OBJECTIVE Myogenic tone, which has a major role in the regulation of local blood flow, refers to the ability of vascular smooth muscle to adapt its contractility to changes in transmural pressure. Although Rho-kinase is involved in myogenic tone, the pathway involved remains unclear, especially concerning translocation to the plasma membrane and activation of RhoA. As caveolae have a key role i...

The mechanisms of adaptation of uterine artery vascular tone to pregnancy are not fully understood. The present study tested the hypothesis that pregnancy decreases the PKC-mediated Ca(2+) sensitivity of the contractile process and attenuates myogenic tone in resistance-sized uterine arteries. In pressurized uterine arteries from nonpregnant (NPUA) and near-term pregnant (PUA) sheep, we measure...

The reverse transcription-polymerase chain reaction (RT-PCR) is the most sensitive method used to evaluate gene expression. Although many advances have been made since quantitative RT-PCR was first described, few reports deal with the mathematical bases of this technique. The aim of the present study was to develop and standardize a competitive PCR method using standard-curves to quantify trans...

Myogenic regulatory factors (MRFs) are a family of skeletal muscle-specific transcription factors that regulate the expression of several muscle genes. This study was designed to determine whether MRF transcripts were increased in hypertrophy-stimulated muscle of adult quails and whether equivalent increases occurred in muscles of older quails. Slow-tonic anterior latissimus dorsi and fast-twit...

The development of skeletal muscle in vertebrate embryos is controlled by a transcriptional cascade that includes the four myogenic regulatory factors Myf5, Myogenin, MRF4 and MyoD. In the mouse embryo, Myf5 is the first of these factors to be expressed and mutational analyses suggest that this protein acts early in the process of commitment to the skeletal muscle fate. We have therefore analys...

Previous studies have demonstrated that the neural tube/notochord complex is required for skeletal muscle development within somites. In order to explore the localization of myogenic inducing signals within the neural tube, dorsal or ventral neural tube halves were cultured in contact with single somites or pieces of segmental plate mesoderm. Somites and segmental plates cultured with the dorsa...

INTRODUCTION The vestibular evoked myogenic potential is a potential of mean latency that measures the muscle response to auditory stimulation. This potential can be generated from the contraction of the sternocleidomastoid muscle and also from the contraction of extraocular muscles in response to high-intensity sounds. This study presents a combined or simultaneous technique of cervical and oc...

Hypertension is characterized by increased peripheral vascular resistance which is related with elevated myogenic response. Recent findings have indicated that epithelial sodium channel (ENaC) is involved in mechanotransduction of the myogenic response. The purpose of this study was to investigate the involvement of ENaC in the elevated myogenic response of posterior cerebral arteries (PCAs) fr...

The abundance and cross-linking of intramuscular connective tissue contributes to the background toughness of meat, and is thus undesirable. Connective tissue is mainly synthesized by intramuscular fibroblasts. Myocytes, adipocytes and fibroblasts are derived from a common pool of progenitor cells during the early embryonic development. It appears that multipotent mesenchymal stem cells first d...