| Autor: |
Tan, K. C. B., Shiu, S. W. M., Pang, R. W. C., Kung, A. W. C. |
| Předmět: |
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| Zdroj: |
Clinical Endocrinology; Feb1998, Vol. 48 Issue 2, p187-194, 8p |
| Abstrakt: |
OBJECTIVES Gonadal steroids are important regulators of lipoprotein metabolism. The aims of this study were to determine the effects of a minimum effective dose of testosterone replacement on high density lipoprotein (HDL) subfractions and apolipoprotein (apo) A-I containing particles (lipoprotein (Lp)A-I) and LpA-I:A-II) in hypogonadal men with primary testicular failure and to investigate the underlying mechanisms of these changes. MEASUREMENTS Eleven Chinese hypogonadal men were started on testosterone enanthate 250 mg intramuscularly at 4-weekly intervals. HDL was subfractionated by density gradient ultracentrifugation and LpA-I was analysed by electro-immunodiffusion after 3, 6 and 12 weeks of treatment. Plasma cholesteryl ester transfer protein (CETP) activity and lipolytic enzymes activities in post-heparin plasma were measured to determine the mechanisms underlying testosterone-induced changes in HDL. RESULTS The dosage of testosterone enanthate used in the present study resulted in suboptimal trough testosterone levels. No changes were seen in plasma total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C,) apo B and apo(a) after 12 weeks. There was a drop in HDL3 -C compared to baseline (0.82 ± 0.17 mmol/l vs . 0.93 ± 0.13, P < 0.01) whereas a small but significant increase was seen in HDL2 -C (0.21 ± 0.13 mmol/l vs . 0.11 ± 0.09, P < 0.05). Plasma apo A-I decreased after treatment (1.34 ± 0.25 g/l vs . 1.50 ± 0.29, P < 0.01), due to a reduction in LpA-I:A-II particles (0.86 ± 0.18 g/l vs . 0.99 ± 0.24, P < 0.01). No changes were observed in the levels of LpA-I particles. No significant changes were seen in plasma CETP and lipoprotein lipase activities after testosterone replacement but there was a transient increase in hepatic lipase (HL) activity at weeks 3 and 6. The decrease in HDL correlated with the increase in HL activity (r = 0.62, P < 0.05). CONCLUSIONS... [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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