1
|
Rowsey DM, Keenan RM, Jansa SA. Dietary morphology of two island-endemic murid rodent clades is consistent with persistent, incumbent-imposed competitive interactions. Proc Biol Sci 2020; 287:20192746. [PMID: 32097592 DOI: 10.1098/rspb.2019.2746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A lineage colonizing a geographic region with no competitors may exhibit rapid diversification due to greater ecological opportunity. The resultant species diversity of this primary-colonizing (incumbent) clade may limit subsequent lineages' ability to persist unless these non-incumbent lineages are ecologically distinct. We compare the diversity in diet-related mandibular morphology of two sympatric murid rodent clades endemic to Luzon Island, Philippines-incumbent Phloeomyini and secondary-colonizing Chrotomyini-to the mandibular morphological diversity of Sahul Hydromyini, the sister clade of Chrotomyini and the incumbent murid lineage on the supercontinent of Sahul. This three-clade comparison allows us to test the hypothesis that incumbent lineages can force persistent ecological distinction of subsequent colonists at the time of colonization and throughout the subsequent history of the two sympatric clades. We find that Chrotomyini forms a subset of the diversity of their clade plus Sahul Hydromyini that minimizes overlap with Phloeomyini. We also infer that this differentiation extends to the stem ancestor of Chrotomyini and Sahul Hydromyini, consistent with a biotic filter imposed by Phloeomyini. Our work illustrates that incumbency has the potential to have a profound influence on the ecomorphological diversity of colonizing lineages at the island scale even when the traits in question are evolving at similar rates among independently colonizing clades.
Collapse
Affiliation(s)
- Dakota M Rowsey
- Department of Ecology, Evolution, and Behavior & Bell Museum of Natural History, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN 55108, USA.,Field Museum of Natural History, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Ryan M Keenan
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN 55108, USA
| | - Sharon A Jansa
- Department of Ecology, Evolution, and Behavior & Bell Museum of Natural History, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| |
Collapse
|
2
|
Ledger KJ, Keenan RM, Sayler KA, Wisely SM. Multi-scale patterns of tick occupancy and abundance across an agricultural landscape in southern Africa. PLoS One 2019; 14:e0222879. [PMID: 31539412 PMCID: PMC6754170 DOI: 10.1371/journal.pone.0222879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/09/2019] [Indexed: 11/19/2022] Open
Abstract
Land use influences the prevalence and distribution of ticks due to the intimate relationship of ticks with their environment. This relationship occurs because land use alters two essential tick requirements: vertebrate hosts for blood meals and a suitable microclimate when off-host. Given the risks to human and animal health associated with pathogens transmitted by ticks, there is an ongoing need to understand the impact of environmental drivers on tick distributions. Here, we assessed how landscape features, neighborhood effects, and edges influenced tick occupancy and abundance across an agricultural landscape in southern Africa. We found that Rhipicephalus appendiculatus and Rhipicephalus simus increased in abundance closer to protected savanna, while Haemaphysalis elliptica increased in abundance closer to human habitation. The composition of the landscape surrounding savanna patches also differentially influenced the occupancy of each tick species; H. elliptica was more likely to be found in savanna patches surrounded by subsistence agriculture while R. appendiculatus and R. simus were more likely to be found in savanna surrounded by sugarcane monocultures. At the local scale we found that R. appendiculatus and R. simus avoided savanna edges. The availability of hosts and variation in vegetation structure between commercial agriculture, subsistence agriculture, and savanna likely drove the distribution of ticks at the landscape scale. Understanding how anthropogenic land use influences where ticks occur is useful for land use planning and for assessing public and animal health risks associated with ticks and tick-borne diseases.
Collapse
Affiliation(s)
- Kimberly J. Ledger
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Ryan M. Keenan
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Katherine A. Sayler
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Samantha M. Wisely
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| |
Collapse
|
3
|
Duffy KJ, Darcy MG, Delorme E, Dillon SB, Eppley DF, Erickson-Miller C, Giampa L, Hopson CB, Huang Y, Keenan RM, Lamb P, Leong L, Liu N, Miller SG, Price AT, Rosen J, Shah R, Shaw TN, Smith H, Stark KC, Tian SS, Tyree C, Wiggall KJ, Zhang L, Luengo JI. Hydrazinonaphthalene and azonaphthalene thrombopoietin mimics are nonpeptidyl promoters of megakaryocytopoiesis. J Med Chem 2001; 44:3730-45. [PMID: 11606138 DOI: 10.1021/jm010283l] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [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: 11/28/2022]
Abstract
High-throughput screening for the induction of a luciferase reporter gene in a thrombopoietin (TPO)-responsive cell line resulted in the identification of 4-diazo-3-hydroxy-1-naphthalenesulfonic acids as TPO mimics. Modification of the core structure and adjustment of unwanted functionality resulted in the development of (5-oxo-1,5-dihydropyrazol-4-ylidene)hydrazines which exhibited efficacies equivalent to those of TPO in several cell-based assays designed to measure thrombopoietic activity. Furthermore, these compounds elicited biochemical responses in TPO-receptor-expressing cells similar to those in TPO itself, including kinase activation and protein phosphorylation. Potencies for the best compounds were high for such low molecular weight compounds (MW < 500) with EC(50) values in the region of 1-20 nM.
Collapse
Affiliation(s)
- K J Duffy
- GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Dhanak D, Christmann LT, Darcy MG, Jurewicz AJ, Keenan RM, Lee J, Sarau HM, Widdowson KL, White JR. Discovery of potent and selective phenylalanine derived CCR3 antagonists. Part 1. Bioorg Med Chem Lett 2001; 11:1441-4. [PMID: 11378373 DOI: 10.1016/s0960-894x(01)00248-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [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: 10/17/2022]
Abstract
The discovery of a series of phenylalanine derived CCR3 antagonists is reported. Parallel, solution-phase library synthesis has been utilized to delineate the structure-activity relationship leading to the synthesis of highly potent, CCR3-selective antagonists.
Collapse
Affiliation(s)
- D Dhanak
- SmithKline Beecham Pharmaceuticals, 1250 South Collegeville Road, PO Box 5089, Collegeville, PA 19426-0989, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Dhanak D, Christmann LT, Darcy MG, Keenan RM, Knight SD, Lee J, Ridgers LH, Sarau HM, Shah DH, White JR, Zhang L. Discovery of potent and selective phenylalanine derived CCR3 receptor antagonists. Part 2. Bioorg Med Chem Lett 2001; 11:1445-50. [PMID: 11378374 DOI: 10.1016/s0960-894x(01)00249-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [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: 10/18/2022]
Abstract
Highly potent CCR3 antagonists have been developed from a previously reported series of phenylalanine ester-based leads. Solution-phase, parallel synthesis optimization was utilized to identify highly potent, functional CCR3 antagonists.
Collapse
Affiliation(s)
- D Dhanak
- SmithKline Beecham Pharmaceuticals, 1250 South Collegeville Road, PO Box 5089, Collegeville, PA 19426-0989, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Dhanak D, Burton G, Christmann LT, Darcy MG, Elrod KC, Kaura A, Keenan RM, Link JO, Peishoff CE, Shah DH. Metal mediated protease inhibition: design and synthesis of inhibitors of the human cytomegalovirus (hCMV) protease. Bioorg Med Chem Lett 2000; 10:2279-82. [PMID: 11055338 DOI: 10.1016/s0960-894x(00)00462-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 10/27/2022]
Abstract
A versatile synthetic route to a novel series of bis-imidazolemethanes designed to inhibit the hCMV protease has been developed and a series of potential metal binding inhibitors has been identified. In selectivity assays, the compounds were highly specific for CMV protease and showed no inhibition (IC50 > 100 microM) of other prototypical serine proteases such as trypsin, elastase, and chymotrypsin. Although the presence of free zinc ions was found to be an absolute requirement for the in vitro biological activity of this class of inhibitor, the potency of the inhibitors could not be improved beyond the micromolar level.
Collapse
Affiliation(s)
- D Dhanak
- SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Miller WH, Keenan RM, Willette RN, Lark MW. Identification and in vivo efficacy of small-molecule antagonists of integrin alphavbeta3 (the vitronectin receptor). Drug Discov Today 2000; 5:397-408. [PMID: 10931657 DOI: 10.1016/s1359-6446(00)01545-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The integrin alphavbeta3 is thought to play a key role in the initiation and/or progression of several human diseases, including osteoporosis, restenosis following percutaneous transluminal coronary angioplasty (PTCA), rheumatoid arthritis, cancer and ocular diseases. Antagonism of integrin alphavbeta3 is therefore expected to provide an approach for the treatment and/or prevention of these diseases. A variety of potent, small-molecule alphavbeta3 antagonists have been identified, several of which are active in disease models, thereby demonstrating the therapeutic potential of alphavbeta3 antagonism. This review will focus on recent advances in the identification of small-molecule alphavbeta3 antagonists, with an emphasis on those studies where small-molecule alphavbeta3 antagonists have been used in proof-of-concept studies in vivo.
Collapse
Affiliation(s)
- WH Miller
- R&D Division, SmithKline Beecham Pharmaceuticals, 1250 South Collegeville Road, PO Box 5089, Collegeville, PA 19426-0989, USA
| | | | | | | |
Collapse
|
8
|
Miller WH, Alberts DP, Bhatnagar PK, Bondinell WE, Callahan JF, Calvo RR, Cousins RD, Erhard KF, Heerding DA, Keenan RM, Kwon C, Manley PJ, Newlander KA, Ross ST, Samanen JM, Uzinskas IN, Venslavsky JW, Yuan CC, Haltiwanger RC, Gowen M, Hwang SM, James IE, Lark MW, Rieman DJ, Stroup GB, Azzarano LM, Salyers KL, Smith BR, Ward KW, Johanson KO, Huffman WF. Discovery of orally active nonpeptide vitronectin receptor antagonists based on a 2-benzazepine Gly-Asp mimetic. J Med Chem 2000; 43:22-6. [PMID: 10633035 DOI: 10.1021/jm990446u] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W H Miller
- Research & Development Division, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Ward KW, Azzarano LM, Bondinell WE, Cousins RD, Huffman WF, Jakas DR, Keenan RM, Ku TW, Lundberg D, Miller WH, Mumaw JA, Newlander KA, Pirhalla JL, Roethke TJ, Salyers KL, Souder PR, Stelman GJ, Smith BR. Preclinical pharmacokinetics and interspecies scaling of a novel vitronectin receptor antagonist. Drug Metab Dispos 1999; 27:1232-41. [PMID: 10534306] [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: 02/14/2023] Open
Abstract
Allometric scaling may be used in drug development to predict the pharmacokinetics of xenobiotics in humans from animal data. Although allometry may be successful for compounds that are excreted unchanged or that are oxidatively metabolized (with corrections for metabolic capacity), it has been more challenging for compounds excreted primarily as conjugates in bile. (S)-10, 11-Dihydro-3-[3-(pyridin-2-ylamino)-1-propyloxy]-5H-dibenzo[ a, d]cycloheptene-10-acetic acid (SB-265123) is a novel alphavbeta3 ("vitronectin receptor") antagonist. In this study, the in vivo pharmacokinetics and in vitro plasma protein binding of SB-265123 were examined in four species: mice, rats, dogs, and monkeys. In monkeys and dogs, SB-265123 exhibited moderate clearance, whereas low clearance (<20% hepatic blood flow) was observed in the rat, and high clearance (>70% hepatic blood flow) was seen in the mouse. The concentration-time profiles indicated the possibility of enterohepatic recirculation; subsequent studies in bile duct-cannulated rats demonstrated extensive biliary excretion of an acyl-glucuronide of SB-265123. In allometric scaling to predict the disposition of SB-265123 in humans, various standard correction factors were applied, including protein binding, maximum lifespan potential, and brain weight; each failed to produce adequate interspecies scaling of clearance (r(2) < 0.72). Consequently, a novel correction factor incorporating bile flow and microsomal UDP-glucuronosyltransferase activity in each species was applied, demonstrating substantial improvement in the correlation of the allometric plot (r(2) = 0.96). This study demonstrates a novel allometric correction that may be applicable to compounds that undergo conjugation and biliary excretion.
Collapse
Affiliation(s)
- K W Ward
- Department of Drug Metabolism and Pharmacokinetics, SmithKline Beecham Pharmaceuticals R&D, King of Prussia, Pennsylvania 19406, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Duffy KJ, Ridgers LH, DesJarlais RL, Tomaszek TA, Bossard MJ, Thompson SK, Keenan RM, Veber DF. Design and synthesis of diaminopyrrolidinone inhibitors of human osteoclast cathepsin K. Bioorg Med Chem Lett 1999; 9:1907-10. [PMID: 10450951 DOI: 10.1016/s0960-894x(99)00322-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 10/27/2022]
Abstract
The structure-based design and synthesis of lactam-constrained azapeptide inhibitors of human cathepsin K are described. Enhanced stability to proteolytic cleavage over acyclic analogues is discussed.
Collapse
Affiliation(s)
- K J Duffy
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19246, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Miller WH, Bondinell WE, Cousins RD, Erhard KF, Jakas DR, Keenan RM, Ku TW, Newlander KA, Ross ST, Haltiwanger RC, Bradbeer J, Drake FH, Gowen M, Hoffman SJ, Hwang SM, James IE, Lark MW, Lechowska B, Rieman DJ, Stroup GB, Vasko-Moser JA, Zembryki DL, Azzarano LM, Adams PC, Huffman WF. Orally bioavailable nonpeptide vitronectin receptor antagonists with efficacy in an osteoporosis model. Bioorg Med Chem Lett 1999; 9:1807-12. [PMID: 10406646 DOI: 10.1016/s0960-894x(99)00283-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [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: 11/18/2022]
Abstract
A new series of potent nonpeptide vitronectin receptor antagonists, based on a novel carbocyclic Gly-Asp mimetic, has been discovered. A representative of this series, SB 265123 (4), has 100% oral bioavailability in rats, and is orally active in vivo in the ovariectomized rat model of osteoporosis.
Collapse
Affiliation(s)
- W H Miller
- Research & Development Division, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Keenan RM, Miller WH, Barton LS, Bondinell WE, Cousins RD, Eppley DF, Hwang SM, Kwon C, Lago MA, Nguyen TT, Smith BR, Uzinskas IN, Yuan CC. Orally bioavailable nonpeptide vitronectin receptor antagonists containing 2-aminopyridine arginine mimetics. Bioorg Med Chem Lett 1999; 9:1801-6. [PMID: 10406645 DOI: 10.1016/s0960-894x(99)00282-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [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: 11/29/2022]
Abstract
A peptide RGD analog containing a novel 2-aminopyridine arginine mimetic was discovered to have good affinity and selectivity for the vitronectin receptor. Incorporation of the 2-aminopyridine arginine mimetic into the 3-oxo-1,4-benzodiazepine-2-acetic acid integrin antagonist series led to novel and potent nonpeptide vitronectin receptor antagonists with promising levels of oral bioavailability.
Collapse
Affiliation(s)
- R M Keenan
- Research & Development Division, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Keenan RM, Callahan JF, Samanen JM, Bondinell WE, Calvo RR, Chen L, DeBrosse C, Eggleston DS, Haltiwanger RC, Hwang SM, Jakas DR, Ku TW, Miller WH, Newlander KA, Nichols A, Parker MF, Southhall LS, Uzinskas I, Vasko-Moser JA, Venslavsky JW, Wong AS, Huffman WF. Conformational preferences in a benzodiazepine series of potent nonpeptide fibrinogen receptor antagonists. J Med Chem 1999; 42:545-59. [PMID: 10052962 DOI: 10.1021/jm980166z] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [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: 11/28/2022]
Abstract
Previously, we reported the direct design of highly potent nonpeptide 3-oxo-1,4-benzodiazepine fibrinogen receptor antagonists from a constrained, RGD-containing cyclic semipeptide. The critical features incorporated into the design of these nonpeptides were the exocyclic amide at the 8-position which overlaid the Arg carbonyl, the phenyl ring which maintained an extended Gly conformation, and the diazepine ring which mimicked the gamma-turn at Asp. In this paper, we investigate conformational preferences of the 8-substituted benzodiazepine analogues by examining structural modifications to both the exocyclic amide and the seven-membered diazepine ring and by studying the conformation of the benzodiazepine ring using molecular modeling, X-ray crystallography, and NMR. We found that the directionality of the amide at the 8-position had little effect on activity and the (E)-olefin analogue retained significant potency, indicating that the trans orientation of the amide, and not the carbonyl or NH groups, made the largest contribution to the observed activity. For the diazepine ring, with the exception of the closely analogous 3-oxo-2-benzazepine ring system described previously, all of the modifications led to a significant reduction in activity compared to the potent 3-oxo-1, 4-benzodiazepine parent ring system, implicating this particular type of ring system as a desirable structural feature for high potency. Energy minimizations of a number of the modified analogues revealed that none could adopt the same low-energy conformation as the one shared by the active (S)-isomer of the 3-oxo-1, 4-benzodiazepines and 3-oxo-2-benzazepines. The overall data suggest that the features contributing to the observed high potency in this series are the orientation of the 3-4 amide and the conformational constraint imposed by the seven-membered ring, both of which position the key acidic and basic groups in the proper spatial relationship.
Collapse
Affiliation(s)
- R M Keenan
- Research and Development Division, SmithKline Beecham Pharmaceuticals, P.O. Box 5089, Collegeville, Pennsylvania 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Dhanak D, Keenan RM, Burton G, Kaura A, Darcy MG, Shah DH, Ridgers LH, Breen A, Lavery P, Tew DG, West A. Benzothiopyran-4-one based reversible inhibitors of the human cytomegalovirus (HCMV) protease. Bioorg Med Chem Lett 1998; 8:3677-82. [PMID: 9934494 DOI: 10.1016/s0960-894x(98)00666-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [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: 11/22/2022]
Abstract
A novel class of CMV protease inhibitors based on a benzothiopyran-S,S-dioxide nucleus has been discovered. Enzyme kinetic data supports a reversible mode of inhibition for a representative member of this class, 2-(3-pyridyl-N-oxide)benzothiopyran-4-one-S,S-dioxide, 1. Experiments in the presence and absence of the disulfide reducing agent DTT suggest that the inhibition by 1 is not due to oxidative inactivation of the enzyme. Also presented are results of some SAR studies of the benzothiopyranone ring system.
Collapse
Affiliation(s)
- D Dhanak
- SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Keenan RM, Miller WH, Lago MA, Ali FE, Bondinell WE, Callahan JF, Calvo RR, Cousins RD, Hwang SM, Jakas DR, Ku TW, Kwon C, Nguyen TT, Reader VA, Rieman DJ, Ross ST, Takata DT, Uzinskas IN, Yuan CC, Smith BR. Benzimidazole derivatives as arginine mimetics in 1,4-benzodiazepine nonpeptide vitronectin receptor (alpha v beta 3) antagonists. Bioorg Med Chem Lett 1998; 8:3165-70. [PMID: 9873696 DOI: 10.1016/s0960-894x(98)00555-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/28/2022]
Abstract
In a 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists containing a benzimidazole as a novel arginine mimetic, we examined the effects of benzimidazole modifications and amide substitutions on both activity and pharmacokinetics.
Collapse
Affiliation(s)
- R M Keenan
- Research & Development Division, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Keenan RM, Lago MA, Miller WH, Ali FE, Cousins RD, Hall LB, Hwang SM, Jakas DR, Kwon C, Louden C, Nguyen TT, Ohlstein EH, Rieman DJ, Ross ST, Samanen JM, Smith BR, Stadel J, Takata DT, Vickery L, Yuan CC, Yue TL. Discovery of an imidazopyridine-containing 1,4-benzodiazepine nonpeptide vitronectin receptor (alpha v beta 3) antagonist with efficacy in a restenosis model. Bioorg Med Chem Lett 1998; 8:3171-6. [PMID: 9873697 DOI: 10.1016/s0960-894x(98)00556-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [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: 10/27/2022]
Abstract
In the 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists, a compound containing an imidazopyridine arginine mimetic was discovered which had sufficient potency and i.v. pharmacokinetics for demonstration of efficacy in a rat restenosis model.
Collapse
Affiliation(s)
- R M Keenan
- Research & Development Division, SmithKline Beecham Pharmaceuticals, Collegeville, PA 19426-0989, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Keenan RM, Miller WH, Kwon C, Ali FE, Callahan JF, Calvo RR, Hwang SM, Kopple KD, Peishoff CE, Samanen JM, Wong AS, Yuan CK, Huffman WF. Discovery of potent nonpeptide vitronectin receptor (alpha v beta 3) antagonists. J Med Chem 1997; 40:2289-92. [PMID: 9240343 DOI: 10.1021/jm970205r] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- R M Keenan
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Samanen JM, Ali FE, Barton LS, Bondinell WE, Burgess JL, Callahan JF, Calvo RR, Chen W, Chen L, Erhard K, Feuerstein G, Heys R, Hwang SM, Jakas DR, Keenan RM, Ku TW, Kwon C, Lee CP, Miller WH, Newlander KA, Nichols A, Parker M, Peishoff CE, Rhodes G, Ross S, Shu A, Simpson R, Takata D, Yellin TO, Uzsinskas I, Venslavsky JW, Yuan CK, Huffman WF. Potent, selective, orally active 3-oxo-1,4-benzodiazepine GPIIb/IIIa integrin antagonists. J Med Chem 1996; 39:4867-70. [PMID: 8960544 DOI: 10.1021/jm960558a] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J M Samanen
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Ku TW, Miller WH, Bondinell WE, Erhard KF, Keenan RM, Nichols AJ, Peishoff CE, Samanen JM, Wong AS, Huffman WF. Potent non-peptide fibrinogen receptor antagonists which present an alternative pharmacophore. J Med Chem 1995; 38:9-12. [PMID: 7837245 DOI: 10.1021/jm00001a003] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- T W Ku
- Research and Development Division, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
Despite the current popularity of smoking as a route of drug self-administration, there have been few human studies characterizing the pharmacokinetics and pharmacodynamics of smoked drugs of abuse. A variety of technological difficulties are encountered in the design of smoking studies, such as delivering reproducible doses and limiting the amount of pyrolysis of parent drug. As part of a concerted research effort to deliver precise, smoked doses of drug, a computer-assisted smoking device was utilized that delivered single puffs of heroin vapor to human subjects under controlled clinical conditions. Recovery studies indicated that the smoking device delivered approximately 89% of parent heroin to subjects. Although only two qualified heroin smokers could be identified as eligible volunteers, their participation provided the unique opportunity to study the pharmacokinetics and pharmacodynamics of smoked heroin. The two subjects were administered four smoked heroin doses in ascending order. In addition, four intravenous doses of heroin were administered for comparison of effects and estimation of bioavailability. Concurrent physiological, behavioral, and performance measures were collected along with blood samples. Blood was analyzed for heroin, 6-acetylmorphine, and morphine by solid-phase extraction gas chromatography-mass spectrometry. Heroin appeared rapidly in blood after administration and peaked 1-5 minutes after smoking, which is similar to that observed following intravenous administration. Heroin concentrations declined rapidly to the limit of detection (1.0 ng/mL) by 30 minutes. 6-Acetylmorphine blood concentrations also peaked and declined rapidly after smoked heroin with peak concentrations occurring at 1-2 minutes after smoking. Morphine levels rose and decayed more slowly. Mean elimination half-lives for heroin, 6-acetylmorphine, and morphine were 3.3 min, 5.4 min, and 18.8 min, respectively, by the smoked route. The bioavailability of smoked heroin was highly variable. Physiological measures such as pupil diameter demonstrated a counterclockwise hysteresis compared with heroin blood levels. The rapid onset of pharmacological effects together with the early appearance of heroin and metabolites in blood following smoked heroin demonstrated the effectiveness of this route of drug administration. It is evident that the smoking route enables individuals to obtain similar pharmacological effects as are produced by intravenous administration of heroin.
Collapse
Affiliation(s)
- A J Jenkins
- Addiction Research Center, NIDA/NIH, Baltimore, MD 21224
| | | | | | | |
Collapse
|
21
|
Abstract
Although a variety of drugs have been detected in sweat, little information is available on the characteristics of drug excretion in sweat under controlled-dosing conditions. A series of clinical studies were designed to determine the identity, concentration, time course, dose dependency, and variability of drug and metabolite excretion in sweat following administration of single doses of cocaine and heroin to human subjects. Sweat was collected by means of a sweat patch that could be worn for a period of several days to several weeks at a time, resulting in accumulation of drug in the patch. Sweat patches were removed at specified times and frozen until analyzed by gas chromatography--mass spectrometry. Cocaine and heroin were the major analytes excreted in sweat following their administration. Smaller amounts of cocaine metabolites were also detected following cocaine administration. 6-Acetylmorphine appeared rapidly after heroin administration and continued to increase while heroin content decreased, suggesting that heroin was undergoing hydrolysis in the sweat patch. Cocaine appeared in sweat within 1-2 hours and peaked within 24 hours in an apparent dose-dependent manner. Analysis of duplicate adjacent patches from individual subjects who had been administered cocaine provided similar quantitative results, suggesting that intrasubject variability was relatively low, whereas intersubject variability was high. These observations regarding the excretion of cocaine and heroin analytes in sweat have important forensic implications to other fields such as hair analysis. Sweat excretion could be an important mechanism by which drugs enter hair. These data also suggest that the sweat patch could serve as a useful monitoring device in surveillance of individuals in treatment and probation programs.
Collapse
Affiliation(s)
- E J Cone
- Addiction Research Center, National Institute on Drug Abuse, Baltimore, MD 21224
| | | | | | | | | |
Collapse
|
22
|
Bondinell WE, Keenan RM, Miller WH, Ali FE, Allen AC, de Brosse CW, Eggleston DS, Erhard KF, Haltiwanger RC, Huffman WF. Design of a potent and orally active nonpeptide platelet fibrinogen receptor (GPIIb/IIIa) antagonist. Bioorg Med Chem 1994; 2:897-908. [PMID: 7712125 DOI: 10.1016/s0968-0896(00)82039-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [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: 01/26/2023]
Abstract
The direct design of the potent nonpeptide platelet fibrinogen receptor (GPIIb/IIIa) antagonist, 8-[[[4- (aminoiminomethyl)phenyl]amino]carbonyl]-2,3,4,5-tetrahydro-3-oxo- 4- (2-phenylethyl)-1H-1,4-benzodiazepine-2-acetic acid, (3) (SB 207448), based on the structure and conformation of the potent and highly constrained cyclic peptide antagonist SK&F 107260 (2), has been reported [Ku et al., J. Am. Chem. Soc. 1993, 115, 8861]. While 3 displayed in vivo activity in the conscious dog following intravenous administration, it was not active following intraduodenal administration; activity was measured with an ex vivo platelet aggregation assay. The secondary amide in 3 was N-methylated in the expectation of increased absorption and bioavailability. The resulting tertiary amide, 4 (SB 208651), also showed high binding affinity for human GPIIb/IIIa and potent antiaggregatory activity in human platelet-rich plasma. Most importantly, 4 was active in vivo following intravenous and intraduodenal administration. Comparison of the iv and id inhibition curves suggests an apparent bioavailability of approximately 10%. Thus, 4 represents the first orally active compound in this series of potent, nonpeptide fibrinogen receptor antagonists.
Collapse
Affiliation(s)
- W E Bondinell
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
The nicotine metabolite cotinine was administered to abstinent cigarette smokers to determine whether it has pharmacologic activity as assessed by various physiologic and subjective measurements. By means of a randomized, double-blind, placebo-controlled counterbalanced-order design, subjects received cotinine base (30 mg) intravenously after 48 hours of abstinence from cigarette smoking. Serum cotinine concentrations increased to levels commonly achieved during daily cigarette smoking, whereas no change in serum nicotine concentration was observed. Cotinine compared with placebo produced subjective differences in self-reported ratings of restlessness, anxiety and tension, insomnia, sedation, and pleasantness. Cotinine had minimal effects on cardiovascular measurements. These findings indicate that cotinine is behaviorally active in the setting of cigarette abstinence at blood concentrations similar to those commonly achieved through daily cigarette smoking.
Collapse
Affiliation(s)
- R M Keenan
- Clinical Pharmacology Branch, NIH/NIDA/ARC, Baltimore, MD 21224
| | | | | | | | | |
Collapse
|
24
|
Abstract
It is well established that nicotine meets all criteria of a highly addictive drug. However, as recognized by the U.S. surgeon general, the nicotine delivery system itself is an important determinant of the toxic and addictive effects engendered by nicotine use. Therefore, altering the form of nicotine dosing may allow for selective therapeutic action in efforts to develop safer and less addictive nicotine replacement therapies. While it is the case that initial tobacco use often escalates to compulsive use accompanied by tolerance and physical dependence, this is not usually observed with nicotine replacement therapies. These observations are consistent with laboratory data indicating that (a) nicotine polacrilex and transdermal systems deliver nicotine more slowly and at lower dose levels than tobacco-based forms, and (b) human data suggesting that the abuse liability of these systems is substantially lower than that of the tobacco-based nicotine delivery systems. Because the drug dosage form can be systematically manipulated and evaluated, further research in developing alternative nicotine delivery forms may hold substantial promise in the treatment of tobacco dependence. Psychological research methods can play an important part in their evaluation.
Collapse
Affiliation(s)
- J E Henningfield
- National Institute on Drug Abuse, Addiction Research Center, Baltimore, Maryland 21224
| | | |
Collapse
|
25
|
Abstract
It is well established that nicotine meets all criteria of a highly addictive drug. However, as recognized by the U.S. surgeon general, the nicotine delivery system itself is an important determinant of the toxic and addictive effects engendered by nicotine use. Therefore, altering the form of nicotine dosing may allow for selective therapeutic action in efforts to develop safer and less addictive nicotine replacement therapies. While it is the case that initial tobacco use often escalates to compulsive use accompanied by tolerance and physical dependence, this is not usually observed with nicotine replacement therapies. These observations are consistent with laboratory data indicating that (a) nicotine polacrilex and transdermal systems deliver nicotine more slowly and at lower dose levels than tobacco-based forms, and (b) human data suggesting that the abuse liability of these systems is substantially lower than that of the tobacco-based nicotine delivery systems. Because the drug dosage form can be systematically manipulated and evaluated, further research in developing alternative nicotine delivery forms may hold substantial promise in the treatment of tobacco dependence. Psychological research methods can play an important part in their evaluation.
Collapse
Affiliation(s)
- J E Henningfield
- National Institute on Drug Abuse, Addiction Research Center, Baltimore, Maryland 21224
| | | |
Collapse
|
26
|
Keenan RM, Weinstock J, Finkelstein JA, Franz RG, Gaitanopoulos DE, Girard GR, Hill DT, Morgan TM, Samanen JM, Peishoff CE. Potent nonpeptide angiotensin II receptor antagonists. 2. 1-(Carboxybenzyl)imidazole-5-acrylic acids. J Med Chem 1993; 36:1880-92. [PMID: 8515425 DOI: 10.1021/jm00065a011] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [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: 01/31/2023]
Abstract
The further evolution of the imidazole-5-acrylic acid series of nonpeptide angiotensin II receptor antagonists is detailed (for Part 1, see: J. Med. Chem. 1992, 35, 3858). Modifications of the N-benzyl ring substitution were undertaken in an effort to mimic the Tyr4 residue of angiotensin II. Introduction of a p-carboxylic acid on the N-benzyl ring resulted in the discovery of compounds with nanomolar affinity for the receptor and good oral activity. SAR studies of these potent antagonists revealed that the thienyl ring, the (E)-acrylic acid, and the imidazole ring in addition to the two acid groups were important for high potency. Also, overlay comparisons of the parent diacid with both angiotensin II and a representative biphenylyltetrazole nonpeptide angiotensin II receptor antagonist are presented. The parent diacid analog, SK&F 108566 or (E)-3-[2-butyl-1-(4-carboxybenzyl)-1H-imidazole-5-yl]-2-[(2- thienyl)methyl]propenoic acid, is currently in clinical development for the treatment of hypertension.
Collapse
Affiliation(s)
- R M Keenan
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Kozlowski LT, Henningfield JE, Keenan RM, Lei H, Leigh G, Jelinek LC, Pope MA, Haertzen CA. Patterns of alcohol, cigarette, and caffeine and other drug use in two drug abusing populations. J Subst Abuse Treat 1993; 10:171-9. [PMID: 8510191 DOI: 10.1016/0740-5472(93)90042-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [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: 01/31/2023]
Abstract
Relationships were explored among the frequencies of use of various drugs by a sample of drug-abusing clients of the Addiction Research Foundation (ARF) in Toronto and by drug abusers volunteering to participate in research at the Addiction Research Center (ARC) in Baltimore. The two groups of drug-abusing individuals differed in a number of characteristics. Those from ARF were admitted primarily for diagnosis and possible treatment for alcohol and non-opioid drug problems, whereas those from the ARC were admitted for participation in research on other drugs of abuse, primarily involving opioids. Patterns of use of certain drugs tended to covary in both groups. Of particular interest was the finding that severity of alcoholism was directly related to various measures of tobacco and caffeinated beverage use. In contrast, there was little correlation between the frequency of use among other drugs of abuse (e.g., heroin, cannabis, glue) and the use of tobacco and caffeine. These findings suggest that dependence on nicotine, caffeine, and alcohol may be governed by the same factors and possibly should be considered jointly in the treatment of alcoholic persons. Frequency of use of other drugs examined may be controlled by other factors than those which determine level of use of tobacco and caffeine.
Collapse
|
28
|
Keenan RM, Weinstock J, Finkelstein JA, Franz RG, Gaitanopoulos DE, Girard GR, Hill DT, Morgan TM, Samanen JM, Hempel J. Imidazole-5-acrylic acids: potent nonpeptide angiotensin II receptor antagonists designed using a novel peptide pharmacophore model. J Med Chem 1992; 35:3858-72. [PMID: 1433195 DOI: 10.1021/jm00099a013] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [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: 12/27/2022]
Abstract
A series of novel nonpeptide angiotensin II receptor antagonists containing a substituted (E)-acrylic acid has been developed. The overlay of 1, an imidazole-5-acetic acid found in the patent literature, on a novel pharmacophore model of AII suggested that extension of the acid side chain and attachment of a second aryl residue to mimic the C-terminal phenylalanine region of AII would lead to increased activity. A study of extended acid side chains at C-5 of the imidazole nucleus led to the discovery of the (E)-acrylic acid 5 as a promising starting point for further exploration. As predicted by the modeling, substitution of a benzyl group on the acrylic acid side chain to mimic the phenylalanine gave increased potency. An extensive study of the SAR of the newly introduced aromatic ring revealed that electron-rich heteroaryl rings provided improved activity, most notably in the in vivo rat models. Compound 40, (E)-3-[2-butyl-1- [(2-chlorophenyl)methyl]imidazol-5-yl]-2-[(2-thienyl)methyl]-2- propenoic acid, has been shown to be a potent, competitive, and orally active small molecule AT-1 receptor antagonist. It exhibits a 2 orders of magnitude increase in binding affinity and a 10-fold improvement in in vivo potency as compared to compound 1 and represents an important milestone in the development of even more potent nonpeptide angiotensin II receptor antagonists.
Collapse
Affiliation(s)
- R M Keenan
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Edwards RM, Stack EJ, Weidley EF, Aiyar N, Keenan RM, Hill DT, Weinstock J. Characterization of renal angiotensin II receptors using subtype selective antagonists. J Pharmacol Exp Ther 1992; 260:933-8. [PMID: 1545405] [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: 12/27/2022] Open
Abstract
Two angiotensin II (AII) receptor subtypes, AT1 and AT2, have recently been identified based on their relative affinities for selective peptide and nonpeptide antagonists. In the present study we used various AII peptide analogs, the AT1 subtype selective antagonists, DuP 753 and SK&F 108566, and the AT2 subtype selective antagonists, WL-19 and CGP 42112A, to determine whether AII receptor subtypes exist in the kidney. In agreement with previous studies, octapeptide (Sar1,Ile8-AII) and heptapeptide (AIII and Ile8-AIII) AII analogs displaced [125I]AII bound to rat glomerular membranes with similar affinities. However, in membranes derived from cortical tubules and the outer medulla, the heptapeptide analogs were 20-fold less potent in competing with [125I]AII binding than octapeptide analogs. The AT1 subtype selective nonpeptide AII antagonists, DuP 753 and SK&F 108566, totally displaced [125I]AII binding from all three membrane preparations in a monophasic manner with IC50 values in the 5 to 30 nM range. The AT2 selective peptide antagonist, CGP 42112A, had a low affinity in AII three membranes (IC50 = 450-1050 nM), whereas the nonpeptide AT2 selective antagonist, WL-19, had no activity at concentrations up to 10 microM. Dithiothreitol and the nonhydrolyzable GTP analog, 5'-guanylyl-imidodiphosphate, inhibited AII binding to all three membrane preparations. Based on these results, we conclude that the AII receptors located on glomeruli, tubules and in the outer medulla belong to the AT1 subtype, and that the physiologically important renal actions of AII are mediated through activation of AT1 receptors.
Collapse
Affiliation(s)
- R M Edwards
- Department of Pharmacology, Smith Kline Beecham Pharmaceuticals, King of Prussia, Pennsylvania
| | | | | | | | | | | | | |
Collapse
|
30
|
Edwards RM, Aiyar N, Ohlstein EH, Weidley EF, Griffin E, Ezekiel M, Keenan RM, Ruffolo RR, Weinstock J. Pharmacological characterization of the nonpeptide angiotensin II receptor antagonist, SK&F 108566. J Pharmacol Exp Ther 1992; 260:175-81. [PMID: 1309870] [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: 12/26/2022] Open
Abstract
The angiotensin II (AII) antagonist activity of (E)-alpha-[[2-butyl-1-[(4-carboxyphenyl)methyl]-1H-imidazol-5- yl]methylene]-2-thiophenepropanoic acid (SK&F 108566), was examined in a number of in vitro and in vivo assays. In rat and human adrenal cortical membranes, SK&F 108566 displaced specifically bound [125I]AII with IC50 of 9.2 and 3.9 nM, respectively. SK&F 108566 also inhibited [125I]AII binding to human liver membranes (IC50 = 1.7 nM) and to rat mesenteric artery membranes (IC50 = 1.5 nM). In rabbit aortic smooth muscle cells, SK&F 108566 caused a concentration-dependent inhibition of AII-induced increases in intracellular Ca++ levels. In rabbit aortic rings, SK&F 108566 produced parallel rightward shifts in the AII concentration-response curve without affecting the maximal contractile response. Schild analysis of the data yielded a KB value of 0.26 nM and a slope not different from 1, indicative of competition antagonism. SK&F 108566 had no effect on the contractile responses to KCl, norepinephrine or endothelin in rabbit aorta. In conscious normotensive rats, i.v. administration of SK&F 108566 (0.01-0.3 mg/kg) produced dose-dependent parallel shifts in the AII pressor dose-response curve. Administration of SK&F 108566 (3-10 mg/kg) intraduodenally or intragastrically to conscious normotensive rats resulted in a dose-dependent inhibition of the pressor response to AII (250 ng/kg, i.v.). At 10 mg/kg, i.d., significant inhibition of the pressor response to AII was observed for 3 hr. In this same rat model, SK&F 108566 had no effect on base-line pressure or on the pressor response to norepinephrine or vasopressin. The data demonstrate that SK&F 108566 is a potent, highly selective, competitive nonpeptide AII antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- R M Edwards
- Department of Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Weinstock J, Keenan RM, Samanen J, Hempel J, Finkelstein JA, Franz RG, Gaitanopoulos DE, Girard GR, Gleason JG, Hill DT. 1-(carboxybenzyl)imidazole-5-acrylic acids: potent and selective angiotensin II receptor antagonists. J Med Chem 1991; 34:1514-7. [PMID: 2016730 DOI: 10.1021/jm00108a043] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J Weinstock
- Research and Development Division, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406-0939
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Hoffman WE, Keenan RM. Implementing the congressional purpose of the immunity and attorneys' fees provisions of the Health Care Quality Improvement Act. Hosp Law Newsl 1991; 8:1-5. [PMID: 10183470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
33
|
Abstract
Smokers (n = 315) who wished to quit were randomly assigned in a double-blind manner to groups using either nicotine or placebo gum. Self-reported and observed symptoms of tobacco withdrawal were collected before cessation and at follow-ups of 1 to 2 weeks, 1 month, and 6 months. Self-reported and/or observed anger, anxiety, craving, difficulty concentrating, hunger, impatience, and restlessness were the most prominent symptoms of tobacco withdrawal. These symptoms had returned to precessation levels by 1 month except increased weight, hunger, and craving continued for 6 months in many smokers. Nicotine gum decreased most symptoms, including craving and hunger but not weight. Abstinent smokers with more intense withdrawal were not more likely to relapse. Abstinent smokers who gained more weight were less likely to relapse.
Collapse
Affiliation(s)
- J R Hughes
- Department of Psychiatry, University of Vermont, Burlington
| | | | | | | | | |
Collapse
|
34
|
Hughes JR, Gust SW, Keenan RM, Fenwick JW. Effect of dose on nicotine's reinforcing, withdrawal-suppression and self-reported effects. J Pharmacol Exp Ther 1990; 252:1175-83. [PMID: 2319467] [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: 12/31/2022] Open
Abstract
Seventy-eight smokers trying to quit were randomly assigned to 0-, 0.5-, 2- and 4-mg doses of nicotine gum and tracked for 9 months. In the 1st week of abstinence, self-administration of gum did not differ by dose (4 mg = 2 mg = 0.5 mg = 0 mg). Higher doses did not more effectively suppress withdrawal than lower doses nor induce more accurate nicotine identification (4 mg = 2 mg = 0.5 mg greater than 0 mg). Higher doses slightly increased ratings of adverse effects in the 1st week (4 mg greater than 2 mg greater than 0.5 mg greater than 0 mg). Over the next 6 months, the two higher doses appeared to support more gum self-administration than the two lower doses (4 mg = 2 mg greater than 0.5 mg = 0 mg) in the subsample of long-term quitters (n = 20). Our results suggest the dose-response curves differ for nicotine gum's reinforcing, withdrawal-suppression and self-reported effects.
Collapse
Affiliation(s)
- J R Hughes
- Department of Psychiatry, University of Vermont, Burlington
| | | | | | | |
Collapse
|
35
|
Keenan RM, Hatsukami DK, Pickens RW, Gust SW, Strelow LJ. The relationship between chronic ethanol exposure and cigarette smoking in the laboratory and the natural environment. Psychopharmacology (Berl) 1990; 100:77-83. [PMID: 2296630 DOI: 10.1007/bf02245794] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [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: 12/31/2022]
Abstract
Few studies have examined the association between ethanol use and cigarette smoking topography. In particular, no study has objectively investigated the relationship between chronic ethanol exposure and cigarette smoking. The aim of this study was to quantify the relationship between cigarette smoking and past and current ethanol use. Male and female cigarette smokers (n = 77) between the ages of 30 and 65 years were recruited and grouped as a function of their past and current ethanol use. Group 1 (n = 18) included subjects who were ethanol abstinent for the 3 months prior to the study and had no history of alcohol abuse (as defined by DSM-III criteria). Group 2 (n = 19) included subjects who were current regular ethanol users and had no history of alcohol abuse. Group 3 (n = 20) included subjects who were ethanol abstinent and had a history of alcohol abuse. Group 4 (n = 20) included current regular ethanol users with a history of alcohol abuse. A history of alcohol abuse was associated with an intensified pattern of cigarette smoking. Significant differences were observed for total daily smoke exposure, cigarette number, puff number, total puff and inhalation volume, and the nicotine, tar and carbon monoxide yields of the cigarettes smoked. Increased expired-air carbon monoxide and serum cotinine levels were also observed. Current ethanol use was not associated with an increased cigarette smoking pattern. These data suggest that alcohol abusers are at greater risk of contracting cigarette-related pathology.
Collapse
Affiliation(s)
- R M Keenan
- Department of Psychiatry, University of Minesota Medical School, Minneapolis 55455
| | | | | | | | | |
Collapse
|
36
|
Hughes JR, Gust SW, Keenan RM, Fenwick JW, Healey ML. Nicotine vs placebo gum in general medical practice. JAMA 1989; 261:1300-5. [PMID: 2644465] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Three hundred fifteen smokers who attended a family practice clinic and wished to quit smoking were assigned in a random, double-blind manner to receive either nicotine (2 mg) or placebo gum. Smokers initially received brief advice from a physician and nurse, a slide presentation and written materials (29 to 35 minutes), and a single follow-up visit (12 to 20 minutes) one week after cessation. After corrections for marital status and income, 10% of those who received nicotine gum and 7% of those who received placebo gum reported continuous abstinence for 11 months and passed observer and biochemical verification (this difference was not statistically significant). We conclude that, when used in a nonselected group of smokers along with a brief intervention in a general medical practice, the pharmacologic effects of nicotine gum to increase cessation are either small or nonexistent.
Collapse
Affiliation(s)
- J R Hughes
- Department of Psychiatry, University of Vermont, Burlington
| | | | | | | | | |
Collapse
|
37
|
Abstract
Health hazards associated with nicotine and tobacco use are well known. A contributing factor, the dependence producing potential of this drug, has become widely accepted. However, there are only a few human and animal studies that provide objective measures of the behavioral consequences of nicotine abstinence. The purpose of the present experiment was to use sensitive measures to examine behavioral disruptions that resulted when nicotine administration was terminated. Six rats were administered 96 daily intravenous infusions of nicotine (0.125 mg/kg/infusion) for at least 10 days. They were trained to respond on a tongue-operated solenoid-driven drinking device that delivered 0.005 ml of a glucose and saccharin solution (G + S) per lick. When nicotine access was terminated for six days, there was a marked suppression in behavior reinforced by the sweetened solution, and this disruption was immediately reversed when nicotine was reinstated. In contrast, nicotine removal also resulted in a decrease in food intake on the first day, but on subsequent days food intake was significantly higher than when nicotine was administered. When cotinine (0.25 mg/kg/infusion), a metabolite of nicotine was substituted for nicotine for six days, similar disruptions resulted in responding maintained by G + S, but food intake was not significantly decreased on the first day of nicotine abstinence. These findings illustrate the utility of sensitive behavioral tests to reveal effects of nicotine abstinence.
Collapse
Affiliation(s)
- M E Carroll
- Department of Psychiatry, University of Minnesota, Minneapolis, MN 55455
| | | | | | | |
Collapse
|
38
|
Abstract
Several past studies have reported reliable changes in reaction time performance and self-rated withdrawal scores as a consequence of cigarette deprivation. The purpose of the present study was to determine, prospectively, the effect 24 h of smokeless tobacco deprivation in regular users has on performance and the associated withdrawal symptomology. Forty smokeless tobacco users (Copenhagen brand) were randomly divided evenly into two groups (N = 20):24 h of deprivation and no deprivation. A third group of ten nonchewers was added as another control group. The results indicated that behavioral, subjective and physiological changes are associated with smokeless tobacco deprivation in regular users. These include increased craving scores, reaction time, self-rated withdrawal symptoms and decreased heart rate.
Collapse
Affiliation(s)
- R M Keenan
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis 55455
| | | | | |
Collapse
|
39
|
Abstract
Sixteen smokers completed a sustained attention task, were randomly assigned to either continue smoking or abstain for 24 h, and were retested. Eight nonsmokers served as a control group. Abstinence increased the variability in responding. Abstinence also appeared to impair the ability to inhibit responding. Abstinence did not potentiate fatigue during the task. These results are consistent with reports that tobacco withdrawal increases difficulty concentrating and impatience but does not increase fatigue.
Collapse
Affiliation(s)
- J R Hughes
- Department of Psychiatry, University of Vermont, Burlington 05401
| | | | | |
Collapse
|
40
|
Abstract
There is an increasing prevalence of smokeless tobacco use. However, very little descriptive information is available on the pattern of use. This study examines topographical features of smokeless tobacco use in a male college-age population (N = 56). Subjects were required to use smokeless tobacco ad lib. for a period of 3 days. During this time, they were asked to record the time of onset and completion of each dip of smokeless tobacco. Smokeless tobacco use was significantly associated with time of day. The mean dips/day was 6.3 (SD +/- 2.2), mean inter-dip interval was 102.6 (SD +/- 42.1) min, mean duration/dip was 39.9 (SD +/- 16.5)min, and mean total dip duration/day was 254.6 (SD +/- 129.3) min. The mean grams of tobacco/dip was 1.97 (SD +/- 0.96) and the total grams of tobacco used/day was 12.0 (SD +/- 6.8) g. There were significant correlations between saliva cotinine and number of dips/day, mean duration/dip, total dip duration/day and mean inter-dip interval, suggesting that smokeless tobacco has the potential for producing dependence.
Collapse
Affiliation(s)
- D K Hatsukami
- Department of Psychiatry, University of Minnesota, Minneapolis 55455
| | | | | |
Collapse
|
41
|
Abstract
This study prospectively examined withdrawal symptoms in persons using Copenhagen smokeless tobacco and in persons smoking cigarettes. Smokeless tobacco chewers (N = 16) and cigarette smokers (N = 11) were examined during a 6-day period, during which time a number of measures were administered. Subjects used smokeless tobacco or smoked cigarettes on an ad libitum basis for a 3-day baseline period and then underwent tobacco deprivation. The significant changes that occurred relative to baseline after smokeless tobacco deprivation included decreased heart rate and orthostatic pulse change and increased craving for tobacco, confusion, eating, number of awakenings, and total scores on a withdrawal symptoms checklist for both self-rated and observer-rated measures. There were more changes and changes of greater severity among cigarette smokers.
Collapse
|
42
|
Hughes JR, Pickens RW, Spring W, Keenan RM. Instructions control whether nicotine will serve as a reinforcer. J Pharmacol Exp Ther 1985; 235:106-12. [PMID: 4045717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Three studies examined self-administration of nicotine among exsmokers given concurrent access to nicotine (2 mg) and placebo gums during the first 2 weeks of abstinence from smoking. In Study 1 subjects were told they would receive either nicotine or placebo gum. With this instructional set, nicotine served as a reinforcer; i.e., subjects consistently self-administered nicotine but not placebo gum. However, subjects could discriminate gums on the basis of side-effects; thus, the ability of nicotine to serve as a reinforcer may have been due, not to its psychoactive effects, but rather because subjects believed the gum with more side-effects to be the active gum. In Study 2 we attempted to change this belief by telling subjects they would receive either the marketed nicotine gum or a new nicotine gum that is as effective as the marketed gum but has less side-effects (i.e., placebo). In Study 3 we attempted to change the belief by telling subjects that placebo gum had more side-effects than nicotine gum. With these two instructional sets, the stimulus properties of nicotine did not serve as reinforcer; i.e., subjects self-administered equal amounts of nicotine and placebo gums. To our knowledge, this is the first demonstration that instructions can control whether a drug will serve as a reinforcer.
Collapse
|
43
|
|
44
|
|