DHT Induces Arterial Stiffening in Female Wild Type Mice

Abstract

Testosterone is the predominant sex hormone in men and is increased in women with polycystic ovarian syndrome (PCOS). PCOS patients also experience an increased risk for cardiovascular diseases including hypertension and arterial stiffness. Our previous work showed significant downregulation of the G protein‐coupled estrogen receptor (GPER) as well as the nuclear estrogen receptor ERα in cultured vascular smooth muscle cells in response to the testosterone metabolite dihydrotestosterone (DHT), which cannot be aromatized to estrogen. Therefore, we hypothesized that DHT may induce arterial stiffness in female mice via downregulation of vascular estrogen receptors. Two groups of female wildtype mice were treated with DHT via silastic capsule for 4 weeks; one group received a dose designed to mimic DHT levels in men while the other group received twice this dose. While post‐treatment systolic blood pressure was not different between the control, single dose, and double dose groups (111 ± 10, 106 ± 3, 110 ± 7, n=8 per group; P=0.22), intracarotid vascular stiffness measured via pulse wave velocity showed a more than two‐fold increase in single dose (4.3 ± 0.8 m/s) and double dose (4.8 ± 1.0 m/s) DHT treated mice when compared with non‐treated controls (1.9 ± 0.3 m/s; P<0.0001). These findings suggest that high testosterone levels in females may promote arterial stiffening and cardiovascular damage independent of changes in blood pressure. Future studies will include histological analysis of aortic sections using Masson’s trichrome to assess changes in the extracellular matrix as well as droplet digital polymerase chain reaction to assess changes in estrogen receptor expression. In conclusion, these findings of arterial stiffening in response to increased DHT levels in females are important for not only PCOS patients but also women using testosterone for fitness, gender transitioning, or reduced libido.