Direct infusion of a variant of insulin-like growth factor-I into the skin of sheep and effects on local blood flow, amino acid utilization and cell replication

Harris, Patricia M.; McBride, B. W.; Gurnsey, M. P.; Sinclair, B. R.; Lee, J.

doi:10.1677/joe.0.1390463

Cited by 21 publications

(14 citation statements)

References 12 publications

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“…The most direct measurement of a local skin response to the infusion of LR3IGF-I is blood flow, and, as in our previous study [15], blood flow to the LR3IGF-I-infused skin increased within 4 0 .…”

Section: Skin Effectssupporting

confidence: 74%

“…Blood handling and analysis Blood oxygen content and PAH concentration were measured as described previously [15]. Plasma (1 ml) for cysteine analysis was mixed with 0.1 ml of 80 mM dithiothreitol and 50 ,ul of 4 mM norleucine for use as an internal standard.…”

Section: Analysesmentioning

confidence: 99%

“…Calculations and statistics Blood flow, uptake of oxygen, glucose and amino acids, lactate output and the utilization of phenylalanine for protein synthesis were all calculated as described previously [15].…”

Section: Nj Usa)mentioning

confidence: 99%

“…blood flow, net uptake of cysteine and phenylalanine and utilization of cysteine by the skin for protein synthesis [15]. These infusions were only undertaken for 4 h and consequently it was not possible to assess whether the effects would be sustained over a longer term, and if so, whether there would be significant changes in the protein pools of the skin and therefore changes in wool production.…”

mentioning

confidence: 99%

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Metabolic response of sheep skin to a chronic infusion of a variant of insulin-like growth factor I

Edwards

Khalaf

Sinclaire³

et al. 1995

Biochemical Journal

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The effects of a chronic (21-day) skin infusion of a variant of insulin-like growth factor I (IGF-I) (long-Arg3-IGF-I; LR3IGF-I) on short-term (48 h) responses of skin metabolism and 21-day plasma hormone concentration, wool-follicle characteristics and wool production were investigated in well-fed castrated Romney sheep. A bilateral arteriovenous preparation was used to infuse LR3IGF-I continuously into the skin on one abdominal flank and saline into the other abdominal flank of six sheep; a further six sheep had one flank infused with saline (controls). LR3IGF-I caused an initial (4-24 h) reduction in the plasma concentrations of amino acids, especially tyrosine, valine and lysine, and, after 24 h, significant (P < 0.05) reductions in blood oxygen and plasma glucose concentrations. After 4 h of LR3IGF-I infusion, there was a significant increase in blood flow (P < 0.05) and oxygen uptake (P < 0.05), and net uptake of amino acids [which was significant (P < 0.05) for valine and phenylalanine] by the LR3IGF-I-infused skin was increased. Total uptake of phenylalanine for skin protein synthesis, measured using [3H]phenylalanine uptake, was also significantly increased after 4 and 24 h of infusion. After 48 h of infusion all LR3IGF-I-dependent measurements of metabolic parameters had fallen to preinfusion values. By day 7 of the 21-day infusion there was a significant (P < 0.05) decrease in circulating endogenous IGF-I in plasma of treated sheep compared with that of control sheep, followed by a significant (P < 0.05) increase between day 7 and 21. Plasma insulin levels followed a similar pattern. There was no change at any stage of infusion in IGF-binding proteins in the plasma of the two LR3IGF-I-infused sheep tested, and it is concluded that LR3IGF-I caused a down-regulation of the type-I IGF-I receptors followed by a rise in endogenous IGF-I concentration consequent on lack of feedback regulation. After 21 days of infusion there was no effect of LR3IGF-I on wool-follicle-bulb-cell mitotic rate, bulb diameter or wool production.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Skin Effectssupporting

confidence: 74%

Section: Analysesmentioning

confidence: 99%

Section: Nj Usa)mentioning

confidence: 99%

mentioning

confidence: 99%

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Metabolic response of sheep skin to a chronic infusion of a variant of insulin-like growth factor I

Edwards

Khalaf

Sinclaire³

et al. 1995

Biochemical Journal

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“…In the present study, GHR gene expression was upregulated in the higher-hairdensity group, which suggests that GHR controls hair follicle development in Rex rabbit foetuses. Furthermore, GHR can induce the expression of insulin-like growth factor I (Kajimura et al, 2002) and its receptors, which all play an important role in follicle development in sheep (Harris et al, 1993). However, we did not find any significant change in the gene expression of insulin-like growth factors I or its receptors between Rex rabbit foetuses with high and low wool density, and we suggest that these conflicting results may be caused by species-specific factors.…”

Section: Discussioncontrasting

confidence: 62%

Differential gene expression profiles in foetal skin of Rex rabbits with different wool density

Liu

Zhu

et al. 2016

World Rabbit Sci.

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This study investigated the mechanisms controlling hair follicle development in the Rex rabbit. The Agilent rabbit gene expression microarray was used to determine differentially expressed genes in Rex rabbit foetuses with different wool densities. The expression patterns of selected differentially-expressed genes were further investigated by quantitative real-time PCR. Compared to low wool density rabbits, 1342 differentially expressed probes were identified in high wool density rabbits, including 950 upregulated probes and 392 downregulated probes. Gene ontology analysis revealed that the most upregulated differentially expressed probes belonged to receptors and the most downregulated differentially expressed probes belonged to DNA binding molecules. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed probes were mainly involved in the sonic hedgehog (Shh) and Eph signalling pathways. The results also suggest that transforming growth factor-beta 1, growth hormone receptor, and the keratin-associated protein 6.1 genes, as well as the Shh and Eph signalling pathways, may be involved in the regulation of hair follicle developmental in Rex rabbits.

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Production of transgenic cashmere goat embryos expressing red fluorescent protein and containing IGF1 hair-follicle-cell specific expression cassette by somatic cell nuclear transfer

Guo

Yang

et al. 2009

SCI CHINA SER C

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In the present study, cashmere goat fetal fibroblasts were transfected with pCDsR-KI, a hair-follicle-cell specific expression vector for insulin-like growth factor 1 (IGF1) that contains two markers for selection (red fluorescent protein gene and neomycin resistant gene). The transgenic fibroblasts cell lines were obtained after G418 selection. Prior to the somatic cell nuclear transfer (SCNT), the maturation rate of caprine cumulus oocytes complexes (COCs) was optimized to an in vitro maturation time of 18 h. Parthenogenetic ooctyes were used as a model to investigate the effect of two activation methods, one with calcium ionophore IA23187 plus 6-DMAP and the other with ethanol plus 6-DMAP. The cleavage rates after 48 h were respectively 88.7% and 86.4%, with no significant difference (P>0.05). There was no significant difference between the cleavage rate and the blastocyst rate in two different media (SO-Faa and CR1aa; 86.3% vs 83.9%, P>0.05 and 23.1% vs 17.2%, P>0.05). The fusion rate of a 190 V/mm group (62.4%) was significantly higher than 130 V/mm (32.8%) and 200 V/mm (42.9%), groups (P>0.05). After transgenic somatic cell nuclear transfer (TSCNT) manipulation, 203 reconstructed embryos were obtained in which the cleavage rate after in vitro development (IVD) for 48 h was 79.3% (161/203). The blastocyst rate after IVD for 7 to 9 d was 15.3% (31/203). There were 17 embryos out of 31 strongly expressing red fluorescence. Two of the red fluorescent blastocysts were randomly selected to identify transgene by polymerase chain reaction. Both were positive. These results showed that: (i) RFP and Neo ( r ) genes were correctly expressed indicating that transgenic somatic cell lines and positive transgenic embryos were obtained; (ii) one more selection at the blastocyst stage was necessary although the donor cells were transgenic positive, because only partially transgenic embryos expressing red fluorescence were obtained; and (iii) through TSCNT manipulation and optimization, transgenic cashmere goat embryos expressing red fluorescence and containing an IGF1 expression cassette were obtained, which was sufficient for production of transgenic cashmere goats.

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Direct infusion of a variant of insulin-like growth factor-I into the skin of sheep and effects on local blood flow, amino acid utilization and cell replication

Cited by 21 publications

References 12 publications

Metabolic response of sheep skin to a chronic infusion of a variant of insulin-like growth factor I

Metabolic response of sheep skin to a chronic infusion of a variant of insulin-like growth factor I

Differential gene expression profiles in foetal skin of Rex rabbits with different wool density

Production of transgenic cashmere goat embryos expressing red fluorescent protein and containing IGF1 hair-follicle-cell specific expression cassette by somatic cell nuclear transfer

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