Hyperthermia (heat shock)-induced protein denaturation in liver, muscle and lens tissue as determined by differential scanning calorimetry

Abstract

Protein denaturation has been shown to occur in cells during heat shock and is closely correlated with the cellular responses to hyperthermia; however, little is known about protein denaturation in tissue. This study describes an analysis of endothermic transitions in the hyperthermic region using differential scanning calorimetry (DSC) in liver, white muscle, and lens tissue from Wistar rat, New Zealand white rabbit, and Rainbow trout. Complex DSC profiles consisting of several transitions were obtained for each tissue. Evidence is given that these transitions are due primarily to protein denaturation. Onset temperatures of denaturation (Tl) for rat liver, muscle, and lens are about 38, 39 and 48 degrees C, respectively. Thus, significant protein denaturation occurs in liver and muscle during mild hyperthermia (40-45 degrees C) with lens considerably more stable. The values of Tl for the same tissue from the different animals correlates well with body temperature (rabbit 39.4, rat 38.2, and trout grown at 11 degrees C); Tl increased in the same order as the body temperature for each tissue. Thus, there is correlation between the onset temperature for protein denaturation in these tissues and body temperature.

Time and temperature dependence of MR parameters during thermal coagulation of ex vivo rabbit muscle

“…4), differential scanning calorimetry measurements of rabbit muscle detect transitions in excess specific heat capacity that are characteristic of protein denaturation (24). In particular, a major transition is observed at 60°C (24), which agrees with the onset of MR changes in T,-weighted and MT-weighted signals, and the temperature at which TI-weighted signal starts to decrease. This suggests that investigating the physical relationship between M R parameters and tissue protein denaturation is also a reasonable step in understanding the MR signal changes produced by thermal coagulation.…”

“…In addition, for temperatures ranging from 50 to 80"C, where significant changes in MR signal intensity occur (Fig. 4), differential scanning calorimetry measurements of rabbit muscle detect transitions in excess specific heat capacity that are characteristic of protein denaturation (24). In particular, a major transition is observed at 60°C (24), which agrees with the onset of MR changes in T,-weighted and MT-weighted signals, and the temperature at which TI-weighted signal starts to decrease.…”

Chronic heat stress up-regulates leptin and adiponectin secretion and expression and improves leptin, adiponectin and insulin sensitivity in mice

“…Chronic heat treatment, by up-regulating ObRb and Adipor1 and Adipor2 gene expression, seemed to elicit a significant increase in leptin and adiponectin sensitivity in WAT, M and L. Previous studies on HS animal models reported that despite marked reductions in nutrient intake, HS animals did not show an increase in plasma NEFA, had lower plasma glucose, increased basal insulin levels and stimulated glucose uptake (Torlinska et al 1987, Ritchie et al 1994, Ronchi et al 1999, Gupte et al 2009, Wheelock et al 2010. All those responses and the up-regulation of ObRb and adiponectin receptors in this study suggest that adiponectin and leptin might play roles in modulating the post-absorptive energetic metabolism of HS subjects.…”

Characterization of goldfish heat shock protein–30 induced upon severe heat shock in cultured cells

“…Although the mechanisms involved in heat-induced cell death is still unclear, thermal denaturation of cellular components such as those contained in nuclear matrix is thought to be primarily attributable to such cell death (Roti et al 1997;Roti et al 1998). Ritchie et al (1995) also analyzed the endothermic reactions of the liver, muscle, and lens tissues homogenates derived from rat, rabbit, and rainbow trout and claimed that the temperature where the endothermic reaction first appears is correlated with their body temperatures. In this study, we also confirmed that the goldfish cellular components had higher thermostability than those of rainbow trout cultured cells did (Fig 2).…”