[Perforin protein and gene expression in the different phases of endometrium]

To study the expression of perforin protein and gene in the different phases of endometrium and the role of perforin in the reproductive system.

Immunohistochemical and in situ hybridization techniques were employed to demonstrate the population, phenotype of the perforin positive cell in endometrum of different phases of menstrual cycle, first-trimester decidua and postmenopausal endometrium.

Perforin positive cells were found to be located in the endometrial stroma and expressed natural killer-like cell surface marker (CD56 antigen, also named NK-like cell or CD56+ lymphocyte). The quantitative analysis of perforin protein cells demonstrated an increase in number from proliferative endometrium to secretory endometrium through first-trimester decidua (P < 0.05). These cells were absent in the postmenopausal endometrium. Perforin mRNA positive cells formed islands in proliferative endometrium stroma, but the perforin protein expression cells were scattered. There was difference between the perforin gene expression and protein expression in proliferative endometrium. In first-trimester decidua, perforin mRNA positive cells incresed. Some perforin mRNA positive cells located around spiral arterioles were observed.

Expression of perforin in the different phases of endometrium is specific and plays an important role in the reproductive function. They probably exert some influence on embryo implantation and may be involved in endometrial stromal breakdown during menstruation.