Faculty Collaboration Database

Testosterone increases myogenic reactivity of second-order mesenteric arteries in both defective and normal androgen receptor adult male rats. Gend Med 2011 Feb;8(1):40-52

Date

04/19/2011

Pubmed ID

21497771

DOI

10.1016/j.genm.2011.01.002

Scopus ID

2-s2.0-79954526466 (requires institutional sign-in at Scopus site)   4 Citations

Abstract

BACKGROUND: Testosterone (T) and the androgen receptor (AR) are involved in mechanisms associated with hypertension and vessel reactivity.

OBJECTIVE: To investigate T and the AR on blood vessel reactivity, testicular feminized male (TFM; AR deficient males) and normal androgen receptor (NAR) male rats were used. Therefore, if the functional AR is necessary for plasma T to regulate vessel responsiveness, TFM males will exhibit altered vessel function compared to NAR males.

METHODS: Adult (16 weeks of age) TFM or NAR males were assigned to the following treatment groups: gonadal intact controls (CONT), castrate (CAST), or castrate with T replacement (CAST+T) with (n=8-10/group).

RESULTS: Plasma T followed a consistent pattern with CAST+T elevated compared to CONT and CAST TFM and NAR males. In addition, CAST plasma T was significantly decreased compared to CONT and CAST+T in TFM and NAR males. In a similar manner for systolic blood pressure (SBP), CAST lowered SBP compared to CONT in both NAR and TFM. Following 8 weeks of treatment, second-order mesenteric artery responses to changes in intraluminal pressure (myogenic reactivity) were analyzed using a pressure arteriograph system. Both TFM (P < 0.05) and NAR (P < 0.05) CAST groups revealed a decrease in myogenic reactivity compared to CONT. Following T treatment the TFM CAST+T myogenic reactivity returned to CONT levels, whereas the NAR CAST+T myogenic reactivity increased a further 10%.

CONCLUSION: The results of this study indicate that T differentially regulates mesenteric artery reactivity in TFM and NAR males. Our data also demonstrate that both AR and/or non-AR mediated mechanisms may partially contribute to SBP regulation.

Author List

Toot JD, Reho JJ, Novak J, Dunphy G, Ely DL, Ramirez RJ

Author

John J. Reho Research Scientist II in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Male
Mesenteric Arteries
Muscle Development
Muscle, Smooth, Vascular
Rats
Receptors, Androgen
Testosterone