Testosterone caused a specific, time- and concentration-dependent 50% reduction of catecholamine-stimulated lipolysis in the subcutaneous depot. This could be an important pathogenic factor underlying regional differences in lipolysis and development of insulin resistance and hyperandrogenic polycystic ovary syndrome. The inhibitory effect was due to the inability of beta-adrenoceptors and cyclic AMP to stimulate the protein kinase A, hormone-sensitive lipase complex.
In vivo measures of systemic lipolysis (palmitate rate of appearance) during a MMTT or IVGTT. Sixty elderly women with low DHEA concentrations and 92 elderly men with low DHEA and bioavailable T concentrations participated in the study. The data presented in this study are available on request from the corresponding author. Not only does it allow us to understand metabolic phenotypes characterized by hormone excess or deficiency, but also lead to the development of new targeted therapies that may modulate hormone. In addition, hormone level varies over time, such as the GH, which increases significantly during adolescence, and can be compared in this sense to estrogen and progesterone in women of reproductive age. Instead, downregulation of FoxO6 suppresses expression of MTP, leading to amelioration of hypertriglyceridemia.
GH served to downregulate genes involved in lipid oxidation (e.g., PPAR-α, acyl CoA oxidase (ACO-1) carnithine palmitoyl transporter-1 (CPT-1)) and increased the expression of acetyl-CoA carboxylase (ACCβ) that promotes lipid synthesis in the liver 174,175,176. Some mechanisms may be involved; the expression of hepatic HSL in bGH transgenic mice was significantly decreased, indicating that GH inhibited lipolysis of intrahepatic TG (IHTG) . Unlike fat cells, GH was considered to induce TG uptake and increase TG storage in liver 173,174. During adipocyte differentiation, GH can turn small adipocytes into larger and mature adipocytes, which are believed to have stronger lipolysis ability .
Aromatase-deficient men who cannot produce estradiol from testosterone will develop steatohepatitis . Consistent with this, DHT inhibits basal AMPK activation in a dose-dependent manner in human adipose cell lines by downregulating liver kinase B (LKB) expression . Prenatal hyperandrogenism induces a decreased expression of Pgc1a and PPARα and overexpression of PPARy, Srebp, Chrebp, thus being more susceptible to hepatic steatosis and damage 116,117.
Unfortunately, we did not have enough protein for additional studies of other adrenoceptors, G-proteins or phosphodiesterases. The amount of cells available for such detailed studies was far too small. As testosterone caused a similar degree of inhibition, regardless of whether lipolysis was stimulated with adrenaline, adrenaline plus yohimbine, isoprenaline or dcAMP, the major inhibitory effect is probably downstream of cyclic AMP formation. The site-specific effect of testosterone is probably not related to adipocyte differentiation, since the hormone had no effect on pre-adipocyte maturation as measured by GPDH activity, a finding which is consistent with previous results .

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