Vascular smooth muscle alpha-actin distribution around endometrial arterioles during the menstrual cycle: increased expression during the perimenopause and lack of correlation with menorrhagia.
Menorrhagia affects approximately 9% of all women, increasing to 20% during the perimenopause. The majority of menstrual loss occurs through the spiral arterioles - specialized endometrial vessels that are intimately involved in controlling menstruation. Our aim was to compare the distribution of vascular smooth muscle alpha-actin using immunohistochemical techniques in the endometrium of women before and during the perimenopause and with or without menorrhagia. We hypothesized that differences in vessel numbers and types exhibiting alpha-actin staining would exist between these groups, reflecting structural/functional differences. The results showed that perimenopausal menorrhagic women had significantly more smooth muscle alpha-actin expression than non-perimenopausal controls in four out of five menstrual cycle stages (P < 0.05), while perimenopausal non-menorrhagic women demonstrated a significant increase at the mid-proliferative stage only (P < 0.007). No significant differences occurred between women with or without menorrhagia before or during the perimenopause. Perimenopausal women had significantly more straight arterioles (P < 0.02) than women prior to perimenopause at the late secretory stage, while non-perimenopausal women demonstrated significantly higher numbers of spiral arterioles (P < 0.002) in the early secretory stage, although this difference had disappeared by the late secretory stage. In conclusion, we found no major differences in endometrial vascular smooth muscle alpha-actin staining between women with and without menorrhagia, but significant increases in alpha-actin staining in women showing perimenopausal symptoms.
Abberton
K M
KM
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria 3168, Australia.
Taylor
N H
NH
Healy
D L
DL
Rogers
P A
PA
D000199:Actins / Q000032:analysis*; D000328:Adult; D001160:Arterioles / Q000737:chemistry; D004717:Endometrium / Q000098:blood supply*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008593:Menopause / Q000502:physiology*; D008595:Menorrhagia / Q000378:metabolism*; D008598:Menstruation / Q000502:physiology*; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000737:chemistry*; D014018:Tissue Distribution
D000199:Actins