KINETIC CHARACTERISTICS OF ALPHA-1-ADRENERGIC CONTRACTIONS IN HUMAN CORPUS CAVERNOSUM SMOOTH-MUSCLE

被引:44
作者
CHRIST, GJ
SCHWARTZ, CB
STONE, BA
PARKER, M
JANIS, M
GONDRE, M
VALCIC, M
MELMAN, A
机构
来源
AMERICAN JOURNAL OF PHYSIOLOGY | 1992年 / 263卷 / 01期
关键词
VASCULAR SMOOTH MUSCLE; ERECTILE DYSFUNCTION; KINETICS; PHENYLEPHRINE;
D O I
10.1152/ajpheart.1992.263.1.H15
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
Kinetic studies were conducted on the contractile response elicited by phenylephrine (PE) activation of the alpha(1)-adrenergic receptor subtype in vascular smooth muscle isolated from the corpus cavernosum of impotent men. PE-induced contractions were separated into distinct phasic and tonic components, and the tonic portion was analyzed using a first-order rate equation to determine the maximal rate constant for onset of contraction (k(obs max)) and the maximum amplitude of the steady-state contractile response (R(eq max)). The k(obs max)) value in tissues from insulin-dependent diabetic patients was significantly greater than that in tissues from either noninsulin-dependent diabetics or nondiabetics. Additionally, the mean k(obs max) value in older patients (60-70 yr) was significantly greater than the mean k(obs max) value in younger patients (32-59 yr). Significant diabetes-related, but not age-related, alterations were also found in R(eq max). The observed changes in contractility resulted in dramatic age- and pathology-dependent alterations in the initial rate and/or magnitude of PE-induced response generation. These kinetic studies extend our previous observations at steady state and provide further evidence for heightened corporal tissue tone in the etiology of erectile dysfunction.
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页码:H15 / H19
页数:5
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