• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.93-98
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• 2006

Purpose : Ghrelin stimulates the secretion of growth hormone and other pituitary hormones, and has orexigenic effects. It may have a physiologic role in fetal and neonatal growth. Leptin secreted by the adipocytes reflects fat mass in infants as well as adults. The aim of this study was to evaluate the relation of cord blood ghrelin and leptin levels to body weight(BW), body mass index(BMI), insulin-like growth factor-I(IGF-I) and insulin-like growth factor binding protein-3(IGFBP-3) levels in appropriate for gestational age(AGA) newborns. Methods : Sixty healthy AGA newborns(31 males and 29 females, gestational age[GA] 34-42 weeks) were included in this study, whose BW and BMI were measured at delivery. Umbilical cord venous blood samples were withdrawn, and ghrelin and leptin were measured by radioimmunoassay. Cord blood IGF-I and IGFBP-3 were determined by immunoradiometric assay. Results : The mean levels of ghrelin were inversely correlated with BW(r=-0.29, P<0.05) and GA (r=-0.28, P<0.05), but were not affected by gender. The mean levels of leptin levels showed positive correlation with BW(r=0.44, P<0.01), GA(r=0.36, P<0.01), and BMI(r=0.28, P<0.05). The leptin levels of females were higher than those of males. There was no gender difference in leptin levels in neonates under GA 37 weeks. However, the leptin levels of females were higher than those of males (P<0.01) in newborns with GA 37 weeks or over. There was no correlation between ghrelin and leptin levels. Ghrelin and leptin levels showed no relations to cord blood IGF-I and IGFBP-3 levels. Conclusion : These data suggest that cord blood ghrelin may have an inverse correlation with BW in AGA newborns, and leptin levels are positively correlated with BW and fat mass. Further study of ghrelin concentrations in cord blood is necessary to elucidate the physiological and pathological roles of ghrelin during the fetal and neonatal periods.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.163-168
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• 2005

The aim of this study was to investigate the changes in insulin-like growth factor-I (IGF-I) and growth hormone (GH) in serum, the quantitation of spermato-genesis and the comparable relationships among these measurements during pubertal period in New Zealand White male rabbits. To investigate the age-related testicular changes in DNA contents of spermatogenic cells, the fine-needle testicular biopsies from males aged 10 to 28 wks were evaluated by flow cytometry(FCM). Body weight increased significantly between the ages of 12 and 20 wks (P<0.05) and reached 3.4 kg at 28 wks of age. The highest serum IGF-I level (451.3ng/mL) was observed at 20wks of age (P<0.05) and thereafter remained stable at low levels. Serum GH level at 18 wks of age was 183.3 pg/mL which was significantly higher compared to the other ages (P<0.05), and the rising time in serum GH tend to be somewhat earlier than that of IGF-I. The relative percentage of It-cells in testicular cell compartments was $48.2\%$ at the age of 18 wks which significantly increased than those of 16-wk-old (P<0.05) and thereafter increased with the advance of age to $68\%$. The percentage of 2C-cells in testis was $26.8\%$ at 18 wks of age which was significantly lower than $54.3\%$ at 16 wks old (P<0.05). The percentage of 4C-cells was constantly maintained $2\~6\%$ except the $9.9\%$ at 18 wks of age. In conclusion, the results suggest that the puberty onset occurred at about the 18 wks of age and that the IGF-I and GH in serum during the pubertal period showed the age/growth-specific changes and these changes might be related to the spermatogenesis. The DNA FCM combined with fine-needle testicular biopsy could offer a very sensitive method to monitor the quantitative spermatogenic events related to the puberty onset.