Nutritional composition in different training stages in young female athletes (swimming) and association with leptin, IGF-1 and estradiol.

OBJECTIVES: To investigate the interaction of serum leptin, IGF-1, estradiol and cortisol in salvia as well as IL-6 with nutritional composition in female athletes (swimming) according to the training protocol (competition (C), sprint (S), recreation (R), endurance (E)). DESIGN/METHODS: In 23 young (10-19 years old) female athletes (Bavarian swimming competition) in different training stages nutritional protocols were evaluated using standardized questionnaires. Body composition was measured by using analysis of bioimpedance. Estradiol, IGF-1, leptin and IL-6 in serum were measured by ELISA. To obtain circadian profiles of cortisol salvia probes were sampled at 4 h intervals and cortisol in saliva was measured. RESULTS: Daily intake of kilocalories varied significantly and was highest during R with the highest percentage of nutritional fat intake (37.3%) when compared to C (28.1%, p=0.001). BMI was associated with leptin in all training stages and IL-6 in R, C and E. Leptin, IGF-1 and cortisol in salvia were dependent on training stages while serum levels of estradiol were not. Nutritional fat intake (p=0.07 in R) as well as serum levels of IGF-1 (p=0.014 in E) were significantly associated with estradiol but not with serum leptin levels or salivary cortisol. CONCLUSIONS: In female athletes nutritional composition has an impact on serum hormones (leptin, IGF-1 as well as estradiol) and may be also on cytokines (IL-6). Leptin, IGF-1 and salivary cortisol levels represent the intensity of physical training and possibly overtraining. In our female athletes no findings indicative of female athlete triad could be demonstrated.

Transcription factors Sp1 and AP-2 mediate induction of acid sphingomyelinase during monocytic differentiation.

Cells from the human monocytic leukemia cell line THP-1 differentiate towards a macrophage-like phenotype when stimulated with phorbol 12-myristate -13- acetate (PMA), 1,25-dihydroxy-vitamin D3, and various other agents. We demonstrate here that the expression of the lysosomal enzyme acid sphingomyelinase (ASM; E.C. 3.1.4.12) is induced during this process and is strongly elevated in differentiated THP-1 cells, as well as in differentiated human mononuclear phagocytes. Using Northern blotting, RNase protection assay, and nuclear run-on analyses, we show that the up-regulation of ASM expression is regulated mainly at the level of transcription and that new protein synthesis is required for enhanced ASM activity. This cell-type specific induction by PMA treatment was further investigated with respect to transcriptional control. A series of 5' deletion derivatives of the upstream regulatory region were used in transient transfection assays to identify promoter elements required for basal and inducible gene expression. A PMA responsive element was localized to a region between -319 and -219 bp upstream of the initiation codon and co-transfections with transcription factor expression plasmids for AP-2 and Sp1 resulted in augmented ASM promoter activity, which was abolished when the binding sites for these two factors were deleted. Using electrophoretic mobility shift assays and supershift assays we demonstrate that this region is specifically bound by Sp1 and AP-2. These factors are present in nuclear extracts prepared from both induced and uninduced THP-1 cells. However, the intensity of the complex formed appeared to increase when nuclear extracts from PMA-treated cells were used. From these studies, we conclude that a concerted action of the transcription factors AP-2 and Sp1 is essential for the up -regulation of ASM expression during the process of macrophage differentiation.