Linear bone growth of oMT1a-oGH transgenic male mice

Oberbauer, Anita M.; Currier, T. A.; Nancarrow, C. D.; Ward, KA; Murray, James D.

doi:10.1152/ajpendo.1992.262.6.e936

Cited by 11 publications

(15 citation statements)

References 5 publications

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“…In the present study, expression of the oGH transgene by zinc induction (Shanahan et al, 1989;Oberbauer et al, 1992) altered IGF-I and BP-3 expression. It is well documented that GH stimulates IGF-I and BP-3 expression in hypophysectomized and GH-deficient/depressed animal models (Copeland et al, 1980;Clemmons et al, 1989).…”

Section: Discussionsupporting

confidence: 45%

“…In conclusion, zinc supplementation stimulates expression of the oMtla-oGH transgene, thereby, causing high circulating oGH levels (Shanahan et aL, 1989;Oberbauer et al, 1992). The circulating GH stimulates the liver and other tissues to synthesize additional IGF-I mRNA and secrete IGF-I.…”

Section: Discussionmentioning

confidence: 93%

“…Circulating GH concentrations are elevated in response to zinc supplementation in oMtla-oGH transgenic mice, resulting in increased growth (Shanahan et al, 1989;Oberbauer et al, 1992). Pomp et al (1992) observed that zinc-induced oMtla-oGH transgenic mice had increased efficiency of hind carcass production to a common weight as compared to mice without the transgene.…”

Section: Discussionmentioning

confidence: 99%

“…The transgene was activated and inactivated by the addition and removal of 25 mM zinc sulfate to the drinking water, respectively. This zinc concentration was previously determined to stimulate transgene expression in these mice (Shanahan et al, 1989;Oberbauer et al, 1992;Pomp et al, 1992). At weaning (21 d), mice were allocated to treatment groups and fed a standard laboratory diet (Purina Mills, St. Louis, MO, USA) throughout the study.…”

Section: Micementioning

confidence: 99%

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Regulation of insulin-like growth factor-l and binding protein-3 expression in oMtla-oGH transgenic mice

Chow

Murray

Pomp

et al. 1994

Transgenic Research

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Growth hormone (GH)-transgenic mice provide a model for studying hormonal regulation of gene products responsible for efficient lean growth. Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (BP-3) are two products involved in mediating the growth promoting actions of GH. Mice carrying the ovine metallothionein la-ovine growth hormone (oMtla-oGH) transgene were used to study GH regulation of IGF-I and BP-3 expression because these mice do not exhibit elevated basal oGH levels without transgene stimulation by exogenous zinc. C57B1/6XCBA mice with (transgenic = TG) and without control = C) the oMtla-oGH transgene were activated (+ Zn) or inactivated (-Zn) by the addition or removal of 25 mM zinc sulfate in the drinking water. Plasma IGF-I and BP-3 levels were determined by radioimmunoassay and western ligand blotting, respectively. Hepatic IGF-I and BP-3 mRNA levels were determined by slot-blot analysis. TG+Zn mice had higher plasma IGF-I (p < 0.05) and hepatic IGF-I mRNA (p < 0.05) levels as compared to TG-Zn, C+Zn and C-Zn mice. Plasma IGF-I and hepatic IGF-I mRNA levels in TG-Zn mice were not different from C+Zn and C-Zn mice. Removal of Zn decreased hepatic IGF-I mRNA levels to C levels in TG mice. Plasma BP-3 and hepatic BP-3 mRNA levels in TG+Zn mice were increased (p < 0.05) as compared to TG-Zn, C-Zn and C+Zn. Plasma BP-3 and hepatic BP-3 mRNA levels did not differ between TG-Zn, C-Zn and C+Zn mice. Expression of the transgene also increased the level of plasma BP-3 during pregnancy as compared to that observed for pregnant C mice. We conclude that oGH regulates IGF-I and BP-3 expression in the oMtla-oGH transgenic mouse model system.

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Section: Discussionsupporting

confidence: 45%

Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Micementioning

confidence: 99%

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Regulation of insulin-like growth factor-l and binding protein-3 expression in oMtla-oGH transgenic mice

Chow

Murray

Pomp

et al. 1994

Transgenic Research

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“…We have developed a line of mice transgenic for an ovine metallothioneinla -ovine growth hormone fusion gene (oMtla-oGH) (Shanahan et al, 1989) and have been characterizing the effects of oGH expression on growth and body composition traits (Oberbauer et al, 1992;Pomp et aL, 1992;Searle et al, 1992). As GH has been shown to downregulate the fatty acid synthetase gene (Mildner and Clarke, 1991), we undertook to investigate the effects of expression of the oMtla-oGH transgene on fatty acid metabolism in the oMtla-oGH transgenic mouse.…”

Section: Introductionmentioning

confidence: 99%

Expression of an ovine growth hormone transgene in mice increases archidonic acid in cellular membranes

Murray

Oberbauer

Sharp

et al. 1994

Transgenic Research

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The degree of unsaturation of membrane lipids has been implicated in a number of physiological disorders, yet its regulation remains poorly understood, especially the regulation of the synthesis and distribution of arachidonic acid levels, the most abundant long chain polyunsaturated fatty acid in membranes. Transgenic mice expressing the ovine metallothionein 1a-ovine growth hormone (oMt1a-oGH) fusion gene exhibited significantly elevated levels of a number of long chain polyunsaturated fatty acids in serum, including arachidonic acid. In oMt1a-oGH transgenic mice the products of all three desaturation pathways are affected by the expression of the ovine growth hormone transgene. The essential precursors of membrane long chain polyunsaturated fatty acids, 18:2n-6 and 18:3n-3, were reduced in transgenics relative to controls, and their desaturation and elongation products, arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3), were elevated. As rare intermediate long chain polyunsaturated fatty acids such as eicosatrienoic acid (20:3n-9) were also significantly elevated, we conclude that these observations reflect increased activity of the delta-5 and delta-6 desaturase enzymes. In contrast, the products of the stearoyl CoA or delta-9 desaturase, were significantly reduced in oMt1a-oGH expressing transgenics relative to their levels in control mice.

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Allometry and adaptation of body proportions and stature in African pygmies

Shea¹,

Bailey²

1996

Am. J. Phys. Anthropol.

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We have analyzed the growth allometry of external body proportions in Efe pygmies from Zaire and combined these data with values from the literature for comparable dimensions in adult pygmies and nonpygmies. We sequentially tested the hypotheses that adult proportion differences between 1) male vs. female Efe, and 2) pygmies vs. nonpygmies result from ontogenetic scaling, or the differential extension of common patterns of growth allometry. Results indicate an almost complete concordance of allometric trajectories for male and female Efe. These preliminary analyses also strongly suggest that adult nonpygmy Africans generally differ from pygmies in their terminal size and correlated allometric consequences, rather than in more fundamental alterations of underlying patterns of growth. Biacromial diameter emerges as the measurement most likely to depart from this general pattern. These results provide further evidence that shifts in systemic growth hormones yielding differences in terminal overall body size may be accompanied by global and coordinated allometric transformations. Certain proportion differences previously interpreted by some as specific evidence of primitive retention in pygmies in fact reflect simple growth allometric correlates of the derive rapid size decrease in these groups. Selected divergent body proportions characterizing adult pygmies, previously interpreted by some as independent evidence of climatic adaptation, also reflect such allometric correlates of ontogenetic scaling. We critically assess arguments that the small overall body size of pygmies was specifically selected for reasons of thermoregulatory efficiency, and consider an alternative or complementary scenario, based on selection for small size in order to reduce caloric requirements.

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Linear bone growth of oMT1a-oGH transgenic male mice

Cited by 11 publications

References 5 publications

Regulation of insulin-like growth factor-l and binding protein-3 expression in oMtla-oGH transgenic mice

Regulation of insulin-like growth factor-l and binding protein-3 expression in oMtla-oGH transgenic mice

Expression of an ovine growth hormone transgene in mice increases archidonic acid in cellular membranes

Allometry and adaptation of body proportions and stature in African pygmies

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