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Tang LQ, Fraebel J, Jin S, Winesett SP, Harrell J, Chang WH, Cheng SX. Calcium/calcimimetic via calcium-sensing receptor ameliorates cholera toxin-induced secretory diarrhea in mice. World J Gastroenterol 2024; 30:268-279. [PMID: 38314127 PMCID: PMC10835527 DOI: 10.3748/wjg.v30.i3.268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/01/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024] Open
Abstract
BACKGROUND Enterotoxins produce diarrhea through direct epithelial action and indirectly by activating the enteric nervous system. Calcium-sensing receptor (CaSR) inhibits both actions. The latter has been well documented in vitro but not in vivo. The hypothesis to be tested was that activating CaSR inhibits diarrhea in vivo. AIM To determine whether CaSR agonists ameliorate secretory diarrhea evoked by cholera toxin (CTX) in mice. METHODS CTX was given orally to C57BL/6 mice to induce diarrhea. Calcium and calcimimetic R568 were used to activate CaSR. To maximize their local intestinal actions, calcium was administered luminally via oral rehydration solution (ORS), whereas R568 was applied serosally using an intraperitoneal route. To verify that their actions resulted from the intestine, effects were also examined on Cre-lox intestine-specific CaSR knockouts. Diarrhea outcome was measured biochemically by monitoring changes in fecal Cl- or clinically by assessing stool consistency and weight loss. RESULTS CTX induced secretory diarrhea, as evidenced by increases in fecal Cl-, stool consistency, and weight loss following CTX exposure, but did not alter CaSR, neither in content nor in function. Accordingly, calcium and R568 were each able to ameliorate diarrhea when applied to diseased intestines. Intestinal CaSR involvement is suggested by gene knockout experiments where the anti-diarrheal actions of R568 were lost in intestinal epithelial CaSR knockouts (villinCre/Casrflox/flox) and neuronal CaSR knockouts (nestinCre/Casrflox/flox). CONCLUSION Treatment of acute secretory diarrheas remains a global challenge. Despite advances in diarrhea research, few have been made in the realm of diarrhea therapeutics. ORS therapy has remained the standard of care, although it does not halt the losses of intestinal fluid and ions caused by pathogens. There is no cost-effective therapeutic for diarrhea. This and other studies suggest that adding calcium to ORS or using calcimimetics to activate intestinal CaSR might represent a novel approach for treating secretory diarrheal diseases.
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Affiliation(s)
- Lie-Qi Tang
- Department of Pediatrics, University of Florida, Gainesville, FL 32610, United States
| | - Johnathan Fraebel
- Department of Pediatrics, University of Florida, Gainesville, FL 32610, United States
- College of Medicine, University of Florida, Gainesville, FL 32610, United States
| | - Shi Jin
- Department of Pediatrics, University of Florida, Gainesville, FL 32610, United States
| | - Steven P Winesett
- Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610, United States
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL 32610, United States
| | - Jane Harrell
- Department of Pediatrics, University of Florida, Gainesville, FL 32610, United States
| | - Wen-Han Chang
- Department of Medicine, Endocrine Research Unit, Veterans Affairs Medical Center, University of California, San Francisco, San Francisco, CA 94121, United States
| | - Sam Xianjun Cheng
- Department of Pediatric Gastroenterology, Hepatology, and Nutrition, University of Florida Shands Children’s Hospital, Gainesville, FL 32608, United States
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Guan YL, Zhang DZ, Yang YX, Wan RJ, Tang LQ, Zeng WQ, Kang J. [The clinical value of von Willebrand factor and VITRO score in evaluating disease progression in patients with HBV infection]. Zhonghua Gan Zang Bing Za Zhi 2022; 30:309-315. [PMID: 35462488 DOI: 10.3760/cma.j.cn501113-20210202-00061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Objective: To explore the clinical value of von Willebrand Factor (vWF) and VITRO score (vWF:Ag/platelet count) in assessing disease progression in patients with HBV infection. Methods: Randomly collect relevant clinical data of 308 patients with HBV infection (including 154 cases of chronic hepatitis B, 66 cases of hepatitis B cirrhosis in compensatory period, 88 cases of hepatitis B cirrhosis in decompensated period) from December 1, 2018 to January 5, 2021 in the Second Affiliated Hospital of Chongqing Medical University. The vWF values are measured by a uniform optical method, and all data are included using a uniform standard. Analyze the difference and significance of plasma vWF level and VITRO score in chronic hepatitis B, hepatitis B cirrhosis in the compensatory phase and decompensated phase. Results: The plasma vWF level and VITRO score of the chronic hepatitis B group were (139.47±76.44) and (0.86±0.8), respectively, and the hepatitis B cirrhosis compensated group was (164.95±67.12 and 1.44±1.14), respectively. Hepatitis cirrhosis decompensated group were (317.48±103.32 and 6.81±4.98), respectively; plasma vWF level and VITRO score increased with the progression of HBV infection, and the difference was statistically significant (F=133.669,P=0.000F=137.598,P=0.000).The plasma vWF level and VITRO score in patients with hepatitis B cirrhosis were (185.65±85.07 and 2.3±2.37) in the Child-Pugh A group, (304.74±105.81 and 6.37±5.19) in the B grade group, and (369.48±73.238.28±5.38) in the C grade group; plasma vWF level and VITRO score in patients with hepatitis B cirrhosis increased with the increase of Child-Pugh grade, and the difference was statistically significant (F=60.236, P=0.000F=32.854, P=0.000). The area under the curve (AUC) of plasma vWF level and VITRO score for diagnosing the decompensated stage of hepatitis B cirrhosis were 0.897 [95% confidence interval (CI): 0.855-0.940, P<0.01], 0.949 [95% CI: 0.916-0.982, P<0.01). When the vWF level and VITRO score were taken as cut-off values of 238.5% and 1.65, respectively, the sensitivity of diagnosing the decompensated stage of hepatitis B cirrhosis was 79.5% and 94.3%, the specificity was 92.3% and 87.7%, and the positive predictive value was 80.5% and 94.3%, the negative predictive value was 91.9% and 97.5%, and the diagnostic accuracy was 88.6% and 89.3%. Among the patients with decompensated hepatitis B cirrhosis, the level of vWF in the group with gastrointestinal bleeding (367.24±68.29)% was significantly higher than that in the group without gastrointestinal bleeding (286.15±109.69)%, and the difference was statistically significant (P<0.001) The VITRO score of the group with gastrointestinal bleeding (9.12±5.4) was significantly higher than that of the group without gastrointestinal bleeding (5.36±4.13), and the difference was statistically significant (P<0.01). The vWF level in the spontaneous peritonitis group was (341.73±87.92)% higher than that in the non-spontaneous peritonitis group (296.32±111.74)%, and the difference was statistically significant (P<0.05). There was no statistical difference in VITRO score between the two groups. significance. Conclusion: Plasma vWF level and VITRO score can evaluate the progression of liver disease and the degree of decompensation of liver cirrhosis in patients with HBV infection, and have a predictive effect on various complications after decompensation of liver cirrhosis, and have certain guiding significance for early intervention measures.
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Affiliation(s)
- Y L Guan
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - D Z Zhang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Y X Yang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - R J Wan
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - L Q Tang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - W Q Zeng
- Institute for viral Hepatitis, Chongqing Medical University, Chongqing 400010, China
| | - Juan Kang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
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Zhang YR, Xu KJ, Bai YL, Tang LQ, Jiang ZY, Liu YP, Liu ZJ, Zhou LC, Zhou XF. Features of the volume change and a new constitutive equation of hydrogels under uniaxial compression. J Mech Behav Biomed Mater 2018; 85:181-187. [PMID: 29906673 DOI: 10.1016/j.jmbbm.2018.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/26/2018] [Accepted: 06/02/2018] [Indexed: 11/26/2022]
Abstract
For high-water content hydrogels in compression, the water inside of hydrogels contributes to the response of hydrogels to external loads directly, but part of the water is expelled from hydrogels in the meantime to change the volume of the hydrogel and reduce the contribution. In order to consider the contribution of the water in the constitution equation, PVA (polyvinyl alcohol) hydrogels with high-water content were used as examples, and compressive experiments were carried out to measure both the stress-strain relation and the change of the volume in the meantime. By considering the effect of the difference of the contribution of water in different directions of the hydrogel, we deduced a new constitutive equation, which can pretty well depict the stress-strain of hydrogels with different water contents. The results showed that the contribution of water to the total stress increases with the compression strain and even exceed that of the polymer, although the expelled water reduces the contribution at the early loading stage, which well explains the difference of elastic moduli of hydrogels in compression and tension.
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Affiliation(s)
- Y R Zhang
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China; Guangdong Institute of Intelligent Manufacturing, Guangzhou, China
| | - K J Xu
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China
| | - Y L Bai
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China; LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
| | - L Q Tang
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China; State Key Laboratory of Subtropical Building Science, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China.
| | - Z Y Jiang
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China
| | - Y P Liu
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China
| | - Z J Liu
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China
| | - L C Zhou
- School of Civil Engineering and Transportation, South China University of Technology, No.381, Wushan Road, Guangzhou, Guangdong, China
| | - X F Zhou
- Guangdong Institute of Intelligent Manufacturing, Guangzhou, China
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Wang GM, Spector A, Luo CQ, Tang LQ, Xu LH, Guo WY, Huang YQ. Prevalence of age-related cataract in Ganzi and in Qinpu. The Epidemiological Study Group. Dev Ophthalmol 2015; 21:33-40. [PMID: 1868946 DOI: 10.1159/000419931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- G M Wang
- Department of Ophthalmology, Eye and ENT Hospital, Shanghai Medical University, People's Republic of China
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Dufner MM, Kirchhoff P, Remy C, Hafner P, Müller MK, Cheng SX, Tang LQ, Hebert SC, Geibel JP, Wagner CA. The calcium-sensing receptor acts as a modulator of gastric acid secretion in freshly isolated human gastric glands. Am J Physiol Gastrointest Liver Physiol 2005; 289:G1084-90. [PMID: 16109841 DOI: 10.1152/ajpgi.00571.2004] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastric acid secretion is activated by two distinct pathways: a neuronal pathway via the vagus nerve and release of acetylcholine and an endocrine pathway involving gastrin and histamine. Recently, we demonstrated that activation of H(+)-K(+)-ATPase activity in parietal cells in freshly isolated rat gastric glands is modulated by the calcium-sensing receptor (CaSR). Here, we investigated if the CaSR is functionally expressed in freshly isolated gastric glands from human patients undergoing surgery and if the CaSR is influencing histamine-induced activation of H(+)-K(+)-ATPase activity. In tissue samples obtained from patients, immunohistochemistry demonstrated the expression in parietal cells of both subunits of gastric H(+)-K(+)-ATPase and the CaSR. Functional experiments using the pH-sensitive dye 2',7'-bis-(2-carboxyethyl)-5-(and 6)-carboxyfluorescein and measurement of intracellular pH changes allowed us to estimate the activity of H(+)-K(+)-ATPase in single freshly isolated human gastric glands. Under control conditions, H(+)-K(+)-ATPase activity was stimulated by histamine (100 microM) and inhibited by omeprazole (100 microM). Reduction of the extracellular divalent cation concentration (0 Mg(2+), 100 microM Ca(2+)) inactivated the CaSR and reduced histamine-induced activation of H(+)-K(+)-ATPase activity. In contrast, activation of the CaSR with the trivalent cation Gd(3+) caused activation of omeprazole-sensitive H(+)-K(+)-ATPase activity even in the absence of histamine and under conditions of low extracellular divalent cations. This stimulation was not due to release of histamine from neighbouring enterochromaffin-like cells as the stimulation persisted in the presence of the H(2) receptor antagonist cimetidine (100 microM). Furthermore, intracellular calcium measurements with fura-2 and fluo-4 showed that activation of the CaSR by Gd(3+) led to a sustained increase in intracellular Ca(2+) even under conditions of low extracellular divalent cations. These experiments demonstrate the presence of a functional CaSR in the human stomach and show that this receptor may modulate the activity of acid-secreting H(+)-K(+)-ATPase in parietal cells. Furthermore, our results show the viability of freshly isolated human gastric glands and may allow the use of this preparation for experiments investigating the physiological regulation and properties of human gastric glands in vitro.
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Dong K, Tang LQ, MacGregor GG, Leng Q, Hebert SC. Novel nucleotide-binding sites in ATP-sensitive potassium channels formed at gating interfaces. EMBO J 2005; 24:1318-29. [PMID: 15775962 PMCID: PMC1142547 DOI: 10.1038/sj.emboj.7600626] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 02/15/2005] [Indexed: 11/09/2022] Open
Abstract
The coupling of cell metabolism to membrane electrical activity is a vital process that regulates insulin secretion, cardiac and neuronal excitability and the responses of cells to ischemia. ATP-sensitive potassium channels (K(ATP); Kir6.x) are a major part of this metabolic-electrical coupling system and translate metabolic signals such as the ATP:ADP ratio to changes in the open or closed state (gate) of the channel. The localization of the nucleotide-binding site (NBS) on Kir6.x channels and how nucleotide binding gates these K(ATP) channels remain unclear. Here, we use fluorescent nucleotide binding to purified Kir6.x proteins to define the peptide segments forming the NBS on Kir6.x channels and show that unique N- and C-terminal interactions from adjacent subunits are required for high-affinity nucleotide binding. The short N- and C-terminal segments comprising the novel intermolecular NBS are next to helices that likely move with channel opening/closing, suggesting a lock-and-key model for ligand gating.
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Affiliation(s)
- Ke Dong
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT, USA
| | - Lie-Qi Tang
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT, USA
| | - Gordon G MacGregor
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT, USA
| | - Qiang Leng
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT, USA
| | - Steven C Hebert
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, New Haven, CT, USA
- Department of Cellular and Molecular Physiology, School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, USA. Tel.: +1 203 785 4041; Fax: +1 203 785 7678; E-mail:
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Dong K, Tang L, MacGregor GG, Hebert SC. Localization of the ATP/phosphatidylinositol 4,5 diphosphate-binding site to a 39-amino acid region of the carboxyl terminus of the ATP-regulated K+ channel Kir1.1. J Biol Chem 2002; 277:49366-73. [PMID: 12381730 DOI: 10.1074/jbc.m208679200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intracellular ATP and membrane-associated phosphatidylinositol phospholipids, like PIP(2) (PI(4,5)P(2)), regulate the activity of ATP-sensitive K(+) (K(ATP)) and Kir1.1 channels by direct interaction with the pore-forming subunits of these channels. We previously demonstrated direct binding of TNP-ATP (2',3'-O-(2,4,6-trinitrophenylcyclo-hexadienylidene)-ATP) to the COOH-terminal cytosolic domains of the pore-forming subunits of Kir1.1 and Kir6.x channels. In addition, PIP(2) competed for TNP-ATP binding on the COOH termini of Kir1.1 and Kir6.x channels, providing a mechanism that can account for PIP(2) antagonism of ATP inhibition of these channels. To localize the ATP-binding site within the COOH terminus of Kir1.1, we produced and purified maltose-binding protein (MBP) fusion proteins containing truncated and/or mutated Kir1.1 COOH termini and examined the binding of TNP-ATP and competition by PIP(2). A truncated COOH-terminal fusion protein construct, MBP_1.1CDeltaC170, containing the first 39 amino acid residues distal to the second transmembrane domain was sufficient to bind TNP-ATP with high affinity. A construct containing the remaining COOH-terminal segment distal to the first 39 amino acid residues did not bind TNP-ATP. Deletion of 5 or more amino acid residues from the NH(2)-terminal side of the COOH terminus abolished nucleotide binding to the entire COOH terminus or to the first 49 amino acid residues of the COOH terminus. PIP(2) competed TNP-ATP binding to MBP_1.1CDeltaC170 with an EC(50) of 10.9 microm. Mutation of any one of three arginine residues (R188A/E, R203A, and R217A), which are conserved in Kir1.1 and K(ATP) channels and are involved in ATP and/or PIP(2) effects on channel activity, dramatically reduced TNP-ATP binding to MBP_1.1DeltaC170. In contrast, mutation of a fourth conserved residue (R212A) exhibited slightly enhanced TNP-ATP binding and increased affinity for PIP(2) competition of TNP-ATP (EC(50) = 5.7 microm). These studies suggest that the first 39 COOH-terminal amino acid residues form an ATP-PIP(2) binding domain in Kir1.1 and possibly the Kir6.x ATP-sensitive K(+) channels.
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MESH Headings
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/chemistry
- Adenosine Triphosphate/metabolism
- Amino Acid Sequence
- Animals
- Arginine/chemistry
- Binding Sites
- Binding, Competitive
- Carrier Proteins/chemistry
- Cytosol/metabolism
- DNA/metabolism
- Dose-Response Relationship, Drug
- Gene Deletion
- Kinetics
- Light
- Maltose-Binding Proteins
- Models, Chemical
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Phosphatidylinositol 4,5-Diphosphate/chemistry
- Phosphatidylinositol 4,5-Diphosphate/metabolism
- Potassium Channels/chemistry
- Potassium Channels/metabolism
- Potassium Channels, Inwardly Rectifying/chemistry
- Protein Binding
- Protein Structure, Tertiary
- Rats
- Recombinant Fusion Proteins/metabolism
- Scattering, Radiation
- Sequence Homology, Amino Acid
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Affiliation(s)
- Ke Dong
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8026, USA
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Vanoye CG, MacGregor GG, Dong K, Tang L, Buschmann AS, Hall AE, Lu M, Giebisch G, Hebert SC. The carboxyl termini of K(ATP) channels bind nucleotides. J Biol Chem 2002; 277:23260-70. [PMID: 11956191 DOI: 10.1074/jbc.m112004200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ATP-sensitive potassium (K(ATP)) channels are expressed in many excitable, as well as epithelial, cells and couple metabolic changes to modulation of cell activity. ATP regulation of K(ATP) channel activity may involve direct binding of this nucleotide to the pore-forming inward rectifier (Kir) subunit despite the lack of known nucleotide-binding motifs. To examine this possibility, we assessed the binding of the fluorescent ATP analogue, 2',3'-O-(2,4,6-trinitrophenylcyclo-hexadienylidene)adenosine 5'-triphosphate (TNP-ATP) to maltose-binding fusion proteins of the NH(2)- and COOH-terminal cytosolic regions of the three known K(ATP) channels (Kir1.1, Kir6.1, and Kir6.2) as well as to the COOH-terminal region of an ATP-insensitive inward rectifier K(+) channel (Kir2.1). We show direct binding of TNP-ATP to the COOH termini of all three known K(ATP) channels but not to the COOH terminus of the ATP-insensitive channel, Kir2.1. TNP-ATP binding was specific for the COOH termini of K(ATP) channels because this nucleotide did not bind to the NH(2) termini of Kir1.1 or Kir6.1. The affinities for TNP-ATP binding to K(ATP) COOH termini of Kir1.1, Kir6.1, and Kir6.2 were similar. Binding was abolished by denaturing with 4 m urea or SDS and enhanced by reduction in pH. TNP-ATP to protein stoichiometries were similar for all K(ATP) COOH-terminal proteins with 1 mol of TNP-ATP binding/mole of protein. Competition of TNP-ATP binding to the Kir1.1 COOH terminus by MgATP was complex with both Mg(2+) and MgATP effects. Glutaraldehyde cross-linking demonstrated the multimerization potential of these COOH termini, suggesting that these cytosolic segments may directly interact in intact tetrameric channels. Thus, the COOH termini of K(ATP) tetrameric channels contain the nucleotide-binding pockets of these metabolically regulated channels with four potential nucleotide-binding sites/channel tetramer.
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Affiliation(s)
- Carlos G Vanoye
- Department of Medicine, Division of Genetic Medicine, Vanderbilt University Medical School, Nashville, Tennessee 37232-6304, USA
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MacGregor GG, Dong K, Vanoye CG, Tang L, Giebisch G, Hebert SC. Nucleotides and phospholipids compete for binding to the C terminus of KATP channels. Proc Natl Acad Sci U S A 2002; 99:2726-31. [PMID: 11880626 PMCID: PMC122415 DOI: 10.1073/pnas.042688899] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inwardly rectifying, ATP-sensitive K+ channels (K(ATP)) couple metabolism to either cell excitability (Kir6.x) or potassium secretion (Kir1.1). Phosphatidylinositol phospholipids, like PI(4,5)P2, antagonize nucleotide inhibition of K(ATP) channels enhancing the coupling of metabolic events to cell electrical or transport activity. The mechanism by which phospholipids relieve ATP block is unclear. We have shown that maltose-binding fusion proteins (MBP) containing the COOH termini of K(ATP) channels (Kir1.1, Kir6.1, and Kir6.2) form functional tetramers that directly bind at least two ATP molecules with negative cooperativity. Here we show that purified phosphatidylinositol phospholipids compete for 2,4,6,-trinitrophenyl (TNP)-ATP binding to the COOH termini of K(ATP) channels with EC50 values for PIP2 between 6-8 microM. The phospholipid potency profile was PIP3 > PIP2 = PIP > PI, suggesting that net phospholipid charge was important. A role for head group charge was supported by polycations (neomycin, spermine, and polylysine) reversing the effect of PIP2 on TNP-ATP binding to the Kir1.1 channel COOH terminal fusion protein. In contrast, the water-soluble charged hydrolytic product of PIP2, inositol(1,4,5)P3 (IP3), had no effect on TNP-ATP binding, suggesting that the acyl chain of PIP2 was also necessary for its effect on TNP-ATP binding. Indeed, neutral and charged lipids had weak, but significant, effects on TNP-ATP binding. Whereas microM concentrations of PIP2 could compete with TNP-ATP, we found that mM concentrations of MgATP were required to compete with PIP2 for binding to these K(ATP) channel COOH termini. Thus the COOH termini of K(ATP) channels form a nucleotide- and phospholipid-modulated channel gate on which ATP and phospholipids compete for binding.
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Affiliation(s)
- Gordon G MacGregor
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8026, USA
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Palom Y, Belcourt MF, Tang LQ, Mehta SS, Sartorelli AC, Pritsos CA, Pritsos KL, Rockwell S, Tomasz M. Bioreductive metabolism of mitomycin C in EMT6 mouse mammary tumor cells: cytotoxic and non-cytotoxic pathways, leading to different types of DNA adducts. The effect of dicumarol. Biochem Pharmacol 2001; 61:1517-29. [PMID: 11377381 DOI: 10.1016/s0006-2952(01)00609-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The six DNA adducts formed in EMT6 mouse mammary tumor cells upon treatment with mitomycin C (MC) fall into two groups: (1) four guanine adducts of MC and (2) two guanine adducts derived from 2,7-diaminomitosene (2,7-DAM), the major reductive metabolite of MC. The two groups of adducts were proposed to originate from two pathways arising from reductive activation of MC: (a) direct alkylation of DNA and (b) formation of 2,7-DAM, which then alkylates DNA. The aim of this study was to test the validity of this proposal and to evaluate the significance of alkylation of DNA by 2,7-DAM. Treatment of the cells with 2,7-DAM itself yielded the same 2,7-DAM-guanine adducts as treatment with MC; however, 2,7-DAM was approximately 100-fold less cytotoxic than MC. The uptake and efflux of 2,7-DAM by EMT6 cells was comparable to that of MC, but 2,7-DAM alkylated DNA with higher efficiency than MC. These results validate the two proposed pathways and show that formation of 2,7-DAM-DNA adducts in MC-treated cells represents a relatively non-toxic pathway of reductive metabolism of MC. A selective stimulatory effect of dicumarol (DIC) on 2,7-DAM-DNA adduct formation in EMT6 cells treated with MC was also investigated. DIC had no effect on alkylation by MC in cell-free systems, nor did it have significant effects on adduct formation or cell survival for cells treated with 2,7-DAM. It is proposed that in the cell DIC stimulates a reductase enzyme located at subcellular sites where the activated MC species has no direct access to DNA and therefore is diverted into the non-cytotoxic pathway, which leads to the formation of 2,7-DAM and its adducts.
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Affiliation(s)
- Y Palom
- Department of Chemistry, Hunter College, City University of New York, NY 10021, USA
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Lagercrantz H, Peyronnet J, Yuan SZ, Tang LQ. Catecholamines, hypoxic defence and the neonatal brain. Dev Med Child Neurol Suppl 2001; 86:28-9. [PMID: 11268722 DOI: 10.1111/j.1469-8749.2001.tb04145.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- H Lagercrantz
- Karolinska Institute, Neonatal Unit, Astrid Lindgren Children's Hospital, S-171/6 Stockholm, Sweden
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12
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Abstract
Maternal caffeine intake has been suggested to influence the offspring. We have studied the effects of maternal caffeine intake on adenosine and GABA receptors, targets for caffeine, during development of the rat brain. Caffeine (0.3 g/L) was added to the drinking water of rat dams during pregnancy and early postnatal life. Adenosine A1 and A2A and GABAA receptor development was studied using receptor autoradiography and in situ hybridization. Pups were examined on embryonic d 14 (E14), E18, E21, 2 h after birth (P2h), P24h, postnatal d 3 (P3), P7, P14, and P21. Adenosine A, receptor mRNA was detected at E14 and receptors at E18. A1 mRNA levels increased from the level reached at E18 between P3 and P14 (maximally a doubling), whereas A, receptors, studied by [3H]-1,3-dipropyl-8-cyclopentyl xanthine binding, increased later and to a much larger extent (about 10-fold) postnatally. Caffeine treatment had no significant effect on adenosine A1 receptors or on A1 receptor mRNA. A2A mRNA had reached adult levels by E18, whereas receptor levels were low or undetectable before birth and increased dramatically until P14. Caffeine did not influence A2A receptors or A2A receptor mRNA at any stage during development. [3H]-flunitrazepam binding, representing GABAA receptors, showed large regional variations during ontogeny, but there were no clear differences between the caffeine-exposed and the nonexposed pups. Thus, exposure to a low dose of caffeine during gestation and postnatal life had only minor effects on development of adenosine A, and A2A receptors and GABAA receptors in the rat brain.
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Affiliation(s)
- U Adén
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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13
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Peyronnet J, Roux JC, Geloën A, Tang LQ, Pequignot JM, Lagercrantz H, Dalmaz Y. Prenatal hypoxia impairs the postnatal development of neural and functional chemoafferent pathway in rat. J Physiol 2000; 524 Pt 2:525-37. [PMID: 10766931 PMCID: PMC2269888 DOI: 10.1111/j.1469-7793.2000.00525.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/1999] [Accepted: 01/10/2000] [Indexed: 11/29/2022] Open
Abstract
1. To define the effects of prenatal hypoxia on the postnatal development of the chemoafferent pathway, ventilation and metabolism, pregnant rats were exposed to normobaric hypoxia (10 % oxygen) from embryonic day 5 to embryonic day 20. Offspring were studied at 1, 3 and 9 weeks of age in three separate protocols. 2. Prenatal hypoxia decreased the dopamine content in the carotid bodies at all ages, and decreased the utilisation rate of noradrenaline in the caudal part of the A2 (A2c), A1 and A5 noradrenergic brainstem cell groups at 3 weeks after birth. At 9 weeks of age, the level of dopamine in the carotid bodies was still reduced but the utilisation rate of noradrenaline was enhanced in A1. 3. Rats from dams subjected to hypoxia during pregnancy hyperventilated until 3 weeks after birth. In these rats, the biphasic hypoxic ventilatory response was absent at 1 week and the increase in minute ventilation was amplified at 3 weeks. 4. Prenatal hypoxia disturbed the metabolism of offspring until 3 weeks after birth. A weak or absent hypometabolism in response to hypoxia was observed in these rats in contrast to control animals. 5. Prenatal hypoxia impairs the postnatal development of the chemoafferent pathway, as well as the ventilatory and metabolic responses to hypoxia. These alterations were mostly evident until 3 weeks after birth.
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Affiliation(s)
- J Peyronnet
- Laboratoire de Physiologie des Regulations Metaboliques, Cellulaires et Moleculaires, UMR CNRS 5578, Faculte de Medecine, 8 Avenue Rockefeller, 69 373 Lyon cedex 08, France.
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14
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Abstract
At birth, the mammalian nervous system must adapt rapidly to the new conditions it encounters in the extra-uterine environment. One aspect of this adaptation, known as arousal, is mediated by catecholamines, the levels of which in the brain increase rapidly after birth. The pattern of gene expression also changes. Shortly after birth, expression of the immediate early gene c-fos, known to reflect general neural activity, is up-regulated. Furthermore, asphyxia often occurs in connection with birth. In order to examine the effects of this phenomenon on the expression of c-fos, as well as on the rate of noradrenaline (NA) turnover, asphyxia was induced in rat pups delivered by caesarean section. Northern blot analysis and in situ hybridization revealed that the increase in expression of c-fos in certain areas of the brain was greatly enhanced by asphyxia of moderate duration; whereas more prolonged asphyxia lowered the level of c-fos mRNA. Asphyxia had a similar effect on the rate of NA turnover. Adrenergic receptor antagonists administered prior to birth attenuated the birth-related induction of c-fos mRNA. However, the potentiation of c-fos expression by asphyxia was not altered by these antagonists. Therefore, we propose that while catecholamines play an important role in the induction of c-fos in the brain at birth, the effects of asphyxia involve a different mechanism.
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Affiliation(s)
- L Q Tang
- Neonatal Program, Karolinska Institute, Astrid Lindgren's Children's Hospital, Stockholm, Sweden
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15
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Tang LQ, Hong PH, Siddiqui Y, Sarkissian ES, Huang RY, Lee E, Krupin T. Effect of beta-adrenergic agents on intracellular potential of rabbit ciliary epithelium. Curr Eye Res 1998; 17:24-30. [PMID: 9472467 DOI: 10.1076/ceyr.17.1.24.5258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To study the effects of beta-adrenergic agents on intracellular potential (Vm) of the isolated and intact rabbit ciliary epithelium. METHODS Vm was measured on the isolated intact ciliary epithelium superfused with adrenergic agents and cyclic AMP modulators. RESULTS The nonselective beta-adrenergic agonist isoproterenol depolarized Vm in a dose-dependent fashion. beta-adrenergic antagonists alone had no effect on baseline Vm. The isoproterenol response was blocked by the nonselective antagonist timolol (5 x 10(-5) M). The selective beta 2-antagonist ICI 118-551 caused a greater inhibition (IC50 approximately 7 x 10(-7)) than the selective beta 1-antagonist betaxolol (IC50 approximately 6 x 10(-6)). The isoproterenol response was also significantly (p < 0.03) blocked by the non-selective alpha-antagonist phentolamine. Cyclic AMP and phosphodiesterase inhibitors significantly decreased Vm. Pretreatment with these inhibitors potentiated the agonist-induced depolarization. Barium, a blocker of Ca(2+)-sensitive K+ channels, significantly decreased baseline Vm. Barium pretreatment blocked the beta-agonist and cAMP induced depolarization of Vm, suggesting that the K+ current is necessary for the observed isoproterenol response. Pretreatment with the cotransport inhibitor bumetanide had no effect on the isoproterenol-induced response. CONCLUSIONS The beta-adrenergic agonist isoproterenol affects ionic transport processes across the ciliary epithelium (beta 2 > beta 1). This effect is likely mediated through adenylate cyclase coupled to adrenoreceptors and requires the presence of the K+ current. Blockage of the isoproterenol-induced decrease in Vm by a nonselective alpha-adrenergic antagonist indicates an interaction between the two adrenergic systems in the ciliary epithelium.
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Affiliation(s)
- L Q Tang
- Department of Ophthalmology, Northwestern University Medical School, Chicago, IL 60611, USA.
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16
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Rosenberg LF, Krupin T, Tang LQ, Hong PH, Ruderman JM. Combination of systemic acetazolamide and topical dorzolamide in reducing intraocular pressure and aqueous humor formation. Ophthalmology 1998; 105:88-92; discussion 92-3. [PMID: 9442783 DOI: 10.1016/s0161-6420(98)91421-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE The study aimed to determine whether topical dorzolamide and systemic acetazolamide have an additive effect on intraocular pressure (IOP) and aqueous humor formation (AHF). DESIGN This was a prospective, open-label, two-protocol clinical study. PARTICIPANTS Sixteen patients with ocular hypertension or with primary open-angle glaucoma were studied. INTERVENTION Baseline AHF was measured by computerized fluorophotometry and IOP by pneumatonometry without antiglaucoma therapy. In the first protocol, dorzolamide was randomized to one eye (N = 10) and IOP and AHF measurements were repeated. One week later, having used dorzolamide in one eye three times daily, patients had measurements performed before and after the single administration of oral acetazolamide 250 mg. In the second protocol, having used acetazolamide 250 mg four times daily for 4 to 7 days (N = 6), patients had measurements performed before and after a single drop of dorzolamide was instilled randomly into one eye. The patient continued acetazolamide and unilateral dorzolamide for 4 to 7 more days and returned for IOP and AHF measurements. MAIN OUTCOME MEASURES Intraocular pressure and AHF were measured in treated and contralateral control eyes. RESULTS In the first protocol, IOP (mmHg +/- standard deviation) was significantly (P = 0.02) lower in the dorzolamide (16.3 +/- 2.6) than in the contralateral control (19.9 +/- 2.9) eyes. Aqueous humor formation (microliter/minute +/- standard deviation) also was lower (P = 0.02) in dorzolamide eyes (1.79 +/- 0.4 vs. 2.33 +/- 0.5). After oral acetazolamide 250 mg, IOP was unchanged in dorzolamide eyes (17.6 +/- 2.0 preacetazolamide vs. 17.9 +/- 2.0 postacetazolamide), whereas it was reduced (P = 0.003) in control eyes (20.5 +/- 2.2 preacetazolamide vs. 16.9 +/- 2.3 postacetazolamide). Aqueous humor formation was reduced in control eyes (2.31 +/- 0.8 preacetazolamide vs. 1.73 +/- 0.6 postacetazolamide; P = 0.005) but not in dorzolamide-treated eyes (1.56 +/- 0.45 preacetazolamide vs. 1.77 +/- 0.39 postacetazolamide). In the second protocol, acetazolamide 250 mg four times daily symmetrically reduced IOP and AHF in both eyes. After single-drop dorzolamide in one eye, IOP and AHF did not change significantly. After 4 to 7 days of acetazolamide and unilateral dorzolamide, IOP and AHF remained reduced to a similar level in dorzolamide and control eyes not receiving topical therapy. CONCLUSION Topical dorzolamide and oral acetazolamide, in the concentrations and doses used in this study, are not additive. Either drug alone results in maximum reduction in IOP and AHF. Concomitant glaucoma therapy of a topical and systemic carbonic anhydrase inhibitor is not warranted.
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Affiliation(s)
- L F Rosenberg
- Department of Ophthalmology, Northwestern University Medical School, Chicago, Illinois, USA
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17
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Tang LQ, Guo XA, Zhang MS. [Epidemiological trend and its impact on malaria control programme in Shenzhen from 1950-1995]. Zhonghua Liu Xing Bing Xue Za Zhi 1997; 18:73-6. [PMID: 9812501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Shenzhen has been developed as the first economic special zone in China. Two large scale outbreaks of vivax malaria have occurred in the history. Anopheles anthropophagus has been identified as the major vector. For the last 45 years, we have adopted an effective measure for malaria control based on the epidemiological characteristics in different period. As a result, the morbidity rate of malaria has been under control given the condition of social and economy development and the big increase of mobile population.
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Affiliation(s)
- L Q Tang
- Shenzhen Municipal Sanitary and Anti-Epidemic Station
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18
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Ringstedt T, Tang LQ, Persson H, Lendahl U, Lagercrantz H. Expression of c-fos, tyrosine hydroxylase, and neuropeptide mRNA in the rat brain around birth: effects of hypoxia and hypothermia. Pediatr Res 1995; 37:15-20. [PMID: 7700728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Arousal at birth is likely to be accompanied by changes in gene expression patterns in the brain. We analyzed the expression levels of genes that may be involved in neonatal adaptation. We have also tried to dissect the effect of hypoxia and hypothermia, two components that may play a role in gene expression at birth. Therefore, we analyzed the expression patterns of the c-fos, tyrosine hydroxylase, enkephalin, preprotachykinin-A, and neuropeptide Y genes in various brain regions of rat pups at various time points after cesarean section under normal conditions and after exposure to hypoxia and hypothermia. We found that c-fos RNA was up-regulated transiently after birth in neocortex, midbrain, and pons-medulla with a maximum of 30 min after cesarean section, and that this transient increase was not further augmented by hypoxia and hypothermia. The expression patterns of the other genes were not significantly altered, with the exception of a very slight increase in tyrosine hydroxylase RNA levels. We discuss tentative mechanisms for the transient increase in c-fos expression and the possible involvement of catecholamines in this process.
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Affiliation(s)
- T Ringstedt
- Department of Biochemistry, Karolinska Institute, Stockholm, Sweden
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Oh J, Krupin T, Tang LQ, Sveen J, Lahlum RA. Dye coupling of rabbit ciliary epithelial cells in vitro. Invest Ophthalmol Vis Sci 1994; 35:2509-14. [PMID: 8163340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
PURPOSE To examine the in vitro properties of gap junctions on the isolated rabbit ciliary epithelium. METHODS Intracellular potential was measured and lucifer yellow (5% in 1 M LiCl) was iontophoretically injected into a ciliary epithelial cell. Fixated tissue was examined with a laser confocal microscope. RESULTS Dye spread was observed throughout both layers (horizontally and vertically) of the ciliary epithelium adjacent to the injected cell that was more intensely labeled. Dye reflux did not occur at the site of microimpalement. Microiontophoretic dye injection in a bathing solution with a high Ca2+ (10 mM) or an acidic pH (6.3) completely inhibited cell-cell dye coupling in the rabbit ciliary epithelial cells. CONCLUSIONS Laser confocal microscopy of intracellularly injected lucifer yellow dye demonstrates the physiologic presence of gap junctions between both ciliary epithelial layers. Extracellular acidosis and high concentration of extracellular Ca2+ cause loss of cell-cell coupling in the rabbit ciliary epithelium.
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Affiliation(s)
- J Oh
- Department of Ophthalmology, Northwestern University Medical School, Chicago, Illinois 60611
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20
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Tang LQ, Krupin T, Milner M, Woods D, Miller K, Carré DA, Civan MM. Halogenated inhalation anesthetic agents decrease transepithelial electrical measurements across the isolated iris-ciliary body. Invest Ophthalmol Vis Sci 1991; 32:1912-5. [PMID: 2032810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transmembrane electrical measurements were performed on the isolated rabbit iris-ciliary body (I-CB) to study the direct effects of halogenated inhalation anesthetic agents on the ciliary epithelium. Addition of either halothane, enflurane, or isoflurane to the control 95% O2:5% CO2 gas mixture resulted in a dose-dependent decrease in the short-circuit current (SCC) and potential difference (PD). This response was reversible after the anesthetic gas was discontinued. Pretreatment with either alpha-adrenergic or beta-adrenergic antagonists (phentolamine or timolol) had no effect on the halothane-induced decrease in SCC. Delivery of the analgestic gas N2O did not alter baseline electrical measurements across the isolated I-CB.
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Affiliation(s)
- L Q Tang
- Department of Ophthalmology, Northwestern University Medical School, Chicago, IL 60611
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21
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Wang GM, Spector A, Luo CQ, Tang LQ, Xu LH, Guo WY, Huang YQ. Prevalence of age-related cataract in Ganzi and Shanghai. The Epidemiological Study Group. Chin Med J (Engl) 1990; 103:945-51. [PMID: 2125917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
It has been reported that the prevalence of cataract is much higher in plateau than that in plain regions. But the data are incomplete and can not be compared because of different examination methods and different diagnostic criteria. A small group of ophthalmologists was sent to Ganzi, Sichuan Province at the altitude of 3.393 m, and to Qinpu in the suburb of Shanghai which is at the sea level. In Ganzi 3,905 (91.97%) people including 822 Hans and 3,083 Zang and in Qinpu 3,101 (93.20%) were studied. Age-related cataract was diagnosed when there are cortical or nuclear, or mixed opacities; and aphakia due to previous extraction of age-related cataract. Direct method was used to standardize the data. The prevalence of age-related cataract in Ganzi is about 82% higher than that in Qinpu in all age groups; from age 16-60, the prevalence of age-related cataract in Ganzi is about 180% (in Hans) and 160% (in Zangs) higher than that in Qinpu. There is no significant difference in the prevalence of age-related cataract between the ethnic groups in Ganzi. In Ganzi, the sunshine hours per year are 1.28 times that in Qinpu, and the global radiation in Ganzi is 1.47 times that in Qinpu. The higher prevalence of cataract in Ganzi than in Qinpu may be due to the greater exposure to the sunshine on the Tibetan plateau. The differences in prevalence between males and females and between indoor and outdoor work are discussed.
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Affiliation(s)
- G M Wang
- Department of Ophthalmology, Eye and ENT Hospital of Shanghai Medical University
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