Lower urinary tract physiology and pharmacology.
This review focuses on what we consider to be the most important findings of the last year relating to the smooth muscle of the lower urogenital system and the different levels of regulation that control its contraction and relaxation. One level is through modulation of the smooth muscle itself or its environment. Recent findings examining myosin isoform composition and collagen content as well as mechanisms that appear to be involved in inducing hyperplasia/hypertrophy of smooth muscle are described. Another method of regulation is via calcium-dependent phosphorylation of the regulatory light chain of myosin, which increases its activity. Interesting results indicating an uncoupling of force from calcium in the bladder are discussed. A third level of regulation is pharmacologic. Thus, the most recent findings related to receptor subtypes, including muscarinic, endothelin, alpha-adrenergic and nicotinic receptors, are presented. In addition, the effects of diabetes, incontinence, and partial bladder outlet obstruction on these modes of contractile regulation are also discussed.
DiSanto
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ME
Division of Urology, 3010 Ravdin Courtyard, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. mdisanto@mail.med.upenn.edu
Wein
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AJ
Chacko
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D000818:Animals; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology; D006801:Humans; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009218:Myosins / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000502:physiology; D011312:Pressure; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D017466:Receptors, Endothelin / Q000187:drug effects; D011976:Receptors, Muscarinic / Q000187:drug effects; D014521:Urethra / Q000187:drug effects / Q000502:physiology*; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology*; D001748:Urinary Bladder Neck Obstruction / Q000503:physiopathology; D014549:Urinary Incontinence
D012739:Gonadal Steroid Hormones; D011942:Receptors, Adrenergic, alpha; D017466:Receptors, Endothelin; D011976:Receptors, Muscarinic; D019001:Nitric Oxide Synthase; D009218:Myosins