FIGURE 3 Changes in cardiac output, peripheral resistance, and arterial pressures in normal pregnancies. (Drawn from the data of Robson SC, Hunter S, Boys RJ, Dunlop W. Am J Physiol 1989; 256:H1060-H1065.)

receptors and, in response to estradiol, rapidly increase their production of vasodilating agents such as nitric oxide and PGI2 (see Chapter 40). Other studies suggest a similar role for progesterone, alone or in the presence of high levels of estrogens. Most recently, studies in rodents have focused on the vasodepressor effects of another ovarian hormone, relaxin (see Chapter 47). Relaxin is a small peptide that is secreted by the corpus luteum throughout pregnancy. Its concentrations in blood increase in the early days of pregnancy in response to human chorionic gonadotropin (hCG) secreted by the implanting embryo (see Chapter 47). Administration of relaxin to rodents reproduces many of the changes in renal and mesenteric blood flow seen in early pregnancy. In these animals, relaxin stimulates endothelial cell production of nitric oxide, especially in the renal and mesenteric vascular beds, but comparable data are not yet available for humans.

Psychology Of Weight Loss And Management

Psychology Of Weight Loss And Management

Get All The Support And Guidance You Need To Be A Success At The Psychology Of Weight Loss And Management. This Book Is One Of The Most Valuable Resources In The World When It Comes To Exploring How Your Brain Plays A Role In Weight Loss And Management.

Get My Free Ebook

Post a comment