$50/ values of GRh2 were 20 and 25 $\mu\textrm{g}$/$m\ell$ in SNU-1 and B16 melanoma F10 cell line, respectively. Co-treatment with ${\beta}$-glucan and GRh2 showed synergistic antitumor activity with cisplatin and mitomycin C both in vitro and in vivo. Single or co-treatment with ${\beta}$-glucan and GRh2 increased tumor bearing mouse life span. Co-treatment with ${\beta}$-glucan and GRh2 showed more increased life span with mitomycin C than that with cisplatin. Antitumor activities were 67% and 72 % by co-injection with ${\beta}$-glucan and GRh2 in the absence or presence of mitomycin C, respectively.

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Subcutaneous Administration of Highly Purified-FSH(HP-FSH) versus Intramuscular Administration of FSH in Superovulation for IVF-ET (체외수정시술을 위한 과배란유도시 Highly Purified Follicle Stimulating Hormone (HP-FSH) 피하주사와 Follicle Stimulating Hormone 근육주사의 비교연구)

  • Bai, S.W.;Kim, J.Y.;Won, J.G.;Jung, C.J.;Chang, K.H.;Lee, B.S.;Park, K.H.;Cho, D.J.;Song, C.H.
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.1
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    • pp.135-141
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    • 1997
  • The early studies demonstrated that the relative amount of FSH was important for stimulating normal ovarian activity and demonstrated the existence of a threshold level for FSH, above which follicular growth was activated. It was found that only a modest increase in circulating FSH level above the threshold (between 10 and 30%) was required to stimulate folliculogenesis. In addition, FSH is primary responsible for initiating estradiol production through the activation of the aromatase enzyme system in granulosa cells, follicular secretion and growth. LH on the other hand, plays a supportive role in ovarian steroidogenesis, stimulating the ovarian thecal cells to produce androgen, the precursor for estradiol synthesis. But there is now an increasing number of reports in the literature demonstrating an adverse effect of LH on fertility and miscarriage in infertile and fertile women. So HP-FSH is the drug of a highly purified FSH preparation which has a higher specific activity and far fewer impurities than FSH. This study was performed to evaluate the efficacy and safety of HP-FSH administered (SC; subcutaneous) versus FSH(IM; intramuscular) for ovulation induction. 20 candidates patients for ovulation induction were participated. All patients underwent pituitary desensitizing with a long gonadotropin-releasing hormone (GnRH) agonist protocol and ovulation induction was started with HP-FSH SC (10 patients; group I) or FSH IM (10 patients; group II). After ovulation, outcome of ovulation induction and local reaction of injection site were compared. There were no difference of outcome of ovulation in two groups except pregnancy rate/embryo transfer. Group I had a higher pregnancy rate/ embryo transfer than Group II (44.4% Vs 28.6%). Pain, redness, tenderness, bruising and itching when the injection received on the first 5 days of treated (50 SC and 50 IM injections) were assessed. There were no significant difference (P>0.05) in the incidence of tenderness, bruising and itching between the IM and SC injection. But IM injection (FSH) had a tendency of higher above incidence. The number of reports of pain, redness were significantly increased in IM injection group (P<0.05). These results indicate that SC administration of HP-FSH has been shown to be as effect for superovulation as traditional gonadotropins, with an improved safety profile due to the removal of extaneous proteins.

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EFFECTS OF CHROMIUM PICOLINATE ON GROWTH PERFORMANCE, CARCASS COMPOSITION AND SERUM TRAITS OF BROILERS FED DIETARY DIFFERENT LEVELS OF CRUDE PROTEIN

  • Kim, S.W.;Han, I.K.;Choi, Y.J.;Kim, Y.H.;Shin, I.S.;Chae, B.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.5
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    • pp.463-470
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    • 1995
  • An experiment was conducted to evaluate the effects of chromium picolinate on growth performance, nutrient utilizability, carcass composition, serum traits and in vitro protein synthesis of 3 day old Arbor Acres broiler chickens when dietary crude protein levels were varying in diets. Six replicates of eight chicks each (average initial weitht = 59.4 g) were randomly assigned to three levels (low, medium, high) of dietary crude protein at two levels of chromium (0, 200 ppb Cr/kg diet) as chromium picolinate. Six chicks/treatment were randomly chosen for analyses of carcass composition, six additional chicks/treatment were randomly chosen for analyses of serum components, and a chick/treatment was chosen for in vitro culture of liver tissue. Chromium picolinate did not affect feed intake, protein and fat utilizability, regradless of dietary crude protein level. But feed/gain ratio were more improved in groups fed the low protein diets added with chromium picolinate compared with groups fed the medium and high protein diets with chromium picolinate. Carcass fat tended to decrease whereas carcass protein tended to increase when added with chromium picolinate. Broilers fed diets with chromium picolinate exhibited lower serum triglyceride and nonesterified fatty acid concentrations than those fed without chromium picolinate (p < 0.05). Both secreted and retained proteins in cultured acinar cell were higher in groups fed diets with chromium picolinate than those fed diets without chromium picolinate (p < 0.05). It could be suggested that chromium picolinate was effective in improving weight gain and nutrient utilizability when dietary crude protein was low (p < 0.05), and also effective in manipulating carcass fat when dietary crude protein level was high (p < 0.05).