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Effects of neutrophil chemotactic factors on cervical ripening
E E Maradny1, N Kanayama, A Halim
1Department of Obstetrics and Gynecology, Hamamatsu University, School of Medicine, Japan.
Abstract:
Our aim was to study the effects of infection mediated by bacterial endotoxins (lipopolysaccharides LPS) and bacterial substrate (N-formyl-methionyl-leucyl-phenylalanine FMLP) on pathological cervical ripening, and compare their effects with the normal physiological mediator interleukin-8 (IL-8). Twenty non-pregnant rabbits were treated vaginally either by placebo, LPS, FMLP or IL-8 for 3 successive days. Water concentration was measured. Neutrophils were counted in 5 random fields of each specimen. Collagen and glycosaminoglycan concentrations were assessed histologically by using picrosirius red and alcian blue staining and optical density was calculated. LPS FMLP as well as IL-8 can induce cervical ripening. Water concentration was found to be significantly increased in these groups (p < 0.0001). Also, significant numbers of neutrophils were found to accumulate in the connective tissue of these cervices (p < 0.0001). Collagen concentration was significantly decreased in the cervices treated by LPS, FMLP and IL-8 (p < 0.0001). Glycosaminoglycan concentration was significantly increased in cervices treated by LPS, FMLI as well as IL-8 (p < 0.0001, 0.006 and 0.001 respectively). LPS, FMLP and IL-8 stimulate cervical ripening in non-pregnant rabbits. This ripening was mediated through the accumulated neutrophils in the connective tissue. IL-8 has a physiological type effect to induce ripening of the cervix.
Insights
Bacterial endotoxins (lipopolysaccharides) and N-formyl-methionyl-leucyl-phenylalanine can induce cervical ripening, similar to interleukin-8. This process involves increased water content and neutrophil accumulation, with decreased collagen and increased glycosaminoglycan.
Area of Science:
- Reproductive biology
- Immunology
- Pathology
Background:
- Cervical ripening is a complex physiological process.
- Bacterial infections can lead to pathological cervical changes.
- Interleukin-8 (IL-8) is a known physiological mediator of cervical ripening.
Purpose of the Study:
- To investigate the effects of bacterial endotoxins (lipopolysaccharides, LPS) and bacterial substrate (N-formyl-methionyl-leucyl-phenylalanine, FMLP) on cervical ripening.
- To compare these effects with the physiological mediator, IL-8.
- To elucidate the mechanisms involved in LPS-, FMLP-, and IL-8-induced cervical ripening.
Main Methods:
- Twenty non-pregnant rabbits were treated vaginally with placebo, LPS, FMLP, or IL-8 for three consecutive days.
- Measurements included water concentration, neutrophil counts in cervical tissue, and histological assessment of collagen and glycosaminoglycan concentrations.
- Picrosirius red and alcian blue staining were used to quantify collagen and glycosaminoglycan levels.
Main Results:
- LPS, FMLP, and IL-8 significantly increased cervical water concentration (p < 0.0001).
- Significant neutrophil accumulation was observed in the connective tissue of cervices treated with LPS, FMLP, and IL-8 (p < 0.0001).
- Collagen concentration decreased significantly (p < 0.0001), while glycosaminoglycan concentration increased significantly in all treatment groups (p < 0.0001 for LPS, p < 0.006 for FMLP, p < 0.001 for IL-8).
Conclusions:
- LPS, FMLP, and IL-8 effectively stimulate cervical ripening in non-pregnant rabbits.
- Neutrophil accumulation in cervical connective tissue mediates this ripening process.
- IL-8 demonstrates a physiological role in inducing cervical ripening.