Effects of Dietary Composition on Somatomedin Activity in Growing Rats

Reeves, R.D.; Dickinson, Linda C.; Lee, Jason; Kilgore, B S; Branham, Bill; Elders, M. Joycelyn

doi:10.1093/jn/109.4.613

Cited by 36 publications

(16 citation statements)

References 15 publications

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“…Feed efficiency seems to improve as serum IGF-I concentration increases in rats (Reeves et al, 1979;Ballard et al, 1993) and cattle (Lund-Larsen et al, 1977;Bishop et al, 1989). In our study, common directional changes were observed over time for serum IGF-I concentration, ADG, and feed efficiency.…”

Section: Discussionsupporting

confidence: 61%

“…Evidence based on pen (i.e., sire group and sex) feed consumption also indicated that a negative correlation existed ( −.24, P < .05) between on-test serum IGF-I concentration and postweaning feed conversion in cattle (Bishop et al, 1989). Blood serum IGF-I concentration was directly related to feed efficiency in rats (Reeves et al, 1979). Murphy and Loerch, 1994) a Contained > 93% NaCl, .35% Zn, .28% Mn, .175% Fe, .035% Cu, .007% I, and .007% Co. b Courtesy of Elanco Products Co., Greenfield, IN.…”

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

Relationship between blood serum insulin-like growth factor I concentration and postweaning feed efficiency of crossbred cattle at three levels of dietary intake.

Stick

Davis

Loerch

et al. 1998

Journal of Animal Science

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Blood serum concentration of IGF-I was analyzed to determine its relationship with individual postweaning feed efficiency (gain/feed) of 36 crossbred steer calves fed at three levels of feed intake (n = 12 at each level). Diets consisted of a corn silage-based growing diet for 84 d followed by a 91% concentrate finishing diet for 56 d. Dietary intake levels were at 80, 90, or 100% of ad libitum. Diets were formulated to ensure equal daily intake of protein, vitamins, and minerals across intake treatment levels. Intake was measured daily; ADG, DMI, and feed efficiency were calculated at 28-d intervals, through d 140. Individual weights and serum samples were collected at the beginning of the study and at 28-d intervals thereafter. The IGF-I concentrations were determined with a RIA. Data were analyzed as a multivariate split-plot in time. Imposed dietary intake restrictions did not affect serum IGF-I concentration (P = .90) or individual feed efficiency (P = .36), even though the least squares means for IGF-I concentration tended to decrease and the feed efficiency means tended to increase under the restricted intake levels. Serum IGF-I concentration, ADG, and feed efficiency were affected (P < .001) by collection date. Residual correlations between IGF-I concentrations at adjacent 28-d sampling times averaged .72. Diet intake level x sampling time interactions existed for ADG (P = .02) and feed efficiency (P < .001). Positive residual correlations of .28 (P < .001) and .16 (P = .07) existed between IGF-I and ADG and between IGF-I and feed efficiency, respectively. Regression analysis indicated that a 1 ng/mL increase in serum IGF-I concentration was associated with a .00135 kg/d increase in ADG (P < .001) and a .0001 kg gain/kg feed increase in feed efficiency (P = .04). These results support the hypothesis that serum IGF-I plays a role in growth and in efficiency of feed utilization in beef cattle.

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Section: Discussionsupporting

confidence: 61%

Section: Introductionmentioning

confidence: 96%

Relationship between blood serum insulin-like growth factor I concentration and postweaning feed efficiency of crossbred cattle at three levels of dietary intake.

Stick

Davis

Loerch

et al. 1998

Journal of Animal Science

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“…Our results show that although undernutrition also depressed IGF-1 serum levels, this effect was less pronounced than after triamcinolone treatment. Indeed, IGF-1 plasma concentration is known to be regulated by nutritional status as previously reported in malnourished humans (19) and in patients (20,21) as well as in rats with dietary protein restriction (22,23), or in young growing rats under acute nutritional deprivation (24). Thus, in animals, a diet deficient in en- ergy and/or protein resulted in decreased plasma IGF-1 levels (19, 25) by a mechanism which has not been elucidated yet.…”

Section: Discussionmentioning

confidence: 83%

Acute Treatment with Corticosteroids Decreases IGF-1 and IGF-2 Expression in the Rat Diaphragm and Gastrocnemius

Gayan‐Ramirez

Vanderhoydonc

Verhoeven

et al. 1999

Am J Respir Crit Care Med

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Massive doses of methylprednisolone (M) or triamcinolone (T) induced diaphragmatic type IIx/b atrophy, resulting in a leftward shift of the force-frequency curve in rats (). To examine the role of insulin-like growth factors (IGFs) in these changes, IGF mRNA content was measured in costal diaphragm, gastrocnemius, and liver removed from 32 rats treated daily during 5 d either with saline (control, C and pair-fed, PF), M, or T (80 mg/kg). Blood samples were taken to measure IGF-1 serum levels. RNA levels were measured by Northern and dot-blots after hybridization with rat IGF-1 or IGF-2 cDNA probes labeled with alpha-32P. Compared with C (845 +/- 128 ng/ml), IGF-1 serum levels were significantly decreased in M (699 +/- 90 ng/ml, p < 0.001 versus C) and PF animals (505 +/- 33 ng/ml, p < 0.001 versus others) and even more so, in T-treated animals (273 +/- 134 ng/ml, p < 0.001 versus others). Along the same lines, IGF-1 expression in the liver was depressed after corticosteroid treatment and in PF, whereas IGF-2 mRNA content remained unchanged. Compared with C, the relative expression of IGF-1 mRNA in the diaphragm was depressed by 44% and 69% in the M and T groups, respectively (p < 0.0001 versus C), while it was unchanged in PF animals. In the gastrocnemius, IGF-1 expression was reduced after M and T (-51% and -59%, respectively, p < 0.0001 versus C) as well as in PF animals (-40%, p < 0.001 versus C). For IGF-2, a similar pattern of expression was found in the diaphragm and the gastrocnemius. Indeed, IGF-2 mRNA tended to decrease in corticosteroid-treated rats (NS) whereas it was unchanged in PF rats. We conclude that decreased IGF expression after corticosteroid treatment was similar in diaphragm and gastrocnemius and may be responsible for the diaphragmatic changes observed after steroid treatment.

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“…The plasma IGF-I concentrations in growing heifers (Houseknecht et al, 1988;Granger et al, 1989). In rats, protein restriction was related to decreased IGF-I activity in plasma (Reeves et al, 1979;Prewitt et al, 1982). Administration of GH normally stimulates plasma IGF-I concentrations (Lema1 et al, 1989;Guyton, 1991;Coleman et al, 1994), and reduction of GH in the blood results in simultaneous reduction in plasma IGF-I concentrations (Armstrong et al, 1990;Kirby et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Dietary protein and(or) energy restriction in mares: plasma growth hormone, IGF-I, prolactin, cortisol, and thyroid hormone responses to feeding, glucose, and epinephrine1

Sticker

Thompson

Fernandez

et al. 1995

Journal of Animal Science

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Sixteen light horse mares were fed diets of bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Plasma IGF-I, prolactin, cortisol, triiodothyronine, and thyroxine were monitored for 33 d. On the 27th d, frequent blood samples were drawn throughout the day for the measurement of growth hormone (GH), and on the 29th d, an epinephrine challenge and an i.v. glucose tolerance test (IVGTT) were performed in the morning and afternoon, respectively. Restriction of protein and(or) energy reduced (P < .001) plasma IGF-I concentrations within 24 h, and the effect persisted through the 24th d. Energy restriction decreased (P = .01) plasma cortisol concentrations, whereas thyroid hormones were not influenced (P > .1) by restriction of protein and(or) energy. Plasma prolactin concentrations were low throughout the experiment and after the IVGTT, but they increased (P = .003) after feeding. Protein restriction increased (P = .09) the occurrence of GH episodes during the 14-h feeding period on d 27; the greatest effect occurred in the mares restricted in both nutrients. In contrast, energy restriction reduced (P = .05) the GH response to epinephrine injection. We conclude that 1) protein deficiency in mares increases GH secretion, whereas energy restriction alone does not, 2) a deficiency in energy and(or) protein reduces IGF-I secretion, and 3) prolactin concentrations increase after feeding, even at a time of year when secretion rates are naturally low.

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Effects of Dietary Composition on Somatomedin Activity in Growing Rats

Cited by 36 publications

References 15 publications

Relationship between blood serum insulin-like growth factor I concentration and postweaning feed efficiency of crossbred cattle at three levels of dietary intake.

Relationship between blood serum insulin-like growth factor I concentration and postweaning feed efficiency of crossbred cattle at three levels of dietary intake.

Acute Treatment with Corticosteroids Decreases IGF-1 and IGF-2 Expression in the Rat Diaphragm and Gastrocnemius

Dietary protein and(or) energy restriction in mares: plasma growth hormone, IGF-I, prolactin, cortisol, and thyroid hormone responses to feeding, glucose, and epinephrine1

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