Differential regulation of aortic growth in male and female rodents is associated with AAA development.

Abstract

BACKGROUND:

The objective was to examine effects of gonadal hormone manipulation on aortic diameter and macrophage infiltration in rodents during abdominal aortic aneurysm (AAA) formation.

METHODS:

Experiment 1: 17-beta estradiol and testosterone pellets were implanted in male (ME) and female (FT) rats. No pellet was implanted in shams (MES, FTS). Experiment 2: Testes and ovaries were removed from males (MO) and females (FO), respectively. No organs were removed from shams (MOS, FOS). Experiment 3: Male and female rats were orchiectomized and oophorectomized, respectively. Four weeks post-castration, testosterone (MOT) and 17-beta estradiol (FOE) pellets were implanted. Shams underwent castration, but no pellet was implanted (MOTS, FOES). All rats underwent infrarenal aortic infusion with elastase postimplantation/postcastration. Diameters were measured on postoperative d 14. Tissue was stained for macrophages by immunohistochemistry.

RESULTS:

Diameter (P = 0.046) and macrophage counts (P = 0.014) decreased in ME compared with shams, but not in females treated with testosterone (FT). Diameter (P = 0.019) and macrophage infiltration (P = 0.024) decreased in MO compared with shams, but not in FO. Diameter increased in MOT compared with MOTS (P = 0.033), but decreased in FOE compared with FOES (P = 0.002). Macrophages decreased in FOE compared with FOES (P = 0.002).

CONCLUSION:

This study documents a decrease in AAA diameter in males treated with estrogen or undergoing orchiectomy, but no changes in females treated with testosterone or undergoing oophorectomy; and an increase in diameter in MOT and a decrease in FOE. These data suggest that gonadal hormones differentially regulate AAA growth in association with changes in macrophages.

• Authors: Brenda S Cho, Derek T Woodrum, Karen J Roelofs, James C Stanley, Peter K Henke, Gilbert R Upchurch Jr
• Journal: The Journal of surgical research (J Surg Res) Vol. 155 Issue 2 Pg. 330-8 (Aug 2009) ISSN: 1095-8673 [Electronic] United States
• PMID: 19111327 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Testosterone
• Estradiol
• Pancreatic Elastase

Topics

• Animals
• Aorta, Abdominal (drug effects, pathology)
• Aortic Aneurysm, Abdominal (chemically induced, pathology, prevention & control)
• Cell Movement (drug effects)
• Disease Models, Animal
• Estradiol (pharmacology, therapeutic use)
• Female
• Humans
• Infusions, Intra-Arterial
• Macrophages (drug effects, pathology)
• Male
• Orchiectomy
• Ovariectomy
• Pancreatic Elastase (administration & dosage, adverse effects)
• Phenotype
• Rats
• Rats, Sprague-Dawley
• Testosterone (pharmacology, therapeutic use)