151
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Hoyo-Vadillo C, Castañeda-Hernández G, Herrera JE, Vidal-Gárate J, Salazar LA, Moreno-Ramos A, Chávez F, Tena I, Hong E. Pharmacokinetics of oral nifedipine: relevance of the distribution phase. J Clin Pharmacol 1989; 29:251-6. [PMID: 2723112 DOI: 10.1002/j.1552-4604.1989.tb03322.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pharmacokinetics of oral Nifedipine was studied in 12 Mexican young healthy volunteers, six men and six women, who received a 10 mg capsule. Plasma levels were determined by a nifedipine specific HPLC assay. Experimental data were fitted and pharmacokinetic parameters were calculated using an open two compartment model. No statistically significant difference was detected between men and women, thus both sexes were considered as a single population. Nifedipine plasma levels rose rapidly (ka = 8.46 +/- 1.96 h-1) reaching a maximum concentration of 145 +/- 23 ng/ml in 0.61 +/- 0.07 h. Plasma levels then decayed with a distribution phase (alpha = 1.98 +/- 0.40 h-1, t1/2 alpha = 0.46 +/- 0.06 h) and a terminal elimination phase (beta = 0.17 +/- 0.03 h-1, t1/2 beta = 4.98 +/- 0.55 h). AUC was 384 +/- 41 ng h/ml. Values of AUC and t1/2 beta were higher than those reported by other authors. Differences in the AUC could be due to ethnic origin, environmental factors or nutritional habits. Ten subjects presented plasma concentration-time curves in which the distribution phase was clearly distinguishable, having a ka/alpha relationship higher than 1.5. For the other two subjects, the distribution phase was not apparent and ka/alpha was lower than 1.5. The results show that an adequate characterization of the distribution phase is required if one pretends to use pharmacokinetic data for dosage regimen design.
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152
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Vidal-Gárate J, Castañeda Hernández G, Hoyo Vadillo C, Herrera Abarca JE, Salazar LA, Moreno Ramos A, Fortino Chávez J, Tena I, Hong E. [Clinical and pharmacokinetic comparison of 2 oral preparations of nifedipine: 10 mg capsules and 20 mg delayed-release tablets]. ARCHIVOS DEL INSTITUTO DE CARDIOLOGIA DE MEXICO 1989; 59:73-80. [PMID: 2486739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects and pharmacokinetic parameters of two oral formulations of nifedipine, 10 mg capsule (Adaltat) and 20 mg slow release tablet (Adalat a.p.). With the 10 mg capsule nifedipine was rapidly absorbed, reaching a maximum concentration of 120 +/- 39 ng/ml in 0.52 +/- 0.07 h, and also rapidly eliminated with an apparent halflife of 5.51 +/- 0.64 h. A fall in blood pressure and a raise in heart rate, that significantly correlated with plasma levels, were observed. 83% of the subjects reported headache, that was probably due to the sudden increase in plasma levels. With the 20 mg slow release tablet nifedipine absorption was slower, reaching a maximum concentration of 39 +/- 7 ng/ml in 1.82 +/- 0.43 h, and the apparent half-life (16.89 +/- 3.14 h) was longer than with the capsule. A fall in blood pressure was observed that significantly correlated with plasma levels; however, there was no significant correlation between these and changes in heart rate. Only 17% of the subjects reported headache. Pharmacokinetic data indicate that, in most subjects, nifedipine therapeutics plasma levels (over 15 ng/ml) can be maintained with the administration of a 20 mg slow release tablet every 12 hours. This, joined to the reduction in side effects, suggest that this formulation is the adequate alternative in chronic treatments with nifedipine, such as arterial hypertension.
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153
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Flores-Murrieta FJ, Hong E, Castañeda-Hernández G. Sensitive high-performance liquid chromatographic assay of pelanserin, a novel antihypertensive agent, in plasma samples. JOURNAL OF CHROMATOGRAPHY 1988; 428:167-72. [PMID: 3170670 DOI: 10.1016/s0378-4347(00)83903-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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154
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de León H, Castañeda-Hernández G, Hong E. Decreased ANF atrial content and vascular reactivity to ANF in spontaneous and renal hypertensive rats. Life Sci 1987; 41:341-8. [PMID: 2955185 DOI: 10.1016/0024-3205(87)90158-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The relationship between ANF activity and hypertension was determined by measuring ANF atrial content and vascular reactivity in two different models: spontaneous hypertensive rats (SHR) and renal hypertensive rats (RHR). Atrial extracts and aortic strips were prepared from hypertensive and normotensive animals. Relaxant activities of extracts, synthetic ANF and nitroglycerin were assayed on superfused aortic strips previously contracted by norepinephrine. ANF atrial content was statistically significantly lower in both models of hypertension, presumably by increased ANF release into the circulation which results in depletion of tissue storage sites. Vascular subsensitivity to ANF and nitroglycerin was found in both models of hypertension. Diminished ANF vascular reactivity in hypertension could be due to receptor down-regulation and/or to a decrease in the ability of cGMP to induce relaxation.
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155
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Mourelle M, Amezcua JL, Hong E. Effect of rioprostil and colchicine on CCl4-acute liver damage in rats. Relationship with plasma membrane lipids. PROSTAGLANDINS 1987; 33:869-77. [PMID: 2890182 DOI: 10.1016/0090-6980(87)90115-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of colchicine (10 g/day p.o. for 7 days) and rioprostil (2-decarboxy, 2-hydroxymethyl-15-deoxy-16-RS-hydroxy-16-methyl-prostaglandin-E1) (20 g/kg s.c., a single dose) on the enzymatic and histological markers of acute liver damage were studied in rats intoxicated with a single oral dose of CCl4. The rats were sacrificed 24 h after CCl4. The lipid composition of the liver plasma membranes was also determined. The increase in Alk. Phosp., GGTP and GPT activities and bilirubin concentration in serum as well as the histological images produced by CCl4 were equally prevented by the treatments with colchicine or rioprostil. CCl4 changed the lipid composition of the liver plasma membrane by increasing PI and PC and decreasing SM, PS and PEA. There was a decrease in the cholesterol/phospholipid ratio at the expense of a reduction of cholesterol/protein ratio and elevation in phospholipid/protein ratio. Colchicine and rioprostil also prevented these lipid alterations. The results suggest that the plasma membrane is an important site of action of CCl4 and of the 2 drugs studied. We postulate that the plasma membrane rather than other organelles is the target for the cytoprotective actions of prostaglandins.
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156
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Montaño LM, Selman M, Hong E. Different effects of epinephrine on the Erythrocebus patas tracheal smooth muscle: predominance of alpha-adrenergic receptors. ARCHIVOS DE INVESTIGACION MEDICA 1985; 16:169-74. [PMID: 2866756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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157
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158
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Villalobos-Molina R, Uc M, Hong E, García-Sáinz JA. Correlation between phosphatidylinositol labeling and contraction in rabbit aorta: effect of alpha-1 adrenergic activation. J Pharmacol Exp Ther 1982; 222:258-61. [PMID: 6123590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Activation of rabbit aortic strips with alpha adrenergic agonists increased the labeling (with [32P]Pi) of phosphatidylinositol (PI) and phosphatidic acid and contracted the vascular preparations in dose-related fashion. Epinephrine, norepinephrine and methoxamine produced maximal effects, whereas clonidine behaved as partial agonist and B-HT 933 (2-amino-6-ethyl-4,5,7,8-tetrahydro-6H-oxazole-[5,4-d] azepin dihydrochloride) was almost without activity in the two experimental models used. Phenylephrine was a full agonist in producing contraction, but failed to elicit the maximal increase in PI labeling. The EC50 values to produce contraction of aortic strips were lower for all agonists than those required to increase the incorporation of radioactive phosphate into PI, but there was a good correlation between the two sets of data. The increased PI labeling and contraction of aortic strips induced by epinephrine were antagonized by prazosin and yohimbine in dose-related fashion, but the first alpha blocker was about three orders of magnitude more potent than the second in antagonizing the two effects. The present results indicate that both stimulation of PI labeling and contraction are mediated through activation of alpha-1 adrenoceptors in rabbit aorta.
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159
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Safdy ME, Kurchacova E, Schut RN, Vidrio H, Hong E. Tryptophan analogues. 1. Synthesis and antihypertensive activity of positional isomers. J Med Chem 1982; 25:723-30. [PMID: 7097726 DOI: 10.1021/jm00348a022] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A series of tryptophan analogues having the carboxyl function at the beta-position was synthesized and tested for antihypertensive activity. The 5-methoxy analogue 46 exhibited antihypertensive activity in the rat via the oral route and was much more potent than the normal tryptophan analogue. The methyl ester was found to be a critical structural feature for activity.
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160
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Hong E. [Excellence of quipazine in the characterization of serotoninergic receptors and mechanisms]. GAC MED MEX 1982; 118:158-64. [PMID: 7117731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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161
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Scriabine A, Taylor DG, Hong E. Central control of arterial pressure by drugs. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 1982; 26:353-71. [PMID: 6128765 DOI: 10.1007/978-3-0348-7111-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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162
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Abstract
The stimulation of central serotonin receptors leading to a decrease in blood pressure is well documented, but the nature of these receptors is not well known. It was therefore decided to characterize such receptors by assessing the modifications in blood pressure and heart rate after the intracerebroventricular administration of several drugs to anesthetized cats. Serotonin produced a dose-related decrease in blood pressure and heart rate, while parachloroamphetamine produced a slowly developing increase in blood pressure, and quipazine did not affect any of the parameters measured. The hypotension produced by serotonin was not modified by pretreatment with methysergide, was partially antagonized by quipazine, and was completely blocked by tolazoline. The present findings suggest that the central serotonin receptors which modulate blood pressure are different not only from peripheral receptors, but also from other receptors of this type.
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163
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Whaite P, Aborhey S, Hong E, Rogers PL. Microprocessor control of respiratory quotient. Biotechnol Bioeng 1978. [DOI: 10.1002/bit.260200911] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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164
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Arndt HC, Gardiner PJ, Hong E, Kluender HC, Myers C, Woessner WD. The synthesis and biological activity of omega-pentanor-15-alkylcyclobutyl-PGE1 analogs. PROSTAGLANDINS 1978; 16:67-77. [PMID: 704925 DOI: 10.1016/0090-6980(78)90202-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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165
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Arndt HC, Biddlecom WG, Hong E, Myers C, Peruzzotti GP, Woessner WD. The synthesis and biological activity of prostaglandin analogs containing spirocyclic rings. PROSTAGLANDINS 1977; 13:837-43. [PMID: 866695 DOI: 10.1016/0090-6980(77)90214-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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166
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Hong E, Lopez C. Influence of the route of administration of prostaglandin E1 on rat gastric secretion. PROSTAGLANDINS 1977; 13:691-6. [PMID: 857271 DOI: 10.1016/0090-6980(77)90240-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Changes in gastric secretion induced by the subcutaneous, intraduodenal or intragastric administration of prostaglandin E 1 (PGE1) were evaluated in pylorus-ligated rats. Subcutaneous and intraduodenal injections produced a dose-related inhibition in both total acid and volume of gastric secretion. Dose-response curves for inhibition obtained by these routes were parallel, although PGE1 was more potent when given subcutaneously. Gastric administration produced a dose-related decrease in acid and an increase in volume. The slope of the dose-response curve for acid inhibition with this route was flatter than with subcutaneous or intraduodenal administrations. The present results suggest that PGE1 inhibits gastric secretion by the same mechanism of action when given subcutaneously or into the duodenum, while the effects observed after gastric administration are consequences of local actions. The difference in potency of PGE1 given subcutaneously and in the duodenum would seem to be due to differences in absorption from the site of administration and/or to a greater metabolism of PGE1 during its absorption from the intestines.
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167
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Vidrio H, Hong E. Vascular tone and reactivity to serotonin in the internal and external carotid vascular beds of the dog. J Pharmacol Exp Ther 1976; 197:49-56. [PMID: 1263132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The effects of intra-arterial infusions of serotonin on internal and external carotid blood flow were determined in anesthetized dogs by electromagnetic flow measurements. Serotonin decreased flow in the internal carotid and increased it in the external carotid. Both responses were blocked by the serotonin antagonist methysergide. The alpha adrenergic antagonist zolertine, the ganglionic blocking agent chlorisondamine and the vasodilator diazoxide blocked external carotid dilator responses but did not modify constriction in the internal carotid. Blockade of external carotid responses by the three drugs was also demonstrated in experiments in which this bed was perfused at a constant rate. These results indicate that the internal and external carotid vascular beds of the dog react in opposite ways to serotonin, that both responses are mediated through the same type of serotonin receptors and that the dilator responses of the external carotid are dependent on vascular tone.
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168
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Hong E. Differential pattern of activity of some prostaglandins in diverse superfused tissues. PROSTAGLANDINS 1974; 8:213-20. [PMID: 4428075 DOI: 10.1016/0090-6980(74)90044-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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169
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Hong E. On the antiserotonin activity of 6-acetamido-3(3-(4-phenyl-1-piperazinyl)-propyl)-284(1h,3h)-quinazolinedione-maleate (MA 1420). ARZNEIMITTEL-FORSCHUNG 1973; 23:1726-8. [PMID: 4801682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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170
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Schut RN, Ward FE, Lorenzetti OJ, Hong E. 2-tetrahydropyridylindoles as histamine and serotonin antagonists. J Med Chem 1970; 13:394-7. [PMID: 4394140 DOI: 10.1021/jm00297a014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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171
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Guzmán-Flores C, Pacheco P, Hong E, Pardo EG. Some behavioral effects induced by quipazine administration in the cat. BOLETIN DE ESTUDIOS MEDICOS Y BIOLOGICOS 1970; 26:225-32. [PMID: 5514964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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172
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Hong E, Phillips BM, Pardo EG. [Study of the pharmacology of the quipazine maleate. I. General pharmacology of quipazine maleate]. GAC MED MEX 1969; 99:741-6. [PMID: 5387704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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173
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Pardo EG, Hong E, Sancillo LF, Vargas R. [Study of the pharmacology of quipazine maleate. 3. Possible analogies between serotonin and quipazine maleate]. GAC MED MEX 1969; 99:758-64. [PMID: 5822129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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174
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Hong E, Sancilio LF, Vargas R, Pardo EG. Similarities between the pharmacological actions of quipazine and serotonin. Eur J Pharmacol 1969; 6:274-80. [PMID: 5816391 DOI: 10.1016/0014-2999(69)90185-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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175
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Sanen FJ, Hong E. [The biotransformation of drugs in animals and in humans]. LA PRENSA MEDICA MEXICANA 1969; 34:14-8. [PMID: 5787500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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