Gender differences in skeletal muscle heat shock proteins induced by diathermy

Abstract

Heat shock treatments have been used to appreciably increase heat shock protein 70 (Hsp70) and phosphorylation of heat shock protein 27 (Hsp27p). These proteins are believed to be involved in the repair process of myofibrils. The purpose of this investigation was to determine whether diathermy can increase Hsp70 and Hsp27p content in skeletal muscle. Fourteen subjects (n= 7 / group, 18–35 y) received a muscle biopsy from the v. lateralis and then underwent 20 min of diathermy followed by 20 min of hot pack heating on the contralateral leg. Twenty-four hours following treatment, a second muscle biopsy was performed on the treated leg. All samples were analyzed for Hsp70 content using western immunoblotting. Images of the blots were obtained and analyzed via densitometry. A paired t-Test was used to examine differences in heat shock protein content between the treated and untreated legs. Significance was set at P<0.05. Twenty-four hours following the heat treatment, female subjects significantly increased Hsp70 (58%) and Hsp27-p (132%) content compared to the untreated leg. Male subjects had non-significant increases in Hsp70 (35%) and Hsp27-p (68%) skeletal muscle content. These results implicate diathermy as an effective countermeasure to induce Hsp70 & Hsp27-p in female populations. Supported, in part, by a University of Kansas General Research Fund grant (P. Gallagher), and a McNair Scholarship (T. Le).