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Dai S, Yu C, Li D, Shen Z, Fang S, Jin J. Phase transition and electron localization in 1T-TaS2. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:1578-1583. [PMID: 9981219 DOI: 10.1103/physrevb.52.1578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Christensen J, Fang S, Rick GA. NADPH-diaphorase-positive nerve fibers in smooth muscle layers of opossum esophagus: gradients in density. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1995; 52:99-105. [PMID: 7542293 DOI: 10.1016/0165-1838(94)00149-e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Nitric-oxide-releasing nerves regulate esophageal smooth muscle function. The density of such nerve fibers may differ in the different functional parts of the esophagus. We used both inspection and gray-scale analysis of digitized images to seek differences in density of such nerve fibers, stained for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase), between esophageal body and esophago-gastric sphincter and between smooth muscle layers in the opossum esophagus. Sections of Swiss roll preparations of the entire organ were stained for NADPH-diaphorase and for immunoreactivity to vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), galanin (GAL), substance P (SP) and constitutive nitric oxide synthase (cNOS). In the circular muscle layer, NADPH-diaphorase-positive fibers were most abundant at the cephalic end of the esophageal body with a significant decline toward and through the esophago-gastric sphincter. In the longitudinal muscle layer and the longitudinally-oriented muscularis mucosae, NADPH-diaphorase-positive nerve fibers were most abundant at the esophago-gastric sphincter with a significant decline toward and through the striated-smooth muscle junction. cNOS immunoreactivity co-localized with NADPH-diaphorase activity. Fibers stained for CGRP immunoreactivity were distributed like the NADPH-diaphorase-positive fibers. Fibers stained for immunoreactivity to the other peptides (VIP, GAL, SP) showed no clear differences in distribution along the esophagus in any of the muscle layers.
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Khudyakov Yu E, Khudyakova NS, Jue DL, Lambert SB, Fang S, Fields HA. Linear B-cell epitopes of the NS3-NS4-NS5 proteins of the hepatitis C virus as modeled with synthetic peptides. Virology 1995; 206:666-72. [PMID: 7530398 DOI: 10.1016/s0042-6822(95)80086-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A set of 150 synthetic peptides spanning the proteins NS3-NS4-NS5 of the hepatitis C virus (HCV) was synthesized and tested with a panel of 20 sera obtained from HCV-infected patients. Of 62 peptides prepared from the NS3 region, none exhibited strong antigenic reactivity. Rather, five peptides from this region demonstrated specific reactivity with only 5-10% of anti-HVC-positive sera. Nonetheless, it is well known that the NS3 region contains strong antigenic epitopes. These epitopes appear to be modeled in a functionally active manner with recombinant proteins and cannot be mimicked properly with short synthetic peptides. This finding suggests that the major NS3 antigenic epitopes are conformationally dependent. Seven of 20 peptides prepared from the NS4 region were immunoreactive. Five peptides from this region demonstrated very strong HCV-specific antigenic reactivity. Four of the five peptides belong to the recognized immunoreactive 5-1-1 region located inside the C100-3 antigen. One peptide demonstrating immunoreactivity with approximately 90% of anti-HCV-positive sera was found outside the C100-3 region at the C-terminal part of the NS4 protein. Of 68 peptides synthesized from the NS5 protein, 30 were immunoreactive. Six of the 30 demonstrated immunoreactivity with 35-50% of anti-HCV-positive sera. Thus, the NS4 and NS5 regions of the HCV polyprotein contain a large number of specific, broadly reactive, linear antigenic epitopes. The highly antigenic reactivity of the NS5 region suggests that this protein may have significant diagnostic potential.
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Christensen J, Fang S. Colocalization of NADPH-diaphorase activity and certain neuropeptides in the esophagus of opossum (Didelphis virginiana). Cell Tissue Res 1994; 278:557-62. [PMID: 7531620 DOI: 10.1007/bf00331374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Nitric oxide and various neuropeptides in the myenteric plexus regulate esophageal motility. We sought colocalization of nitric oxide synthase and neuropeptides in frozen sections of mid-portion of smooth-muscled opossum esophagus using NADPH-diaphorase activity to mark the synthase and immunoreactivity to detect peptides. The peptides, all with demonstrated physiological activity in this organ, were calcitonin gene-related peptide, galanin, neuropeptide Y, substance P, and vasoactive intestinal polypeptide. The ExtrAvidin Peroxidase immunostain for each peptide was carried up to the final peroxidase reaction with 3-amino-9-ethyl-carbazole. The NADPH-diaphorase reaction was applied with short incubation to provide light staining just before the peroxidase reaction was performed. We examined sections for the proportions of singly and dually labeled nerve cells in the myenteric plexus. NADPH-diaphorase activity was highly colocalized with calcitonin gene-related peptide (59%), galanin (54%), and vasoactive intestinal polypeptide (53%). It showed little colocalization with neuropeptide Y (10%) and substance P (8%). The proportions of all nerve cells containing each of the substances were: NADPH-diaphorase--33%, calcitonin gene-related peptide--30%, galanin--55%, neuropeptide Y--16%, substance P--35%, and vasoactive intestinal polypeptide--58%. We conclude that the nerves responsible for peristalsis in the esophagus may act by releasing nitric oxide along with other inhibitory substances, calcitonin gene-related peptide, galanin, and vasoactive intestinal polypeptide, but not excitatory substances, neuropeptide Y and substance P.
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Fang S, Ledlow A, Murray JA, Christensen J, Conklin JL. Vasoactive intestinal contractor: localization in the opossum esophagus and effects on motor functions. Gastroenterology 1994; 107:1621-6. [PMID: 7958671 DOI: 10.1016/0016-5085(94)90800-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND/AIMS Vasoactive intestinal contractor (VIC), an endothelinlike peptide and a putative gastrointestinal hormone, contracts gastrointestinal smooth muscle. The aim was to study VIC in relation to esophageal function. METHODS Intramural nerves in opossum esophageal smooth muscle strips were stimulated in the presence of various concentrations of VIC and were stained for VIC immunoreactivity. RESULTS VIC caused an atropine-resistant increase in the amplitude of nerve-induced contractions of the circular muscle. VIC alone contracted longitudinal muscle, and this effect was nearly eliminated by 1 mmol/L atropine. VIC caused an atropine-resistant increase in the resting tone of the lower esophageal sphincter muscle, but it did not affect nerve-induced relaxation of that muscle. VIC-immunoreactive nerve fibers occurred in the longitudinal muscle layer, in the muscularis mucosae, and around the ducts of esophageal glands. A few such fibers were found in the circular muscle layer. Nerve fibers and cell bodies of the myenteric plexus showed VIC immunoreactivity. In the stomach, immunoreactive nerve fibers occurred in muscularis mucosae and circular muscle but not in longitudinal muscle. CONCLUSIONS VIC is localized in neuronal elements of the opossum esophagus and excites contractions in esophageal smooth muscle.
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Fang S, Christensen J, Conklin JL, Murray JA, Clark G. Roles of Triton X-100 in NADPH-diaphorase histochemistry. J Histochem Cytochem 1994; 42:1519-24. [PMID: 7930535 DOI: 10.1177/42.11.7930535] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Triton X-100 is widely but not universally used in NADPH-diaphorase histochemical staining. We investigated its effect on the staining and examined nitroblue diformazan (NBF) production under the influence of Triton X-100. Exposure of opossum esophagus, intestine, and colon tissues to Triton X-100 before staining enhanced staining of nerve cells and fibers and suppressed staining of non-neural structures. Long exposures and high concentrations nearly abolished the staining of non-neural structures and decreased the staining of nerves. The use of an incubation medium containing Triton X-100 achieved the best staining of nerve cells and fibers. Addition of Triton X-100 to the incubation medium changed its color from yellow to purple; in the presence of tissues, this color change occurred much more quickly. Spectral analysis showed that Triton X-100 increases the rate of NBF formation in the presence of tissue supernatant. Triton X-100 increases it less in the absence of tissue supernatant. Therefore, Triton X-100 improves the histochemical staining, probably by catalyzing the activity of NADPH-diaphorase, by keeping the extracellular NBF in solution and thus suppressing the staining of non-neural structures, and by increasing the permeability of cell membranes.
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Knapp RJ, Malatynska E, Peterson P, Zalewska T, Fang S, Hruby VJ, Smith TL, Yamamura HI. [N-methylnorleucine-(28,31)]cholecystokinin-(26-33) (SNF 8702) activity at a cloned rat CCKB receptor. Eur J Pharmacol 1994; 269:133-8. [PMID: 7851490 DOI: 10.1016/0922-4106(94)90079-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
[N-methyl-Nle 28,31)]cholecystokinin-(26-33) (SNF 8702) is a highly selective ligand for the CCKB type of receptor present in the vertebrate central nervous system. Radioligand binding data showing that SNF 8702 binding affinity is reduced by the GTP analog guanylyl-imidodiphosphate suggest that SNF 8702 is an agonist but the ability of SNF 8702 to activate CCKB receptors has not been demonstrated. The present study shows that SNF 8702 is a highly potent agonist at rat CCKB receptors expressed on COS-7 cells and that these receptors are coupled to the mobilization of intracellular calcium. The A50 measured for SNF 8702-induced calcium mobilization (66 pM) is over 6-fold less than that of cholecytstokinin octapeptide (420 pM). Data are also presented showing that SNF 8702 has high binding affinity for these receptors with a Kd value (760 pM) consistent with previous measurements using guinea pig brain tissue preparations.
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Wohlhueter RM, Parekh K, Udhayakumar V, Fang S, Lal AA. Analysis of binding of monoclonal antibody to a malarial peptide by surface plasmon resonance biosensor and integrated rate equations. THE JOURNAL OF IMMUNOLOGY 1994. [DOI: 10.4049/jimmunol.153.1.181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Using biosensor technology and integrated rate equations, we have developed procedures to determine the kinetic parameters and equilibrium affinity constant of Ag-Ab interactions. The Ag used in these studies was a peptide that represents the major B cell epitope of the circumsporozoite protein of Plasmodium falciparum, a promising malaria vaccine candidate Ag. Measurements of association and dissociation rate constants of this peptide with the mAb 2A10 were determined by fitting integrated rate equations to binding data obtained with a BIAcore surface plasmon-resonance biosensor. We examined whether accurate estimates of initial velocity and final equilibrium levels of binding of Ab to peptides can be obtained using these methods, and whether kinetic rates and equilibrium constants obtained with systematic variation of the experimental parameters conform to a simple bimolecular model of binding. We found that initial velocity was approximately first order with respect to Ab concentration. When we used a series of four sensor cells with different peptides loads, however, we found that the initial velocity of binding appeared to be nearly independent of peptide concentration. Equilibrium analyses yielded dissociation constants of approximately 3 x 10(-7) M. Integrated rate treatment of biosensor data supports a critical examination of the assumptions on which the binding models are based and suggests a need to refine such models. Nevertheless, it provides a powerful quantitative tool for assessing the Ag-Ab binding reaction.
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Wohlhueter RM, Parekh K, Udhayakumar V, Fang S, Lal AA. Analysis of binding of monoclonal antibody to a malarial peptide by surface plasmon resonance biosensor and integrated rate equations. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1994; 153:181-9. [PMID: 8207235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Using biosensor technology and integrated rate equations, we have developed procedures to determine the kinetic parameters and equilibrium affinity constant of Ag-Ab interactions. The Ag used in these studies was a peptide that represents the major B cell epitope of the circumsporozoite protein of Plasmodium falciparum, a promising malaria vaccine candidate Ag. Measurements of association and dissociation rate constants of this peptide with the mAb 2A10 were determined by fitting integrated rate equations to binding data obtained with a BIAcore surface plasmon-resonance biosensor. We examined whether accurate estimates of initial velocity and final equilibrium levels of binding of Ab to peptides can be obtained using these methods, and whether kinetic rates and equilibrium constants obtained with systematic variation of the experimental parameters conform to a simple bimolecular model of binding. We found that initial velocity was approximately first order with respect to Ab concentration. When we used a series of four sensor cells with different peptides loads, however, we found that the initial velocity of binding appeared to be nearly independent of peptide concentration. Equilibrium analyses yielded dissociation constants of approximately 3 x 10(-7) M. Integrated rate treatment of biosensor data supports a critical examination of the assumptions on which the binding models are based and suggests a need to refine such models. Nevertheless, it provides a powerful quantitative tool for assessing the Ag-Ab binding reaction.
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160
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Knapp RJ, Malatynska E, Hashimoto S, Fang S, Hunt M, Wamsley JK, Peterson P, Zalewska T, Hruby VJ, Yamamura HI. [3H]SNF8702 autoradiography of CCK-B receptors in guinea pig brain and studies with a cloned rat CCK-B receptor. Ann N Y Acad Sci 1994; 713:380-3. [PMID: 8185194 DOI: 10.1111/j.1749-6632.1994.tb44099.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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161
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Marshall J, Fang S, Ostedgaard LS, O'Riordan CR, Ferrara D, Amara JF, Hoppe H, Scheule RK, Welsh MJ, Smith AE. Stoichiometry of recombinant cystic fibrosis transmembrane conductance regulator in epithelial cells and its functional reconstitution into cells in vitro. J Biol Chem 1994; 269:2987-95. [PMID: 7507932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have generated several clones of Chinese hamster ovary, mouse epitheloid C127, and pig kidney epithelial LLCPK1 cells producing high levels of functional recombinant human cystic fibrosis transmembrane conductance regulator (CFTR). Processing of CFTR to the mature and fully glycosylated form in these cells is inefficient with only approximately 40% of all newly synthesized CFTR being converted to the mature form. Furthermore, expression of the most frequent mutant allele of the cystic fibrosis (CF) gene, the delta F508 mutant in these epithelial cells, indicated that it is biosynthetically arrested at the endoplasmic reticulum and fails to traffic to the plasma membrane. Using a combination of CFTR mutants and monoclonal antibodies, all the detectable recombinant CFTR in these cells was determined at least under the conditions used, to be present as a monomer. To demonstrate the feasibility of protein replacement therapy, we were able to effect the physical transfer of functional recombinant CFTR produced in Chinese hamster ovary cells to the plasma membranes of Ha3b fibroblasts, a cell line devoid of cAMP-stimulated chloride channels. Transfer of CFTR was mediated by the hemagglutinin viral fusion protein of influenza virus present on the Ha3b cells. Efficiency of transfer was up to 25% of the target cells, and CFTR chloride channel activity was detectable for up to 12 h post-fusion. Therefore, with the development of an appropriate formulation of fusogenic proteoliposome or virosome containing reconstituted purified CFTR, it should be feasible to introduce functional CFTR into CF-affected cells.
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Fang S, Christensen J. Distribution of NADPH diaphorase in intramural plexuses of cat and opossum esophagus. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1994; 46:123-33. [PMID: 8120336 DOI: 10.1016/0165-1838(94)90149-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Nonadrenergic noncholinergic (NANC) nerves, releasing nitric oxide (NO), regulate peristalsis in esophageal smooth muscle. The NADPH diaphorase reaction identifies nitric oxide synthase (NOS). NO-synthesizing (NANC) nerves should be more abundant in esophageal smooth muscle than in striated muscle. We used NADPH diaphorase histochemistry in whole-mounts of the esophagus of cat (predominantly striated muscle) and opossum (predominantly smooth muscle) to compare striated and smooth muscle regions. In the opossum myenteric plexus, 90% of nerve cells were stained, with two populations, dark-staining and light-staining cells. Dark cells constituted 35-51% of stained cells with no difference between striated muscle and smooth muscle regions. In the cat myenteric plexus, 50% of cells were unstained in the striated muscle segment, but only 10% in the smooth muscle segment. Stained cells constituted two populations, dark cells and light cells, dark cells making up 48-60% of stained cells in both striated and smooth muscle segments, with no difference between segments. Both dark cells and light cells lay in clusters in opossum, but not in cat. Dark cells showed no selectivity for large or small ganglia of myenteric plexus in either region in opossum. Many more NADPH diaphorase positive nerve fibers lay in the circular smooth muscle layer than in the other layers. They were not found in striated muscle. Interstitial cells of Cajal in the circular layer of smooth muscle were also positive. In the submucosal plexus of opossum, all cells were stained, 10% being dark cells in both striated and smooth muscle segments. The cat has almost no nerve cells in the submucosal plexus. The similarity of the myenteric plexus in striated muscle and smooth muscle regions of the esophagus suggests that NADPH diaphorase positive nerves have other functions besides regulation of smooth muscle. Also, a positive reaction may not dictate that NO is the sole transmitter released.
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Fang S, Wu R, Christensen J. Intramucosal nerve cells in human small intestine. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1993; 44:129-36. [PMID: 8227952 DOI: 10.1016/0165-1838(93)90025-p] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We investigated the intramucosal nerve cells of the human small intestine with histochemical methods to demonstrate nicotinamide adenine dinucleotide diaphorase and acetylcholinesterase and with morphometry. Intramucosal neurons appeared as solitary cells or in small groups, especially in the ileum. Most intramucosal nerve cell bodies were round or oval; some were flat or spindle-shaped. They mostly lay close to the muscularis mucosae, but some were located within the muscularis mucosae and others were some distance away from it. The processes of some mucosal neurons projected towards the submucosa. Most mucosal nerve cells showed acetylcholinesterase activity. The frequency distribution of nerve cell profile areas in the intramucosal cells in the duodenum differed from that of cells in the ileum (P < 0.001). There were more large mucosal nerve cells in the mucosa of the duodenum than in the ileum. There was no significant difference between the frequency distributions of cell profile areas of cells of the mucosa and cells of Meissner's and Henle's plexuses in the same region. We conclude that intramucosal nerve cells, similar to those of the submucosal plexus, exist in the human small intestine. The size of intramucosal nerve cell profiles differs between the duodenum and ileum. This is consistent with their possible different functions.
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Sato M, Abe K, Yasujima M, Omata K, Fang S, Tsunoda K, Kudo K, Takeuchi K, Hagino T, Kanazawa M. Inhibitory effect of cicletanine on vascular smooth muscle cell proliferation. ARCHIVES DES MALADIES DU COEUR ET DES VAISSEAUX 1989; 82 Spec No 4:63-6. [PMID: 2514671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We investigated the effect of cicletanine on vascular smooth muscle cell proliferation. In cultured vascular smooth muscle cells from rat mesenteric artery, cicletanine (10(-5) to 10(-4) M) increased prostacyclin synthesis (measured as 6-keto-PGF1 alpha by radioimmunoassay) dose-dependently. When added to cells in which mitogenesis was activated by 10% fetal bovine serum, cicletanine (3.3 x 10(-5) to 10(-4) M) inhibited [3H] thymidine incorporation up to 31% of the control level. Inhibitory effect of cicletanine on mitogenesis was also confirmed at 48 h by cell counts (control: 18965 +/- 629, cicletanine 10(-4) M: 14840 +/- 430, n = 6). The effect of cicletanine on platelet-derived growth factor (PDGF)-stimulated [3H] thymidine incorporation was not abolished by prostaglandin synthesis inhibition with aspirin, but the prostacyclin analogue OP-41483 (125-1000 ng/ml) inhibited it dose-dependently. Calcium entry blockers, nifedipine (3.3 x 10(-6) M) and diltiazem (10(-4) M), inhibited both [3H] thymidine incorporation and cell proliferation, while furosemide did not affect it. Cicletanine also inhibited PDGF-stimulated [3H] thymidine incorporation in cultured glomerular mesangial cells. We conclude that cicletanine stimulates prostacyclin synthesis and inhibits cell proliferation in cultured vascular smooth muscle cells, which may possibly be related to the intracellular calcium mobilization. Such a property might be contributory to the antihypertensive activity of cicletanine.
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165
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Fang S, Abe K, Omata K, Yasujima M, Yoshinaga K. The effects of aging on urinary kallikreins and other vasoactive substances in essential hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1989; 247B:139-44. [PMID: 2692411 DOI: 10.1007/978-1-4615-9546-5_23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Sato M, Abe K, Takeuchi K, Yasujima M, Fang S, Kanazawa M, Yoshida K, Yoshinaga K. Papillary collecting tubule responsiveness to vasoactive hormones in spontaneously hypertensive rats. JOURNAL OF HYPERTENSION. SUPPLEMENT : OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF HYPERTENSION 1988; 6:S476-8. [PMID: 2853755 DOI: 10.1097/00004872-198812040-00150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Renal papillary collecting tubule (RPCT) hormone responsiveness was compared between cultured RPCT cells from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Unstimulated cells from 4-week-old SHR produced less prostaglandin E2 (PGE2) and cyclic (c)AMP than comparable cells from WKY, while cells from both stains synthesized similar amounts of PGE2 after stimulation with arachidonate, A23187 or bradykinin and similar amounts of cAMP after stimulation with vasopressin or PGE2. There was no difference in basal or stimulated levels of cyclic (c)GMP between the strains. In RPCT cells from 16-week-old rats, basal levels of cAMP, cGMP and PGE2 were significantly lower than those from 4-week-old rats, but they did not differ between the strains. These results suggest that RPCT cells of SHR and WKY at the post-weaning period may differ in the metabolism of PGE2 and cAMP. This difference may be attributed to the possible defect in arachidonate availability in SHR.
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Takeuchi K, Abe K, Sato M, Yasujima M, Hagino T, Fang S, Yoshinaga K. Effect of in vitro aging on prostaglandin synthesis in cultured rat vascular smooth muscle cells. AGENTS AND ACTIONS. SUPPLEMENTS 1987; 22:49-54. [PMID: 3324719 DOI: 10.1007/978-3-0348-9299-5_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cultured rat vascular smooth muscle cells from mesenteric artery produced prostaglandin (PG)E2, PGF2 alpha, PGI2 and thromboxane (TX)A2 in response to arachidonic acid, calcium ionophore A23187, vasopressin and angiotensin II. PGI2 was the major product among these PGs. PG synthesis in these cells decreased with in vitro aging, but the distribution pattern of PG synthesis did not change up to the passage level 56. Therefore, it is suggested that imbalance among PGs may not be directly implicated in vascular diseases in aging.
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Sato M, Abe K, Takeuchi K, Yasujima M, Hagino T, Fang S, Kohzuki M, Yoshinaga K. Inhibitory effect of sulindac on prostaglandin synthesis in cultured renal and vascular cells. AGENTS AND ACTIONS. SUPPLEMENTS 1987; 22:37-42. [PMID: 3324718 DOI: 10.1007/978-3-0348-9299-5_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Sulindac, a non-steroidal anti-inflammatory drug (NSAID), is said to be less toxic to the kidney than the other NSAIDs. To examine this hypothesis we investigated the effects of sulindac and other NSAIDs on prostaglandin (PG) synthesis in cultured rat renal and vascular cells. In all cells examined, indomethacin, tiaprofenic acid, aspirin and ibuprofen (3.3 x 10(-5)-3.3 x 10(-4)M) inhibited both basal and arachidonic acid (AA)-stimulated PGE2 or PGI2 synthesis (measured as 6-keto-PGF1 alpha), while sulindac (3.3 x 10(-5)-3.3 x 10(-4)M) inhibited both basal and AA-stimulated PGE2 synthesis in renal papillary collecting tubule cells but not basal PGI2 synthesis in vascular smooth muscle cells or AA-stimulated PGE2 synthesis in glomerular mesangial cells. The order of potency for NSAIDs to inhibit PG synthesis in these cells was tiaprofenic acid, indomethacin greater than ibuprofen, aspirin greater than sulindac. It is suggested that the prodrug sulindac is biotransformed to the active sulfide in the intact kidney cells, which may be less prominent in glomerular mesangial or vascular smooth muscle cells.
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Fang S, Takemori AE, Portoghese PS. Activities of morphinone and N-(cyclopropylmethyl)normorphinone at opioid receptors. J Med Chem 1984; 27:1361-3. [PMID: 6207298 DOI: 10.1021/jm00376a026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Morphinone (3) and N-(cyclopropylmethyl)normorphinone (4) were synthesized and tested on electrically stimulated smooth muscle preparations (guinea pig ileum and mouse vas deferens) and in mice. Compound 3 behaved as an agonist and 4 as an antagonist in vitro and in vivo. No pronounced nonequilibrium agonist or antagonist activity was observed with either compound.
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Liao S, Liang T, Fang S, Castañeda E, Shao TC. Steroid structure and androgenic activity. Specificities involved in the receptor binding and nuclear retention of various androgens. J Biol Chem 1973; 248:6154-62. [PMID: 4353633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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171
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Glazer AN, Fang S, Brown DM. Spectroscopic properties of C-phycocyanin and of its alpha and beta subunits. J Biol Chem 1973; 248:5679-85. [PMID: 4198883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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172
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Glazer AN, Fang S. Chromophore content of blue-green algal phycobiliproteins. J Biol Chem 1973; 248:659-62. [PMID: 4630849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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173
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Glazer AN, Fang S. Formation of hybrid proteins form the and subunits of phycocyanins of unicellular and filamentous blue-green algae. J Biol Chem 1973; 248:663-71. [PMID: 4630850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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174
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Bonaventura J, Schroeder WA, Fang S. Human erythrocyte catalase: an improved method of isolation and a reevaluation of reported properties. Arch Biochem Biophys 1972; 150:606-17. [PMID: 5044042 DOI: 10.1016/0003-9861(72)90080-x] [Citation(s) in RCA: 151] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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175
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Fang S, Liao S. Androgen receptors. Steroid- and tissue-specific retention of a 17 beta-hydroxy-5 alpha-androstan-3-one-protein complex by the cell nuclei of ventral prostate. J Biol Chem 1971; 246:16-24. [PMID: 5541757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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176
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Liao S, Fang S. Receptor-proteims for androgens and the mode of action of androgens on gene transcription in ventral prostate. VITAMINS AND HORMONES 1970; 27:17-90. [PMID: 4911119 DOI: 10.1016/s0083-6729(08)61124-3] [Citation(s) in RCA: 192] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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177
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Fang S, Anderson KM, Liao S. Receptor proteins for androgens. On the role of specific proteins in selective retention of 17-beta-hydroxy-5-alpha-androstan-3-one by rat ventral prostate in vivo and in vitro. J Biol Chem 1969; 244:6584-95. [PMID: 5361546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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178
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Liao S, Sagher D, Lin AH, Fang S. Magnesium and manganese specific forms of soluble liver RNA polymerase. Nature 1969; 223:297-8. [PMID: 5792724 DOI: 10.1038/223297a0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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179
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Fang S, Liao S. Antagonistic action of anti-androgens on the formation of a specific dihydrotestosterone-receptor protein complex in rat ventral prostate. Mol Pharmacol 1969; 5:428-31. [PMID: 5816873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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