Insulin-like growth factors I and II of nonmammalian sera

Daughaday, William H.; Kapadia, Milan; Yanow, Caryl E.; Fabrick, Kurt; Mariz, Ida K.

doi:10.1016/0016-6480(85)90384-3

Cited by 91 publications

(40 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values for binding capacity measured in the sera of these species were also higher in rats than in toads. Thus, with the concerns already mentioned regarding absolute serum levels of IGF in the toad, these levels together with the differences recorded in the number of IGF-1 binding sites, their affinity constants and their percentage of occupancy might indicate an uneven relationship between the fraction of free and bound IGF-1 in the serum of toads and rats as previously suggested by Daughaday et al (1985). According to these authors this fact might explain the relatively greater biological activity of nonmammalian serum in bioassays than in receptor and immunoassays (Shapiro and Pimstone, 1977;Wilson and Hintz, 1982).…”

Section: Discussionsupporting

confidence: 51%

“…Wider variations were reported by other authors who have measured IGF-I in pooled serum of various anuran species (Daughaday et a/., 1985;Pancak-Roesler and Lee, 1990); furthermore it has been reported that serum lGF-1 levels in toad undergo circannual variations (Pancak-Roesler and Lee, 1990). Plasma protein also has circannual variations but with an otherwise uneven distribution of peak and trough values (Robertson, 1986).…”

Section: Discussionmentioning

confidence: 88%

“…Although this parallelismwhich we have confirmed-and the above mentioned hormone-molecular homology grant validity to the comparison of relative IGF-1 serum levels, there is no certainty regarding the real absolute values since the standard employed in the immunoassays was hIGF-1. To avoid this problem, other authors have expressed the hormone values as nanograms of equivalents of h!GF-1 (Daughaday et al, 1985;Pancak-Roesler and Lee, 1990). Despite this fact, it seems to be that lGF-1 levels measured in toads are 50 to 200 times lower than those re- ported in human (Ranke et al, 1988) and rat (Yang et al, 1989) serum.…”

Section: Discussionmentioning

confidence: 99%

“…The presence of IGFBP in toads was initially reported by Daughaday et al (1985) using 125 !-IGF-II as a tracer and gel filtration for its determination. According to these authors, the bound tracer to the serum protein fractions was not displaced by added unlabeled IGF-ll and consequently was considered nonspecific.…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Comparative Study of IGFBP Properties in Toad and Rat Sera

Cortizo

Braziunas

Jásper

et al. 1993

General and Comparative Endocrinology

View full text Add to dashboard Cite

The levels of IGF-1 have been simultaneously measured by radioimmunoassay in samples of the toad Bttfo arenanun and of normal male Wistar rats. In addition, the different fractions of IGF-1 binding proteins (IGFBP) and their binding properties have been identified by lignnd blot and Scatchard analysis in the serum of both species. In the toad, we have measured levels of IGF-1 (2.78 ± 0.48 ng/ml) similar lo those previously reported in amphibians but far below those found in rats. IGFBP levels \Vere estimated at 129 ::!:: 23 and 4249 ± 321 pg/ml in toad and rat serum samples. Two main IGFBP fractions of 30-34 kDa, acco1npanied by a n1inor component of 24 kDa and seldom by another of 40 kDa, were identified in toad serum. In rat serum-as already reported-three bands of 40, 30, and 24 kDa were identified, the first being the main component and the last the minor one. The Scatchard analysis of a competitive binding assay showed two types of binding sites in toad serum: one of high affinity-low capacity (Ka 1 "" I .6 x 10io M-1 ; R 1 = I .2 x 10-11 M) and another with low affinity-high capacity (Ka 2 = 1.9 X 10 8 M-1 ; R 2 = 1.9 x 10-10 M). The percentage fraction of these binding sites occupied by lGF-l was 13.5%. The figures for K 1 and K 2 were lower and those for R 1 and R 2 were higher in rat than in load serum. The percentage fraction of occupied rat lOF binding sites was 3.6%. The lGF carrier levels (IGFBP,.) estin1ated in our laboratory in samples of rat and toad serum gave figures that were almost 33 times lower in the latter than in the former. Hence, the fraction of free and bound IUF-1 in toad and rat blood might be different. Our results provide new evidence of the presence and the properties of IGFBP in an1phibians, confirming the wide distribution of this carrier among different species and its possible role as modulator of IGF-1 biological effects. C

show abstract

Section: Discussionsupporting

confidence: 51%

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Comparative Study of IGFBP Properties in Toad and Rat Sera

Cortizo

Braziunas

Jásper

et al. 1993

General and Comparative Endocrinology

View full text Add to dashboard Cite

show abstract

“…Serumfree DMEM was conditioned by incubation for 24 h with the muscle cells. Samples of conditioned medium were subjected to acid-ethanol extraction to remove IGF-binding proteins from the secreted IGF-I as described previously (18) according to the method of Daughaday et al (21). Briefly, aliquots of conditioned medium were added to an acidethanol mixture (87.5% ethanol:1.5% 2 N HCl (v/v)) at a ratio of 1:4.…”

mentioning

confidence: 99%

Insulin-like Growth Factor-binding Protein-5 (IGFBP-5) Stimulates Growth and IGF-I Secretion in Human Intestinal Smooth Muscle by Ras-dependent Activation of p38 MAP Kinase and Erk1/2 Pathways

Kuemmerle¹,

Zhou²

2002

Journal of Biological Chemistry

View full text Add to dashboard Cite

Effects of insulin-like growth factor-I, corticosterone, and 3,3?,5-tri-iodo-L-thyronine on glycosaminoglycan synthesis in vertebral cartilage of the clearnose skate,Raja eglanteria

Gelsleichter

Musick

1999

J. Exp. Zool.

View full text Add to dashboard Cite

Effects of insulin‐like growth factor‐I (IGF‐I), corticosterone, and triiodothyronine (T3) on in vitro growth of vertebral cartilage of the clearnose skate, Raja eglanteria, were investigated. Uptake of [35S]sulfate in cultured vertebrae was used to characterize glycosaminoglycan (GAG) synthesis and cartilage growth. IGF‐I significantly enhanced cartilage growth when concentrations of 1.28 and 12.8 nM were present in the culture system. Corticosterone significantly inhibited vertebral GAG synthesis at concentrations of 1, 10, and 100 nM. This effect was markedly pronounced in cartilage exposed to 1 and 10 nM corticosterone, in which GAG synthesis was virtually ceased. In contrast, T3 (0.75, 7.5, and 75.0 nM) had no significant effect on sulfate uptake. These data suggest that IGF‐I and corticosteroids may play important roles in regulating skeletal growth of elasmobranchs, as they appear to do in other vertebrates. While T3 does not appear to exert an immediate, direct effect on vertebral growth, it may still influence elasmobranch chondrogenesis over longer culture periods or indirectly through other regulatory pathways. Thus, further information is necessary to characterize the role of thyroid hormones in the skeletal growth of these fishes. The present study is the first in vitro investigation on the hormonal regulation of elasmobranch cartilage growth. As such, the methods described herein provide a useful technique for examining these physiological processes. J. Exp. Zool. 284:549–556, 1999. © 1999 Wiley‐Liss, Inc.

show abstract

Insulin-like growth factors I and II of nonmammalian sera

Cited by 91 publications

References 16 publications

Comparative Study of IGFBP Properties in Toad and Rat Sera

Comparative Study of IGFBP Properties in Toad and Rat Sera

Insulin-like Growth Factor-binding Protein-5 (IGFBP-5) Stimulates Growth and IGF-I Secretion in Human Intestinal Smooth Muscle by Ras-dependent Activation of p38 MAP Kinase and Erk1/2 Pathways

Effects of insulin-like growth factor-I, corticosterone, and 3,3?,5-tri-iodo-L-thyronine on glycosaminoglycan synthesis in vertebral cartilage of the clearnose skate,Raja eglanteria

Contact Info

Product

Resources

About