Jayachandran Muthuvel, Okano Hiroya, Chatrath Ritu, Owen Whyte G, McConnell Joseph P, Miller Virginia M
Dept. of Surgery, Mayo Clinic Rochester, 200 First St. SW, Rochester, MN 55905, USA.
J Appl Physiol (1985). 2004 Oct;97(4):1445-52. doi: 10.1152/japplphysiol.01074.2003. Epub 2004 May 28.
Cardiovascular disease may begin early in adolescence. Platelets release factors contributing to vascular disease. Experiments were designed to test the hypothesis that hormonal transitions associated with sexual maturity differentially affect platelet aggregation and secretion in males and females. Platelets were collected from juvenile (2-3 mo) and sexually mature (adult; 5-6 mo) male and female pigs (n=8/group). Maturation was evidenced by increased weight of reproductive tissue and changes in circulating levels of gonadal hormones. Aggregation to ADP (10 microM) and collagen (6 microg/ml) and ATP secretion to 50 nM thrombin were determined by turbidimetric analysis and bioluminescence, respectively. Total platelet counts, platelet turnover, and mean platelet volume did not change with maturity. Platelet aggregation and ATP secretion decreased in females but increased in males with maturity, whereas total ATP content remained unchanged in platelets from females but increased in platelets from males. Platelet fibrinogen receptor, P-selectin expression, and receptors for sex steroids did not change with sexual maturation. Plasma C-reactive protein and brain-type natriuretic peptide also did not change. Results indicate that changes in platelet aggregation and secretion change with sexual maturity differently in females and males. These observations provide evidence on which clinical studies could be designed to examine platelet characteristics in human children and young adults.
心血管疾病可能在青春期早期就开始了。血小板释放导致血管疾病的因子。设计实验来检验这样一个假设：与性成熟相关的激素转变对雄性和雌性的血小板聚集和分泌有不同影响。从幼年（2 - 3个月）和性成熟（成年；5 - 6个月）的雄性和雌性猪（每组n = 8）采集血小板。生殖组织重量增加和性腺激素循环水平变化证明了性成熟。分别通过比浊法分析和生物发光法测定对ADP（10微摩尔）和胶原蛋白（6微克/毫升）的聚集以及对50纳摩尔凝血酶的ATP分泌。血小板总数、血小板周转率和平均血小板体积不会随着成熟而改变。随着成熟，雌性的血小板聚集和ATP分泌减少，而雄性增加，而雌性血小板中的总ATP含量保持不变，雄性血小板中的总ATP含量增加。血小板纤维蛋白原受体、P - 选择素表达和性类固醇受体不会随着性成熟而改变。血浆C反应蛋白和脑钠肽也不会改变。结果表明，血小板聚集和分泌的变化在雌性和雄性中随着性成熟而有所不同。这些观察结果为设计临床研究以检查人类儿童和年轻人的血小板特征提供了依据。
