Interleukin-1 type I receptor messenger ribonucleic acid expression in human endometrium throughout the menstrual cycle.

OBJECTIVE

To investigate the messenger ribonucleic acid (mRNA) expression of interleukin-1 (IL-1) type I receptor in the endometrial tissue of normal patients during the menstrual cycle.

DESIGN

Prospective longitudinal study.

SETTING

Department of Obstetrics and Gynecology, Stanford University Medical Center, Stanford, California.

PATIENTS

Twenty fertile women between 19 and 41 years of age underwent hysterectomy for benign reasons (n = 9) and laparoscopy for tubal ligation (n = 11). In all cases, endometriosis was not visualized.

INTERVENTIONS

Endometrial biopsy using the Novak curette was obtained at the time of surgery.

MAIN OUTCOME MEASURE

Total RNA extracted from unfractioned endometrial tissue was analyzed on Northern blots by using specific complementary deoxyribonucleic acid probes.

RESULTS

We found IL-1 type I receptor mRNA expression in endometrial tissue throughout the entire menstrual cycle. However, IL-1 type I receptor mRNA levels were significantly higher during both early and late luteal phases than follicular and midluteal phases.

CONCLUSIONS

Our results demonstrate the presence of the IL-1 system in the human endometrium and that the receptor is regulated throughout the menstrual cycle with a 4.1-fold increased expression of the IL-1 receptor gene in the early luteal phase compared with preovulatory endometrium.