OBJECTIVE: This study investigated whether exercise training, initiated at the onset of diabetes, could preserve the contractile properties of ventricular myocytes. RESEARCH DESIGN AND METHODS: The effects of a heavy exercise training program on shortening and intracellular Ca(2+) in unloaded ventricular myocytes from streptozotocin (STZ)-induced diabetic rats were examined. Animals were divided into four groups: control sedentary (CS), diabetic sedentary (DS), control heavy exercise (CHE), and diabetic heavy exercise (DHE). Exercise protocol: 5x60 min/week, 18 m/min, 5% gradient. Exercise training began 1 week after STZ treatment and continued for 12-23 (mean 17.5) weeks. RESULTS: Diabetes induced prolongation of time-to-peak (TPK) shortening (124+/-2 ms in DS compared to 97+/-2 ms in CS rats), which was further increased by exercise (133+/-3 ms in DHE and 112+/-2 ms in CHE myocytes). Diabetes had no significant effects on time-to-half (THALF) relaxation of shortening (61+/-2 ms in DS compared to 56+/-2 ms in CS myocytes). Exercise induced significant prolongation of THALF in control (66+/-3 ms) but not in diabetic (69+/-3 ms) myocytes. Diabetes, though not exercise, significantly prolonged TPK (76+/-3 ms in DS compared to 64+/-2 ms in CS) and THALF recovery (160+/-5 ms in DS compared to 118+/-4 ms in CS) of the Ca(2+) transient. Neither diabetes nor exercise had significant effects on the amplitude of myocyte shortening and the Ca(2+) transient. CONCLUSIONS: Heavy long-term exercise alters the dynamics but not the amplitude of unloaded myocyte contraction in the STZ-induced diabetic rat. Copyright 2010 Elsevier Inc. All rights reserved.
OBJECTIVE: This study investigated whether exercise training, initiated at the onset of diabetes, could preserve the contractile properties of ventricular myocytes. RESEARCH DESIGN AND METHODS: The effects of a heavy exercise training program on shortening and intracellular Ca(2+) in unloaded ventricular myocytes from streptozotocin (STZ)-induced diabeticrats were examined. Animals were divided into four groups: control sedentary (CS), diabetic sedentary (DS), control heavy exercise (CHE), and diabetic heavy exercise (DHE). Exercise protocol: 5x60 min/week, 18 m/min, 5% gradient. Exercise training began 1 week after STZ treatment and continued for 12-23 (mean 17.5) weeks. RESULTS:Diabetes induced prolongation of time-to-peak (TPK) shortening (124+/-2 ms in DS compared to 97+/-2 ms in CSrats), which was further increased by exercise (133+/-3 ms in DHE and 112+/-2 ms in CHE myocytes). Diabetes had no significant effects on time-to-half (THALF) relaxation of shortening (61+/-2 ms in DS compared to 56+/-2 ms in CS myocytes). Exercise induced significant prolongation of THALF in control (66+/-3 ms) but not in diabetic (69+/-3 ms) myocytes. Diabetes, though not exercise, significantly prolonged TPK (76+/-3 ms in DS compared to 64+/-2 ms in CS) and THALF recovery (160+/-5 ms in DS compared to 118+/-4 ms in CS) of the Ca(2+) transient. Neither diabetes nor exercise had significant effects on the amplitude of myocyte shortening and the Ca(2+) transient. CONCLUSIONS: Heavy long-term exercise alters the dynamics but not the amplitude of unloaded myocyte contraction in the STZ-induced diabeticrat. Copyright 2010 Elsevier Inc. All rights reserved.
Authors: K A Salem; M A Qureshi; V Sydorenko; K Parekh; P Jayaprakash; T Iqbal; J Singh; M Oz; T E Adrian; F C Howarth Journal: Mol Cell Biochem Date: 2013-04-26 Impact factor: 3.396
Authors: Manal M A Smail; Muhammad A Qureshi; Anatoliy Shmygol; Murat Oz; Jaipaul Singh; Vadym Sydorenko; Alya Arabi; Frank C Howarth; Lina Al Kury Journal: Physiol Rep Date: 2016-11
Authors: Lina T Al Kury; Vadym Sydorenko; Manal Ma Smail; Muhammad A Qureshi; Anatoly Shmygol; Dimitrios Papandreou; Jaipaul Singh; Frank Christopher Howarth Journal: J Diabetes Investig Date: 2020-11-30 Impact factor: 4.232