My lab is currently exploring the mechanisms by which cardiac and skeletal muscle adapt in response to changes in physiological demand. One basic and one applied project are currently active. The regulation of cytoplasmic messenger RNA is studied by molecular biological techniques in cultured cardiac cells. The relationship between aging and neuro-muscular injury is studied by physiological and cell biological techniques in women and rats with stress incontinence.
Adaptation is of utmost importance in overloaded or failing hearts because the total myofibrillar mass in the heart determines cardiac strength. Study of post-transcriptional regulation of cytoplasmic mRNA is an exciting area and may well be a key to understanding rapid regulatory events in cardiac hypertrophy. To dissect mechanisms between stimulation and hypertrophy, we examine changes occurring in the first hour after growth stimulation of cultured cardiac cells. Rapid changes are made by pharmacological interventions to the b-adrenergic pathway. Techniques include immunochemistry for protein localization, RNA analysis for message abundance, and in situ hybridization to examine changes in subcellular message distribution.
Clinically an important subgroup of women are diagnosed with intrinsic sphincter deficiency - implying that the delicate neuro-muscular structures of the continence mechanism for control of micturition have failed completely. Dysfunction of muscles innervated by the pudendal nerve may be a major contributory factor for stress incontinence in women. We believe that there is a continuum of sphincteric function which can be elucidated using a combination of conventional incontinence tests (video-urodynamics), newer techniques of electrodiagnosis (motor latency testing and quantitative EMG) and state-of-the-art cellular and molecular biology techniques for muscle. In collaboration with clinical colleagues we study normal and stress incontinent women, aged 20 to 80 and evaluate biopsies by immunochemistry, in situ hybridization and morphometric analysis. The human studies are complemented by studying the effects of pudendal nerve injury on muscles of the pelvic floor of rats. Induced injuries include: mild injury by stretching and severe injury by transection.
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E-mail to: Dr. Brenda Russell @ uic.edu