An in vitro rat colonic sac method developed in this study was found to be suitable for frequent collection of samples and determination of transpott of compounds from serosal and mucosal medium, since the volume of both was large. Under no a treatment condition, both cefmetazole and inulin penetrated the intestinal mucosa via the paracellular route, but did so very poorly. Phenothiazines as well as disodium ethylenediaminetetraacetic acid increased the transport of cefmetazole and inulin, probably via the paracellular route, while diethyl maleate increased the transport of only cefmetazole, probably via the intracellular route. The effect of phenothiazines in increasing the clearance rate for both cefmetazole and inulin showed dependency on their initial concentrations in the mucosal medium with maximum action at a concentration of 30 μM for trifluoperazine, 20 μM for perphenazine, 75 μM for profenemine and 50 μM for propericiazine.

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Antitumor activity of grifolan NMF-5N, a β-1, 3-glucan obtained from mycelia of Grifola frondosa, was examined. Grifolan NMF-5N showed antitumor activities in allogeneic and syngeneic murine tumor systems. In the allogeneic tumor system, a potent antitumor activity over 95% was observed against the solid form of sarcoma 180 when grifolan NMF-5N was injected intraperitoneally (i.p.) at 25-200 μg/mouse daily for 10 successive days. In the syngeneic tumor systems, significant antitumor activities were observed against Meth A fibrosarcoma and MM 46 carcinoma by injection at 100 μg/mouse daily for 5 successive days, especially i.p. injection at day 7-11, when the tumor cells were inoculated subcutaneously (s.c.) on day 0. Moreover, when grifolan NMF-5N was injected i.p. every other week, significant antitumor activity was also observed. In addition, a single treatment with grifolan NMF-5N at 500 μg/mouse showed antitumor activities. Grifolan NMF-5N exhibited antitumor activities against these two syngeneic tumors by intraveneous (i.v.) injection. However, a marked inhibitory activity was observed by intratumorous (i.t.) injection against Meth A fibrosarcoma but not against MM46 carcinoma. These results suggest that antitumor activities of grifolan NMF-5N in murine syngeneic tumor systems depend on not only dosage but also injection routes and timing.

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The possible involvement of sulphatides (CS), phosphatidylserine (PS) and phosphatidylinositol (PI) in [³H] tryptamine binding to various reconstituted fractions of these acidic lipids was examined by Sephadex LH₂₀ column chromatography. The results indicated that each of the four systems, PS, PS-CS, PS-PI and PS-CS-PI, had the same binding capacity for [³H] tryptamine, whereas other systems (CS, PI and CS-PI systems) had no binding capacity. Furthermore, competitive inhibition experiments revealed that among these four reconstituted systems, the PS-CS system exhibited the highest affinity for 5-methoxytryptamine. Kinetic studies suggested that at least two binding components (or sites) are implicated in the binding of [³H] tryptamine to the reconstituted system of PS and CS with apparent K_D values of 3 and 10 nM. Displacement studies with various compounds indicated that only tryptamine and 5-methoxytryptamine inhibited the [³H] tryptamine binding to this fraction, while other indoleamine analogues and neurotransmitters had no effect. In addition, we subjected whole rat brain synaptic plasma membranes to treatment with several kinds of lipid-modifying reagents and examined the [³H] tryptamine binding capacities of the membranes by a radioreceptor-binding assay. [³H] Tryptamine binding was decreased by treatment with Azure A and phospholipase A₂, while phospholipase D had no effect. All these observations led to the inference that PS and CS may be involved in the tryptamine binding activities as recognition sites.

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The mechanisms of absorption enhancing effect by polyacrylic acid gel were investigated in rats. Polyacrylic acid gel significantly enhanced rectal absorption of phenol red, a hydrophilic compound. The enhanced absorption was concentration dependent in the range of 0.01-0.05% w/v polyacrylic acid in gel. The gel also significantly increased the influx and the net influx on water movement in rat rectum. Further, the histological change in rectal epithelium after administration of the polyacrylic acid gel was examined with transmission electron microscopy. The structural changes, which were removal of the mucus and fenestrations of the intercellular spaces 5 and 10 min after administration of polyacrylic acid gel, were observed. These changes were reversible and returned relatively soon to normal levels. Thus, the absorption promoting effect by polyacrylic acid gel may occur mainly with increased water influx as a driving force.

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A metalloproteinase was extracted from a medium of cultured gastric tissues following acetic acid-induced ulcer or taurocholic acid-induced gastritis, and the enzyme was partially purified by Sephadex G-200 column chromatography. This proteinase was released in active and latent forms with apparent molecular weights of 170000 and 210000, respectively. Its activity was abolished by treatment with ethylenediaminetetraacetic acid or 1, 10-phenanthroline, but not with phenylmethylsulfonyl fluoride or soybean trypsin inhibitor. This enzyme degraded type I gelatin and type IV collagen but did not attack type I collagen. In contrast, very little of this enzyme was released from gastric tissue following erosion caused by water-immersion stress or from normal gastric tissue. These results suggest that this metalloproteinase plays an important role in gastric lesions by breaking down the basement membrane.

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The effect of barbiturates on an adenylate cyclase system in rat brain was examined. The activity of the catalytic unit of this system isolated from the synaptic membrane was inhibited by phenobarbital in dose- and time-dependent manners. The mode of the inhibition was non-competitive with respect to Mg-adenosine triphosphate (ATP). The activity of the synaptic membrane-bound adenylate cyclase was also inhibited by phenobarbital in a similar manner. The inhibitory effect of phenobarbital was more potent on the activation of the enzyme by 5'-guanylylimidodiphosphate (GppNHp) than on the basal enzyme activity. The inhibitory effect, however, was not observed in the synaptic membrane preparation in which the guanine nucleotide-binding stimulatory regulatory protein (N_s) and the catalytic unit of adenylate cyclase system had been functionally coupled by pretreatment with GppNHp. Similar results were obtained with other pharmacologically active barbiturates. These findings indicate that barbiturates primarily affect the activation of the catalytic unit by an interaction with N_s resulting in the inhibition of the enzyme activity.

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Mite dialysate prepared from an extract of house dust mite, Dermatophagoides farinae, suppressed 48-h homologous passive cutaneous anaphylaxis (PCA) in rats caused by a non-dialyzable fraction of the mite extract (mite antigen), and the suppression was dosedependent with a high specificity for the antigen. The mite dialysate itself slightly elicited the PCA. Fraction 3 obtained from the mite dialysate by means of DEAE-Sephadex A-25 column chromatography suppressed PCA in rats and guinea pigs more potently than mite dialysate. Histamine release from sensitized rat peritoneal exudate cells (PEC) induced by the mite antigen was suppressed in a dose-dependent manner when the PEC had been previously incubated with fraction 3. However, incubation of the PEC with fraction 3 caused a significant release of histamine compared to the spontaneous value. Fraction 3 clearly inhibited the passive hemagglutination of the mite antigen-conjugated sheep red blood cells caused by rat hyperimmunized serum. From these results it was considered that certain haptenic substances might be present in the mite dialysate.

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