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Blood levels of neuropeptide Y are elevated in pregnant women with preeclampsia and eclampsia, according to a study of 24 pregnant women. This indicates that both of these complications of pregnancy are partly caused by activation of the sympathetic nervous system.

Stretching of fetal membranes and uterine muscle, as occurs in late pregnancy, may encourage labor through an increase in levels of interleukin-8. Researchers obtained samples of fetal membranes, placenta, and muscle strips from the lower uterus from women who underwent elective cesarean deliveries and stretched the tissues for two to four hours. Levels of interleukin-8 increased in fetal membranes, placenta, and uterine muscle. Fetal membranes exhibited higher levels of interleukin-8 than did placenta. Interleukin-8 may initiate ripening of the cervix and labor by causing an inflammatory response that breaks down the collagen content of the cervix. Stretching of fetal membranes caused their collagen content to degrade. Interleukin-8 levels in amniotic fluid increase gradually in late pregnancy.

Byline: Emad El Maradny, Naohiro Kanayama, Abdul Halim, Kayoko Maehara, Toshihiko Terao Keywords: Amnion; amniochorion; interleukin-8; collagenase activity; stretching; muscles of lower uterine segment Abstract: OBJECTIVE: The aim of this study was to determine whether stretching of fetal membranes can increase interleukin-8 concentration and collagenase activity. STUDY DESIGN: Strips of whole fetal membranes, amnion, or muscles of the lower uterine segment were stretched for 2 or 4 hours. Interleukin-8 and collagenase activity were measured in homogenized control and stretched samples. Immunohistochemical staining for interleukin-8 was carried out. RESULTS: The interleukin-8 concentration increased significantly after the whole fetal membranes were stretched for 2 and 4 hours (p < 0.0007 and 0.001, respectively). Also, stretching of amnion and muscles of the lower uterine segment for 2 and 4 hours increased the concentration of interleukin-8 significantly (p < 0 .0007 after 2 and 4 hours, respectively). Collagenase activity was significantly increased after stretching of amnion, amniochorion, and muscles of the lower uterine segment for 4 hours (p < 0.0007, 0.006, and 0.0007, respectively). After stretching, samples were darkly stained for interleukin-8 compared with control nonstretched samples. CONCLUSION: Stretching of amnion, amniochorion, and muscles of the lower uterine segment increased interleukin-8 production and collagenase activity. (Am J Obstet Gynecol 1996;174:843-9.) Author Affiliation: Hamamatsu, Japan Article History: Received 18 April 1995; Revised 1 August 1995; Accepted 11 August 1995 Article Note: (footnote) [star] From the Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine., [star][star] Reprint requests: Emad El Maradny, Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, 3600 Handa-cho, 431-31 Hamamatsu, Japan., a 0002-9378/96 $5.00 + 0 6/1/68535

Byline: Abdul Halim, Naohiro Kanayama, Emad el Maradny, Akira Nakashima, A.B. Bhuiyanb, Selina Khatun, Toshihiko Terao Keywords: P selectin (GMP-140); glycocalicin; preeclampsia-eclampsia; platelet activation; endothelial cell activation Abstract: OBJECTIVE: We measured the concentrations of plasma P selectin (or GMP-140) and glycocalicin in preeclamptic and eclamptic women. Correlations between these two parameters and blood pressures, platelet counts, or plasma thrombin-antithrombin complex values were evaluated. STUDY DESIGN: By use of enzyme-linked immunosorbent assays we measured the plasma GMP-140 and glycocalicin levels in normal pregnancies (n = 10) and preeclamptic (n = 10) and eclamptic (n = 20) pregnancies. The glycocalicin index was calculated as follows: (glycocalicin x [250 x 10.sup.6/ml])/(Individual platelet counts). Correlations between plasma GMP-140, glycocalicin, glycocalicin index values, blood pressures, platelet counts, and plasma thrombin-antithrombin complex values were analyzed. RESULTS: Plasma GMP-140 levels were found to be significantly elevated in preeclamptic (p < 0.0005) and eclamptic cases (p < 0.0001) compared with normotensive controls. Plasma glycocalicin (p = 0.01, 0.007) and glycocalicin index (p = 0.005, 0.002) values were also markedly elevated in preeclamptic and eclamptic patients compared with normal pregnant patients. Significant correlations between platelet counts or plasma thrombin-antithrombin complex levels and their corresponding plasma GMP-140 and glycocalicin and glycocalicin index values have been found in preeclamptic and eclamptic cases. However, blood pressures had correlations with GMP-140, glycocalicin, and glycocalicin index values in eclamptic cases. CONCLUSIONS: We demonstrated an elevation of plasma GMP-140 and platelet glycocalicin in preeclampsia and eclampsia. This study also reflects the usefulness of glycocalicin as a marker of platelet activation or turnover and endothelial dysfunction in these diseases. (AM J OBSTET GYNECOL 1996;174:272-7.) Author Affiliation: Hamamatsu, Japan, and Dhaka, Bangladesh Article History: Received 13 December 1994; Revised 14 April 1995; Accepted 15 May 1995 Article Note: (footnote) [star] From the Departments of Obstetrics and Gynecology, Hamamatsu University School of Medicine,a and Dacca Medical College and Hospital. b , [star][star] Reprint requests: Abdul Halim, MB, BS, Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, 3600 Handa-cho, Hamamatsu 431-31, Japan., a 0002-9378/96 $5.00 + 0 6/1/66316

Urinary trypsin inhibitor in fetal urine appears to relax uterine muscles and suppress spontaneous uterine contractions. Samples of the muscle coat of the uterus were taken from 20 healthy pregnant women during elective cesarean section. The samples were cut into small strips to be used in the experiment. Neonatal urine of the fetuses delivered by cesarean were collected and centrifuged. Urinary trypsin inhibitor was shown to restrict uterine contractions induced by the stimulants oxytocin, prostaglandins, and lipopolysaccharide. This inhibitor apparently mediates increases of calcium flow to uterine muscles that would be necessary for their contraction.

Use of interleukin-8 may contribute to 'cervical ripening,' the softening and dilatation of the cervix necessary for vaginal birth. Eight rabbits in mid-pregnancy and 10 nonpregnant rabbits were treated with vaginal suppositories containing interleukin-8 (IL-8). The water content of the rabbit cervices increased after IL-8 application, suggesting that increased water content contributes to cervical softening. Measurements of neutrophils (white blood cells) and total concentration of particular carbohydrates increased after IL-8 administration. Both of these contribute to the breakdown of collagen in the cervical tissue that occurs throughout pregnancy to facilitate vaginal delivery.