2型糖尿病大鼠血浆同型半胱氨酸与阴茎海绵体内NOS和内源性CO的相关性研究

目的:研究2型糖尿病性大鼠血浆同型半胱氨酸(Hcy)与阴茎海绵体内NOS和内源性CO的相关性。方法:选取3月龄雄性Wistar大鼠50只,随机选取10只为对照组(A组);高糖高脂饲料饲养4周后从其他40只大鼠中筛选出30只构建成功的糖尿病(DM)大鼠模型,随机分成3组:DM大鼠组(B组);胰岛素治疗组(C组)和叶酸+维生素B12治疗组(D组)。8周及12周后注射阿朴吗啡观察各组大鼠阴茎勃起情况。12周后测各组大鼠血浆总Hcy含量及阴茎海绵体内NOS活性和CO含量。结果:与A组比较,B组大鼠血浆Hcy浓度明显升高,阴茎勃起功能明显降低,阴茎海绵体NOS活性和CO含量均下降,差异有显著性(P<0.01)。2型DM大鼠中高Hcy血症发生率为55%。与B组比较,C组和D组中大鼠血浆Hcy浓度显著下降,阴茎勃起功能、阴茎海绵体NOS活性均升高(P<0.01),Hcy与NOS(rA=-0.89,rB=-0.76,rC=-0.91,rD=-0.91)及CO含量(rA=-0.82,rB=-0.77,rC=-0.93,rD=-0.81)均呈负相关。结论:2型DM大鼠血浆中的高Hcy可能是引起阴茎海绵体NOS活性下降、CO含量下降,进而导致DM ED发病的分子机制之一。胰岛素、叶酸和维生素B12可以改善DM大鼠的勃起功能,提高阴茎海绵体NOS活性和CO含量。     

尼古丁对大鼠阴茎勃起功能及阴茎海绵体内源性一氧化氮(NO)和一氧化碳(CO)含量的影响

目的探讨尼古丁对成年雄性大鼠阴茎勃起功能及阴茎海绵体内源性NO及CO含量的影响.方法将40只成年雄性大鼠随机分为4组,对照组、尼古丁皮下注射1、2、3月组.给药方式采用皮下注射.处理后,阿朴吗啡试验观察大鼠阴茎勃起情况.取阴茎海绵体,用硝酸还原酶法检测其NO含量,用改良双波长分光光度法检测其CO含量.结果与对照组比较,尼古丁各组阴茎勃起次数、NO及CO含量明显减少(P <0.01).阴茎勃起次数除尼古丁皮下注射2月组与尼古丁注射1月组之间比较差异无统计学意义(P=0.216)外,其余各组两两比较差异均具有统计学意义(P<0.01).阴茎海绵体NO及CO含量,尼古丁注射各组间两两比较差异均具有统计学意义(P<0.01).阴茎勃起次数、阴茎海绵体中NO及内源性CO含量与尼古丁给药时间呈负相关(r分别为:-0.780、-0.956、-0.914,P=0.000).各组大鼠阴茎海绵体NO与内源性CO含量呈正相关(r=0.876,P=0.000).结论尼古丁可导致成年雄性大鼠阴茎勃起功能减弱,阴茎海绵体中N0及内源性CO含量下降;其影响呈给药时间依赖性;表明内源性CO是尼古丁致阴茎勃起障碍的重要信使分子,尼古丁可能通过降低NO及内源性CO含量致ED.     

高脂血症对大鼠阴茎海绵体中NOS及CO含量影响的研究

目的 探讨高脂血症对大鼠阴茎海绵体中一氧化氮合成酶(NOS)活性及一氧化碳(CO)浓度的影响及两者之间的关系.方法 将32只雄性wistar大鼠随机分为2组:高脂血症组和正常对照组,每组各16只大鼠.通过建立大鼠高脂血症模型,于实验开始后10d和20d,分别随机取各组1/2大鼠观察其勃起功能;用分光光度法分别测定海绵体匀浆中NOS活性和CO浓度.结果 在第10天及第20天,高脂血症组和正常对照组相比,大鼠阴茎海绵体内NOS活性、CO浓度及阴茎勃起次数差异均有统计学意义(P<0.05);而且第20天高脂血症组NOS活性、CO浓度及阴茎勃起次数,均明显低于第10天,两两比较差异均有统计学意义(P<0.05).结论 高脂血症大鼠阴茎海绵体中NOS及CO下降,这可能是高脂血症引起勃起功能障碍的发病机制之一.     

尼古丁对大鼠阴茎海绵体内源性CO浓度及NOS活性的影响

目的:观察尼古丁对成年雄性大鼠阴茎海绵体内源性一氧化碳(CO)浓度及一氧化氮合酶(NOS)活性的影响,探讨吸烟对勃起功能损害的可能机制。方法:40只成年雄性Wistar大鼠分为4组,尼古丁注射1个月组、2个月组、3个月组和对照组,尼古丁注射组尼古丁0.5 mg/(kg.d)皮下分别注射1、2、3个月,对照组注射生理盐水。处理后,取阴茎海绵体,用改良双波长分光光度法检测CO浓度,改良Griess法检测NOS活性。结果:对照组CO浓度为(13.66±0.40)μmol/mg prot,NOS活性为(9.72±0.47)U/mg prot。尼古丁注射1个月,CO浓度和NOS活性分别下降为(12.43±0.56)μmol/mg prot和(8.44±0.69)U/mg prot,显著低于对照组(P均<0.01);尼古丁注射2个月,CO浓度和NOS活性分别下降为(11.41±0.52)μmol/mg prot和(7.53±0.24)U/mg prot,显著低于对照组和尼古丁注射1个月组(P<0.01);尼古丁注射3个月,海绵体CO浓度和NOS活性分别下降为(10.52±0.59)μmol/mg prot和(6.64±0.31)U/mg prot,均显著低于对照组和尼古丁注射1个月、2个月组(P均<0.01)。结论:尼古丁可导致成年雄性大鼠阴茎海绵体内源性CO浓度及NOS活性下降,提示内源性CO及NOS参与吸烟引起勃起功能障碍的病理生理过程。     

Hhcy大鼠阴茎海绵体内NOS及CO含量的研究

目的:检测高同型半胱氨酸血症(Hhcy)大鼠阴茎组织内一氧化氮合酶(NOS)和一氧化碳(CO)的含量并探讨其对阴茎勃起功能的影响。方法:取成年雄性Wistar大鼠20只,随机均分为2组:正常对照组和Hhcy组。Hhcy组给予3%高蛋氨酸饲料喂养,正常对照组给予普通饲料喂养,4周后取血,测定血清Hhcy含量;取阴茎海绵体组织、匀浆,测定NOS和CO的含量。结果:Hhcy组血清中同型半胱氨含量[(22.32±1.65)μmol/L]显著高于正常对照组[(4.90±1.73)μmol/L],阴茎组织中的NOS[(6.45±1.12)nmol/(g·min)]和CO[(10.60±0.92)μmol/L]含量明显低于正常对照组[(10.77±0.60)nmol/(g·min)和(13.36±0.44)μmol/L]。结论:给予4周高蛋氨酸饮食的Wistar大鼠能引起Hhcy。Hhcy大鼠阴茎海绵体组织中内源性NOS和CO降低。Hhcy是大鼠阴茎勃起功能障碍的独立危险因素。     

高脂血症大鼠阴茎海绵体中VEGF含量变化对NOS的影响

目的 探讨高脂血症引起大鼠阴茎海绵体中血管内皮生长因子(VEGF)含量的变化,以及这种变化对一氧化氮合酶(NOS)活性的影响.方法 将32只雄性wistar大鼠随机分为2组,高脂血症组和正常对照组各16只,通过建立大鼠高脂血症模型,于实验开始后10d和20d,分别随机取各组1/2大鼠观察其勃起功能;采用免疫组化方法观察大鼠阴茎海绵体内VEGF,并用图像分析法测定其含量;用分光光度法分别测定海绵体匀浆中NOS活性.结果 造模开始后第10天,高脂血症组和正常对照组相比,大鼠阴茎海绵体内VEGF含量、NOS活性及阴茎勃起次数差异均有显著性(P＜0.05):造模开始后第20天,两组的VEGF含量、NOS活性及阴茎勃起次数差异均有显著性(P＜0.05).高脂血症组VEGF含量、NOS活性及阴茎勃起次数,第20天均明显低于第10天,两两比较差异均有显著性(P＜0.05).结论 高脂血症大鼠阴茎海绵体中VEGF明显减少,内皮细胞增殖下降,进而NOS下降,这可能是高脂血症引起勃起功能障碍(ED)的发病机制之一.     

生长激素补充对老龄大鼠勃起功能及阴茎海绵体nNOS表达的影响

目的探讨生长激素(GH)补充对老龄大鼠勃起功能及阴茎海绵体神经型一氧化氮合酶(nNOS)表达的影响。方法20只18月龄SD大鼠随机均分成A、B两组,10只2月龄SD大鼠为C组。A组给予GH1U/(kg·d),B、C组给予相同剂量的生理盐水,均皮下注射8周。于8周末观察阿朴吗啡(APO)皮下注射与大鼠海绵体内注射罂粟碱诱导的阴茎勃起情况,并用免疫组化SP法检测阴茎海绵体组织中nNOS神经纤维的数目。结果8周末时,A、C组大鼠APO诱导的勃起次数、海绵体内注射罂粟碱诱导的最大海绵体内压以及阴茎海绵体组织中nNOS神经纤维数目均显著高于B组(P<0.05或P<0.01)。结论老龄大鼠勃起功能及阴茎海绵体nNOS表达较成年大鼠明显下降,GH补充可以部分改善老龄大鼠的勃起功能,其机制之一可能与GH补充增加了老龄大鼠阴茎海绵体组织中nNOS神经纤维数目有关。     

左旋精氨酸对糖尿病大鼠阴茎海绵体氧化应激损伤的保护作用

目的 探讨左旋精氨酸(L-Arg)对糖尿病大鼠阴茎海绵体氧化应激损伤的保护作用.方法 大剂量STZ腹腔注射建立糖尿病大鼠模型,随机分为糖尿病组、L-Arg治疗组,并设正常对照组.治疗8周后用电刺激各组大鼠勃起神经测定海绵体内压评价勃起功能采用黄嘌呤氧化酶法检测阴茎海绵体组织中超氧化物歧化酶(SOD)活性,硫代芭比妥酸法测丙二醛(MDA)含量;光镜下观察Masson染色切片.结果 糖尿病组较正常对照组,阴茎海绵体MDA含量显著增高(P<0.01),SOD活性显著下降(P<0.05),最大海绵体内压(ICP)显著降低(P<0.05);与糖尿病组比较,L-Arg可使海绵体MDA含量明显降低(P<0.05),显著提高其SOD活性及ICP(P<0.05).糖尿组大鼠阴茎组织中胶原纤维含量明显减少,排列紊乱、稀疏,平滑肌减少变薄,出现断裂;L-Arg组大鼠阴茎组织结构可见明显改善.结论 糖尿病大鼠阴茎海绵体存在氧化应激损伤,导致海绵体结构的改变是其勃起水平下降的重要因素,通过补充L-Arg,可以减轻勃起组织的氧化应激损伤,改善组织结构,从而提高勃起能力.     

利拉鲁肽对糖尿病大鼠阴茎海绵体eNOS表达的影响

目的:研究胰高血糖素样肽-1(GLP-1)类似物利拉鲁肽对糖尿病(DM)大鼠阴茎海绵体内皮型一氧化氮合酶(e NOS)表达的影响,探讨利拉鲁肽对DM勃起功能障碍(DED)大鼠勃起功能的作用。方法:取6周龄雄性SD大鼠,分为正常对照组(NC,n=10)与实验组(n=20),实验组构建DM大鼠模型,随机将实验组分为DM组(n=8)与GLP-1组(n=8)。干预12周后,检测各组空腹血糖(FPG)、空腹胰岛素(FINS)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、睾酮、白介素-6,计算胰岛素敏感指标Homa-IR与Homa-β,比较各组大鼠勃起功能;Western印迹检测各组大鼠阴茎海绵体组织Akt/p-Akt、e NOS/p-e NOS的表达。结果:DM组大鼠勃起次数(0.90±1.14)及勃起率(37.5%)较GLP-1组(2.90±1.53,25.0%)、NC组(4.20±1.05,100%)均明显减少(P0.05);GLP-1组大鼠勃起率及勃起次数亦少于NC组大鼠(P0.05)。免疫荧光染色提示e NOS主要表达在海绵体血管、血窦内皮细胞的细胞质中,DM组、GLP-1组e NOS蛋白表达水平显著低于正常对照组(P0.05),且GLP-1组明显高于DM组(P0.05)。DM、GLP-1组大鼠阴茎组织e NOS/p-e NOS表达水平较NC组明显下降(P0.01或0.05)。与DM组相比,GLP-1组大鼠阴茎组织p-e NOS表达水平明显升高(P0.05)。3组大鼠阴茎组织Akt比较无显著差异(P0.05)。DM、GLP-1组大鼠阴茎组织p-Akt表达水平较NC组明显下降(P0.01或0.05)。与DM组相比,GLP-1组大鼠阴茎组织p-e NOS表达水平明显升高(P0.05)。结论:GLP-1可能通过调节Akt/e NOS信号通路,保护阴茎海绵体组织内皮细胞功能,改善DED大鼠的勃起功能,提示GLP-1的使用可能是将来治疗和预防DED的重要方法之一。     

褪黑素抗氧化治疗糖尿病大鼠阴茎勃起功能障碍的研究

目的 观察褪黑素对糖尿病大鼠阴茎勃起功能的影响,探讨氧化应激在糖尿病性勃起功能障碍发病机制中的作用.方法 一次性腹腔注射STZ建立糖尿病大鼠模型,随机分为糖尿病组、褪黑素(MT)治疗组以及对照组.8周后通过电刺激各组大鼠勃起神经来检测海绵体内压,评价勃起功能;采用硫代芭比妥酸法检测阴茎海绵体组织中丙二醛(MDA)含量,黄嘌呤氧化酶法测超氧化物氧化酶(SOD)活性;免疫组化染色半定量分析各组大鼠阴茎海绵体中平滑肌及内皮的含量.结果 与正常对照组相比,阴茎海绵体组织中MDA含量显著增加(P＜0.01),SOD活性降低(P＜0.05),最大海绵体内压(ICP)亦显著降低(P＜0.05);与糖尿病组相比,MT组大鼠海绵体MDA含量明显降低(P＜0.05),其SOD活性和ICP显著升高(P＜0.05);且其海绵体平滑肌及海绵窦内皮细胞含量明显提高.结论 MT可通过改善组织中氧化应激水平,促进阴茎海绵体平滑肌和内皮组织修复,提高勃起功能;抗氧化治疗可能为糖尿病性勃起功能障碍的防治提供新的策略.     

RhoA/Rho-kinase: a novel player in the regulation of penile erection.

Current research has centered around the role of nitric oxide in the stimulation of cavernosal vasodilation and erection. However, recent evidence from our lab details the importance of endogenous vasoconstrictor mechanisms in maintaining a flaccid penile state, and further demonstrates that the inhibition of endogenous vasoconstriction is sufficient to stimulate erection in a rat model. In this article, we suggest inhibition of endogenous vasoconstriction as a potential therapeutic avenue in the treatment of erectile dysfunction. We also speculate on potential physiologic mechanisms by which endogenous vasoconstriction is inhibited in order for arousal-initiated vasorelaxation, and erection, to occur.     

不同月龄大鼠阴茎组织中内源性一氧化碳与环磷酸鸟苷和环磷酸腺苷的关系

目的:探讨增龄对大鼠阴茎组织中内源性一氧化碳(CO)与环磷酸鸟苷(cGMP)、环磷酸腺苷(cAMP)含量的变化。方法:8、16、24个月大鼠各8只,分别注射阿朴吗啡(APO)进行大鼠阴茎勃起功能实验;麻醉后取阴茎海绵体,用改良双波长分光光度法测量其CO浓度,并测量其cAPM、cGMP含量。结果:随月龄增加,CO含量降低,各月龄组间差异有显著性(P均<0.01);cGMP、cAMP含量均随月龄增加而逐渐下降,各月龄组间差异有显著性(P均<0.01)。结论:随月龄的增加,大鼠阴茎组织中CO、cAMP、cGMP含量下降,提示衰老对大鼠阴茎组织中CO、cAMP、cGMP含量影响显著。     

Airway response to inhaled salbutamol in hyperthyroid and hypothyroid patients before and after treatment.

For many years the development of thyrotoxicosis has been known to cause a deterioration in asthma but the mechanism is unknown. We have studied the effect of thyroid function on airway beta adrenergic responsiveness in 10 hyperthyroid and six hypothyroid subjects before and after treatment of their thyroid disease. Airway adrenergic responsiveness was assessed by measuring specific airway conductance (sGaw) after increasing doses of inhaled salbutamol (10-410 micrograms). After treatment there was no difference in resting FEV1, sGaw, or thoracic gas volume. FVC increased in the hyperthyroid subjects but did not change in the hypothyroid subjects. In the hyperthyroid subjects there was a significant increase in delta sGaw after 35, 60, 110, and 41 micrograms salbutamol; in sGaw after 60, 110, and 410 micrograms salbutamol; and in the area under the salbutamol dose response curve (AUC) after treatment of the thyroid disorder. In the hypothyroid subjects there was a significant reduction in sGaw after 10 and 60 micrograms salbutamol and in the AUC after treatment. When all subjects were considered, there was a negative correlation between the AUC and serum thyroxine values. These findings suggest that an inverse relationship exists between the level of thyroid function and airway beta adrenergic responsiveness.     

The effect of sildenafil on electrostimulation-induced erection in the rat model

This study was conducted to show the effect of sildenafil on electrostimulation-induced erection in the rat model. Fifteen 12-week-old male Wistar Kyoto rats were used. The intracavernous pressure and arterial blood pressure were simultaneously monitored through electric cavernous nerve stimulation before and after the administration of sildenafil (2 mg/kg). Statistical analysis was performed on maximal intracavernous pressure (MIP), mean arterial blood pressure (MAP), the MIP/MAP and detumescence time. MAP decreased significantly by about 20 mmHg after sildenafil administration. The MIP/MAP increased significantly after sildenafil administration. The effect of sildenafil on the MIP/MAP was marked especially at lower (2-3 Hz) frequencies. The detumescence time significantly increased after sildenafil administration. We have shown that sildenafil is effective for enhancing erection at lower frequencies and prolonging penile erection in rats. After the administration of sildenafil, penile erection would be induced by weak stimuli that will not cause penile erection under normal conditions.     

Experimentally induced hypo- and hyper-thyroidism influence on the antioxidant defence system in adult rat testis

The objective of the present experiment was to study the effect of thyroid hormone on the antioxidant defence system of rat testis. Hypothyroidism induced in rats by 6-n propyl 2-thiouracil (PTU) treatment resulted in a reduction in body weight, seminal vesicle and ventral prostate gland. A further decrease in the weight of seminal vesicle was recorded following administration of T3 to hypothyroid rats. The oxidative stress parameters such as hydrogen peroxide and protein carbonyl content increased in the crude homogenate of testis of hypothyroid rats. T3 administration to hypothyroid rats resulted in no further change in the hydrogen peroxide level but the protein carbonyl content further elevated in the crude homogenate of testis. No significant change was observed in the endogenous lipid peroxidation level of the crude homogenate of testis whereas the FeSO4/ascorbic acid induced lipid peroxidation level decreased in hypothyroid rats and did not change further by T3 administration. Although the reduced glutathione level in the crude homogenate of testis did not change following hypothyroidism, oxidized glutathione level increased. The reduced and oxidized glutathione level decreased and increased, respectively following T3 administration to hypothyroid rats in comparison with PTU-treated rats. Activities of superoxide dismutase and catalase decreased in the post-mitochondrial fraction (PMF) of testis of hypothyroid rats. T3 injection to PTU-treated rats resulted in an elevation in the level of catalase activity only. The activity of glutathione peroxidase in the PMF of testis elevated in the hypothyroid rats and reduced following T3 treatment to hypothyroid rats. The results of the present study suggest that any alteration in the thyroid hormone level in the body affects the antioxidant defence system of testis of adult rats and, thereby, may affect the physiology of testis through oxidative stress.     

硫化氢与阴茎勃起功能关系研究进展

硫化氢(H2S)是继NO和CO之后第3种被发现的具有内源性活性的气体信号分子,在哺乳动物体内H2S主要由两种蛋白酶———胱硫醚-β-合酶(CBS)和胱硫醚-γ-裂合酶(CSE)合成产生。H2S在体内具有重要的生理调节功能,它可作用于ATP敏感性钾离子通道(K+-ATP)舒张血管平滑肌,与睾酮及NO协同作用舒张阴茎海绵体平滑肌,促进阴茎勃起等。目前,治疗勃起功能障碍(ED)主要应用选择性的5-型磷酸二酯酶(PDE5)抑制剂,而临床发现PDE5抑制剂对部分ED患者治疗无效,因此,进一步研究H2S在阴茎勃起过程中的调节机制及作用,可能为ED提供了新的治疗途径。     

The effects of androgen on penile reflex, erectile response to electrical stimulation and penile NOS activity in the rat

Aim: To investigate the effects of androgen on penile erection through the reflex arc and penile corpus cavernosum,and study the respective roles of testosterone (T) and dihydrotestosterone (DHT) in penile erection ira rats. Methods:Male Sprague-Dawley rats were castrated and implanted with silastic brand silicone tube containing T or DHT, with orwithout daily injections of a 5a-reductase inhibitor, MKM-434. The penile reflex, erectile response to electrical stimula-tion (ES) of the cavernous nerves and penile nitric-oxide synthase (NOS) activity were observed under varying andro-genic status. Results: Penile reflex erection in the rat was, on the whole, related to serum T levels though the numberof glans engorgernents was not. The number of cups and flips was significantly decreased by castration, and restoredto the control level by T supplementation. Erectile response to ES and NOS activity in penile tissue was also related toserum T level. T administered together with a ,5a-reductase inhibitor no longer restored the number of reflex erection,erectile responses to ES and NOS activity in the corpus cavemosum. Conclusion: Androgen influenced the penile re-flex arc, corpus cavemosum, and the perinea] striated muscles, ha reflex erection, erectile response to ES and penileNOS activity in the rat, T seeras to be first conyerted to DHT, the more active androgen modality. (Asian JAndrol1999Dec; 1: 169-174)     

不同月龄大鼠勃起功能状况的实验研究

目的:探讨不同月龄组大鼠勃起功能的变化规律,为建立增龄性大鼠ED模型提供动物实验依据。方法:80只雄性Wistar大鼠,分为3、6、12和18月龄组,分别灌胃枸橼酸西地那非进行阴茎勃起功能实验;20只3月龄雌性Wistar大鼠,随机分为4组,建立发情雌鼠模型,观察不同月龄雄鼠的勃起状况与勃起次数。结果:3、6、12和18月龄组Wistar大鼠勃起率及勃起次数分别为85%、75%、40%、30%及(2.27±0.80)、(2.00±0.61)、(1.40±0.51)、(1.29±0.49)次,不同月龄勃起率与勃起次数比较,差异有统计学意义(P<0.05),且随着月龄的增加,各组大鼠勃起功能有降低的趋势。分别将6、12、18月龄组的勃起率及勃起次数与3月龄组大鼠做两两比较,发现6月龄组与12月龄组较3月龄组的差异无统计学意义(P>0.05);18月龄组较3月龄组有明显降低,且差异有显著性(P<0.05)。结论:衰老是大鼠发生ED的主要危险因素,18月龄大鼠已具备建立增龄性大鼠ED模型的条件。     

Effects of hypothyroidism on bronchial reactivity in non-asthmatic subjects.

The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms). The dose producing a 35% decrease in sGaw (PD35) was determined from the cumulative log dose-response curve by linear regression analysis. Mean baseline sGaw values were similar when the patients were hypothyroid and when they were hyperthyroid (1.35 (0.36) and 1.41 (0.56) s-1 kPa-1). The interstudy coefficients of variation of baseline sGaw were higher in the thyroid patients than in a euthyroid control group (14% versus 8%). Geometric mean PD35 was lower when the patients were hypothyroid (97 micrograms) than when they were mildly hyperthyroid (192 micrograms). It is concluded that acute hypothyroidism increases non-specific bronchial reactivity in nonasthmatic subjects.