Sarcotubular anomalous rectification of frog sartorius muscle
Related Experiment Video
Updated: Oct 8, 2026

Collection of Skeletal Muscle Biopsies from the Superior Compartment of Human Musculus Tibialis Anterior for Mechanical Evaluation
Published on: September 27, 2020
Abstract:
The membrane site responsible for anomalous rectification was determined in frog sartorius muscle fibers. The total current-voltage relation of glycerol-treated fibers which represents mainly the properties of the sarcolemma was linear for membrane potentials between about -90 and -50 mV. Thus moderate depolarization-induced anomalous rectification in intact fibers represents a property of the sarcotubular system. The absence of slow hyperpolarization in glycerol-treated fibers was caused by the abolition of early conductance increase, and the sarcotubular system is responsible for the inward rectifier. Picrotoxin selectively inhibited both moderate depolarization-induced anomalous rectification and hyperpolarization-induced early conductance increase. This suggests that the same component in the sarcotubular system is responsible for these conductance changes. The inhibition with picrotoxin of moderate depolarization-induced anomalous rectification suggests the possibility that it is caused by an electrogenic effect rather than a decrease in K conductance. A sarcolemmal hyperpolarization-activated slow conductance increase was revealed.
Related Concept Videos
Skeletal Muscle Anatomy
Bones of the Lower Limb: Femur and Patella
Microscopic Anatomy of Skeletal Muscles
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
Fascicle Arrangement in Skeletal Muscles
The four primary types of muscle based on fascicle arrangement are:
Muscles that Move the Leg
Anterior Compartment
The quadriceps femoris, the most visible muscle of the anterior compartment, is integral for leg extension and thigh flexion. It is formed by merging four distinct muscles — the vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris. The quadriceps tendon, a shared tendon of the four quadriceps muscles, is affixed to...
Muscles of the Leg that Move the Foot and Toes
Anterior Compartment
The anterior compartment includes muscles that contribute to the dorsiflexion of the foot. This compartment houses the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles.

