I A Siegel

Publications (26)57.98 Total impact

• Article: Prostaglandin activity and sulcular flow in carrageenan-injected gingiva of the dog.

  W Yoda, R Sproat, K T Izutsu, I A Siegel
  Journal of Periodontal Research 02/1984; 19(1):14-20. · 1.69 Impact Factor
• Article: Rat parotid gland pathophysiology following 137Cs irradiation.

  J C Rice, K T Izutsu, E L Truelove, T W Menard, M W Anderson, T H Morton, I A Siegel
  Radiation Research 06/1982; 90(2):330-8. · 2.68 Impact Factor
• Article: Mechanisms of non-electrolyte penetration across dog and rabbit oral mucosa in vitro.

  I A Siegel, K T Izutsu, E Watson
  Archives of Oral Biology 02/1981; 26(5):357-61. · 1.60 Impact Factor
• Article: Permeability of oral mucosa to organic compounds.

  I A Siegel, K T Izutsu
  Journal of Dental Research 11/1980; 59(10):1604-5. · 3.49 Impact Factor
• Article: Mediation of beta-adrenergic stimulated amylase release from mouse parotid gland.

  E L Watson, J Friedman, I A Siegel
  Life Sciences 07/1980; 26(22):1919-26. · 2.53 Impact Factor
• Article: Calcium mediation of cholinergic-stimulated amylase release from mouse parotid gland.

  E L Watson, J A Williams, I A Siegel
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  ABSTRACT: Amylase release from mouse parotid fragments was stimulated independently by cholinergic and beta-adrenergic agents. The cholinergic agonist, carbachol, significantly increased release of amylase only in Ca2+ containing medium whereas isoproterenol-stimulated amylase release was unaffected by Ca2+ removal. The ionophore, A23187, mimicked the effect of cholinergic stimulation when Ca2+ was present in the medium. Uptake of 45Ca2+ into tissue fragments was enhanced by carbachol and A23187 but not by isoproterenol; atropine blocked the effect of carbachol. Diphenylhydantoin (DPH) and verapamil partially inhibited carbachol-stimulated amylase release and 45Ca2+ uptake, whereas diazoxide potentiated these effects; in all cases there was good parallelism between 45Ca2+ uptake and amylase release. It was concluded that the primary step in the release of amylase from mouse parotid gland in response to cholinergic agents is an increased influx of Ca2+.
  The American journal of physiology 06/1979; 236(5):C233-7.
• Article: HCO-3-ATPase activity distribution in rat liver cell fractions prepared by zonal centrifugation.

  K T Izutsu, I A Siegel, E A Smuckler
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  ABSTRACT: Plasma membrane sheets prepared by zonal centrifugation of a premicrosomal pellet obtained from a rat liver homogenate are devoid of HCO-3-ATPase activity. Since the microsomal fraction is also lacking in this ATPase activity, it can be concluded that the HCO-3-ATPase is not involved in the secretion of HCO-3 into bile.
  Experientia 07/1978; 34(6):731-3.
• Source

  Available from: sagepub.com

  Article: Physical properties of zinc phosphate cement prepared on a frozen slab.

  R Tuenge, I A Siegel, K T Izutsu
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  ABSTRACT: The physical properties of a zinc phosphate cement prepared on a room temperature slab were compared to those of the cement prepared on a frozen slab. Solubility, compressive strength, and setting time of cements prepared on both types of slabs were within the limits set by A.D.A. Specification No. 8.
  Journal of Dental Research 05/1978; 57(4):593-6. · 3.49 Impact Factor
• Article: Factors affecting calcium accumulation and release in canine submandibular salivary microsomes.

  E L Watson, I A Siegel
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  ABSTRACT: Microsomes isolated from canine submandibular glands were examined for ATP-dependent calcium accumulation and calcium release. Calcium uptake (10 to 20 nmoles per min per mg protein at 37 °C) was linear with time up to 20 min and with the amount of microsomal protein in the range of 15 to 200 μg/ml of incubation medium. Of the nucleotide triphosphates tested, only adenosine triphosphate (ATP) supported calcium accumulation. Ruthenium red and ethacrynic acid, at concentrations of 90 μg/ml and 10−4 M respectively, almost completely inhibited calcium uptake. Metabolic inhibitors such as 2,4 dinitrophenol, azide and oligomycin only partially affected microsomal calcium uptake.Incubation of prelabelled microsomes in a calcium-free solution resulted in the release of calcium at a rate of 0.025/min. The rate was decreased at 0 °C and by inclusion of 4.5 mM ATP in the medium. Addition of 2 mM calcium or removal of magnesium also reduced release. Ruthenium red at a concentration that decreased calcium uptake by greater than 90 per cent did not affect calcium outflow; whereas ethacrynic acid (5 × 10−4M) induced a significant increase in calcium loss.
  Archives of Oral Biology 02/1978; 23(4):323-8. · 1.60 Impact Factor
• Article: Properties of the HCO-3-stimulated Mg2+ -ATPase activity in red cell membranes.

  K T Izutsu, P R Madden, E L Watson, I A Siegel
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  ABSTRACT: The HCO-3-stimulated Mg2+ -ATPase activity in red cell ghost fragments was investigated. Increasing the HCO-3 concentration in the incubation medium resulted in increased ATPase activity. NaHCO3 appeared to be more effective than KHCO3 in this regard. The ATPase activities were slightly stimulated by increases in ionic strength and utilized ITP almost as readily as ATP. A Mg/ATP ratio of 1.0 and a pH of 7.6 yielded maximum activity. These properties are of interest since the present enzyme is the only unquestionable instance where a HCO-3 ATPase is located in the surface membrane of a cell.
  Pflügers Archiv - European Journal of Physiology 07/1977; 369(2):119-24. · 4.46 Impact Factor
• Article: Effects of autonomic agents and cyclic AMP on calcium accumulation and release in dog submandibular microsomes.

  E L Watson, I A Siegel
  Biochemical Pharmacology 02/1977; 26(2):125-7. · 4.70 Impact Factor
• Article: Diphenylhydantoin effects on salivary secretion and microsomal calcium accumulation and release.

  E L Watson, I A Siegel
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  ABSTRACT: Diphenylhydantoin inhibited calcium uptake into dog submandibular microsomes at concentrations of 0.05 mM and greater but did not affect calcium release; mesantoin and hydroxyphenyl-phenylhydantoin were without effect. Diphenylhydantoin (20 mg/kg) given i.v. significantly reduced, and mesantoin slightly reduced secretion from submandibular and parotid glands, but hydroxyphenyl-phenylhydantoin was without effect. These data suggest that the reduced secretory volume produced by diphenylhydantoin may be related to its effect on transmembrane calcium movements.
  European Journal of Pharmacology 06/1976; 37(1):207-11. · 2.52 Impact Factor
• Article: Transfer of alcohols and ureas across the oral mucosa measured using streaming potentials and radioisotopes.

  I A Siegel, K T Izutsu, J Burkhart
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  ABSTRACT: The permeability of the oral mucosa to an alcohol and a urea series was studied using radioisotope transfer and the measurement of streaming potentials. Both methods yielded similar quantitative estimates of permeability. The rate of transfer of the smallest member of both series (methanol and urea) was greater than the second member (ethanol and methylurea). In the alcohol series, permeability increased as the chain length increased from ethanol to butanol. In contrast, the permeability of the oral mucosa to ethylurea and propylurea was less than to methylurea. However, butylurea had a greater rate of transfer than either propylurea or ethylurea.
  Journal of Pharmaceutical Sciences 02/1976; 65(1):129-31. · 3.06 Impact Factor
• Article: Bicarbonate ion-ATPase in rat liver cell fractions.

  K T Izutsu, I A Siegel
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  ABSTRACT: The distribution of HCO3MINUS-ATPase activity was studied in cell fractions prepared from homogenates of rat liver. The level of mitochondrial contamination in the microsomal fraction depended on the fractionation procedure and on the method of homogenization. With proper care, microsomes with undetectable mitochondrial contamination could be prepared. These microsomes had no detectable HCO3MINUS-ATPase activity. Approximately 85% of the total HCO3minus-ATPase activity of the post 6000 times g-min supernatant was recovered in the mitochondrial fraction. The properties of this mitochondrial HCO3minus-ATPase were not distinguishable from those of the various microsomal HCO3minus-ATPases previously described by other investigators.
  Biochimica et Biophysica Acta 04/1975; 382(2):193-203. · 4.66 Impact Factor
• Article: The effect of ionic strength on a Mg2+-ATPase and its relevance to the determination of (Na+ plus K+)-ATPase.

  K T Izutsu, I A Siegel, D L Brisson
  Biochimica et Biophysica Acta 01/1975; 373(3):361-8. · 4.66 Impact Factor
• Article: Ca2+-ATPase activity in isolated secretory granule membranes.

  E L Watson, I A Siegel, M R Robinovitch
  Experientia 09/1974; 30(8):876-7.
• Article: An investigation of the ionic calcium assay based on the jellyfish protein aequorin.

  K T Izutsu, S P Felton, I A Siegel, J I Nicholls, J Crawford, J McGough, W T Yoda
  Analytical Biochemistry 05/1974; 58(2):479-84. · 3.00 Impact Factor
• Article: Ion specificity of the aequorin luminescent reaction.

  K T Izutsu, S P Felton, I A Siegel, W T Yoda, J Crawford, J McGough
  Physiological chemistry and physics 02/1974; 6(4):299-308.
• Article: Calcium-stimulated ATPase of dog submandibular gland.

  E L Watson, K T Izutsu, I A Siegel
  Archives of Oral Biology 02/1974; 19(1):13-6. · 1.60 Impact Factor
• Article: Ouabain-induced calcium concentration increases in dog submandibular saliva.

  I A Siegel, K T Izutsu, W T Yoda
  Archives internationales de pharmacodynamie et de thérapie. 02/1974; 207(1):101-6.