• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1473-1478
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• 2008

An experiment was conducted to investigate the mechanism for the effect of tetrabasic zinc chloride (TBZC) in enhancing growth performance of weanling piglets. Gut-brain peptides play an important role in the regulation of growth and appetite in animals. This study evaluated the effects of TBZC on blood concentrations of growth hormone (GH), ghrelin, insulin-like growth factor-I (IGF-I), cholecystokinin (CCK) and neuropeptide Y (NPY). Seventy-two weanling piglets (Landrace$\times$Large White) with an initial body weight (BW) of $6.7{\pm}0.16kg$ and aged $24{\pm}1days$ were assigned to three dietary treatments: i) control diet without TBZC supplement, ii) the control diet supplemented with 2,000 mg Zn from TBZC/kg and iii) TBZC-supplemented diet pair-fed with respect to the control diet. Each treatment had six replications (pens) of four piglets. At the end of a 14-d experimental period, piglets were weighed and feed consumption was measured, and blood samples were collected for assays of GH, ghrelin, IGF-I, CCK and NPY concentrations. The inclusion of TBZC in the diet increased average daily gain (p<0.01), average daily feed intake (p<0.05), and feed conversion ratio (p<0.05). Pair-fed piglets had higher ADG, and lower FCR than (p<0.05) Control piglets. Supplementation of the diet with TBZC increased (p<0.05) serum GH and plasma ghrelin levels in weanling piglets, but did not affect (p>0.05) serum IGF-I and plasma NPY and CCK concentrations. Pair-fed piglets had lower (p<0.05) serum GH levels than TBZC-supplemented piglets, but did not (p>0.05) differ from Control piglets. These data indicated that TBZC elevated the concentration of ghrelin and GH. This observation may partly explain the beneficial effects of TBZC on growth performance of weanling piglets.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1359-1364
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• 2013

The purpose of this study was to find any association of the bovine growth hormone (bGH) gene with growth and carcass quality traits in Korean native cattle, Hanwoo. Genomic DNA was extracted from 21 Hanwoo individuals, and the 47 to 2,528 bp region of the bGH 2,856 bp (GenBank accession number M57764) including the promoter and the five exons was sequenced. A total of ten bGH SNPs were confirmed, including four (253 C>T, 303 C>T, 502 C>T, and 559 G>A) in the promoter, one (679 C>T) in exon 1, one (1,692 T>C) in intron 3, and four (2141 C>G, 2258 C>T, 2277 C>T, and 2291 A>C) in exon 5. The ten bGH SNPs were genotyped for a sample of 242 Hanwoo steers and association tests were performed to find any significant SNP that was correlated with growth and carcass quality. Of the SNPs, the 303 C>T SNP in the promoter region was significantly associated with 6-month-old weight, the 559 G>A SNP with longissimus dorsi muscle area, the 2141 C>G SNP in exon 5 with daily weight gain, and the 2258 C>T SNP with daily weight gain and carcass weight (p<0.05). The significant SNPs need to be verified in other Hanwoo populations before considering implementation of marker-assisted selection for genetic improvement of growth and carcass quality in Hanwoo.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.37-41
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• 2012

Autotransgenic manipulation with a growth hormone (GH)-construct is a potential approach to improving the growth rates of farmed fish. Here, we present the generation of GH-autotransgenic common carp Cyprinus carpio carrying a transgene comprised of the carp homologous GH gene and a ${\beta}$-actin regulator. Autotransgenic carp showed similar viability to their non-transgenic siblings. Early growth characteristics of founder autotransgenic carp up to 50 days postfertilization were highly variable among individuals; i.e., some fish exhibited significant growth depression, while others showed dramatic acceleration of growth, achieving greater than sixfold increases in body weight relative to their non-transgenic counterparts. Stimulated growth performance became more notable with age and many transgenic individuals of the largest class reached 5 kg within 8 or 9 months, which is at least 10 times heavier than the average body weight of communally grown non-transgenics. Four of six founder transgenic males were successful in passing the transgene to their $F_1$ offspring with frequencies ranging from 19 to 36%. Growth stimulations were also persistent in all $F_1$ progeny groups examined.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1193-1198
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• 2003

An increase in frequency of administration of exogenous growth hormone (GH) or GH-releasing hormone was reported to be a model to increase blood circulating insulin-like growth factor-1 (IGF-1) and to improve growth performance in animals. We have investigated the effect of twice daily administration of GH-releasing peptide-2 (GHRP-2) on growth performance, GH responsiveness and plasma insulin-like growth factor IGF-1 in swine. We administered to eight swine, 3 control and 5 treatment, a twice daily s.c. injections of GHRP-2 ($30{\mu}g/kg\;BW$) for a period of 10 days. Every day blood samples immediately taken before injections of GHRP-2 or saline, at 08:00 h and 16:00 h, were measured for IGF-1 concentrations. Blood samples for GH assay were collected every 20 min on days 1, 6 and 10, from 1 hour before and 3 h after GHRP-2 or saline injections at 08:00 h. GH peak concentrations and GH area under curve (GH AUC) on day 1, 6 and 10 in treatment group of swine were higher than those in control swine (p<0.05). Twice daily administration of GHRP-2 caused a significantly attenuation (p<0.05) of GH peak concentrations ($80.25{\pm}13.87$, $39.73{\pm}5.72$ and $27.57{\pm}6.06ng/ml$ for day 1, 6 and 10, respectively) and GH AUCs ($3,536.15{\pm}738.35$, $1,310.31{\pm}203.55$ and $934.37{\pm}208.99ng/ml$ for day 1, 6 and 10, respectively). However, there was no significant difference in GH peak concentration and GH AUC between day 6 and 10. Plasma IGF-1 concentration levels were higher in treatment than control group of swine (p<0.05) after 3 days of the treatment, and the levels reached a plateau from day 3 to 10 of experiment. Growth performance did not alter by GHRP-2 administration, even though a numerical increase of body weight gain and feed efficiency was observed. These results indicate that twice daily administration of GHRP-2 for 10 days in swine did not significantly influence on growth performance, caused an overall attenuation of GH response, and that elevation of plasma GH concentrations caused by GHRP-2 administration increased plasma IGF-1 concentrations, even though an attenuation of GH response was observed.

• Toxicological Research
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• v.22 no.4
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• pp.307-313
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• 2006

The development of in vitro assays has been recommended to screening and testing the potential endocrine disruptors (EDs). These assay systems focus only on identifying the estrogenic or antiestrogenic activity of EDs, whereas a few studies have been carried out to screen the thyroid hormone (TH) disruptors. The aim of this study was to evaluate a test system to detect TH disruptors using rat pituitary tumor $GH_3$ cells. The test system is based on the TH-dependent increase in growth rate. As expected, L-3,5,3-triiodothyronine ($(T_3)$ markedly induced a morphological change in $GH_3$ cells from flattened fibroblastic types to rounded or spindle-shaped types. $T_3$ stimulated $GH_3$ cell growth in a dose-dependent manner with the maximum growth-stimulating effect being observed at a concentration $1{\times}10^9M$. In addition, $T_3$ increased the release of growth hormone and prolactin into the medium of the $GH_3$ cells culture. Using this assay system, the TH-disrupting activities of bisphenol A (BPA) and its related compounds were examined. BPA, dimethy/bisphenol A (DMBPA), and TCI-EP significantly enhanced the growth of $GH_3$ cells in the range of $1{\times}10^{-5}M\;to\;1{\times}10^{-6}M$ concentrations. In conclusion, this in vitro assay system might be useful for identifying potential TH disruptors. However, this method will require further evaluation and standardization before it can be used as a broad-based screening tool.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1668-1676
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• 2010

The somatotropic axis plays a key role in proliferation and differentiation of avian organs during both pre- and posthatching periods. This review discusses the complexity of regulation of the endocrine system for chicken development and growth by growth hormone (GH), insulin-like growth factor (IGF), and IGF binding protein (IGFBP). In addition, the thyrotropic axis, including thyrotropin-releasing hormone (TRH) and thyroid hormones ($T_4$ and $T_3$), is also involved in the GH-secreting pattern. In mammals, IGFI and -II are always sequestered in a 150 kDa non-covalent ternary complex. This complex consists of one molecule each of IGF-I or IGF-II, IGFBP-3 or IGFBP-5 and an acid labile subunit (ALS). Chick ALS is identified in different strains for the first time, and further investigation of the expression of ALS on developmental stage and ALS effect on IGF bioavailability may be addressed in the future.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.19-23
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• 1998

Effects of pituitary and thyroid hormones on estradiol-induced vitellogenin (VTG) induction were electrophoretically examined in primary hepatocyte cultures of rainbow trout. Hepatocytes were precultured for 2 days and then estradiol-17 $\beta$ $(E_2,\;2 \times 10^{-6}M)$>, triiodothyronine $(T_3,\;10^{-8}-10^{-6}M)$, bovine growth hormone (bGH, 10-100 ng/ml), ovine prolactin (oPRL, 100-500 ng/ml), and pituitary extract (PE) of rainbow trout (0.75PE/dish) were added to the incubation medium. The hepatocytes were cultured for 7 more days. The addition of oPRL to the incubation medium was not effective in increasing VTG production at any concentrations. The addition of PE to the incubation medium with $E_2$ was not effective in increasing VTG production. The addition of bGH to the incubation medium with $E_2$ was not effective in increasing the rate of VTG production at concentrations of 10-50 ng/ml. However, a higher concentration of bGH, 100 ng/ml, increased VTG production. The various concentrations of $T_3$ were ineffective in stimulating VTG production. These results suggest that GH could be one of stimulus factors for VTG production in rainbow trout.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.161-164
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• 2003

The polymorphism of the growth hormone gene in 12 pig breeds (total n=475) was detected by PCR-Apa I-RFLP, and allele A (449 bp, 101 bp and 55 bp) or allele B (316 bp, 133 bp, 101 bp and 55 bp) were observed. In these pig breeds, we found that European pig breeds had high frequencies of allele B, while Chinese native pig breeds had high frequencies of allele A. In addition, the role of porcine GH was investigated in 117 Nanchang White pigs and 361 Large Yorkshire pigs. Eight traits about growth and carcass were recorded for analyzing associations between GH gene polymorphism and performance quantitative traits. In the Nanchang White pigs, no significant difference was observed between different genotypes and different growth and carcass traits. In Large Yorkshire pigs, those with BB genotype had more lean percentage than pigs with AA genotype (p<0.05). Based on these results, we conclude that the GH locus should be further investigated in commercial breeds to determine its suitability for use in marker-assisted selection programmes.

• BMB Reports
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• v.40 no.6
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• pp.1016-1020
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• 2007

In this study, dioscin was isolated from Dioscoreae Rhizoma (DR), which is the rhizome of Dioscorea batatas DECNE. that inhabits broad areas of Korea and Japan. To determine whether dioscin induced growth hormone (GH) release, we evaluated its induction effects on GH release both in vitro and in vivo. The 70% methanol extract of DR, and its n-hexane and n-BuOH fractions, induced rat GH (rGH) release in rat pituitary cells 10-fold, 8-fold, and 5-fold higher than the control ($0.36{\pm}0.02 nM$), respectively (p < 0.05 each). The dioscin-induced rGH release of the cells was concentration-dependent and its $ED_{50}$ was $1.14{\times}10^{-5} M$. Within 90 minutes after intravenous administration of $10{\mu}g$/kg (p < 0.05 at $t_{max}$), dioscin caused the greatest increase in rGH concentration ($C_{max}$) in the rat plasma ($34.16{\pm}14.10 ng/ml$) (n = 4), which was twice as high as the control group ($12.88{\pm}3.29 ng/ml$) (n = 27).

• Journal of the Korean Chemical Society
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• v.52 no.6
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• pp.608-613
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• 2008