title: Ischemia Increases the Twitch Latent Period in the Soleus and Extensor Carpi Radialis Longus Muscles from Adult Rats.
abstract: Complete ischemia and reperfusion effects on twitch force (∫(F·t)), twitch latent period (TLP), maximal rate of rise of twitch tension (δF/δt)max, and twitch maximum relaxation rate (TMRR) were assessed. We divided 36 adult rats into four groups; two control groups (n = 9), a group undergoing 1 hour of ischemia followed by 1 hour of reperfusion (n = 9), and one group exposed to 2 hours of ischemia followed by 1 hour of reperfusion (n = 9). We have induced twitch contractions every 10 minutes in the soleus and the extensor carpi radialis longus (ECRL). Twitch contractions were recorded and then analyzed for ∫(F·t), TLP, (δF/δt)max, and TMRR. During 1 hour and 40 minutes of ischemia, TLP increased to 179 ± 24% (p < 0.05) in the soleus and to 184 ± 16% (p < 0.05) in the ECRL, an effect that was partially recovered during 1 hour of reperfusion. This increase started after 20 minutes of ischemia in the soleus and after 40 minutes of ischemia in the ECRL. The increase was faster in the ECRL and peaked at the same time for both muscular groups. ∫(F·t) and (δF/δt)maxdecreased during 1 hour of ischemia to 46 ± 7% (p < 0.05) in the soleus and to 40 ± 7% (p < 0.05) in the ECRL. TMRR decreased during 1 hour of ischemia to 39 ± 5% (p < 0.05) in the soleus and to 54 ± 8% (p < 0.05) in the ECRL. During 1 hour of reperfusion all of them recovered close to control values.
authors: a Pontificia Universidad Javeriana-Cali, Departamento de Ciencias Básicas de la Salud, Grupo de Investigación en Ciencias Básicas y Clínicas de la Salud , calle 18 No 118-250, Cali , 0001 Colombia.
authors: Camilo
authors: C
authors: Morales
authors: b Universidad del Valle, Departamento de Ciencias Fisiológicas, Facultad de salud, Grupo de Investigación de Farmacología Univalle , Calle 4B No 36-00, Cali , 439 Colombia.
authors: Leonardo
authors: L
authors: Fierro
mesh_terms: D000818:Animals; D007511:Ischemia / Q000503:physiopathology*; D008297:Male; D009129:Muscle Tonus; D018482:Muscle, Skeletal / Q000098:blood supply / Q000503:physiopathology*; D017208:Rats, Wistar
keywords: extensor carpi radialis longus; ischemia-reperfusion; maximal rate of rise of twitch tension; skeletal muscle; soleus; twitch force; twitch latent period; twitch maximum relaxation rate