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PubMed · 7820121

Age-dependent decrease in platelet aggregation in rats.

K Oshima·T Morikawa·M Hagiwara
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Abstract

The degree of platelet aggregation induced by ADP and collagen was examined in platelet-rich plasma from 7- to 90-week-old rats. The aggregation induced by ADP was unchanged at 90 weeks. Collagen-induced aggregation decreased remarkably at 60 and 90 weeks. Therefore, collagen-induced platelet activation is highly age-dependent, with rats of advanced age showing a lower response than younger rats.

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Adenosine DiphosphateAgingAnimalsCollagenMalePlatelet AggregationRatsRats, WistarJournal Article

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K Oshima, T Morikawa, M Hagiwara. 1994. Age-dependent decrease in platelet aggregation in rats.. https://doi.org/10.1248/bpb.17.1124

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Adenosine Diphosphate↗
PubMed1995

A 35-A movement of smooth muscle myosin on ADP release.

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Adenosine Diphosphate↗
PubMed1995

Proton NMR investigation of the [4Fe--4S]1+ cluster environment of nitrogenase iron protein from Azotobacter vinelandii: defining nucleotide-induced conformational changes.

This work presents the complete assignment of the isotropically shifted 1H NMR resonances of Azotobacter vinelandii nitrogenase iron protein (Fe protein) to beta-CH2 and alpha-CH protons of the [4Fe--4S]1+ cluster cysteinyl ligands. Four resonances were observed for the reduced Fe protein with chemical shifts of 49, 23, 17, and 13 ppm. T1 measurements and analysis of relative peak areas coupled with one-dimensional nuclear Overhauser effect (NOE) difference spectra were used to assign the two most downfield-shifted resonances (49 and 23 ppm) to cysteinyl ligand beta-CH2 protons and the 17 and 14 ppm resonances to cysteinyl ligand alpha-CH protons. Temperature dependent studies of the isotropically shifted protons revealed both Curie and anti-Curie behavior. These results, along with previous Mossbauer studies of the Fe protein, allowed the assignment of signal A (49 ppm) to four beta-CH2 protons and signal C (17 ppm) to 2 alpha-CH protons of two cysteinyl ligands bound to a mixed-valence iron pair (Fe3(+)--Fe2+) of the [4Fe--4S]1+ cluster. Signal B (23 ppm) was assigned to four beta-CH2 protons, and signal C (17 ppm) and D (13 ppm) were assigned to two alpha-CH protons of two cysteinyl ligands bound to a ferrous pair of irons (2Fe2+). The effects of MgATP, MgADP, and Mg-adenosine-beta, gamma-methylene-5'-triphosphate binding to the Fe protein on the assigned resonances were established and are discussed in the context of nucleotide-induced changes in the protein environment of the [4Fe--4S] cluster.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗