Effects of denervation on cell-to-cell communication between acinar cells of rat submandibular salivary gland

Communication measured by electrical cell coupling and dye transfer decreased transiently 1 day after parasympathectomy and then recovered 2 days later. Parasympathectomy decreased communication again 2 weeks later, coinciding with a decrease in the wet weight of the gland, but sympathectomy did not affect it. Thus parasympathetic nerve activity may be required for the regulation and maintenance of cell-to-cell communication in the rat submandibular gland.

[Biliary excretion and clinical evaluation of cefoperazone in the biliary tract infections]

Biliary excretion Cefoperazone (CPZ) in a dose of 1 g was intravenously injected to each of 13 cases with obstructive jaundice. Entire bile was collected through percutaneous transhepatic cholangiodrainage (PTCD) catheter in every 1 hour for 6 hours. The mean concentration of CPZ in serum was 112.1 +/- 17.8 micrograms/ml (mean +/- S.E.) at 1 hour and 55.1 +/- 19.2 micrograms/ml at 6 hours after injection. The mean recovery of CPZ in bile within 6 hours was 1.13 +/- 0.60%. Average CPZ concentrations in bile were 64.0 +/- 45.8 micrograms/ml in the 1 hour fraction, 142.7 +/- 78.4 micrograms/ml in the 2 hours fraction and 72.2 +/- 34.0 micrograms/ml in the 6 hours fraction. Biliary excretion of CPZ was low in cases where the serum concentration of total bilirubin was high, but maximum CPZ level in bile in patients with higher serum bilirubin concentrations than 30 mg/dl was still more than 3 micrograms/ml. Clinical evaluation. CPZ was administered to 43 patients with biliary tract infections. The efficacy ratio was 88.4% (excellent and good cases) in all cases, and especially high in cases with cholecystolithiasis. But no difference in efficacy ratio was observed among cases with cholecystolithiasis, choledocholithiasis without gallstone and cases subjected to PTCD. In 10 patients examined by ultrasonography, 8 cases showed reduced diameters of gallbladder. No adverse effect of CPZ was noted in any cases. These results suggest that a fairly large portion of CPZ was excreted through bile and that CPZ is a very useful drug for the treatment of biliary tract infections.

Transepiphyseal plate osteotomy for severe tibia vara in children: follow-up study of four cases

Transepiphyseal plate osteotomy of the medial tibial condyle was performed in three children (four knees) with severe progressive tibia vara and excessive ligamentous laxity. Two knees with Blount disease underwent tibial valgus osteotomy and epiphysiodesis associated with transepiphyseal plate osteotomy, and two knees with pseudoachondroplasia underwent tibial valgus osteotomy. Follow-up study at the time of skeletal maturity revealed satisfactory alignment of the leg, favorable congruity of the joint, and good ligamentous stability in all cases. Our experience indicates that the present procedures are excellent, although there are very few documented cases and almost no description of the postoperative clinical courses.

Postoperative evaluation of quadriceps contracture in children: comparison of three different procedures

Sixty-five patients (73 legs) with quadriceps contracture involving mainly the rectus femoris muscle were operated on. The average follow-up was 6.3 years. In the postoperative overall results, the rating system score was significantly decreased from a preoperative mean of 7.0 points to a postoperative mean of 1.9 points. Three different operative methods were used: release of the pelvic origin, sartorius plasty and release of the pelvic origin, and sartorius plasty and release of the fibrosis. The most satisfactory results were obtained in the group treated by release of the fibrosis.

Intercellular communication capacity as a possible determinant of transformation sensitivity of BALB/c 3T3 clonal cells

While clonal cell variants of BALB/c 3T3 with high and low susceptibilities to ultraviolet radiation- and benzo(a)pyrene-induced transformation show similar intercellular communication capacities when they are in the growing phase, a significant loss in communication occurs at confluence only in transformation-sensitive clonal variant cells. A potent tumor promoter, 12-O-tetradecanoylphorbol-13-acetate, which also enhances BALB/c 3T3 cell transformation induced by methylcholanthrene, inhibited intercellular communication of these variants to a similar extent. These results suggest that intrinsic differences in the control of intercellular communication may be a determinant of the susceptibility of these variants to the induction of transformation.

Modulation of cell communication and carcinogenesis

In this paper, recent studies on the role of cell communication in cancer induction, particularly in two-stage carcinogenesis, were reviewed. Cell communication has been proposed to play an important role in cell growth and differentiation since its discovery. The recent finding that tumor promoters inhibit cell communication supports this possibility. The inhibition of cell communication by phorbol ester tumor promoters was also shown to correlate with enhancement of in vitro carcinogenesis in Balb/c 3T3 cells. This strongly suggests that the blocked cell communication may play a crucial causative role in the process of carcinogenesis. Accumulated evidence indicates that phorbol ester may induce blockage of cell communication through binding to its membrane receptor which is presumably Ca2+/phospholipid-dependent kinase. cAMP enhances cell communication and protects its inhibition by phorbol ester, presumably through activating cAMP-dependent kinase. This indicates the possibility that the two kinases may be key elements for physiological regulation of cell communication. It is proposed that the disturbance of the kinase systems by endogenous and exogenous factors may be responsible for the promotion phase of cancer induction. However, the true physiological role of cell communication in carcinogenesis remains to be demonstrated more directly. Especially, what kinds of molecules can pass through the gap junction and regulate cell functions in a cell community must be challenged in future. Some such molecules were speculatively described in this review.

Inhibition of cell communication between Balb/c 3T3 cells by tumor promoters and protection by cAMP

The effect of phorbol ester tumor promoters on the communication between individual cells in confluent culture was studied using a fluorescent dye transfer method. Cell-cell communication between mouse Balb/c 3T3 cells and between Chinese hamster V79 cells was inhibited almost completely by tumor-promoting phorbol esters, but not by nonpromoting derivatives; the effect was reversed upon removal of the promoter. Intercellular communication between Balb/c 3T3 cells, but not Chinese hamster V79 cells, was increased significantly in the presence of dbcAMP and caffeine, and these compounds counteracted the effects of tumor promoters. Inhibition of cell communication by phorbol esters appears to be receptor-mediated, since specific binding of 3H-phorbol-12,13-dibutyrate to Balb/c 3T3 cells was inhibited only by compounds that also inhibit intercellular dye transfer. A study with cycloheximide suggests that the reversible inhibition of intercellular communication by phorbol esters may not need de novo protein synthesis, while upregulation of communication by cAMP requires protein synthesis.

Inhibitory action of thyrotropin-releasing hormone on serum amylase activity and its mechanism

The effect of im administration of 500 micrograms TRH on serum amylase activity was studied in 34 normal women, 6 women with primary hypothyroidism, 1 woman with anorexia nervosa, 6 women with hyperthyroidism due to Graves' disease, and 5 women with renal failure on chronic hemodialysis. Serum amylase activity decreased significantly in 31 of 34 normal subjects 60 to 120 min after administration of TRH. However, amylase isoenzymes were not significantly affected after administration of TRH, suggesting that TRH equally affects pancreatic and salivary amylase activity. TRH was also effective in patients on chronic hemodialysis, indicating that TRH does not reduce serum amylase activity by increasing urinary excretion of amylase. Since TRH reduced serum amylase activity in hyperthyroid patients in whom TRH failed to stimulate TSH secretion, TRH does not reduce serum amylase activity through increased secretion of TSH. The action of TRH was not mediated by serum thyroid hormone levels since TRH was similarly effective in patients with hypothyroidism or hyperthyroidism. TRH did not inhibit or interfere with amylase determination when added in vitro to heparinized blood. Perfusion of the dog pancreas with TRH reduced amylase activity in pancreatic juice and pancreatic venous blood. The magnitude of the decrease was related to the dose of TRH used. Since decrease in amylase activity of the pancreatic juice preceded that in pancreatic venous blood, TRH probably directly acts on the pancreas to reduce amylase secretion. As a result, serum amylase activity decreased after administration of TRH.

Protective effect of cAMP on tumor promoter-mediated inhibition of cell-cell communication

The formation and maintenance of electrical cell coupling is inhibited by 100 ng/ml 12-O-tetradecanoylphorbol-13-acetate (TPA). This inhibition could be prevented by db-cAMP and aminophylline when added together with TPA, though they did not restore the cell coupling once it had already been blocked by TPA. It is suggested that db-cAMP affects the early membrane effects of TPA in FL cells.

Monoclonal antibody ECCD-1 inhibits intercellular communication in teratocarcinoma PCC3 cells

The monoclonal antibody ECCD-1 recognizing a certain class of cell surface proteins inhibits the Ca2+-dependent cell-to-cell adhesion in teratocarcinoma stem cells. In this paper, we studied the effect of ECCD-1 on cell-to-cell communication in PCC3 cells by measuring the transfer of lucifer yellow between cells. To this aim, PCC3 cells were cultured in the presence of ECCD-1 for various periods, and then the fluorescent dye was injected into a cell located in the center of cell colonies, followed by counting number of cells to which the dye was transferred. The results showed that ECCD-1 inhibits the dye transfer between cells, suggesting that the Ca2+-dependent cell-to-cell adhesion system (CDS) is essential for the functions of gap junction.

Tumour promoter-mediated reversible inhibition of cell-cell communication (electrical coupling). Relationship with phorbol ester binding and de novo macromolecule synthesis

A tumour promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA), reversibly inhibits the onset and maintenance of cell-cell communication measured by electrophysiological method. We have now studied the mechanism by which TPA inhibits communication of human cells (FL) in culture. Using [3H]phorbol-12,13-dibutyrate [( 3H]PDBu), we found a class of specific, high-affinity, saturable binding sites in intact FL cells; they have a dissociation constant of 15.4 nM, and at saturation about 3 X 10(5) PDBu molecules were bound to each cell. The binding of [3H]PDBu to FL cells was inhibited by TPA, phorbol-12-13-didecanoate and mezerein, whereas phorbol and 4 alpha-phorbol-12-13-didecanoate had no effect. There is a close correlation between the ability of the former compounds to inhibit [3H]PDBu binding and their capacity to inhibit cell-cell communication. When FL cells are dispersed with EDTA and plated onto a culture dish, they start to couple electrically within 2 h; such cell coupling was not affected by the presence of cycloheximide or actinomycin D. TPA inhibits the formation of electrical cell coupling as well as its maintenance, even in the presence of cycloheximide; the recovery of cell-cell communication after the removal of TPA was not significantly affected by the addition of cycloheximide or actinomycin D. Taken together, these results suggest that TPA-mediated reversible inhibition of intercellular communication is mediated by specific binding of TPA to cellular receptors and that macromolecular synthesis is not necessary.

Tumor promoters cause a rapid and reversible inhibition of the formation and maintenance of electrical cell coupling in culture

The effect of tumor promoters on electrical coupling between human FL cells was investigated with a microelectrode technique. When a low concentration (100 ng/ml) of 12-O-tetradecanoylphorbol 13-acetate (TPA) was added to culture medium, only 6% of the cells showed electrical coupling after 5 hr, whereas in control medium more than 90% of the cells were coupled. In the presence of TPA, cell coupling remained suppressed for at least another 19 hr. When TPA was washed out from the culture medium, the cells commenced electrical coupling: 90% of the cells were coupled within 4 hr of the removal of TPA, a rate very similar to that of nontreated control cells. Therefore, TPA-mediated inhibition of cell coupling is reversible. When TPA was added to a culture in which more than 90% of the cells had already established electrical coupling, the percentage of coupled cells decreased to 6% within 8 hr, indicating that TPA can also diminish already established cell coupling. Inhibition of cell coupling also was achieved with other mouse skin tumor promoters--phorbol 12,13-didecanoate, ingenol dibenzoate, and mezerein--whereas nonpromoting derivatives--phorbol and 4 alpha-phorbol 12,13-didecanoate-showed no effect. None of these compounds changed the membrane potential, membrane resistance, or growth rate of FL cells. Thus, it appears that TPA and structurally-related tumor promoters specifically disturb the formation or function, or both, of cell-cell junctions, without significantly affecting the general properties of the surface membrane or the growth of FL cells.

Inhibition of the formation of electrical cell coupling of FL cell by tumor promoters

The effect of tumor promoters on the formation of electrical cell coupling between human FL cells was investigated by means of a microelectrode technique. In culture medium containing 100 ng/ml of 12-O-tetradecanoyl phorbol-13-acetate (TPA), only 6% of the cells were coupled after 24 hr while more than 90% of the cells were coupled in control medium. The formation of cell coupling was also inhibited by other tumor promoters, phorbol-12,13-didecanoate, ingenol-13, 20-dibenzoate and mezerein, whereas non-promoting derivatives, phorbol and 4 alpha-phorbol-12, 13 didecanoate did not affect cell coupling formation. 7, 12-Dimethylbenz [a] anthracene, benzo [a] pyrene and N-methyl-N'-nitro-N-nitrosoguanidine did not affect the cell coupling. None of the chemicals used changed any electrical properties of the cell membrane, such as membrane potential and membrane resistance, of FL cells. Thus, it appears that TPA and other related tumor promoters inhibit the formation of cell coupling without changing the physiological properties of the membrane significantly.

[Estimation of the urinary aldosterone (author's transl)]

The urinary aldosterone (ALD) was measured by aldosterone RIA kit and the following results were obtained. (1) We have known that ten percent solution of bovine serum albumin (BSA) instead of free serum LAD is used as the diluent of the urine in aldosterone RIA kit. (2) The upper limits of free ALD, HCl-ALD and beta-glucuronidase ALD in the urine diluted with 10% BSA were 1.6, 9.0 and 9.5 micrograms/dl respectively. (3) The values of urinary conjugated HCl-ALD and beta-glucuronidase ALD were approximately 3.5 times and 4 times as much as that of free ALD respectively. (4) A good correlation was obtained among the results of three methods (HCl-ALD, beta-glucuronidase ALD and free ALD). (5) No difference was found in the values of the urinary ALD in the healthy subjects and the patients with essential hypertension, kidney diseases and acute liver diseases.

A scanning and transmission electron microscope study of the premetamorphic papillae: possible chemoreceptive organs in the oral cavity of an anuran tadpole (Rana japonica)

Premetamorphic papillae of an anuran tadpole (Rana japonica) were studied by scanning and transmission electron microscopy. Premetamorphic papillae of several shapes are seen in and around the oral cavities of tadpoles during late larval and early metamorphic stages. These papillae are composed of three parts: the apical cellular part, the underlying connective tissue core and the epithelial covering. In the apical cellular part, two populations of cells are observed: apical and basal cells. The apical cell has a slender cytoplasmic process whose apical surface is exposed in the oral cavity. The basal cell is located at the basal portion of the apical cellular part of the papilla without researching the oral cavity. A long solitary microvillus and a bunch of short microvilli are seen on the apical surface of each apical cell. The apical cells contain dense-cored vesicles of 100 nm diameter and make synaptic contacts at their basal membranes with terminals of nerve fibers. Possible chemoreceptive function of the premetamorphic papilla is discussed.

The cell-to-cell channel

Cells of most organized tissues are interconnected at their junctions by aqueous membrane channels, shown in one instance to be at least 14--16 A in diameter. During junction formation, nascent channels are detected as quantal steps in cell-to-cell conductance, growing progressively in number. The channels detected are stable. Elevation of cytoplasmic free Ca2+ concentration can cause graded closure of channels.

Quantum jumps of conductance during formation of membrane channels at cell-cell junction

The cell-to-cell conductance of a nascent cell junction increases by stable quantal steps. The steps evidently reflect the opening of stable cell-to-cell channels, all alike and growing progressively in number.

Further study on the effect of mersalyl, an organic mercurial, on relaxing response of a molluscan smooth muscle to monoamines

The effect of mersalyl on the relaxation of catch by various monoamines was studied in the anterior byssal retractor muscle of Mytilus. As has already been reported, mersalyl blocked the relaxing response to indoleamines but not block that to catecholamines. The relaxations in response to catecholamine-related compounds (dopa, octopamine, tyramine, phenylephrine, beta-phenylethylamine and phenylethanolamine) and hexylamine were, however, antagonized more or less effectively with mersalyl. It was suggested that the catecholamine-related compounds and hexylamine can act on relaxing nerve endings to increase neurotransmitter serotonin in the junctional clefts, and mersalyl antagonizes the relaxation in response to these compounds by blocking the serotonin.

Effects of heavy metal ions on the electrical properties of mucous epithelial cells in the newt stomach

Zinc ion, Cu2+ and Cd2+ at 10(-4) M or lower concentrations caused a marked decrease in the membrane potential of mucous epithelial cells in the isolated newt stomach without appreciable change in the effective membrane resistance and electrical coupling ratio. Cysteine and acetylpenicillamine antagonized the action of these ions. These ions as well as ouabain blocked the hyperpolarization of membrane due to an increase in intracellular Na+. The effect of the ions on the relationship between external K+-concentration and membrane potential was similar to that of ouabain. Discussion is made on the possibility that the ions inhibit active ion transport by combining with a SH-group of the cell membrane and, thus, bring about a decrease in membrane potential.

The relationship between membrane potential and ATP content in rat liver during ischemia

Both ischemia and ethionine decreased the membrane potential and ATP content in rat liver. In ethionine-treated rat liver, ischemia brought about a further decrease in membrane potential without significant decrease in ATP content.

Energy requirement for the maintenance of membrane potential in rat liver cells in situ

The transmembrane potential of female rat liver cells in situ was-52.4 mV. This was decreased to -42.9 mV by ethacrynic acid (4 mg/100 g), but not by ouabain (1 mg). DL-Ethionine (25-100 mg) caused a decrease in the membrane potential and tissue ATP content. A high dose ethionine (100 mg) increased tissue Na content and decreased K content. By applying adenine (25 mg) to the animals treated with ethionine (100 mg), the membrane potential, ATP content and K content were increased and the Na content was decreased. The repolarized membrane potential in the animals treated with adenine following the ethionine was again depolarized by the administration of ouabain, but not by the administration of ethacrynic acid. These results suggest that two kinds of active ion transport mechanisms, ethacrynic acid-sensitive and ouabain-sensitive mechanisms, may be involved in maintenance of the membrane potential of rat liver cells.