Presence and production of migration inhibitory activity in the peritoneal cavity.

The presence of migration inhibitory (MI) activity was investigated in the delayed hypersensitivity (DH) reaction induced by i.p. injection of PPD into FCA-sensitized guinea-pigs. Peritoneal exudates were studied at several times before and after the induction of the DH reaction and a non-immune control inflammation. Lymphokine (LK) fractions were prepared from individual exudates and tested in a conventional macrophage migration inhibition assay at concentrations determined to occur in vivo. The results suggest a continuous local production of MI activity and an augmented production during development of a DH reaction.     

The inflammatory response to paraffin in the peritoneal cavity of the rat.

The inflammatory response to intraperitoneal paraffin in hte rat has been defined in terms of the fluid influx and the pattern of cell accumulation. The volume of fluid exudate in the peritoneal cavity was small and did not change dramatically with time, but there was a moderate cellular influx which was biphasic with peaks at 24 and 72 h. Mononuclear phagocytes and eosinophils were the major cell types found in the exudate, neutrophils, lymphocytes, and mast cells being much less numerous. The neutrophil influx was apparent by 4 h. It was early, short-lived and of low magnitude. In contrast, the eosinophil response was later and more prolonged, cell numbers reaching a peak at 72 h when they were the predominant cell type. The response of the mononuclear phagocytes was multiphasic, with peaks in cell numbers occurring at 24 and 96 h, and 3 weeks after stimulation, by which time they exhibited the morphological features of large activated macrophages which were highly phagocytic for paraffin. The method is useful for the production of mixed inflammatory cell populations from which the fluid phase can readily be separated, and may be a valuable model for the study of esoinophil kinetics.     

Fluid dwell impact induces peritoneal fibrosis in the peritoneal cavity reconstructed in vitro

Peritoneal fluid dwell impacts the peritoneum by creating an abnormal physiological microenvironment. Little is known about the precise effects of fluid dwell on the peritoneum, and no adequate in vitro models to analyze the impact of fluid dwell have been established. In this study, we developed a peritoneal fluid dwell model combined with an artificial peritoneal cavity and fluid stirring generation system to clarify the effects of different dwelling solutions on the peritoneum over time. To replicate the peritoneal cavity, we devised a reconstructed peritoneal cavity utilizing a mesothelial layer, endothelial layer, and collagen membrane chamber. The reconstructed peritoneal cavity was infused with Dulbecco’s modified Eagle’s medium, saline, lactated Ringer’s solution or peritoneal dialysis solution with repeated 4-h dwells for 10 or 20 consecutive days. The above-described solutions induced epithelial–mesenchymal transition (EMT) and hyperplasia of mesothelial cells. All solution types modulated nitric oxide synthase activities in mesothelial and endothelial cells and nitric oxide concentrations in dwelling solutions. Inhibition of nitric oxide synthase activity acted synergistically on mesothelial EMT and hyperplasia. The present findings suggest that solutions infused into the peritoneal cavity are likely to affect nitric oxide production in the peritoneum and promote peritoneal fibrosis. Our newly devised peritoneal cavity model should be a promising tool for understanding peritoneal cellular kinetics and homeostasis.     

Distribution of fluid within the peritoneal cavity: a cadaveric study

This study assesses the distribution of varying volumes of fluid within the peritoneal cavity of cadavers of different sizes (small < or =60 kg; medium = 60-100 kg; large > or =100 kg). The results help to predict the volumes of therapeutic solutions (e.g., adhesiolysis solutions used in the prevention of post-operative adhesion formation) that would be required to reach all the relevant spaces within the greater sac of the peritoneal cavity. Twenty-one cadavers (9 male, 12 female) were selected randomly. Midline laparotomy and bilateral subcostal incisions were made to visualize the distribution of 500 ml of water into the pelvic cavity, paracolic gutters, right subhepatic, and subphrenic spaces. A further 500 ml of water was then added and the distribution was again recorded. The results showed that 500 ml of water was found to distribute to all areas in 47.8% of cadavers, and 1,000 ml distributed to all areas in 81.0% of cadavers. One hundred percent of small cadavers achieved maximum distribution with 500 ml irrespective of gender. Seventy percent of medium cadavers achieved maximum distribution with 1,000 ml, and 75% of large cadavers achieved maximum distribution with 1,000 ml. Anatomical variation in the size of the phrenicocolic ligament was found to be an important limiting factor in the distribution of fluid to the space inferior to the left lobe of the liver and the left subphrenic space. Pre-existing intra-abdominal pathology and previous abdominal surgery also influenced the distribution of fluid within the peritoneal cavity.     

Omental lymphoid organ as a source of macrophage colony stimulating activity in peritoneal cavity.

To test the hypothesis that the omental lymphoid organ (OLO) made by peritoneal milky spots is either a source of haemopoietic (macrophage) progenitors or growth factors we attempted to culture OLO cells in vitro in a variety of assay combinations. With the culture in vitro in semisolid agar it was found that OLO cells do not form granulocyte-macrophage or macrophage colonies in response to stimulants. However, when in the same assay marrow cells were used as the targets and OLO-related preparations as stimulants it was observed that marrow cells formed exclusively macrophage colonies. These marrow cells, in response to stimulants derived from other organs, produced granulocyte-macrophage, granulocyte and macrophage colonies. OLO-related preparations tested for macrophage-colony stimulating activity included partly purified medium conditioned by OLO cells derived from mice, either injected with endotoxin or not, and medium conditioned by OLO cells after 14 days, liquid culture in vitro. While these results were observed in Swiss mice, C3H/W mice, which are genetically endotoxin-unresponsive, failed to show this reaction. These data may suggest that the local production of macrophage-colony stimulating activity in the peritoneal cavity could be one physiological role for OLO. OLO is the first organ in adult mice identified to stimulate exclusively macrophage colony growth, and not granulocyte-macrophage or pure granulocyte colonies.     

A Chlamydia from the peritoneal cavity of mice

During continuous intraperitoneal passage of liver and spleen suspension in normal stock mice, a syndrome developed which involved ascites and certain other visceral changes but seldom clinical illness and never fatality. From these mice, a chlamydia was established in yolk sacs of chick embryos and in tissue cultures. This agent readily infects mice when inoculated intranasally but is without effect intracerebrally. It has very low pathogenicity for guinea pigs and is resistant to sodium sulfadiazine. These characteristics, together with results of serum neutralization tests, indicate that the agent is different from the Nigg and DeBurgh strains of mouse pneumonitis.     

Surface phagocytosis and host defence in the peritoneal cavity during continuous ambulatory peritoneal dialysis

Since patients on continuous ambulatory peritoneal dialysis are at high risk for peritonitis, the opsonins in peritoneal dialysis effluent responsible for phagocytosis and a neutrophil chemiluminescence response to surface-adherentStaphylococcus epidermidis were examined. In surface phagocytosis assays uninfected dialysate was as opsonic as 1 % serum. The opsonic activity was heat stable and equal to that of purified IgG at the same concentration (0.1 mg/ml). In contrast, optimal chemiluminescence to surface-adherentStaphylococcus epidermidis was dependent on complement. C3 deposition onStaphylococcus epidermidis opsonized in dialysate was quantitated by an enzyme immunoassay (EIA) and represented 13 % of control C3 deposited with opsonization in 10 % serum. Unused dialysate was found to be inhibitory to neutrophil phagocytosis and complement deposition. A combination of the low pH and high dextrose concentration of dialysate was responsible, but restoration of the pH to 7.4 largely restored both indices. During peritonitis there was a parallel increase in IgG levels and C3 deposition (r=0.8), and surface phagocytosis was also enhanced. On further analysis, subjects with a single episode of peritonitis had a significantly more opsonic peritoneal effluent than those who had two infections during the study. This latter group had a poor IgG response to infection. This study demonstrates the relative deficiencies of host defence in the peritoneal cavity and indicates that measures to improve opsonin delivery and reduce the inhibitory effects of dialysate would be beneficial.     

The modulation of inflammatory response in the peritoneal cavity through stimulation of the pleural cavity: an experimental study in the rat.

To establish whether local inhibition of emigration or a centrally acting mechanism is responsible for the diminished response to a second inflammatory stimulus, three groups of young adult male Sprague-Dawley rats received in intrapleural injections of glycogen followed 4 h later by intra-peritoneal Beef Heart Infusion/protease Peptone. Two, 4 and 8 h after the second injection cell counts were made on both the pleural and peritoneal effusions. Circulating PMNs were also monitored using tail vein blood. The prior injection of glycogen intrapleurally significantly suppressed the subsequent accumulation of peritoneal PMNs in response to the second stimulus. The mechanism of this suppression is discussed.     

Antigen presentation by murine peritoneal cavity macrophage-derived dendritic cells.

Murine peritoneal cavity macrophage derived dendritic cells (PEC-DC) generated using early growth factors, interleukin 4 and granulocyte-macrophage colony-stimulating factor followed by maturation in interferon-gamma plus either, Toxoplasma lysate antigen (TLA) or lipopolysaccharide, bind TLA by a nonspecific mechanism and continue to express major histocompatibility complex class II antigens after 24 h of culture in vitro. Moreover, the proliferation of CD3+ spleen T cells from mice immunized with Toxoplasma gondii homogenate, induced by PEC-DC-mediated antigen presentation was statistically significant and of consistent amplitude. This accessory function of PEC-DC is antigen specific.     

Clearance of histamine from the peritoneal cavity of rats

To study the clearance of histamine from the peritoneal cavity of rats, histamine was either injected i.p. or released locally by the injection of compound 48/80. At various intervals peritoneal fluid was removed and analysed for histamine concentration by a fluorometric assay. Exogenous and endogenous histamine were cleared from the peritoneal cavity at the same rate with a half life of 20 minutes. The rate was not altered by different histamine concentrations, by injection of heparin, and by the removal of peritoneal leukocytes. Repeated injections of large amounts of histamine resulted in a decreased clearance. The results suggest that histamine concentrations above the physiological level are quickly degraded. Activities of histamine as an inflammatory mediator are likely to be of short duration.     

The mast cell: distribution and maturation in the peritoneal cavity of the adult rat.

In the peritoneal cavity of the adult rat mast cells at the four stages of progressive maturation (and corresponding increase of sulphation of granules) are best demonstrated in free peritoneal fluid. Of the 0.1-0.2x10(6) cells in the free fluid, 26% are at stage 1 of maturation (all granules are stained by Alcian blue). 24% at stage 2 (majority of granules are stained by Alcian blue, minority by safranin), 20% at stage 3 (majority of granules are safranin-positive), and 30% at stage 4 (all granules are safranin-positive). Peritoneal washings yield a mean of about 1.3-1.8x10(6) mast cells of which 16% are at stage 1, 24% at stage 2, 34% at stage 3 and 26% at stage 4. The greater number recovered by washing, compared with the number in free peritoneal fluid, suggests that a substantial number of mast cells lie on the surface of the peritoneal membranes.     

Recipient age determines the success of intraperitoneal transplantation of peritoneal cavity B cells.

In vivo studies of lymphocyte biology have used intravenous (i.v.) injection as the primary mode of cell transfer, a protocol consistent with the anatomic distribution of most lymphocytes. However, for study of peritoneal cavity B cells, i.v. injection does not correlate with anatomical localization. This report describes the restoration of B-cell function in B lymphocyte-defective X-chromosome-linked immune-defective (XID) mice after intraperitoneal transfer of immunoglobulin heavy chain (Igh)-disparate peritoneal cavity (PerC) cells. In contrast to i.v. transfer, intraperitoneal (i.p.) transfer restored B-cell function in young, but not adult (> 8 weeks), XID mice. When host and donor Igh allotype matched, PerC B-cell engraftment was noted in older recipients; this reconstitution however, was also age-dependent. Migration from the peritoneum to systemic circulation was necessary for serum IgM production as shown by the presence of donor antibody-secreting cells in the host spleen. Host lymphocytes also influenced the success of i.p. transplantation as severe combined immune-deficient mice, regardless of age, exhibited donor serum IgM production. Recipient age, Igh allotype, and immune-deficiency were found to have an impact on the ability of i.p.-transferred PerC B cells to restore B-cell function in XID mice.     

The inflammatory response to paraffin in the peritoneal cavity of the rat

The inflammatory response to intraperitoneal paraffin in hte rat has been defined in terms of the fluid influx and the pattern of cell accumulation. The volume of fluid exudate in the peritoneal cavity was small and did not change dramatically with time, but there was a moderate cellular influx which was biphasic with peaks at 24 and 72 h. Mononuclear phagocytes and eosinophils were the major cell types found in the exudate, neutrophils, lymphocytes, and mast cells being much less numerous. The neutrophil influx was apparent by 4 h. It was early, short-lived and of low magnitude. In contrast, the eosinophil response was later and more prolonged, cell numbers reaching a peak at 72 h when they were the predominant cell type. The response of the mononuclear phagocytes was multiphasic, with peaks in cell numbers occurring at 24 and 96 h, and 3 weeks after stimulation, by which time they exhibited the morphological features of large activated macrophages which were highly phagocytic for paraffin. The method is useful for the production of mixed inflammatory cell populations from which the fluid phase can readily be separated, and may be a valuable model for the study of esoinophil kinetics.     

Antigen-presenting capacity of macrophages and dendritic cells in the peritoneal cavity of patients treated with peritoneal dialysis

In this study the antigen-presenting capacity of human peritoneal cells and the influence of continuous ambulant peritoneal dialysis (CAPD) were studied. On average 6% of the peritoneal cells were dendritic cells (DC), with no difference between CAPD and control peritoneal cells. DC were enriched by selecting for non-adherent, Fc receptor-negative, low density cells. A typical spot-like CD68 positivity was seen in DC, in contrast to the pancytoplasmic staining pattern in macrophages. Peritoneal DC morphologically and functionally showed features of cells belonging to the DC lineage. Peritoneal DC were superior antigen-presenting cells for both allo-antigen, and Candida albicans antigen or purified protein derivative. CAPD peritoneal macrophages were two- to threefold better stimulator cells for allogeneic T cells compared with control macrophages. The level of integrins/adhesins or MHC class I or II, as measured semi-quantitatively on the FACS, could not account for this phenomenon. In addition, a double chamber system showed that dialysate-activated macrophages produced soluble factors that could enhance DC-induced allogeneic T cell proliferation. In conclusion, human peritoneal cells contain a relatively high percentage of classical DC. CAPD treatment does not impair the antigen-presenting capacity of peritoneal cells, but instead up-regulates the allo-antigcn-presenting capacity of peritoneal macrophages.