EFFECTS OF PROGESTOGENS ON LIPEMIA AND LIPOLYSIS IN RAT: EFFECTS OF PROGESTERONE, MEGESTROL ACETATE, NORETHINDRONE ACETATE, AND NOMEGESTROL ACETATE

Effects of 4 progestogens at equal dosages (5 mg/kg/day) on lipid metabolism and plasma glucose levels of adult female rats were compared. The 4 progestogens studied were progesterone (P) by SC injection, and megestrol acetate (MEG), norethindrone acetate (NOR), and nomegestrol acetate (NOM) PO. MEG, a 17 alpha-hydroxyprogesterone derivative, induced significant increases in glucose, total and high-density lipid (HDL) cholesterol, triglyceride, and phospholipid plasma levels. Treatment with NOR, a 19-nortestosterone derivative, resulted in a reduced gain in body wt and in a marked decrease in all plasma lipid parameters. The 19-norprogesterone derivative NOM, like P, did not alter lipid or glucose metabolism, despite a significant increase in body wt gain. In particular, no reduction in the HDL cholesterol level occurred. Plasma and tissue lipolytic activities remained unchanged. The results of this study confirm interest in the therapeutic class of 19-norprogesterone-derived progestogens, exemplified by NOM, with respect to their lack of metabolic side effects.     

A way of preventing the free fatty acid concentration in the serum of rabbits from rising

A scheme of administration of nicotinic acid by mouth is suggested in order to prevent any increase in the free fatty acid concentration in the serum after intravenous injection of heparin or triiodothyronine, prolonged starvation, and thyroid feeding.Laboratory of Pathological Physiology, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 8, pp. 122–125, August, 1974.     

Study of a new oral beta-adrenergic drug,clenbuterol, in patients with chronic bronchitis

Summary In a double-blind, placebo-controlled, incomplete cross-over study the bronchodilator, cardiovascular, respiratory and metabolic effects of 3 different oral doses of clenbuterol were studied in 12 patients suffering from partly reversible airways obstruction due to chronic bronchitis. The ventilatory response to oral clenbuterol or placebo was assessed by measurement of specific airway resistance (sRaw) to detect changes in central airways, and of flow at 85% of vital capacity ( _{85% VC}) to detect change in peripheral airways. Clenbuterol 20, 30 and 40 µg produced a significant decrease in sRaw between 15 and 480 min after administration. Its effect on the large airways was not related to the dose. Clenbuterol 30 and 40 µg caused a significant increase in _{85% VC} between 60 and 480 min after administration. After 20 µg a significant improvement in _{85% VC} was found between 120 and 240 min. The over-all effect of 30 µg on the small airways was significantly more pronounced than that of 20 µg and was more sustained than that of 40 µg 120 min after administration. No significant changes in heart rate, ECG or blood pressure were noted. Decreases in PaO₂ and O₂-saturation after clenbuterol were not related to dose. Slight falls in PaO₂ and O₂-saturation were also observed after placebo. These observations are briefly discussed. There was negligible lipid mobilization after either the placebo or bronchodilator. A slight but insignificant rise in blood glucose was observed after both 30 and 40 µg of clenbuterol.     

Astragaloside IV attenuates lipolysis and improves insulin resistance induced by TNFalpha in 3T3-L1 adipocytes

Increased circulating free fatty acid (FFA) concentrations have been demonstrated to potentially link obesity, insulin resistance and cardiovascular diseases. Astragaloside IV (AS-IV) is a saponin which is widely used in traditional Chinese medicine to treat type 2 diabetes and cardiovascular diseases. The purpose of the present study was to examine the effects of AS-IV on the lipolysis and insulin resistance induced by tumor necrosis factor-alpha (TNFalpha) in cultured 3T3-L1 adipocytes. TNFalpha promotes lipolysis in mammal adipocytes via the mitogen activated protein kinase (MAPK) family resulting in reduced expression/function of perilipin. Application of AS-IV inhibited TNFalpha-induced accelerated lipolysis in a dose-dependent manner, which was compatible with suppressed phosphorylation of ERK1/2 and reversed the downregulation of perilipin. Moreover, TNFalpha induced downregulation of key enzymes in lipogenesis, including LPL, FAS and GPAT, were also attenuated by AS-IV. Further studies showed that AS-IV improved TNFalpha-induced insulin resistance in 3T3-L1 adipocytes. This study provides the first direct evidence of the antilipolytic action of AS-IV in adipocytes, which may allow this agent to decrease the circulating FFA levels, thus increase insulin sensitivity and treat cardiovascular diseases.     

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目的检测肿瘤恶病质脂肪组织脂解通路受体的表达改变。方法对2008年5月至2009年11月复旦大学附属中山医院用Real-time PCR测定34例(分为肿瘤恶病质组12例、肿瘤对照组13例、良性疾病对照组9例)皮下脂肪标本脂解通路受体的资料进行分析。检测肾上腺素受体β1、2、3、α2C亚型(ADRB1,ADRB2,ADRB3,ADRA2C)、心房钠尿肽受体A(NPRA)、胰岛素受体(IR))及激素敏感脂肪酶(HSL)的mRNA水平;用Western blot检测β1-AR和HSL蛋白水平。结果肿瘤恶病质组中,ADRB1和HSL的mRNA水平升高约0.5倍;ADRB1蛋白水平高于肿瘤对照组1.5倍、良性疾病对照组3.0倍;HSL蛋白升高2.0～2.5倍,与ADRB1呈正相关。结论肿瘤恶病质病人脂肪组织ADRB1表达增加,与HSL表达量正相关,可能参与脂肪消耗。     

Common variants in the β2-(Gln27Glu) and β3-(Trp64Arg) -adrenoceptor genes are associated with elevated serum NEFA concentrations and Type II diabetes

Abstract Aims/hypothesis. Higher NEFA concentrations predict Type II (non-insulin-dependent) diabetes mellitus but it is not known whether higher NEFA concentrations are genetically determined or reflect coexisting obesity. To address this question we studied whether common variants in two genes encoding for key regulators of lipolysis, the β ₂- and β ₃- adrenoceptors (B2AR and B3AR) are associated with NEFA concentrations and Type II diabetes. Methods. A total of 1054 Swedish subjects with varying degrees of glucose tolerance were genotyped for the Gln27Glu variant in the B2AR and for the Trp64Arg variant in the B3AR genes using PCR-RFLP. Results. The B2AR Gln27 allele was more frequent in 219 Type II diabetic patients than in 237 non-diabetic subjects (59.8 % vs 52.3 %; OR = 1.72, p = 0.02) while there was no significant difference in the frequency of the B3AR Arg64 allele. Subjects homozygous for the protective alleles (Glu27 and Trp64) had, however, a lower prevalence of diabetes than subjects with other genotype combinations (OR = 0.58, p = 0.03). Among sibling pairs discordant for the B2AR Gln27Glu polymorphism, siblings with an excess of the Gln27 allele had higher fasting insulin (n = 217; p = 0.02) and NEFA concentrations (107 sex-matched pairs; p = 0.01) than siblings with an excess of the Glu27 allele. Among sibling pairs discordant for the B3AR Trp64Arg variant, siblings with the Arg64 allele had higher 2 h glucose (n = 48; p = 0.01) and NEFA concentrations (16 pairs matched for sex; p < 0.04) than siblings with the Trp64Trp64 genotype. Conclusions/interpretation. Common variants in the β ₂- and β ₃- adrenoceptor genes are associated with increased fasting insulin and NEFA concentrations and could increase susceptibility to Type II diabetes. [Diabetologia (2001) 44: 629–636] Received: 30 November 2000 and in revised from: 15 January 2001     

The pathogenesis of tumour hypoglycaemia: Blocks of hepatic glucose release and of adipose tissue lipolysis

Summary Earlier findings on the pathogenesis of tumour hypoglycaemia [15] were confirmed and extended in a second patient with this disease. — A block of hepatic glucose release was found to be the main cause of hypoglycaemia in both patients suffering from large tumours of non-endocrine origin. The free fatty acid level failed to increase upon hypoglycaemia. Low free fatty acid levels correlated with an increased rate of glucose assimilation and glucose oxidation. — Immunoreactive, suppressible and nonsuppressible ILA measuredin vitro andin vivo were normal. — However, the serum of patient Z.B. inhibited lipolysis of adipose tissuein vitro to a greater extent than serum of normal subjects. This difference was no longer present after dialysis of the sera and the antilipolytic activity was now found in the diffusate. — The block of hepatic glucose release may be overcome by a pharmacological dose of intravenous glucagon. The block of hepatic glucose release is of paramount importance for the development of hypoglycaemia since the pharmacological blocking of lipolysis alone does not lead to hypoglycaemia, although it may increase glucose assimilation and glucose oxidation. — An attempt is being made to characterize further the antilipolytic substance which is present in increased amounts in the serum of patients with tumour hypoglycaemia.This work was supported by grants from the Schweizerische Nationalfonds (3336) and from the U.S. Public Health Service (AM 5387).