Abstract P086: Blood Pressure And Salt Differentially Regulate Testicular Immune Cell Populations In Hypertensive Mice Academic Article uri icon

abstract

  • We recently reported that increased proinflammatory (M1) macrophages, inflammation, and inflammation-associated lymphangiogenesis is associated with reproductive dysfunction in mice with salt-sensitive HTN (SSHTN). However, it is unknown whether these effects are primarily due to increased systemic pressure and/or salt. We hypothesized that artificial lowering of blood pressure may not reverse the inflammatory environment within the testes, that is associated with SSHTN. Male C57BL6/J mice were made hypertensive by providing L-NAME (0.5 mg/mL) in the drinking water for 2 weeks, followed by a 2-week washout period, and a subsequent 3-week 4% high salt diet (SSHTN). In another group, mice received L-NAME 2 weeks, followed by a 2-week washout period and a subsequent 3-week 4% high salt diet along with hydralazine (250mg/L) in their drinking water (SSHTN+HDZ). Control (C) mice received L-NAME for 2 weeks and then tap water and normal diet. Systolic blood pressure in SSHTN mice (1411 mm Hg) was significantly increased when compared to C mice (1023 mm Hg), but the pressure decreased to 1191 mm Hg (p<0.05) in SSHTN+HDZ mice. Flow cytometry analysis revealed a significant decrease in M2 macrophages in the testes of SSHTN and SSHTN+HDZ mice when compared to control mice (C: 15.8%1, SSHTN: 9.8%2, SSHTN+HDZ: 8.4%2; p<0.05). There was an increase in Th1 T cells in the testes of SSHTN and SSHTN+HDZ mice when compared to control mice (C:4.8%1, SSHTN:11.4%1, SSHTN+HDZ: 10.1%1; p<0.05), whereas Th17 T cells (C:13.6%2, SSHTN:19.5%1, SSHTN+HDZ: 14.8%1; p<0.05), CD4+TNFa+ (C:8.2%2, SSHTN:12.5%1, SSHTN+HDZ: 9%2; p<0.05) and gamma-delta T cells (C:73%4, SSHTN:83.5%1, SSHTN+HDZ: 80%2; p<0.05) were significantly increased in SSHTN mice but were decreased significantly in SSHTN+HDZ mice. These data demonstrate that high systemic pressure and salt together act on some immune cell populations while others are only altered by salt. Further investigations on the effect of lowering blood pressure on inflammatory markers, lymphatics, and testicular function might help in better understanding the mechanisms behind the differential regulation of immune cells.

published proceedings

  • Hypertension

author list (cited authors)

  • Navaneethabalakrishnan, S., Goodlett, B., Smith, H., & Mitchell, B. M.

citation count

  • 0

complete list of authors

  • Navaneethabalakrishnan, Shobana||Goodlett, Bethany||Smith, Hannah||Mitchell, Brett M

publication date

  • January 2022