In this work, we evaluated the effect of adaptation to heat on the fall of blood pressure (BP) induced by heat shock (HS) and the interrelation between nitric oxide (NO) and heat shock protein, HSP70. Experiments were carried out on Wistar rats. It was shown that HS resulted in a generalized and transient increase in NO production (the electron paramagnetic resonance method) and a fall of BP from 113± 3 to 88± 1 mm Hg (?<0.05). Adaptation to heat itself did not affect BP, but completely prevented the NO overproduction and hypotension induced by HS. The adaptation simultaneously increased the brain NO-synthase content and induced HSP70 synthesis (the Western blot analysis) in various organs. Both the antihypotensive effects of adaptation and HSP70 accumulation were completely prevented by L-NNA, an inhibitor of NO synthesis, or quercetin, an inhibitor of HSP70 synthesis. The data suggest that adaptation to heat stimulates NO synthesis and NO activates synthesis of HSP70. HSP70, which hampers NO overproduction, thus restricts the BP fall induced by heat shock., I. Yu. Malyshev, L.A. Bayda, A.I. Trifonov, N.P. Larionov, L.D. Kubrina, V.D. Mikoyan, A.F. Vanin, E.B. Manukhina., and Obsahuje bibliografii
It is known that HSP70 plays an important role in the antiischaemic effect of adaptation to stress. The aim of our study was to verify the hypothesis that nitric oxide (NO) may contribute to the activation of HSP70 synthesis and to enhance thereby the resistance of organism to the ischaemic and reperfusion damages. We observed that heat shock potentiated NO production in the heart NO formation was completely blocked by the NO synthase inhibitor N^-nitro-L-arginine (L-NNA). L-NNA also significantly attenuated the heat shock-induced accumulation of HSP70 (by 45 % in heart). Both heat shock and NO donor induced time- and concentration-dependent HSP70 synthesis in the culture of human hepatoblastoma cells Hep G2. Prior injection of NO donor (30-100 mg per rat) exerted a dose- dependent protective effect on the isolated heart in ischaemia and reperfusion within 24 hours. We suggest that NO is involved in the activation of HSP70 synthesis which can play an important role in the delayed protective effect of NO donors.
The widespread Mediterranean Pinus pinea showed exceptionally low genetic diversity and low differentiation between traits in the adult phase. We explored the adaptation potential of seedlings from four main Iberian provenances during their regeneration phase. We assessed the variability of shoot growth, allometry, physiological traits, and phenotypic plasticity to the interactive effect of light and water environments during 8-month moderate water-stress cycle and after one-week heat wave. The effect of shade and drought was mainly orthogonal whatever the provenance. The inland La Mancha provenance showed higher shoot growth and biomass compared to the southern coastal Depresión-del-Guadalquivir provenance. Following the heat wave, La Mancha presented higher net photosynthetic rates, a lower decrease in maximal quantum efficiency of PSII, and a higher accumulated relative height growth, thus, showing an adaptive advantage. The observed differences corroborated the ecological grouping of the provenances along latitudinal and inland-coastal gradients. We confirmed the high adaptive plasticity of Pinus pinea to the unpredictable Mediterranean environment., M. Pardos, R. Calama., and Obsahuje bibliografii