硫氮Zuo酮对氨茶碱血药浓度的影响

观察口服氨茶碱治疗的支气管哮喘患者６４例，在加服硫氮Ｚｕｏ酮前后血清氨茶碱浓度的变化及临床表现。结果显示，加用硫氮Ｚｕｏ酮后平均血清氨茶碱浓度增加了０．２％（Ｐ＞０．０５），ＦＥＶ１增加了９、２％（Ｐ＜０．０１），ＰａＯ２增加了５．３％（Ｐ＜０．０１），ＰａＣＯ２下降了７．１％（Ｐ＜０．０１），临床总有效率增加了２５％（Ｐ＜０．０１）。提示加用硫氮Ｚｕｏ酮后未见血清氨茶碱显著增高及其相应的临床症状     

氧疗及正压通气对慢性阻塞性肺病患者夜间低氧血症的疗效

为了观察夜间氧疗及加用持续正压通气对急性加重期慢性阻塞性肺病（ＣＯＰＤ）患者夜间低氧血症的治疗效果，用脉搏氧饱和度仪对５８例患者进行监测描记，并作动脉血气分析。结果表明，白天动脉血氧分压（ＰａＯ２）、动脉血二氧化碳分压（ＰａＣＯ２）及基础脉搏氧饱和度（ＳｐＯ２）与夜间平均脉搏氧饱和度（ＭＳｐＯ２）之间有显著的正相关（ｒ＝０．７０２，ｒ＝０．６１３，ｒ＝０．６０５，Ｐ值均＜０．０１），与夜间呼吸空气时比较，３７例患者夜间氧疗效果良好，夜间平均ＳｐＯ２、平均最低ＳｐＯ２（ｍＳｐＯ２）升高（Ｐ＜０．０１），氧降累计时间百分比（ＣＴＮＯＤ％）降低（Ｐ＜０．０１）。其余２１例患者疗效不佳，改用夜间氧疗加持续正压通气（ＢｉＰＡＰ）后效果极好，夜间ＭＳｐＯ２、ｍＳｐＯ２与ＣＴＮＯＤ％三项指标均显著改善（Ｐ＜０．０１），且睡后ＰａＯ２升高（Ｐ＜０．０１），ＰａＣＯ２降低（Ｐ＜０．０１）。证实夜间氧疗能纠正多数ＣＯＰＤ患者的夜间低氧血症，对疗效不良者加用无创持续正压通气可获满意效果。     

支气管哮喘患者血浆内皮素1含量及临床意义

采用特异性放射免疫技术测定了２８例支气管哮喘急性发作（发作组）、２２例支气管哮喘临床控制（缓解组）和２０名健康对照者（对照组）的血浆内皮素１（ＥＴ１）含量。结果显示：发作组血浆含量（１３．４±５．２ｐｍｏｌ／Ｌ）分别显著高于缓解组（８．４±３．９ｐｍｏｌ／Ｌ，Ｐ＜０．０１）和对照组（６．６±２．６ｐｍｏｌ／Ｌ，Ｐ＜０．０１）；而缓解组与对照组间的差异无显著性；发作组血浆ＥＴ１含量分别与血氧分压（ＰａＯ＿２）和一秒钟用力呼气容积占用力肺活量比值（ＦＥＶ＿１％）呈显著负相关（ｒ＝－０．８２５７，ｒ＝－０．８１５７，Ｐ＜０．０１）。上述结果提示ＥＴ１可能涉及到支气管哮喘急性发作的病理生理过程。     

溴化异丙托品与氨茶碱片对支气管扩张作用的对比观察

目的比较定量雾化吸入溴化异丙托品与口服氨茶碱片对支气管扩张的作用。方法对２６例稳定期慢性阻塞性肺疾病（ＣＯＰＤ）患者采用安慰剂控制的双盲交叉试验，于试验前及试验后３０分，１，２，３，４，５，６小时分别测定第一秒用力呼气容积（ＦＥＶ１）。结果使用溴化异丙托品及氨茶碱后ＦＥＶ１平均峰值较基础值增加分别为３４％及１９％（Ｐ＜０．０１）；达峰时间分别为１～２小时及２～３小时；ＦＥＶ１较基础值增加＞１５％的患者分别为９０％及５０％（Ｐ＜０．０１）；ＦＥＶ１＞１５％的平均持续时间为３．６小时及１．６小时，６小时内ＦＥＶ１较基础值平均增加分别为１８％及８％（Ｐ＜０．０１）。结论对ＣＯＰＤ患者雾化吸入溴化异丙托品较口服氨茶碱片能更有效的扩张支气管作用     

肺心病患者吸入一氧化氮即刻血液动力学效应

目的：评价一氧化氮（ＮＯ）对肺心病肺动脉高压的急性治疗作用。方法：１３例（男９例，女４例）肺心病患者，平均年龄５２±１１岁（２１～５６岁）。检查前３天停服血管扩张药，在心导管检查时吸入ＮＯ（２０～８０ｐｐｍ）１０～１５分钟，吸入前后测右房压、肺动脉压同时取动脉及混合静脉血测血氧饱和度、血氧分压（ＰａＯ２）及混合静脉血氧饱和度（ＳｖＯ２）。结果：吸入ＮＯ后，肺动脉压下降，收缩压、舒张压及平均压分别下降３６．０％、３２．４％及２８．１％（Ｐ均＜０．００１）；肺血管阻力降低３８．５％（Ｐ＜０．０１）；肺动脉收缩压与体动脉收缩压比值从０．３９下降到０．２４，心脏指数增加１０．５％（Ｐ＜０．０１）；ＰａＯ２、ＳｖＯ２均值分别增加４．７％、８．７％（Ｐ均＜０．０５）。结论：吸入ＮＯ可使肺心病肺动脉高压患者肺血管扩张，降低肺动脉压及右室后负荷能预防或延缓心力衰竭的发生。     

双水平气道正压通气治疗重症呼吸衰竭的疗效观察

观察在常规治疗基础上加用经鼻（面）罩双水平气道正压通气治疗重症呼吸衰竭的疗效。结果：Ⅰ型呼吸衰竭患者１６例，平均通气２４．４小时（１９～３２小时），ＰａＯ２由６．６９±１．１１上升至９．４３±０．８２ｋＰａ（Ｐ＜０．０１）；Ⅱ型呼吸衰竭患者４２例，平均通气２８．３小时（２４～７２小时）后，ＰａＯ２由７．０６±２．５７上升至８．５８±１．８８ｋＰａ．（Ｐ＜０．０５），ＰａＣＯ２由１０．９１±２．１６下降至７．２９±１．１７ｋＰ３（Ｐ＜０．０１）。表明双压通气在治疗重症呼吸衰竭中是一种行之有效的治疗方法。     

高血压患者血浆一氧化氮浓度的变化

探讨一氧化氮（ＮＯ）与高血压的发病关系及其临床意义。方法用重氮法检测５０例高血压患者治疗前后和３６例正常对照组血浆ＮＯ浓度的变化。结果（１）高血压患者ＮＯ浓度（１４．９１±２．１８μｍｏｌ／Ｌ）较正常对照组明显地降低（Ｐ＜０．０１）；降压治疗后高血压患者血浆ＮＯ浓度有明显地增高（Ｐ＜０．０１），但仍明显低于正常对照组（Ｐ＜０．０１）。（２）高血压患者血浆ＮＯ浓度Ⅰ期最高，Ⅱ期居中，Ⅲ期最低，各期之间比较差异有显著性（Ｆ＝６７．５８，Ｐ＜０．０１）。（３）重度患者血浆ＮＯ浓度明显地低于轻度、中度患者（Ｐ＜０．０１）；中度明显低于轻度（Ｐ＜０．０１）。（４）并发心力衰竭组血浆ＮＯ浓度明显低于无心力衰竭组（Ｐ＜０．０１）。结论ＮＯ参与高血压的发生和发展，并与病情有关。检测血浆ＮＯ浓度可作为判断高血压患者病情的指标     

中高海拔地区藏族低氧通气反应的特征

对居住在海拔２０００～３０００ｍ（中海拔）和４０００～４７００ｍ（高海拔）地区藏族的低氧（１２％Ｏ＿２）及运动通气反应进行了测定。结果：中、高海拔组的低氧通气反应斜率（ΔＶ＿Ｅ／ΔＳａＯ＿２）分别为０．８１±０．０７和０．４６±０．０４Ｌ／ｍｉｎ／％Ｓａｏ＿２（Ｐ＜０．０１），最大运动通气量（Ｖ＿（ｍａｘ））分别为７８．３±３．５和６８．２±２．１Ｌ／ｍｉｎ（Ｐ＜０．０５）。ΔＶ＿Ｅ／ΔＳａＯ＿２和Ｖ＿（Ｅｍａｘ）之间呈现正相关，其回归式分别为ｙ＝４７．０±３７．３Ｘ，ｒ＝０．７０和ｙ＝５３．８±３１．４Ｘ，ｒ＝０．６７。高海拔组最大心率（ＮＲ＿（ｍａｘ））明显低于中海拔组（Ｐ＜０．０１）。本研究提示，中海拔组对低氧的刺激反应保持较高的通气反应，而高海拔组则显示钝化。因此，高原人通气反应的钝化与居住的海拔高度有关。     

肺癌患者围术期换气功能的研究

目的研究肺癌患者围术期换气功能的改变规律及影响机制。方法用氧合指数（Ｐ／Ｆ）、动脉肺泡氧分压比（ａ／Ａ）、动脉血氧饱和度５０％的氧分压（Ｐ５０Ｏ２）、动脉血二氧化碳分压（ＰａＣＯ２）４项指标对６８例５０岁以上男性肺癌患者分别于术前、术后即日、１、２、３、７日围术期换气功能进行监测。结果肺癌术后３日内Ｐ／Ｆ、ａ／Ａ较术前显著降低（Ｐ＜０．０１）；ＰａＣＯ２、Ｐ５０Ｏ２术后即日较术前显著增加（Ｐ＜０．０１）；术后２日内全肺切除氧合功能降低大于肺叶切除（Ｐ＜０．０５）；低肺功能患者术后换气及通气功能障碍较肺功能正常者显著（Ｐ＜０．０５）。结论肺癌术后３日换气功能明显减退，尤以氧合功能降低显著。应重点监测氧合功能变化，加强全肺及低肺功能患者的换气功能监测。     

激素和血生化在肾性骨病中的变化

我们观察了５５例尿毒症肾性骨营养不良症（简称肾性骨病，包括甲状旁腺功能亢进性骨病、低转化软骨病、混和性骨病）中血甲状旁腺激素（ＰＴＨ）、１．２５（ＯＨ）＿２Ｄ＿３、血钙、磷、ＡＫＰ、血铝及骨铝的变化。结果发现：各型肾性骨病血ＰＴＨ显著高于正常（Ｐ＜０．００１），血１．２５（ＯＨ）＿２Ｄ＿３和血钙显著低于正常（Ｐ＜０．００１）。在低转化软骨病组，血１．２５（ＯＨ）＿２Ｄ＿３显著低于甲旁亢骨病组（Ｐ＜０．０５）；血磷与正常对照无显著性差异，而显著低于甲旁亢骨病组及混合性骨病组（Ｐ＜０．０５）。ＰＴＨ与１．２５（ＯＨ）＿２Ｄ＿３呈线性负相关（Ｐ＜０．０５），而与ＡＫＰ呈线性正相关（Ｐ＜０．０５）。ＰＴＨ与血透时间、血钙、血铝及骨铝不相关。１．２５（ＯＨ）＿２Ｄ＿３与血透时间、血磷、血铝及骨铝不相关。骨铝染色阳性组与阴性组之间，ＰＴＨ、１．２５（ＯＨ）＿２Ｄ＿３及ＡＫＰ升高率均无显著性差异。     

Clinical relevance of the interaction of theophylline with diltiazem or nifedipine

The results of previously published studies indicate that calcium channel blockers are capable of competitively inhibiting cytochrome P-450 activity in hepatic microsomes, the pathway of theophylline metabolism. In addition, case reports have suggested that theophylline serum concentrations change when a calcium channel blocker has been added to or deleted from a stable theophylline regimen. To determine the clinical relevance of this potential interaction in patients with chronic asthma, we measured a peak steady-state theophylline serum concentration in 21 subjects while receiving theophylline alone (400 to 1,500 mg/day), and again, at least seven days later, after the addition of continuous therapy with maximally tolerated doses of either diltiazem (n = 18) or nifedipine (n = 16). The diltiazem dose was increased in 120 mg/day increments, as tolerated, to a maximum of 240 to 480 mg/day, while the nifedipine dose was increased in increments of 40 mg/day, to a maximum dose of 80 to 160 mg/day. The mean +/- SEM theophylline serum concentrations were 13.6 +/- 1.4 micrograms/ml before and 14.0 +/- 1.2 micrograms/ml during concurrent diltiazem therapy, and 12.6 +/- 1.0 micrograms/ml before and 12.2 +/- 1.1 micrograms/ml during nifedipine (p greater than 0.05). With this sample size there is a 5 percent chance that we missed a 20 percent change in serum concentration (type II error). Thus, maximum tolerated doses of diltiazem or nifedipine do not impair the metabolism of theophylline to a clinically relevant degree and adjustment of theophylline dosage is not required after the addition or discontinuation of diltiazem or nifedipine. In addition, these data suggest that currently available in vitro techniques for evaluating drug interactions in the hepatocyte do not predict the clinical relevance of such an interaction in patients who might require both drugs for different therapeutic indications.     

氨茶碱对急进高原者抗缺氧效应的研究

目的:探讨氨茶碱对急进高原者抗缺氧的效应。方法:总共100名青年男性入选本试验。随机分为2组:氨茶碱组50名(A组),对照组50名(C组)。所有参试者均为从四川省(海拔400米)招募的新兵。在乘飞机从四川进入拉萨(海拔3658米)前7 d,A组和C组分别开始口服氨茶碱和安慰剂。在3个时间点(服药前、服药后7d、进入高原后3 d)抽血测定血浆一氧化氮(NO)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化氢(H2O2)、乳酸(LA)和动脉血氧饱和度(SaO2)。结果:在平原地区服药前、后两组的缺氧和氧化指标比较无统计学差异。进入高原后3 d,所有参试者的血浆SOD,CAT(仅对照组),H2O2,LA水平增加(P<0.01),NO,SaO2下降(P<0.05,<0.01)。A组的SOD,CAT,H2O2,LA水平较C组低(P<0.01),而NO和SaO2水平高于C组(P<0.05,P<0.001)。结论:氨茶碱具有抗高原缺氧和抗氧化作用。     

依那普利与地尔硫卓治疗心脏X综合征疗效的比较

目的 观察应用依那普利与地尔硫卓治疗心脏X综合征（CSX）患者的疗效。 方法 将43例心脏X综合征患者随机接受依那普利 (21例,依那普利组) 或地尔硫卓(22例,地尔硫卓组)治疗,随访治疗3个月后的临床情况并复查平板运动试验、冠状动脉血流储备（CFR）及一氧化氮（NO）、血浆内皮素-1（ET-1）的含量。结果 与本组治疗前比较,用药3个月后两组胸痛例数及最大ST段压低幅度明显减少,ET-1水平明显下降,CFR及NO的水平明显升高,运动总时间、ST段压低1 mm时间明显延长（P<0.01或P<0.05）。与地尔硫卓组相比,依那普利组胸痛例数及最大ST段压低幅度明显减少 (均为P<0.05),ET-1水平明显下降（P<0.01）,CFR及NO的水平明显升高(均为P<0.05),运动总时间、ST段压低1 mm时间明显延长（P<0.01,P<0.05）。结论 依那普利与地尔硫卓均能改善CSX患者的内皮细胞功能提高患者的运动耐量及CFR,且依那普利较地尔硫卓更为有效。     

Effects of aminophylline in the conscious dog after coronary occlusion

The effects of aminophylline were examined in 19 conscious dogs subjected to coronary arterial occlusion. Measurements were made of left ventricular pressure and its first derivative (dP/dt), segment length and the velocity of segment length shortening in normal and severely ischemic zones. Regional blood flow was measured in these zones using the radioactive microsphere technique. Coronary occlusion increased heart rate, mean arterial pressure and left ventricular end-diastolic pressure but did not change left ventricular systolic pressure or dP/dt significantly. It also resulted in increased end-diastolic segment length and reduced segment length shortening (114 ± 6 percent, that is, paradoxical bulging) associated with marked reduction of blood flow to ischemic myocardium. Aminophylline, 1 mg/kg per min for 9 to 15 minutes administered after occlusion, increased heart rate 6 ± 2 beats/min, mean arterial pressure 5 ± 1 mm Hg, left ventricular systolic pressure 9 ± 2 mm Hg and left ventricular dP/dt 670 ± 50 mm Hg/s while reducing left ventricular end-diastolic pressure by 3.4 ± 0.3 mm Hg. In severely ischemic zones aminophylline increased transmural blood flow by 21 ± 8.0 percent (p < 0.02), reduced end-diastolic segment length by 0.23 ± 0.05 mm (p < 0.01) and reduced paradoxical bulging by 0.15 ± 0.06 mm (p < 0.02). Thus, in the presence of coronary arterial occlusion, aminophylline increased mean arterial pressure, left ventricular dP/dt and heart rate while reducing left ventricular end-diastolic pressure. In severely ischemic myocardium aminophylline appeared to exert a salutary effect and improved both regional perfusion and function.     

老年糖尿病患者脂肪餐后血管内皮活性因子的变化

目的 观察老年糖尿病患者脂肪餐后血管内皮活性因子的动态变化及其与血脂的关系. 方法 选择老年糖尿病患者(糖尿病组)36例和健康老年人(对照组)20例进行6 h脂肪餐负荷试验.糖尿病组根据空腹和脂肪餐后4 h三酰甘油(TG)水平分为空腹TG增高组、餐后TG增高组和餐后TG正常组3个亚组.各组均测定脂肪餐前后血清一氧化氮(NO)、内皮素-1(ET-1)、纤溶酶原激活物抑制物-1(PAI-1)、组织型纤溶酶原激活物(t-PA)的浓度,并分析与TG的相关性. 结果 (1)NO、ET-1及NO/ET-1的变化:对照组脂肪餐后2 h NO浓度显著升高、ET-1水平显著降低,6 h均恢复至餐前水平;而糖尿病各亚组脂肪餐后NO逐渐降低、ET-1逐渐升高,餐后6 h变化最为明显.与对照组比较,糖尿病各亚组脂肪餐后各点NO/ET-1均显著降低(P<0.01),而餐后TG增高组和空腹TG增高组与餐后TG正常组比较差异有统计学意义(P<0.05或P<0.01).(2)t-PA、PAl-1及PAl-1/t-PA的变化:各组脂肪餐后4 h PAl-1水平轻度升高、t-PA水平轻度降低;与对照组比较,糖尿病组PAI-1/t-PA显著升高,糖尿病各亚组比较,餐后TG增高组和空腹TG增高组显著高于餐后TG正常组(P<0.05或P<0.01).(3)与TG的相关性分析:直线相关分析显示,糖尿病组TG与NO、t-PA显著负相关(r=-0.360,P<0.05;r=-0.649,P<0.01),与ET-1、PAI-1显著正相关(r=0.421,P<0.01;r=0.520,P<0.01). 结论 老年糖尿病患者存在血管内皮活性因子平衡失调,血脂异常可加重这一改变和血管内皮功能的损伤.     

美多洛尔、苯那普利和非洛地平对高血压血管活性肽的影响

目的:探讨原发性高血压(EH)患者的血清血管紧张素I、Ⅱ(Ang I、Ⅱ)、心钠素(ANF)和醛固酮 (ALD)水平,及美多洛尔、苯那普利和非洛地平干预治疗后的变化和意义。方法:放射免疫法测定356例EH组和 68例非高血压组血清Ang I、Ⅱ,ANF和ALD水平,对EH患者分组给予美多洛尔、苯那普利和非洛地平干预治疗, 比较其治疗前、后的变化。结果:EH患者血清Ang I、Ⅱ和ALD水平显著高于对照组(P均<0．01),ANF则否 (P>0．05);高血压I、Ⅱ、Ⅲ期组间血清4种活性肽水平的差异无显著性(P均>0．05)。Ang I与AngⅡ(r=0．511, P<0．01),ALD与Ang Ⅱ间(r=0．431,P<0．05)呈显著正相关,Ang I与ANF、ALD,AngⅡ与ANF,ANF与 ALD间无显著相关性(P均>0．05);Ang I、Ⅱ,ALD水平均与平均动脉压呈显著正相关(r=0．451,0．432,0．512, P均<0．01),ANF则否(P>0．05)。EH患者中,美多洛尔干预组(66例)治疗后血清Ang I、Ⅱ、ALD水平分别显著下降(P均<0．01);苯那普利干预治疗组(68例)后血清AngⅡ水平显著下降、ALD水平却显著升高(P均 <0．01);非洛地平干预组(80例)治疗后血清Ang I水平显著升高(P<0．05)。结论:EH患者血清Ang I、Ⅱ和 ALD水平显著升高,美多洛尔可使三者水平均显著下降,苯那普利仅使AngⅡ水平显著下降,ALD水平却显著升高, 而非洛地平却使血清Ang I水平显著升高。     

卡托普利对糖尿病大鼠主动脉胶原非酶糖化的抑制作用

在链脲佐菌素所致糖尿病大鼠模型中，观察了卡托普利对糖尿病大鼠主动脉胶原非酶糖化的影响。     

Diltiazem and digoxin interaction. Development of digoxin plasma levels and electrocardiographic parameters in healthy subjects

In order to determine the interaction between diltiazem and digoxin, plasma digoxin concentrations and the principal ECG parameters (24 hour Holter monitoring) were measured in 10 healthy volunteers under basal conditions (P0), with 0.375 mg/day of digoxin (P1 = 17 days), during association with 240 mg/day of diltiazem (P2 = 17 days) and then again on digoxin alone (P3 = 10 days). The addition of diltiazem was associated with a 20.4% rise in plasma digoxin concentrations (0.59 ng/ml vs 0.49 ng.ml). There was no significant variation of plasma digoxin after withdrawal of diltiazem; in some cases it remained unchanged, in others it fell or continued to rise. During the administration of digoxin and diltiazem, the mean RR period and the duration of the maximal pauses increased (p less than 0.05); the RR interval also increased (p less than 0.01) but the mean QRS duration and the QTc interval did not change significantly with respect to their values on digoxin alone. After withdrawal of diltiazem, the PR interval was the only parameter to decrease significantly (p less than 0.05). These results suggest that patients receiving this drug association should be followed up carefully.     

肾病综合征患者可溶性白介素2受体变化及意义

为了探讨肾病综合征（ＮＳ）患者可溶性白介素２受体（ＳＩＬ－２Ｒ）变化的临床意义，我们检测３６例ＮＳ血清及尿液ＳＩＬ－２Ｒ。结果表明：ＮＳ发作组血清及尿液ＳＩＬ－２Ｒ浓度明显高于ＮＳ缓解组（Ｐ＜０．０１）及健康对照组（Ｐ＜０．０１），而ＮＳ缓解组血清及尿液ＳＩＬ－２Ｒ浓度和健康对照组无显著性差异（Ｐ＜０．０５）。血ＳＩＬ－２Ｒ和血肌酐呈正相关（ｒ＝０．４４，Ｐ＜０．０１），尿　ＳＩＬ－２Ｒ和尿蛋白排泄量呈正相关（ｒ＝０．４８，Ｐ＜０．０１）。研究提示ＳＩＬ－２Ｒ浓度升高可作为ＮＳ活动及（或）肾功能恶化的指标。     

The calcium channel blocker diltiazem lowers serum parathyroid hormone levels in vivo and in vitro

PTH secretion is inversely related to the extracellular and cytosolic calcium (Ca2+) concentrations and, therefore, might be affected by calcium channel blockers such as diltiazem. To investigate the effects of diltiazem on parathyroid function in vivo, 15 subjects were treated with diltiazem (120-360 mg/day), and 15 subjects were treated with the nonspecific vasodilator hydralazine (75-150 mg/day). Diltiazem lowered serum PTH levels from 1.07 +/- 0.07 to 0.87 +/- 0.07 pg/L (P = 0.001), and increased urinary calcium and decreased urinary phosphate excretion (P less than 0.001 and P less than 0.01, respectively). The hydralazine-treated subjects had no significant differences in any of these parameters. To investigate this effect further, dispersed bovine parathyroid cells were incubated for 2 h with or without diltiazem. Regression analysis of PTH released vs. the concentration of diltiazem (10(-7)-10(-4) mol/L) revealed a significant negative relationship (P less than 0.01) with 40% inhibition of PTH release at 10(-4) mol/L (P less than 0.01). The cytosolic Ca2+ concentration, measured using the Ca2+-sensitive fluorescent dye fura-2, was significantly increased in the presence of 10(-4) mol/L diltiazem (P less than 0.01). In summary, diltiazem lowered PTH levels in vivo and in vitro, perhaps acting as a Ca2+ channel agonist in the parathyroid cell and inhibiting PTH release through a rise in the cytosolic Ca2+ concentration.