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Viviane Santos López Droguett,1 Amilton da Cruz Santos,2 Carlos Eduardo de Medeiros,2 Douglas Porto Marques,2 Leone Severino do Nascimento,2 Maria do Socorro Brasileiro-Santos2 1Department of Pathology, Federal University of Pernambuco, Recife, Pernambuco, Brazil; 2Department of Physical Education, Federal University of Paraiba, João Pessoa, Paraiba, BrazilPurpose: To investigate the heart rate (HR) and its autonomic modulation at baseline and during dynamic postexercise (PEX) with intensities of 40% and 60% of the maximum HR in healthy elderly.Methods: This cross-sectional study included ten apparently healthy people who had been submitted to a protocol on a cycle ergometer for 35 minutes. Autonomic modulation was evaluated by spectral analysis of HR variability (HRV).Results: A relevant increase in HR response was observed at 15 minutes postexercise with intensities of 60% and 40% of the maximum HR (10±2 bpm versus 5±1 bpm, respectively; P=0.005), and a significant reduction in HRV was also noted with 40% and 60% intensities during the rest period, and significant reduction in HRV (RR variance) was also observed in 40% and 60% intensities when compared to the baseline, as well as between the post-exercise intensities (1032±32 ms versus 905±5 ms) (P

beta- and gamma-lumicolchicines are photoproducts formed by the cycloisomerization of the tropolone ring of colchicine (COL) alkaloids. The mechanism of the photoconversion, suggested to involve the triplet state, is examined here by studying the effect of the solvent polarity on the lumicolchicine photoisomer ratio. Triplet COL, detected by laser flash photolysis, is quenched by oxygen, but not by transtilbene or 1-methylnaphtalene. Neither the quantum yield of conversion of COL nor the photoproduct ratio was altered by the presence of oxygen. Likewise, energy transfer to COL from triplet acetone produced by either isobutanal/horseradish peroxidase system or tetramethyldioxetane thermolysis failed to provoke photoreaction of COL. Our data argue against the intermediacy of a COL triplet state in the photoisomerization and stress on the role of specific solvent-solute interactions in determining the partitioning of excited singlet state into the beta- and gamma-isomer formation.