Amalia B. Martelli

Platelet Blockade of Particle Absorption from the Peritoneal Surface of the Diaphragm

Abstract Particulate material is absorbed from the peritoneal cavity via respiration-induced gaps between mesothelial cells on the peritoneal surface of the diaphragm and is then collected into diaphragmatic and retrosternal lymph vessels. The effect of platelets on this process was examined by (i) comparing the appearance of these lymph vessels after intraperitoneal (ip) injection of Radiopaque or carbon particles in control and experimental rats receiving, respectively, an ip injection of either platelet-rich (PRP) or platelet-poor (PPP) plasma or saline solution 1 hr prior to the injection of particles; and by (ii) inspecting lymph vessels on the pleural side of 20 freshly excised pieces of rabbit or dog diaphragm (secured pleural side down, to the mouth of a suction flask) 5 min after application of India ink with either PRP or PPP (or saline) to the peritoneal surface. In each case injection or application of PRP either blocked or markedly restricted particle absorption. Electron microscopic (EM) observations indicate that platelets block absorption of particles by plugging gaps between adjacent mesothelial cells.

Spontaneous Reconstitution of the Mammalian Intestinal Tract following Complete Transection

Abstract To determine whether the mammalian intestinal tract is capable of reconstituting itself following complete transection, a 1-cm segment of the small or large bowel was excised in 44 rats. In an additional group of 52 rats the colon was transected distal to a diverting colostomy. In each case the open-cut ends of the intestine were simply dropped back into the peritoneal cavity and the abdominal incision was closed with sutures. Eight animals survived simple transection (18%) regaining functional intestinal continuity in 2 weeks and a morphologically normal appearing intestine in 1 month. When the colon was transected distal to a diverting colostomy the survival rate increased almost four-fold with complete reconstitution of the transected segment in 80% of the survivors.

Alterations in Tissue Reactivity of Thoracic Duct Lymph Produced by Retention of Excess Pancreatic Secretion

Summary Sudden distension of the pancreatic exocrine system by excess pancreatic secretion releases substances into thoracic duct lymph which initiate an acute inflammatory reaction when injected into rats. Lymph becomes more potent in this respect when either the exocrine duct system or the thoracic duct is obstructed and especially when these two maneuvers are combined.