Lye S J, Christopher P, Casper R F
Research Institute, St. Joseph's Hospital, London, Ont., Canada.
Can J Physiol Pharmacol. 1987 Nov;65(11):2297-301. doi: 10.1139/y87-364.
Recent studies have reported that beta-adrenergic agonists stimulate the production of stimulatory prostaglandins (PGs) by intrauterine tissues in vitro. These drugs are used clinically to inhibit uterine contractions; consequently an increase in stimulatory PGs in vivo might have potentially adverse effects. We have, therefore, investigated whether beta-adrenergic agonists increase plasma PG concentrations in vivo. Samples of peripheral (aorta) and uterine venous enriched (vena cava) blood from nonpregnant sheep were collected at 15-min intervals for 1 h before, 3 h during, and 1 h postinfusion of either (a) the beta-adrenergic agonist isoproterenol (Isop) at a dose of 0.16 microgram.kg-1.min-1; (b) Isop at a dose of 0.08 microgram.kg-1.min-1; or (c) saline, 1 mL/h via a jugular vein catheter. The sheep were also equipped with intrauterine recording balloons to record intrauterine pressure and myometrial electromyographic (EMG) electrodes to measure EMG activity. Infusion of Isop at 0.16 microgram.kg-1.min-1 produced a significant initial inhibition of uterine activity, although contractions returned (within 60 min) despite continued administration of Isop. Plasma PGE2 (but not PGF2 alpha or 13,14-dihydro-15-keto-PGF2 alpha (PGFM] concentrations were significantly elevated during the Isop infusion. Administration of Isop at 0.08 microgram.kg-1.min-1 produced no effects on uterine contractile activity but was associated with a significant elevation in plasma PGE2 (but not PGF2 alpha or PGFM) concentrations. No changes in plasma PGE2, PGF2 alpha, or PGFM occurred during saline infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
最近的研究报告称，β-肾上腺素能激动剂可在体外刺激子宫内组织产生刺激性前列腺素（PGs）。这些药物在临床上用于抑制子宫收缩；因此，体内刺激性PGs的增加可能会产生潜在的不良影响。因此，我们研究了β-肾上腺素能激动剂在体内是否会增加血浆PG浓度。在非妊娠绵羊静脉注射以下物质前1小时、注射期间3小时和注射后1小时，每隔15分钟采集外周（主动脉）血和子宫静脉富集（腔静脉）血样本：（a）剂量为0.16微克·千克⁻¹·分钟⁻¹的β-肾上腺素能激动剂异丙肾上腺素（Isop）；（b）剂量为0.08微克·千克⁻¹·分钟⁻¹的Isop；或（c）通过颈静脉导管以1毫升/小时的速度注射生理盐水。绵羊还配备了子宫内记录气囊以记录子宫内压力，并配备了子宫肌层肌电图（EMG）电极以测量EMG活动。以0.16微克·千克⁻¹·分钟⁻¹的剂量输注Isop会产生明显的子宫活动初始抑制，尽管持续输注Isop，但收缩仍会恢复（60分钟内）。在输注Isop期间，血浆PGE2（但不是PGF2α或13,14-二氢-15-酮-PGF2α [PGFM]）浓度显著升高。以0.08微克·千克⁻¹·分钟⁻¹的剂量输注Isop对子宫收缩活动没有影响，但与血浆PGE2（但不是PGF2α或PGFM）浓度的显著升高有关。在输注生理盐水期间，血浆PGE2、PGF2α或PGFM没有变化。（摘要截断于250字）
