Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in phosphoinositide turnover and is involved in a variety of physiological functions. We analyzed PLC␦1 knockout mice and found that PLC␦1 is required for the maintenance of skin homeostasis. However, there were no remarkable abnormalities except hair loss and runting in PLC␦1 knockout mice, even though PLC␦1 is broadly distributed. Here, we report that mice lacking both PLC␦1 and PLC␦3 died at embryonic day 11.5 (E11.5) to E13.5. PLC␦1/PLC␦3 doubleknockout mice exhibited severe disruption of the normal labyrinth architecture in the placenta and decreased placental vascularization, as well as abnormal proliferation and apoptosis of trophoblasts in the labyrinth area. Furthermore, PLC␦1/PLC␦3 double-knockout embryos supplied with a normal placenta by the tetraploid aggregation method survived beyond E14.5, clearly indicating that the embryonic lethality is caused by a defect in trophoblasts. On the basis of these results, we conclude that PLC␦1 and PLC␦3 are essential in trophoblasts for placental development.Phosphoinositide-specific phospholipase C (PLC) hydrolyzes phosphatidylinositol 4,5-bisphosphate to generate two second messengers, diacylglycerol and inositol 1,4,5-trisphosphate. Diacylglycerol mediates the activation of protein kinase C, and inositol 1,4,5-trisphosphate releases calcium from intracellular stores (1,19).PLC can be categorized into six types, ␤, ␥, ␦, ε, , and , on the basis of sequence homology and activation mechanism (5,13,20,21,23,24,34). Each isozyme is composed of subtypespecific and conserved domains. All PLC isozymes contain catalytic X and Y domains, as well as various regulatory domains, including the C2 domain, EF-hand motif, and pleckstrin homology domain. Subtype-specific domains contribute to the specific regulatory mechanisms. These domains include the src homology domain in PLC␥ (23) and the Ras-associating domain and Ras-GTPase exchange factor-like domain in PLCε (15,29).PLC␦ types are evolutionarily conserved from lower to higher eukaryotes, and these isozymes are thought to be the primary forms expressed in mammals. Therefore, PLC␦ is expected to have important and basic physiological functions. There are three PLC␦ isozymes, PLC␦1, -␦3, and -␦4 (10). It has been suggested that PLC␦1 is involved in Alzheimer's disease (27) and essential hypertension (14,35). Recently, we analyzed PLC␦ knockout (KO) mice and found that PLC␦1 has an important role in skin homeostasis (18) and that PLC␦4 is involved in the acrosome reaction of sperm (6, 7). These results provide some clarification of the physiological functions of PLC␦1 and PLC␦4; however, the function of PLC␦3 remains unknown.In the present study, to elucidate the physiological roles of PLC␦3, we analyzed PLC␦3 KO mice. Thus far, PLC␦3 KO mice have exhibited no obvious abnormalities. Because PLC␦3 is most similar to PLC␦1, we generated mice lacking both PLC␦1 and PLC␦3 genes (PLC␦1/PLC␦3 double-knockout [DKO] mice). We found that simultaneous disruption of PLC␦...

Background: Proton pump inhibitors (eg, omeprazole) commonly are administered concurrently with nonsteroidal anti-inflammatory drugs (NSAIDs; eg, carprofen) as prophylaxis to decrease the risk of gastrointestinal (GI) injury. However, evidence to support this practice is weak, and it might exacerbate dysbiosis and inflammation. Hypothesis/Objectives: To evaluate the effect of carprofen alone or combined with omeprazole in dogs. We hypothesized that coadministration of omeprazole and carprofen would significantly increase GI permeability and dysbiosis index (DI) compared to no treatment or carprofen alone. Animals: Six healthy adult colony beagle dogs. Methods: Gastrointestinal permeability and inflammation were assessed by serum lipopolysaccharide (LPS) concentration, plasma iohexol concentration, fecal DI, and fecal calprotectin concentration in a prospective, 3-period design. In the first 7-day period, dogs received no intervention (baseline). During the 2nd period, dogs received 4 mg/kg of carprofen q24h PO for 7 days. In the 3rd period, dogs received 4 mg/kg of carprofen q24h and 1 mg/kg of omeprazole q12h PO for 7 days. Gastrointestinal permeability testing was performed at the end of each period. Data were analyzed using repeated measures mixed model analysis of variance with Tukey-Kramer post hoc tests (P < .05). Results: Serum LPS and plasma iohexol concentrations did not differ between treatments. Fecal calprotectin concentrations differed between treatments (P = .03). The DI varied over time based on the treatment received (P = .03). Coadministration of omeprazole and carprofen significantly increased fecal calprotectin concentration and DI compared to baseline and carprofen alone.

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There is no FDA approved therapy for the treatment of celiac disease (CeD), aside from avoidance of dietary gluten. Larazotide acetate (LA) is a first in class oral peptide developed as a tight junction regulator, which is a lead candidate for management of CeD. A delayed release formulation was tested in vitro and predicted release in the mid duodenum and jejunum, the target site of CeD. The aim of this study was to follow the concentration versus time profile of orally administered LA in the small intestine using a porcine model. A sensitive liquid chromatography/tandem mass spectrometry method was developed to quantify LA concentrations in porcine intestinal fluid samples. Oral dosing of LA (1 mg total) in overnight fasted pigs resulted in time dependent appearance of LA in the distal duodenum and proximal jejunum. Peak LA concentrations (0.32–1.76 μM) occurred at 1 hour in the duodenum and in proximal jejunum following oral dosing, with the continued presence of LA (0.02–0.47 μM) in the distal duodenum and in proximal jejunum (0.00–0.43 μM) from 2 to 4 hours following oral dosing. The data shows that LA is available in detectable concentrations at the site of CeD.

A device to irradiate a monolayer of cultured cells with alpha-particles using an Am-241 alpha-source (33.4 MBq) was designed to investigate RBEs of alpha-particles in cell killing, induction of chromosome aberration, mutagenic changes and transformation. This device can be used conveniently in a common laboratory by a small number of researchers without any limitation of machine time. The device performs as follows: (1) The energy of alpha-particles at the entrance of the cell layer is 3.20 MeV with a standard deviation of 0.25 MeV, (2) the incident angle to the cell layer is 82.8 degrees with a standard deviation of 3.2 degrees, (3) the fluence rate is 4.7 x 10(5) cm-2.min-1, (4) the average LET infinity for a cell layer 5 microns thick is 138 keV/micron, (5) the average dose rate for a cell layer 5 microns thick is 0.10 Gy/min., (6) a temperature and CO2 concentration conducive to cell cultivation are maintained during irradiation.