Synthesis and biological activity of 4-amino-5-chloro-2-ethoxy-3-hydroxybenzamides, metabolites of a new gastroprokinetic agent, mosapride

To confirm the proposed structures of the minor metabolites of a potential gastroprokinetic agent, mosapride, 4-amino-5-chloro-2-ethoxy-3-hydroxy-N-(2-morpholinylmethyl)benzamide (3) and the N-(5-oxo-2-morpholinyl)-methyl analogue 4 were prepared. As the common intermediate, 2-ethoxy-3-hydroxy-4-nitrobenzoic acid (15) was prepared via the regioselective ethylation of 2,3-dihydroxybenzaldehyde (10) and subsequent nitration of the resultant 2-ethoxy-3-hydroxybenzaldehyde (11). The key intermediate 15 was converted into the benzamides 3 and 4. After enzymatic treatment of the isolated metabolites, their structures were identified by comparison with the synthetic compounds. Serotonin-4 receptor binding affinity of these metabolites was found to be lower than that of mosapride.

Bacterially expressed rat retinol-binding protein is functional for retinol and transthyretin bindings

Retinol-binding protein (RBP) was expressed in Escherichia coli using the cDNA for rat RBP, and characterized. The expressed RBP was fused to maltose-binding protein (MBP) at the N-terminal end (MBP-RBP), and MBP was enzymatically removed from the MBP-RBP with proteinase factor Xa. The binding of retinol and transthyretin (TTR) to the recombinant RBP was monitored by means of gel filtration. The recombinant RBP specifically bound to retinol with an affinity similar to that of purified RBP from rat serum. Furthermore, the retinol-bound recombinant RBP formed hetero-complexes with TTR similar to RBP. Thus, the results showed that the recombinant RBP expressed in E. coli is as functional as serum RBP in terms of retinol and TTR bindings.

cDNA cloning and functional analysis of the p97 subunit of the 26S proteasome, a polypeptide identical to the type-1 tumor-necrosis-factor-receptor-associated protein-2/55.11

Molecular cloning of cDNA for a new regulatory subunit, designated p97, of the human 26S proteasome showed that the polypeptide consists of 908 amino acid residues with a calculated molecular mass of 100184 Da and an isoelectric point of 4.94. Computer analysis showed that p97 is very similar to type-1 tumor-necrosis-factor (TNF)-receptor-associated protein (TRAP)-2 and 55.11, both of which were identified recently as binding proteins of the cytoplasmic domain of type-1 TNF receptor by yeast two-hybrid screening. This finding suggests that the 26S proteasome might serve as a mediator molecule in the TNF signaling pathway in cells. Computer-assisted similarity analysis also revealed the high sequence similarity of p97 with a yeast protein whose function is yet unknown, the gene for which is here termed NAS1 (non-ATPase subunit 1). Disruption of NAS1 resulted in several phenotypes, including lethality and temperature-sensitive growth, depending on the genetic background of the cells used. The human p97 cDNA suppressed the growth defect of nas1 disruptant cells, when expressed from single-copy or multi-copy vectors, indicating that p97 is functionally equivalent to yeast Nas1p. Culturing of the temperature-sensitive nas1 cells at the restrictive temperature promoted the accumulation polyubiquitinated cellular proteins, implying that the 26S proteasome requires a functional Nas1p subunit for ubiquitin-dependent proteolysis. These results indicate that p97/Nas1p plays an important regulatory role in the function of the 26S proteasome.

Squamous cell carcinoma in a Müllerian duct cyst: report of a case

A 36-year-old man presented with a pelvic mass which proved to be a Müllerian duct cyst. The cyst was determined to be squamous cell carcinoma which involved the rectum and the bladder. A total pelvic exenteration was carried out for complete resection.

Electrophoretic characterization of boar epididymal antiagglutinin

Boar epididymal antiagglutinin, previously shown to inhibit sperm head-to-head agglutination, was purified from cauda epididymal plasma by precipitation with ammonium sulfate, anion-exchange chromatography, and reverse-phase HPLC, and was characterized by electrophoretic and membrane blotting techniques. Blotting techniques, using the ECL Glycoprotein Detection System (Amersham Life Science, Buckinghamshire, UK) and wheat germ agglutinin (WGA)-peroxidase, established the presence of sialic acid residues on purified antiagglutinin. Removal of sialic acid residues from antiagglutinin greatly reduced its immunoreactivity with the specific antiserum. Further purification by two-dimensional PAGE established the presence of one major and two minor forms that cross-reacted with the antiserum, with only the major form reacting with WGA-peroxidase. Extracts of washed epididymal spermatozoa contained a polypeptide with the same electrophoretic mobility as the major form. Additionally, the antiserum detected cross-reacting material in seminal plasma and in extracts from ejaculated spermatozoa. When spermatozoa were incubated under conditions shown to promote capacitation, the cross-reacting material could not be detected in sperm extracts. These results are consistent with the following conclusions: 1) antiagglutinin contains sialic acid residues that may be related to its immunoreactivity and molecular heterogeneity, and 2) either sperm-bound antiagglutinin is released or its epitope recognized by the antiserum is altered after ejaculation and in vitro capacitation.

Dopamine transporter gene polymorphism and psychiatric symptoms seen in schizophrenic patients at their first episode

To investigate the possible role of the dopamine transporter (DAT) gene in determining the phenotype in human subjects, allele frequencies for the 40-bp variable number of tandem repeats (VNTR) polymorphism at this site were compared between 117 Japanese normal controls and 118 schizophrenic patients, including six subgroups: early-onset, those with a family history, and those suffering from one of the following psychiatric symptoms at their first episode: delusion and hallucination; disorganization; bizarre behavior; and negative symptoms. No significant differences were observed between the group as a whole or any subgroup of schizophrenic patients and controls. The results indicate that VNTR polymorphism in the DAT gene is unlikely to be a major contributor to any of the psychiatric parameters examined in the present population of schizophrenic subjects.

Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis. I. Study of IL-1 beta mRNA expression

In this study, we introduce a novel research methodology, the evaluation of mRNA expression of cells contacting with polymeric materials using reverse transcription-polymerase chain reaction (RT-PCR) analysis HL-60 was used as a model of the macrophages. The expression of interleukin-1 beta (IL-1 beta) mRNA, a cytokine secreted by macrophages, was selected to estimate the extent of inflammation. The expression of IL-1 beta mRNA in the HL60 cells cultured on various substrates and in various conditions was studied. Expression of IL-1 beta could be successfully determined by RT-PCR analysis. A 48 h incubation period was necessary to clarify the expression of IL-1 beta mRNA. It became clear that lipopolysaccharide stimulation was not necessary in this analysis because of the high sensitivity of RT-PCR analysis. It is concluded that RT-PCR analysis is a powerful tool for studying cell-polymer interaction, and is a complementary method for ELISA.

[Mitomycin C-DNA adduct detection in rat organs and human liver]

Mitomycin C-DNA adduct formation was detected in rat organs and also in human tissues by 32P-postlabeling assay. The adduct levels were 1-4 adduct/ 10(8) nucleotides in the human liver after 20 mg of mitomycin C by intra-artery administration and which level was higher comparing with the levels in the rat liver after 10 times more dosages of mitomycin C administration by intra-venous injection. The levels in the human liver were maintained at least 56 days after administration. Organ-specific differences of adduct levels were observed in rat experiments: the adduct levels of liver, lung and kidney were stable but rapidly decreased in stomach and colon. These results, which were obtained from the experiments using the normal parts of each organs may indicate that the drug effectivity for adduct formation was sufficient with smaller dose in the stomach and colon, but disappeared quickly, mean while, the drug effectivity was undergoing in relatively high levels for longer periods in the liver lung and kidney. The analysis of human liver samples may suggest that the selective intra-artery injection induced stronger drug effectivity for adduct formation in human organs.

Reactive oxygen species involved in the glutamate toxicity of C6 glioma cells via xc antiporter system

We recently demonstrated that continuous L-glutamate exposure led to cell death in C6 glioma cells over a period of 24-36 h, due to inhibition of cystine uptake through the cystine/glutamate (XC) antiporter. The antioxidant vitamin E provided protection against this effect, supporting the hypothesis that depletion of glutathione might be responsible, resulting from insufficient cystine uptake. To clarify the content of oxidative stress after glutathione depletion, the present study was done to investigate accumulation and target molecules of reactive oxygen species induced by glutamate treatment. The accumulation of reactive oxygen species was increased three-fold as compared to a control culture. Membrane oxidation, as judged by lipid peroxidation, was increased two-fold after glutamate treatment. Cellular ATP content was significantly reduced by glutamate exposure. For the two cytosolic enzymes examined, activity of glyceraldehyde 3-phosphate dehydrogenase was slightly enhanced by glutamate treatment, while activity of glutamine synthetase was not changed. Impairment of nuclear DNA after glutamate exposure was also revealed by nuclear chromatin condensation with DNA fragmentation. Thus, the multiple targets (membrane, cytoplasm and nuclei) of oxygen radicals in glutamate toxicity through the xc antiporter system were evaluated for the first time. Furthermore, prevention from cell death and from cellular toxicity induced by oxygen radicals could be seen using three specific oxygen radical scavengers, catalase, 3,3,5,5-tetramethyl-pyrroline N-oxide and alpha-phenyl-N-t-butylnitrone, without restoring the glutathione deficit. This indicates that radical scavengers did not interact with the xc antiporter system, but directly scavenged the oxygen radicals. Taken together, the data strongly suggest that O2-, H2O2 and OH accumulate in response to oxidative stress after glutathione depletion, resulting in glutamate cell death of C6 glioma cells.

Role in nitric oxide in Kupffer cell-mediated hepatoma cell cytotoxicity in vitro and ex vivo

The metabolic change in tumor cells (AH70, a rat hepatoma cell line) cocultured with isolated rat Kupffer cells were visualized and analyzed by a laser scanning confocal imaging system. When AH70 cells were cocultured with Kupffer cells, fluorescence intensity of rhodamine 123 (Rh123) decreased, indicating the reduction of mitochondrial function. The reduction in Rh123 was eliminated by NG-monomethyl-L-arginine (L-NMMA), an analogue of L-arginine, suggesting the involvement of nitric oxide (NO). Two hour after the cells were cocultured, membrane compromised AH70 cells which were observed as propidium from 2.8% to 25%. This increase was also attenuated by L-NMMA, suggesting that Kupffer cell-mediated injury of tumor cells largely depends on NO. The concentrations of NO-2 + NO-3 in the culture medium markedly increased after coculture of AH70 cells with Kupffer cells. Moreover, NO synthase (NOS) activity in Kupffer cells significantly increased after coculture. These in vitro results suggest that NO mediates Kupffer cell-induced tumor cell damage characterized by reduced mitochondrial function and diminished barrier function. In the ex vivo study of the perfused liver to which AH70 cells were injected via the catheter inserted into the portal vein, some AH70 cells were arrested in the upper stream of sinusoid and the fluorescence intensity of Rh123 in adherent AH70 cells decreased in a time-dependent manner within 2 hours. The number of PI-positive AH70 cells also increased 2 hours after the injection of AH70 cells. These changes were inhibited by either administration of N omega-L-nitroarginine-methylester (L-NAME) to perfusate or pretreatment of the rat liver with GdCl3, which is known to deplete Kupffer cell function. Thus, the present study suggests that NO from Kupffer cells induces mitochondrial dysfunction in tumor cells followed by membrane barrier dysfunction in the liver sinusoid.

Stimulation of acid secretion in rat stomach following exposure to taurocholate in the presence of the nitric oxide synthase inhibitor

1. The role of nitric oxide (NO) in the acid secretory response of the rat stomach following damage was investigated. A rat stomach was mounted in an ex-vivo chamber, perfused with saline, and the potential difference (PD), luminal pH, acid and HCO3- responses were measured before and after the mucosal exposure to 20 mM taurocholate (TC) for 30 min, with or without pretreatment with NG-nitro-L-arginine methyl ester (L-NAME). 2. Exposure of the stomach to TC caused a reduction of PD, a decrease of acid secretion and an increase in luminal HCO-. Pretreatment with L-NAME did not affect such PD and HCO3- responses, but completely attenuated the decreased acid secretory response and rather enhanced this secretion. 3. These effects of L-NAME were significantly antagonized by the co-administration of L-arginine but not D-arginine. The enhanced acid secretory response in the presence of L-NAME was significantly inhibited by prior administration of cimetidine or FPL-52694 (a mast-cell stabilizer). 4. The mucosal exposure to TC significantly decreased the number of mucosal mast cells and increased the luminal histamine output. 5. Damage in the stomach may activate the histamine-dependent acid stimulatory pathway in addition to the NO-dependent inhibitory mechanism, although the latter effect overcomes the former, resulting in a decrease of acid secretion. L-NAME unmasks the stimulation of acid secretion by suppressing the inhibitory pathway.

Intron retention generates a novel isoform of the murine vitamin D receptor that acts in a dominant negative way on the vitamin D signaling pathway

We identified and characterized a novel rat vitamin D receptor isoform (rVDR1), which retains intron 8 of the canonical VDR (rVDR0) during alternative splicing. In this isoform protein directed by the stop codon in this newly identified exon, a part of the ligand binding domain (86 amino acids) is truncated at the C-terminal end but contains 19 extra amino acids. The rVDR1 transcript was expressed at a level 1/15 to 1/20 of that of rVDR0 in the kidney and intestine in adult rats but not in embryos. The recombinant rVDR1 protein showed no ligand binding activity. Homo- and heterodimers of the recombinant rVDR0 and rVDR1 proteins bound to a consensus vitamin D response element (VDRE) but not to consensus response elements for thyroid hormone and retinoic acid. However, unlike rVDR0, rVDR1 did not form a heterodimeric complex with RXR on the VDRE. A transient expression assay showed that this isoform acted as a dominant negative receptor against rVDR0 transactivation. Interestingly, the dominant negative activities of rVDR1 differed among VDREs. Thus, the present study indicates that this new VDR isoform negatively modulates the vitamin D signaling pathway, through a particular set of target genes.

Effect of the type of serum in the medium on sodium ascorbate-induced cytotoxicity

Sodium ascorbate induced cytotoxicity against human glioblastoma T98G cells in RPMI1640 medium supplemented with fetal bovine serum or human serum samples was studied. Several human serum samples significantly reduced the cytotoxic activity of sodium ascorbate, regardless of sex, age or the disease of the serum donor with or without heat-inactivation of the serum. ESR spectroscopy revealed that this serum effect was not simply due to the alteration of the ascorbyl radical intensity, produced from sodium ascorbate. The present study suggests that the apoptosis-inducing activity of sodium ascorbate might be significantly affected by human serum.

Alterations in basal and glucose-stimulated voltage-dependent Ca2+ channel activities in pancreatic beta cells of non-insulin-dependent diabetes mellitus GK rats

In genetically occurring non-insulin-dependent diabetes mellitus (NIDDM) model rats (GK rats), the activities of L- and T-type Ca2+ channels in pancreatic beta cells are found to be augmented, by measuring the Ba2+ currents via these channels using whole-cell patch-clamp technique, while the patterns of the current-voltage curves are indistinguishable. The hyper-responsiveness of insulin secretion to nonglucose depolarizing stimuli observed in NIDDM beta cells could be the result, therefore, of increased voltage-dependent Ca2+ channel activity. Perforated patch-clamp recordings reveal that the augmentation of L-type Ca2+ channel activity by glucose is markedly less pronounced in GK beta cells than in control beta cells, while glucose-induced augmentation of T-type Ca2+ channel activity is observed neither in the control nor in the GK beta cells. This lack of glucose-induced augmentation of L-type Ca2+ channel activity in GK beta cells might be causatively related to the selective impairment of glucose-induced insulin secretion in NIDDM beta cells, in conjunction with an insufficient plasma membrane depolarization due to impaired closure of the ATP-sensitive K+ channels caused by the disturbed intracellular glucose metabolism in NIDDM beta cells.

Early diagnosis and estimation of pulmonary congestion and edema in patients with left-sided heart diseases from histogram of pulmonary CT number

To establish an early diagnosis and have a quantitative estimation of congestion or edema, pulmonary CT scans were performed to detect the increase of regional lung water volume of patients with congestive heart failure. CT scanning of the upper, middle, and lower lung fields at maximum inspiration and hemodynamic analysis to ensure a hemodynamically chronic stable condition after the heart failure therapy for 5 weeks by cardiac catheterization within 2 weeks before CT scanning were performed in 10 normal subjects and 25 patients with left-sided heart failure. Patients were divided into two groups according to the presence or absence of pulmonary congestion or edema on chest radiographs, and the mean pulmonary wedge pressure (mPWP). The pulmonary congestion group (14 patients) had pulmonary congestion or edema, and mPWP was greater than 13 mm Hg despite the heart failure therapy. The nonpulmonary congestion group (11 patients) had no pulmonary congestion or edema, and mPWP was lower than 10 mm Hg. Histograms of pulmonary CT numbers were graphed to a set region of interest (ROI) on transverse CT images in all subjects; then changes of pulmonary CT numbers when pulmonary congestion or edema occurred were estimated from those histograms. We found that when severe pulmonary congestion or edema occurred in 6 patients with severe left heart failure, the pulmonary CT numbers within the ROI rapidly increased from -650 to -750 Hounsfield units (HU). We defined the amount ratio between the pixels (pixel counts between -650 and -750 HU within these R0Is) and the pixels (pixel counts between -300 and -950 HU) of the CT number (which were all pixels composing these R0Is) x100(%) as "%PXL." %PXL showed a linear correlation with mPWP. Compared with the %PXL in the normal group, the %PXL in the pulmonary congestion group was significantly higher than that in the normal group (p<0.05, p<0.01, p<0.001) in all lung fields. Similarly, compared with the %PXL in the normal group, %PXL in the nonpulmonary congestion group was significantly higher than that in the normal group in the middle and lower lung fields (p<0.05, p<0.01) in the posterior field. From these results, we concluded that %PXL was a good index to identify abnormal water content usually not recognizable by routine chest radiograph in the lungs.

Successful engraftment of allogeneic CD34-enriched marrow cell transplantation from HLA-mismatched parental donors

The CD34 antigen is expressed on pluripotent stem cells and the CD34+ cell has been shown to be capable of hematopoietic reconstitution in animal and human autologous grafts. We asked if CD34+ cells could reconstitute hematopoiesis in human allogeneic transplantation from a HLA-mismatched donor. Three pediatric patients with advanced leukemia received allogeneic CD34-enriched marrow cell graft from HLA two (two patients) or three (one patient) loci-mismatched parental donors. CD34+ cell selection was performed with mouse anti-CD34 antibody 9C5 and magnetic beads coated sheep anti-mouse IgG1. 1.53 to 2.48 x 10(9) marrow cells were processed and 2.53 to 7.89 x 10(7) positively selected cells were recovered. The selected population showed 93.7 to 99.0% CD34+ cells and total recovery of CD34+ cells from the starting population was 54.6 to 62.3%. CD34+ cell selection resulted in more than 99.9% depletion of CD5+ cells from the bone marrow. The patients received 2.53 to 7.25 x 10(6) CD34-enriched cells/kg after myeloablative therapy. All patients achieved trilineage engraftment that was confirmed by various genetic markers. Acute graft-versus-host disease (GVHD) was grade 0 (two patients) or grade I (one patient), and hematological recovery was successfully achieved as follows; the days to reach granulocytes over 0.5 x 10(9)/I were 11 to 13 days, reticulocytes over 2% was 18 to 28 days, platelets over 50 x 10(9)/I was 33 to 58 days. One patient is surviving without relapse of leukemia and two patients died after either mixed hematopoietic chimerism or leukemia relapse was observed. These studies suggest that CD34+ marrow cells are capable of hematopoietic reconstitution from HLA two or three loci-mismatched donors even with the lowest dose of mature T cells.

[Infantile onset chronic inflammatory demyelinating polyneuropathy with clinical course of 23 years; a case report]

We report a 23-year-old female with infantile onset chronic inflammatory demyelinating polyneuropathy. Muscle weakness was noticed when she was 1 year old, and, together with sensory disturbances, gradually progressed in an asymmetric manner. Nerve conduction studies disclosed slowing of conduction velocities, temporal dispersion, and decreased amplitude of compound muscle action potentials, the degrees of which were markedly different amongst different nerves even in the same limbs. The sural nerve biopsy showed various degrees of nerve fiber amongst different fascicles. Marked inter-nerve and intra-nerve differences of involvement and clinical improvement after steroid therapy supported the diagnosis of chronic inflammatory demyelinating polyneuropathy. It should be noted that even after a long clinical course of 23 years, her clinical symptoms remained asymmetrical and multi-focal lesions could be clearly demonstrated.

Retinoic acid differentially up-regulates the gene expression of retinoic acid receptor alpha and gamma isoforms in embryo and adult rats

The diverse biological effects of retinoic acid (RA) are exerted by its nuclear receptor-mediated gene expression. One of the two nuclear retinoic acid receptor subfamilies is composed of three subtypes of the all-transretinoic acid receptor (RAR-alpha, RAR-beta, and RAR-gamma). Furthermore, several isoforms are generated from each of three RARs by differential promoter usage and/or alternative splicing. It is thus thought that the developmental stage-specific actions of RA are modulated through the spatio-temporal expression of the subtype and isoforms of RARs. In this study, the auto-regulation of the RAR subtypes (RAR-alpha total, RAR-beta total and RAR-gamma total) and their major isoforms (RAR-alpha 1, alpha 2, RAR-beta 1, beta 2 and RAR-gamma 1, gamma 2) by RA was examined by means of Northern blotting in the 11.5 day embryo and maternal tissues by administering pregnant rats with an excess of all-trans RA. The expression of RAR-beta isoforms as well as the RAR-beta total was auto-regulated by RA in all maternal tissues and embryos examined. The gene expression of RAR-alpha 2, which was not affected by RA in the maternal tissues, was up-regulated in embryos, though there were no significant effects of RA on the levels of RAR-alpha 1 and the alpha total in the maternal tissues and the embryos. Likewise, RA did not affect the levels of RAR-gamma 1 and gamma total. However, unlike RAR-alpha 2, RAR-gamma 2 expression was up-regulated by RA only in the maternal tissues. Thus, these results indicates that two retinoic acid receptor isoforms (RAR-alpha 2 and RAR-gamma 2) are differentially auto-regulated in embryo and adult rats.

Stapedial reflex in amyotrophic lateral sclerosis

OBJECTIVE

To examine mechanisms controlling the stapedial reflex in patients with amyotrophic sclerosis (ALS).

METHODS

The stapedial reflex was examined using impedance audiometry in 38 patients with sporadic ALS and in 25 age matched controls.

RESULTS

All patients showed normal reflex decay test results. There were no significant differences between patients with ALS and control subjects in reflex threshold, latency, amplitude, or contraction time (C50). Although each reflex variable in the patients with classic or progressive muscular atrophy types of ALS showed no significant difference from that in control subjects, the patients with bulbar type ALS showed significantly longer latency, C50, and retraction time (D50), and significantly lower amplitude than control subjects. Three types of abnormal reflex waveforms (polyphasic, abnormally delayed retraction, and abnormally early retraction) were noted in six patients.

CONCLUSION

The subclinical involvement of the stapedius motor neurons or of the supranuclear stapedius motor system might be responsible for the abnormalities of the stapedial reflex in ALS.

The distribution and architecture of lymphatic vessels in the rat stomach as revealed by an enzyme-histochemical method

Enzyme-histochemical methods of staining for 5'-nucleotidase (5'-Nase) and alkaline phosphatase (ALPase) were successfully applied to study the distribution and architecture of lymphatic vessels and their relationships to blood vessels in the rat stomach. Extensively lymphatic capillary networks were found in the gastric wall, but there were significant differences in their extent, pattern, distribution and structure in the four different zones: esophagus-stomach (E-S), forestomach-corpus (F-C), corpus-antrum (C-A) and antrum-duodenum (A-D). 5'-Nase-ALPase double staining revealed that the 5'-Nase-positive lymphatic vessels run in close proximity to ALPase-positive arteries and veins. The fine blood capillary network was located superficially to the lymphatic network within the same layer in the gastric wall. The abundant lymphatic network located in the deep lamina propria and the lamina muscularis mucosa was always closely associated with the base of the lowest gastric glands, and yet no interglandular lymphatic capillaries were encountered in the corpus or antrum. In contrast, fewer lymphatic capillaries were present in the lamina propria beneath the squamous epithelium of the forestomach. The distribution of the well-developed lymphatic networks with valve-like structures in the submucosa and subserosa exhibited typical features, i.e., the distribution was annular in the submucosa and fan-shaped in the subserosa in the antrum near the duodenum. Open junctions of lymphatic endothelial cells were seen in the deep lamina propria and submucosa. Collecting lymphatics containing valves were mainly located deep in the submucosa and subserosa. The deep lamina propria and submucosa may play a key role in lymph formation and interstitial tissue fluid homeostasis as well as in pathological processes in certain diseases. The present findings obtained by interstitially injecting ultra-fine carbon particle suspensions or Evans blue showed that a great deal of lymph drained into the lymphatics accompanying the left gastric artery. The existence of a forestomach may explain the complicated organization and constitution of lymphatic networks in the rat stomach.