Spelling suggestions: "subject:"potassium chloride"" "subject:"potassium dichloride""
71 |
Relaxation of Isolated Human Myometrial Muscle by beta2-Adrenergic Receptors but Not beta1-Adrenergic ReceptorsLiu, Ying L., Nwosu, Uchenna C., Rice, P. J. 01 October 1998 (has links)
OBJECTIVE: Human myometrium contains both beta1-adrenergic and beta2-adrenergic receptors. This study was designed to assess the importance of each beta-adrenergic receptor subtype in relaxation of human myometrial muscle strips. STUDY DESIGN: Radioligand binding studies were used to establish the presence of each beta-adrenergic receptor subtype, whereas highly selective beta1-antagonists and beta2-antagonists were used to assess the contribution of beta-adrenergic receptor subtypes to myometrial relaxation after exposure to (-)-isoproterenol. RESULTS: Membranes prepared from myometrium contained 82% +/- 4% beta2-adrenergic receptors. After contraction produced by exposure to potassium chloride (35 mmol/L), isoproterenol produced relaxation with half maximal effect at 0.02 micromol/L and a maximal relaxation of 52% +/- 3%. Beta1-antagonist CGP-20712A had no significant effect, whereas beta2-antagonist ICI-118551 produced a characteristic rightward shift of the isoproterenol concentration-relaxation relationship. CONCLUSIONS: Although both beta1-adrenergic receptors and beta2-adrenergic receptors are present in human myometrial tissue at term, relaxation by nonselective beta-agonist isoproterenol is mediated exclusively by beta2-adrenergic receptors.
|
72 |
Third Place Winner of the Conrad Jobst Award in the Gold Medal Paper Competition. Prevention of Spinal Cord Dysfunction in a New Model of Spinal Cord IschemiaLopez, S, Manahan, E, Evans, J. R., Kao, R. L., Browder, W. 01 January 1995 (has links)
Paraplegia or paraparesis caused by temporary cross-clamping of the aorta is a devastating sequela in patients after surgery of the thoracoabdominal aorta. No effective clinical method is available to protect the spinal cord from ischemic reperfusion injury. A small animal (rat) model of spinal cord ischemia is established to better understand the pathophysiological events and to evaluate potential treatments. Eighty-one male Sprague-Dawley rats weighing 300 g to 350 g were used for model development (45) and treatment evaluation (36). The heparinized and anesthetized rat was supported by a respirator following tracheostomy. The thoracic aorta was cannulated via the left carotid artery for post-clamping intra-aortic treatment solution administration. After thoracotomy, the aorta was freed and temporarily clamped just distal to the left subclavian artery and just proximal to the diaphragm for different time intervals: 0, 5, 10, 15, 20, 25, 30, 35, and 40 minutes (five animals per group). The motor function of the lower extremities postoperatively showed consistent impairment after 30 minutes clamping (5/5 rats were paralyzed), and this time interval was used for treatment evaluation. For each treatment, six animals per group were used, and direct local intra-aortic infusion of physiologic solution (2 mL) at different temperatures with or without buffer substances was given immediately after double cross-clamp to protect the ischemic spinal cord. Arterial blood (2 mL) was infused in the control group. The data indicate that the addition of HCO3-(20 mM) to the hypothermic (15 degrees C) solution offered complete protection of the spinal cord from ischemic injury.(ABSTRACT TRUNCATED AT 250 WORDS)
|
Page generated in 0.0392 seconds