A Comparison of Follicular Fluid Levels of Insulin‐like Growth Factor‐1 in Normal Dominant and Cohort Follicles, Polycystic and Multicystic Ovaries

Eden, John; Jones, Janet; Carter, G. D.; Alaghband‐Zadeh, Jamshid

doi:10.1111/j.1365-2265.1988.tb01231.x

Cited by 88 publications

(40 citation statements)

References 17 publications

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“…In the rat, a high concentration of FSH directly induces IGFBP-4 protease and suppresses IGFBP-4 m RNA expression [36]. Human preovulatory follicles contain high levels of FSH, whereas FSH concen trations in atretic follicles are much lower [37], Similar levels of IGF-I have been shown in human follicular fluid obtained from both normal and PCO S [38] women. Since we observed high IGFBP-4 proteolytic activity in devel oping healthy follicles and low activity in atretic follicles, it is more likely that FSH directly regulates IGFBP-4 pro teolysis rather than through IGF-mcdiated regulation.…”

Section: Igfbp-4 In Human Folliculogenesismentioning

confidence: 69%

Physiological Role of Insulin-Like-Growth-Factor-Binding Protein-4 in Human Folliculogenesis

et al. 1996

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Insulin-like growth factor (IGF)-I and IGF-II, and their binding proteins (IGFBPs) have been demonstrated to play important roles in follicular development as intraovarian regulators. Previous studies have demonstrated that the follicular fluid of atretic follicles contains high levels of IGFBP-2 and IGFBP-4, which are known to inhibit the action of IGFs. In this study, we identified IGFBP-4 protease activity in the follicular fluid of developing but not atretic follicles. To elucidate the regulation mechanism of IGFBP-4 proteolytic activity in the ovary, cultured luteinized granulosa cells (GCs) were incubated with various hormones, and proteolyzed IGFBP-4 in the medium was analyzed. IGFBP-4 proteolytic activity was increased when GCs were incubated with IGFs, estradiol or follicle-stimulating hormone (FSH) but not with testosterone. We also showed that IGFBP-4 inhibited IGF-I-induced estradiol release by GCs while proteolyzed IGFBP-4 did not. These results suggest that human luteinized GCs produce IGFBP-4 protease, and that FSH and IGFs may stimulate folliculogenesis by modulating IGFBP-4 degradation in the ovary.

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Section: Igfbp-4 In Human Folliculogenesismentioning

confidence: 69%

Physiological Role of Insulin-Like-Growth-Factor-Binding Protein-4 in Human Folliculogenesis

et al. 1996

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“…If granulosa cell derived IGF-I is responsible for increased IGF-I levels in PCOS patients, the positive relationship between levels of IGF-I and the LH or LH/FSH ratio is easily explained by the above hypothesis. Although concentrations of IGF-I in follicular fluids were demonstrated to increase along with follicular development and correlate with serum levels of IGF-I, follicular fluid IGF-I levels in PCOS were similar to those in the circulation [40]. Therefore, granulosa cell derived IGF-I is not the pri mary lesion in PCOS.…”

Section: Discussionmentioning

confidence: 88%

Plasma Levels of Insulin-Like Growth Factor-I and Its Binding Protein in Polycystic Ovary Syndrome

et al. 1990

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Patients with polycystic ovary syndrome (PCOS) had significantly higher levels of total insulin-like growth factor (IGF-I) than those in age- and weight-matched controls (PCOS, 230 ± 21 ng/ml; control, 180 ± 16 ng/ml; mean ± SE, p < 0.05) as well as free IGF-I (PCOS, 3.8 ± 0.2 ng/ml; control, 3.0 ± 0.2 ng/ml; p < 0.05). These elevated levels of IGF-I were correlated slightly with levels of LH and LH/FSH ratio (r = 0.171, p < 0.05 and r = 0.239, p < 0.01, respectively). Elevated fasting levels of insulin and decreased levels of IGF binding protein (32K-BP) were also observed in PCOS, and the levels of 32K-BP in PCOS were negatively correlated with insulin (r = -0.39, p < 0.01). These results suggest that elevated IGF-I levels and decreased 32K-BP levels in the circulation are one of the endocrinological features of PCOS and that insulin is responsible for the clinical manifestation of decreased 32K-BP levels in PCOS.

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“…Indeed, higher IGF-1 con-centrations have been demonstrated in the dominant compared with cohort follicles in women (Eden et al 1988). …”

mentioning

confidence: 99%

The Effect of Exogenous Growth Hormone on the Endocrine Status and the Occurrence of Estrus in Gilts

Kirkwood¹,

Thacker²,

Guedo³

et al. 1989

Can. J. Anim. Sci.

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30-32 d after the first observed estrus at which time their ovaries were recovered for the determination of ovulation rates. All controi gilts and all but one GH17 gilt exhibited normal estrous cycles. However, of the 21 gilts assigned to GHl4, only 9 (43%)had normal estrous cycles (P<0.001). In gilts exhibiting a second estrus, there was no effect of pGH treatment on the duration of the estrous cycle (20.4, 20.9 and 20.5 d) or on ovulation rate (14.6,13.9 and 13.5) for GHl4, GH17 and controls, respectively.

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A Comparison of Follicular Fluid Levels of Insulin‐like Growth Factor‐1 in Normal Dominant and Cohort Follicles, Polycystic and Multicystic Ovaries

Cited by 88 publications

References 17 publications

Physiological Role of Insulin-Like-Growth-Factor-Binding Protein-4 in Human Folliculogenesis

Physiological Role of Insulin-Like-Growth-Factor-Binding Protein-4 in Human Folliculogenesis

Plasma Levels of Insulin-Like Growth Factor-I and Its Binding Protein in Polycystic Ovary Syndrome

The Effect of Exogenous Growth Hormone on the Endocrine Status and the Occurrence of Estrus in Gilts

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