Del Rio G, Zizzo G, Bonati M E, Macdonald I A, Velardo A
Department of Internal Medicine, University of Modena, Italy.
Int J Obes Relat Metab Disord. 1995 Jul;19(7):475-9.
To investigate central alpha-2 adrenergic activity, one of the main inhibitory factors affecting norepinephrine secretion, in human obesity.
Cardiovascular and catecholamine responses to clonidine (300 micrograms per os) were evaluated in a group of obese subjects.
10 obese men (OM) and 14 obese women (OW).
Mean arterial pressure, pulse rate, plasma norepinephrine (NE) and epinephrine (E) before and 120', 130', 140' after clonidine (CL) administration.
The mean arterial pressure decreased after CL administration in obese patients (from 92 +/- 12 to 79 +/- 2 mmHg; P < 0.001) with no significant differences between OM and OW. The values of pulse rate were reduced in obese patients after clonidine (60 +/- 1 b/min vs 65 +/- 1 b/min before clonidine; P < 0.01) with no differences between OM and OW. Plasma E was not affected by the administration of clonidine and no sex related differences were found in the basal (OM: 0.23 +/- 0.03 vs OW: 0.15 +/- 0.03 nmol/L; P = NS) and in the post-CL E levels (OM: 0.22 +/- 0.02 vs OW: 0.14 +/- 0.03 nmol/L; P = NS). Basal plasma NE values were not different between OM (1.32 +/- 0.15 nmol/L) and OW (1.03 +/- 0.11 nmol/L; P = NS). Plasma NE decreased after CL in obese patients (from 1.20 +/- 0.10 to 0.59 +/- 0.08 nmol/L; P < 0.001) and a significant difference was found in the post-CL values between OM and OW (0.74 +/- 0.11 vs 0.40 +/- 0.06 nmol/L respectively; P < 0.01). The decrease in plasma NE was strongly correlated with the basal value of NE (r = 0.70; P < 0.001). The sex-related differences in plasma NE responses to clonidine in obese subjects did not differ with those previously observed in control subjects (P = NS).
The cardiovascular and catecholamine response to CL in obese patients were similar to that previously observed in normal subjects, indicating a normal alpha-2 adrenergic activity. The sex related difference in the NE response to CL, previously reported in normal subjects, was maintained in obese patients.
研究人类肥胖症中中枢α-2肾上腺素能活性，其为影响去甲肾上腺素分泌的主要抑制因素之一。
对一组肥胖受试者评估可乐定（口服300微克）引起的心血管和儿茶酚胺反应。
10名肥胖男性（OM）和14名肥胖女性（OW）。
服用可乐定（CL）前及服用后120分钟、130分钟、140分钟时的平均动脉压、脉搏率、血浆去甲肾上腺素（NE）和肾上腺素（E）。
肥胖患者服用CL后平均动脉压下降（从92±12 mmHg降至79±2 mmHg；P<0.001），OM和OW之间无显著差异。肥胖患者服用可乐定后脉搏率降低（服用前65±1次/分钟，服用后60±1次/分钟；P<0.01），OM和OW之间无差异。血浆E不受可乐定给药影响，基础水平（OM：0.23±0.03 vs OW：0.15±0.03 nmol/L；P=无显著性差异）及服用CL后E水平（OM：0.22±0.02 vs OW：0.14±0.03 nmol/L；P=无显著性差异）均未发现性别相关差异。OM（1.32±0.15 nmol/L）和OW（1.03±0.11 nmol/L；P=无显著性差异）的基础血浆NE值无差异。肥胖患者服用CL后血浆NE下降（从1.20±0.10 nmol/L降至0.59±0.08 nmol/L；P<0.001），OM和OW服用CL后的NE值存在显著差异（分别为0.74±0.11 vs 0.40±0.06 nmol/L；P<0.01）。血浆NE的下降与NE基础值密切相关（r=0.70；P<0.001）。肥胖受试者中血浆NE对可乐定反应的性别相关差异与之前在对照受试者中观察到的差异无不同（P=无显著性差异）。
肥胖患者对CL的心血管和儿茶酚胺反应与之前在正常受试者中观察到的相似，表明α-2肾上腺素能活性正常。正常受试者中之前报道的NE对CL反应的性别相关差异在肥胖患者中依然存在。
