Blood Serum Insulin-like Growth Factor Research Articles

Role of insulin and insulin-like growth factor I receptor expression in the pathogenesis of genital endometriosis

BACKGROUND: Growth factors play an important role in the pathogenesis of genital endometriosis. Insulin and insulin-like growth factors are involved in mitosis and differentiation in the endometrium during the menstrual cycle and early pregnancy, and are likely to indirectly affect the invasion of the endometrium during retrograde menstruation and the development of pain syndrome in endometriosis. However, the available literature data on insulin-like growth factors and insulin in the endometrium and endometrioid heterotopies in patients with genital endometriosis are scarse and contradictory.
 AIM: The aim of this study was to investigate the expression of insulin receptors and insulin-like growth factor I receptors in the eutopic endometrium and endometrioid heterotopies of patients with genital endometriosis.
 MATERIALS AND METHODS: This cross-sectional study included immunohistochemical analysis of surgical material obtained from two groups of women in the proliferative phase of the menstrual cycle: patients with endometriosis who received surgical treatment (endometrium and endometrioid heterotopies) and patients without endometriosis who were examined due to infertility (endometrium). The study also included investigation of carbohydrate metabolism (glucose tolerance test) and determination of blood serum insulin-like growth factor I, insulin and sex hormone levels. The material was stained to detect the expression of insulin receptors and insulin-like growth factor I receptors. Then, the relative area and optical density of the receptor expression were determined and the obtained data were analyzed statistically.
 RESULTS: We analyzed the examination results of 131 women matched in age and weight and height characteristics: 101 patients with genital endometriosis and 30 patients in the control group. Carbohydrate metabolism was characterized by a 2.1-fold increase in glucose-stimulated insulin secretion in patients with genital endometriosis compared with the control subjects. The blood level of insulin-like growth factor I did not differ in the study groups. Statistically significant differences in receptor expression were obtained between the groups. In the endometrium of patients with genital endometriosis, the optical density of insulin receptors was lower (p = 0.007) and the expression of insulin-like growth factor I receptors higher (p = 0.002) compared to the endometrium of the control subjects. The median values of insulin receptor expression in endometrioid heterotopies were decreased compared to the endometrium of the control group (p 0.001). The expression of insulin-like growth factor I receptors in endometrioid heterotopies was reduced compared to the endometrium of the same patients (p 0.001).
 CONCLUSIONS: The data obtained indicate significant features in the functioning of the insulin / insulin-like growth factor I system in patients with genital endometriosis: glucose-stimulated insulin secretion and relative endometrial insulin resistance due to the decreased expression of insulin receptors and the increased expression of insulin-like growth factor I receptors in the endometrium.

Clinical evaluation of recombinant human growth hormone injection in children with growth hormone deficiency

Recombinant human growth hormone (rhGH) has been widely used in the clinical treatment of growth hormone deficiency. To simplify the injection process and increase drug compliance, application of the GH injection has become a new treatment plan in recent years. The purpose of the current study was to evaluate the efficacy and safety of rhGH injection for the treatment of growth hormone deficiency (GHD) in children in China. In a nationwide, noncomparative, prospective, randomized, open trial, 31 children with confirmed complete GHD received subcutaneous injection of rhGH at 0.25 mg/kg·wk (0.107 IU/kg·d). The injection was given daily and the total weekly amount was separated into 6–7 injections. The patients were followed up at 3-month intervals and the treatment duration was 12 months. The height (HT), annual growth velocity (GV), mean height standard deviation score (HT SDS), blood serum insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), and bone maturity before and after treatment were compared, and the safety of the treatment was analyzed. The mean HT, GV, and HT SDS were increased from 109.0±14 cm, 2.7±0.9 cm/yr, and −4.62 ±1.46 at baseline to 121.8±13.4 cm, 12.9±3.3 cm/yr, and −2.47±1.86 after 12 months of treatment, respectively (P<0.001). At the same time, blood IGF-I and IGFBP- 3 were increased significantly [41.27±64.43 μg/L vs 159.21±167.92 μg/L and 1540.00±1325.11 mg/L vs 3533.93±1413.82 mg/L, respectively (P<0.001)]. The bone age assessments performed 6 and 12 months after the treatment showed that no advanced bone maturation was noted. No serious adverse events occurred during the treatment, and the drug-related adverse events were mainly decreased thyroid function. We conclude that rhGH injection is a safe and effective drug for treatment of growth hormone deficiency in children.

Analysis of female reproductive traits in Angus beef cattle divergently selected for blood serum insulin-like growth factor I concentration

Insulin-like growth factor-I (IGF-I) is an anabolic polypeptide involved in reproductive performance in several species. The objectives of this study were to determine relationships of pregnancy rate, and age of heifers at puberty and at first calving with serum IGF-I concentration in Angus beef cattle. Data were obtained from an ongoing divergent selection experiment for IGF-I concentration involving purebred Angus cows. The IGF-I concentrations measured at Days 28, 42, and 56 of the 140-day postweaning test are abbreviated as IGF28, IGF42, and IGF56, respectively. Pregnancy rate did not differ between high and low IGF-I line females ( P = 0.95; n = 2618), but high line heifers tended to be 4.02 ± 2.18 days younger ( P = 0.07; n = 281) at first calving. Residual correlations of age of heifers at first calving (AFC) with IGF-I measurements were not significant. The linear and quadratic terms for regression of AFC on IGF-I concentrations were also non-significant. Contrast analysis showed no difference in age at puberty between the high and low IGF-I line heifers (5.3 ± 6.4 days earlier in the high line; P = 0.43; n = 51). Residual correlations of age of heifers at puberty with IGF28, IGF42, IGF56, and mean IGF-I were −0.30 ( P = 0.03), −0. 22 ( P = 0.12), −0.35 ( P = 0.01), and −0.34 ( P = 0.01), respectively. The observed relationships between female reproductive traits and IGF-I concentration in Angus beef cattle suggest complex and multiple roles for IGF-I in reproduction.

Association of single nucleotide polymorphisms in the growth hormone and growth hormone receptor genes with blood serum insulin-like growth factor I concentration and growth traits in Angus cattle.

This study was conducted to identify polymorphisms in the promoter and coding regions of the bovine growth hormone and growth hormone receptor genes and to study association of polymorphisms identified in these genes with growth traits and serum insulin-like growth factor-I (IGF-I) concentration. The denaturing gradient gel electrophoresis method and sequencing were utilized to identify three new single nucleotide polymorphisms in the promoter region of the growth hormone gene in Angus cattle. Polymerase chain reaction-based restriction fragment length polymorphism procedures were developed for rapid determination of the single nucleotide polymorphism genotypes in the growth hormone and the growth hormone receptor genes among Angus calves from lines divergently selected for high or low blood serum IGF-I concentration. The IGF-I concentration and growth traits were analyzed using animal models. The single nucleotide polymorphism in the promoter region of the growth hormone receptor gene was associated with serum IGF-I concentration on d 42 of the postweaning test and with mean IGF-I concentration. The associated effects of the markers need to be verified in other populations.

Economic evaluation of Hereford cattle breeding schemes incorporating direct and indirect measures of feed intake

A deterministic approach was used to evaluate the effect of incorporating direct and indirect measures of feed intake as additional selection criteria in breeding schemes for Hereford cattle. A 2-tier nucleus breeding scheme consisting of a nucleus and a commercial sector was assumed. Four breeding objectives specific to Australian Hereford cattle were considered. These addressed production systems that targetted 4 markets (Domestic Supermarket, 'Hereford Prime', Short-fed Export, and Long-fed Export). The breeding objectives differed especially in the feed cost involved for differing amounts of grain finishing and in the extent to which marbling is valued by the market (from none to quite a lot). The breeding schemes evaluated differed in the measures available for use as selection criteria. The schemes ranged from one that utilised growth, scanned carcass and fertility criteria currently available to Australian cattle breeders (Scheme 1) to one which also incorporated residual feed intake (RFI) and blood serum insulin-like growth factor I (IGF-1) criteria (Scheme 5). The latter scheme included selection of sires for the nucleus using a 2-stage selection process, with a proportion of bulls selected after weaning for measurement of RFI. Schemes utilising either IGF-1 or RFI or both as criteria generated additional genetic gain and profitability for each breeding objective. Profit was optimal across all the Hereford cattle breeding objectives when the top 5% of bulls was measured for RFI after being selected on an index incorporating IGF-1 and other information available on the bull and its relatives at a young age. Further increase in the proportion of bulls measured for RFI for consideration in the second selection stage resulted in a slow decline in profit per cow in the population and a flat response in genetic gain. In the absence of more breed-specific information, these results may also have application in breeds other than Herefords.

Impact of blood serum insulin-like growth factor I on platelet-activating factor in bull spermatozoa

The objective of this study was to examine differences in platelet-activating factor [1- O-alkyl-2-acetyl- sn-glycero-3-phosphorylcholine; PAF] in spermatozoa between two lines of Angus beef cattle divergently selected for blood serum insulin-like growth factor I (IGF-I) concentration. Endogenous lipids were extracted from the spermatozoa and endogenous PAF content was determined by radioimmunoassay. The amount of PAF detected in spermatozoa obtained from high IGF-I bulls ( n = 8) ranged from 0.145 to 3.571 pM/10 6 cells. The level of PAF extracted from spermatozoa obtained from low IGF-I- bulls ( n = 5) ranged from 0.001 to 1.024 pM/10 6 cells. Polynomial regression analysis revealed a significant cubic relationship (R 2 = 0.374; F = 6.292; P < 0.05) between spermatozoa PAF content and blood serum IGF-I concentration. Spermatozoa-derived PAF levels (mean ± SEM) were significantly higher (P < 0.05) in the high IGF-I group (1.90 ± 0.39 pM/10 6 cells) than in the low IGF-I group (0.59 ± 0.20 pM/10 6 cells). High IGF-I bulls have a greater than three-fold higher PAF content in their spermatozoa than low IGF-I bulls. The data demonstrate that not only is PAF present in bull spermatozoa but that levels are significantly higher in individuals with high serum IGF-I concentrations.

Reproductive performance of bulls divergently selected on the basis of blood serum insulin-like growth factor I concentration.

The objectives of this study were to examine differences in scrotal circumference, sperm motility, and percentage of normal sperm cells between two lines of Angus beef cattle divergently selected for blood serum IGF-I concentration. Data were obtained from an ongoing experiment involving 100 spring-calving (50 high and 50 low line) and 100 fall-calving (50 high and 50 low line) purebred Angus cows. Scrotal circumference, percentage of motile sperm cells, and percentage of normal sperm cells did not differ between high and low IGF-I line yearling bulls (P = .79, .50, and .56, respectively). The IGF-I concentrations measured at d 28, 42, and 56 of the postweaning test are abbreviated as IGF28, IGF42, and IGF56, respectively. Coefficients for the quadratic regression of scrotal circumference on IGF28 and IGF42 tended to be negative (P = .07 and .08, respectively), as did the coefficient for the quadratic regression of the percentage of motile sperm cells on IGF42 (P = .08). The coefficient for the linear regression of percentage of normal sperm cells on IGF28 was positive (P = .02). The coefficient for the quadratic regression of percentage of normal sperm cells on IGF56 was negative (P = .04). Coefficients for the quadratic regression of scrotal circumference and percentage of normal sperm cells on mean IGF-I concentrations were negative and important (P = .04 and .08, respectively). Thus, scrotal circumference and percentage of normal sperm cells are related to blood serum IGF-I concentration in yearling Angus bulls.

Divergent selection for blood serum insulin-like growth factor I concentration in beef cattle: I. Nongenetic effects3

Data were obtained from an ongoing experiment involving divergent selection for blood serum IGF-I concentration in purebred Angus cattle. The experiment includes approximately 100 spring-calving (50 high and 50 low line) and 100 fall-calving (50 high and 50 low line) cows. The selection criterion is the mean of IGF-I concentrations measured on each animal at d 28, 42, and 56 of the postweaning performance test. Mean IGF-I values were available for a total of 526 bull and heifer calves. Pooled across years and breeding seasons, high line progeny averaged 21 +/- 6, 17 +/- 6, and 23 +/- 5 ng/mL more IGF-I (P < .01) than low line progeny at d 28, 42, and 56 of the postweaning test. Season effects on IGF-I approached statistical significance only at d 42 and 56 of the postweaning period. Pooled across years and selection lines, spring minus fall differences were 9 +/- 10 (P = .52), -17 +/- 10 (P = .10), -22 +/- 9 (P = .07), and -9 +/- 6 (P = .45) ng/mL for IGF-I concentrations at d 28, 42, and 56 of the postweaning test and for mean IGF-I, respectively. Sex effects on serum IGF-I concentration were highly significant, with greater IGF-I expression in bulls, but were confounded with diet and location. Age of dam effects were not significant. Regressions of IGF-I concentration on on-test age of calf ranged from .46 +/- .13 to 1.08 +/- .20 ng.mL-1.d-1 and were highly significant for all measures of IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)

A note on consequences of single-trait selection for insulin-like growth factor 1 (IGF-1) in beef heifers

Eight sets of identical twin heifers and their first three calf crops were used to determine effects of single-trait selection for blood serum insulin-like growth factor 1 (IGF-1). Twin heifers were offspring of Simmental sires and Hereford × Simmental or Hereford × Angus dams. All 16 heifers were mated with the same Simmental bull in each year of the study to produce calves born in 1989, 1990 and 1991 (no. = 16, 13 and 10, respectively). Although differences were noted in performance of progeny from the four twins with the highestv.the four with the lowest IGF-1 concentrations, they zoere not large enough to recommend single-trait selection for blood serum IGF-1 in beef heifers.