普伐他汀干预激素性股骨头坏死兔模型的组织学变化：大体和光镜下比较和印证

背景：研究表明普伐他汀可通过上调内源性骨形成蛋白2、核心结合因子α1和血管内皮生长因子等基因的表达从而产生促进激素性股骨头坏死兔模型坏死股骨头修复的作用。 目的：验证性观察普伐他汀干预激素性股骨头坏死兔模型大体和光镜下的组织学改变,并进行相互比较和印证。 方法：将80只新西兰白兔按随机数字表法分为对照组18只,实验组62只。向实验组耳缘静脉注射大肠杆菌内毒素(10 μg/kg) 2次,注射间隔24 h。并于第2次注射大肠杆菌内毒素后,臀肌注射甲强龙(20 mg/kg)3次,注射间隔24 h,制备兔激素性股骨头缺血坏死模型。造模第5周,将造模成功的39只新西兰白兔以随机数字表法分配其中的36只至模型组和他汀组,每组18只。他汀组以普伐他汀(1.2 mg/kg)灌胃,1次/d;模型组和对照组以等体积的蒸馏水灌胃。造模后8,12,16周,取股骨头,分别进行大体和光镜观察。 结果与结论：大体观察及光镜观察显示模型组出现明显的骨坏死灶,骨髓腔内可见大量脂肪细胞增生;与模型组比较,他汀组骨细胞受损程度较轻,骨小梁密度较高,空骨陷窝比率较少,骨坏死面积和髓腔内脂肪细胞数量明显减少,骨坏死修复迹象明显。说明普伐他汀可有效促进早期激素性股骨头坏死兔模型坏死股骨头的修复。     

激素性兔股骨头坏死模型的建立

背景：激素的应用已经成为激素性股骨头缺血坏死发病的首要原因。 目的：拟应用马血清与皮质醇激素联合制备兔股骨头缺血性坏死早期模型,探讨激素性股骨头坏死的发病机制。 方法：新西兰大白兔随机分成3组。激素联合马血清组静脉注射马血清10 mL/kg,3周后再次注射马血清6 mL/kg,再2周后注射甲强龙45 mg/kg,1次/d,连续5 d。激素组注射甲强龙45 mg/kg,1次/d,连续5 d。正常对照组不做任何处理。于激素给予前及激素注射后1,3,7和14 d检测定血胆固醇、三酰甘油水平;于激素注射后第2、4、8周行股骨头MRI和组织病理学检测。 结果与结论：与对照组比较,激素联合马血清组和激素组大白兔血清三酰甘油和总胆固醇分别于激素注射后1 d 和3 d明显高于对照组(P < 0.01)。MRI检测结果显示,激素联合马血清组大白兔股骨头于激素注射后第4周出现坏死信号;激素组第8周出现坏死信号。组织学检测结果显示,激素联合马血清组大白兔于激素注射第4周时股骨头出现骨小梁部分变细、断裂,空骨陷窝增加;第8周骨小梁稀疏、破碎,脂肪细胞增大,空骨陷窝明显增大。激素组病理坏死程度各时段均较激素联合马血清组轻。结果表明,激素联合马血清方法可成功制备股骨头坏死早期模型。     

丹参骨髓腔内注射预防激素性股骨头坏死的可能性

背景：由于股骨头缺血性坏死的确切发病机制尚不清楚，其治疗方法尚不理想。 目的：观察丹参注射液骨髓腔内注射预防激素性股骨头缺血性坏死的可行性和机制。 设计、时间及地点：随机对照动物实验，细胞病理学观察，于2005-04/2007-05在遵义医学院完成。 材料：健康家兔30只，雌雄各半，6月龄,体质量（2.5±0.25）kg, 随机分为对照组、模型组、预防组，每组10只。丹参注射液。 方法：对照组臀肌注射生理盐水。模型组臀肌注射醋酸泼尼松龙,每次7.5 mg/kg，每周2次，共8周。预防组臀肌注射醋酸泼尼松龙制作糖皮质激素诱导激素性股骨头坏死动物模型，同时采用髂骨穿刺针在股骨第三转子尖下方0.3~0.5 cm处由外向内上方穿入后注入丹参注射液，每侧0.4 mL/kg，每周2次，共8周。 主要观察指标：观察3组家兔血脂、血钙磷、X射线、发射型计算机断层扫描及组织病理学指标的变化。 结果：模型组血清钙和钙磷乘积明显降低，X射线示股骨头密度不均，可见大小不一的囊状透亮区，部分骨小梁模糊不清，但股骨头保持完整，关节间隙正常；发射型计算机断层扫描显示股骨头在血流、血池相放射性分布稀疏，延迟相放射性异常浓聚；组织病理学观察显示，股骨头骨皮质变薄，骨小梁变细，结构紊乱，骨髓明显坏死和脂肪化，空骨陷窝率明显增多。预防组血清钙、血清钙磷乘积升高；X射线示除骨小梁略微不清外,股骨头形态和骨密度均接近正常；发射型计算机断层扫描显示动态与静态图像已接近正常兔核素放射性骨显像结果；组织病理学观察显示，骨小梁变细不明显，排列较规则，陷窝内骨细胞数量稍有减少，细胞核固缩边聚现象不严重，空骨陷窝数量较模型组明显减少。 结论：复方丹参注射液可通过改善血液流变学、降低空骨陷窝率而产生对股骨头缺血性坏死的预防作用。     

激素性股骨头缺血性坏死兔模型的构建☆

背景：成人股骨头缺血性坏死可导致股骨头塌陷和髋关节破坏，但其真正的病因和发病机制尚未完全明了。因此建立实验性动物模型是目前研究激素性股骨头缺血性坏死的重要手段之一。 目的：建立兔激素性股骨头缺血性坏死模型，探讨其可能的发病机制。 方法：将健康成年新西兰白兔以抽签法随机分成4组。对照组，注射生理盐水；激素组，注射甲基泼尼松龙3次；单次内毒素组，静脉注射大肠杆菌内毒素24 h后，立即注射甲基泼尼松龙3次；双次内毒素组，大肠杆菌内毒素注射24 h后重复给药1 次，随后注射甲基泼尼松龙3次。造模前及造模后行X射线片、MRI 检查及组织学检查、透射电镜观察，并计算空骨陷窝率。 结果与结论：造模第8周时激素组、单次内毒素组、双次内毒素组空骨陷窝率较对照组明显增高(P < 0.01)，并且双次内毒素组空骨陷窝率明显高于激素组和单次内毒素组(P < 0.01)。双次内毒素组较激素组及单次内毒素组股骨头出现坏死的时间更早、坏死的效果更显著，并且随着时间的推移股骨头坏死的效果越来越明显。说明在相同的实验条件下，实施双次内毒素与激素联合诱发股骨头坏死出现最早、坏死效果最明显，且骨陷窝空虚率随时间的延长而增加。 关键词：股骨头缺血性坏死；甲基泼尼松龙；激素；内毒素；动物模型；骨陷窝     

激素性股骨头坏死早期细胞凋亡相关基因表达及阿仑磷酸钠的干预

背景：近年研究发现激素性股骨头坏死病例中凋亡的骨细胞增多，因此认为激素性股骨头坏死是骨细胞凋亡所致，而并非缺血性坏死。 目的：观察大鼠激素性股骨头坏死早期bcl-2、半胱氨酸天冬氨酸蛋白酶3(cysteinyl aspartate specific protease 3，caspase-3)的表达，以及阿仑磷酸钠的干预效果。 设计、时间及地点：随机对照动物实验，于2006-03/2007-02在吉林大学基础医学院病理实验室完成。 材料：健康Wister大鼠100只，随机分为正常对照组、激素模型组、藻酸双酯钠组、阿仑磷酸钠组、联合用药组，20只/组。藻酸双酯钠片为吉林东丰制药厂产品，阿仑磷酸钠为杭州默沙东制药有限公司产品。 方法：除正常对照组外，其余4组大鼠均给予醋酸泼尼松龙臀肌注射建立激素性股骨头坏死模型。藻酸双酯钠组、阿仑磷酸钠组分别灌服对应药物，联合用药组灌服藻酸双酯钠+阿仑磷酸钠。各组肌注用药1次/周，灌服药1次/d，实验持续6周。所有大鼠均强迫间断站立，4 h/d。 主要观察指标：光镜观察股骨头病理变化。S-P免疫组织化学染色法检测股骨头组织bcl-2、caspase-3的表达。 结果：给药第4周与正常对照组比较，激素模型组股骨头坏死现象明显，骨小梁变细甚至断裂，空骨陷窝数量明显增多(t=2.629，P < 0.01)；藻酸双酯钠组骨小梁和空骨陷窝数量介于前2组之间(t=1.713，P < 0.01)；阿仑磷酸钠组、联合用药组骨小梁和空骨陷窝数量接近正常对照组(t=1.462，t=1.657，P > 0.05)。与激素模型组比较，藻酸双酯钠组、阿仑磷酸钠组、联合用药组股骨头组织bcl-2阳性细胞率均明显升高(t=2.146，P < 0.05；t=2.815，P < 0.01；t=2.947，P < 0.01)，caspase-3阳性细胞率均明显降低(t=2.97，P < 0.01；t=2.462，P < 0.01；t=1.854，P < 0.05)，其中阿仑磷酸钠组及联合用药组升高尤为明显(t=2.503，t=1.959，P < 0.05)。 结论：大剂量激素可能通过抑制bcl-2表达和促进caspase-3表达引起股骨头坏死。阿仑磷酸钠可能通过与其相反的途径来防止骨细胞凋亡，从而预防早期激素性股骨头坏死。     

普伐他汀修复激素性股骨头坏死兔模型的超微结构评价

背景：研究表明普伐他汀可通过上调内源性骨形成蛋白2、核心结合因子α1和血管内皮生长因子等基因的表达从而产生促进激素性股骨头坏死兔模型坏死股骨头修复的作用。 目的：验证性观察普伐他汀干预激素性股骨头坏死兔模型的超微结构改变。 方法：将80只新西兰白兔按随机数字表法分为对照组18只,实验组62只。实验组制备兔激素性股骨头缺血坏死模型。造模第5周,以随机数字表法分配36只模型兔至模型组和他汀组,每组18只。他汀组以普伐他汀(1.2 mg/kg)1次/d灌胃,模型组和对照组以等体积的蒸馏水灌胃。造模后8,12,16周,截取股骨头行透射电镜观察。 结果与结论：透射电镜观察显示模型组骨细胞变性坏死严重,大部分骨陷窝内骨细胞消失,残存的骨细胞内脂肪沉积增多;与模型组比较,他汀组骨细胞受损程度较轻,形态基本正常,胞浆内脂肪沉积少。说明普伐他汀可有效促进早期激素性股骨头坏死兔模型坏死股骨头的修复。     

骨髓间充质干细胞联合茶黄素治疗兔激素性股骨头坏死

背景：股骨头坏死形成机制中,脂代谢紊乱学说受到许多学者的重视。茶叶提取物茶黄素具有降脂作用,在骨髓间充质干细胞培养中可抑制激素诱导的成脂分化,加强其成骨能力。 目的：观察骨髓间充质干细胞联合茶黄素治疗激素性股骨头坏死的效果。 设计、时间及地点：随机对照动物实验,于2008-03/06在安徽医科大学实验中心完成。 材料：洁净级健康成年新西兰大白兔24只,随机分为4组：模型对照组、单纯减压组、细胞移植组、细胞联合茶黄素组,6只/组。实验所用茶黄素为茶黄素单体,纯度>60%,由上海嘉会生物科技有限公司生产,批号20040828。 方法：体外分离培养兔自体骨髓间充质干细胞,传至第3代后调整细胞密度为2×1010 L-1复合于3 cm×2 cm明胶海绵上,每块明胶海绵含细胞悬液60μL,在细胞培养箱中孵育4 h备用。各组兔均采用液氮冷冻法建立激素性股骨头坏死模型,自然复温后钻孔,模型对照组不作任何处理,单纯减压组植入明胶海绵,细胞移植组、细胞联合茶黄素组植入复合有兔自体骨髓间充质干细胞的明胶海绵,同时细胞联合茶黄素组每天分3次灌服茶黄素250 mg,直至处死。 主要观察指标：动物一般情况,髋部MRI扫描观察股骨头坏死区信号变化,以及股骨头标本组织学观察、扫描电镜观察结果。 结果：造模后8周,细胞移植组、细胞联合茶黄素组兔活动明显增加,走路姿势逐步好转。造模后4周,各组均未见明显坏死区信号改变;造模后8周,模型对照组坏死低信号区明显扩大,单纯减压组低信号区无明显变化,细胞移植组低信号区范围略微缩小,细胞联合茶黄素组低信号区明显缩小,骨密度信号接近正常。与其余3组比较,造模后4,8周细胞联合茶黄素组空骨陷窝阳性数均明显减少(P < 0.05)。扫描电镜下,造模后8周模型对照组骨小梁多处断裂塌陷,髓腔内有大量脂肪细胞堆积;单纯减压组部分骨小梁可见裂痕;细胞移植组骨小梁不致密;细胞联合茶黄素组骨小梁结构规整致密,成骨细胞多,骨细胞及基质胶原纤维正常,髓腔规则。 结论：茶黄素能促进骨髓间充质干细胞成骨,在髓芯减压并骨髓间充质干细胞移植的基础上灌服给予茶黄素治疗兔激素性股骨头坏死的效果较好。     

低剂量激素诱导股骨头缺血性坏死模型的建立

背景：激素性股骨头缺血性坏死的发病机制尚未明确。 目的：单纯应用低剂量激素作用于新西兰大白兔，建立激素性股骨头缺血性坏死模型并观察造模效果。 方法：将30只新西兰大白兔随机分为2组。实验组每周经臀肌注射4 mg/kg甲泼尼龙琥珀酸钠，对照组于相同时间点注射等量生理盐水。同时迫使动物直立进食、饮水，以增加股骨头的负重。 结果与结论：肌注甲泼尼龙琥珀酸钠后，白兔出现不同程度的精神萎靡、活动减少、体质量减轻等。给药4周后，兔血清总三酰甘油及低密度脂蛋白增高、高密度脂蛋白降低(P < 0.05)；血清碱性磷酸酶及总胆固醇分别在给药6，8周后明显增高 (P < 0.05)。苏木精-伊红染色显示；给药4周后，兔股骨头骨髓腔内脂肪细胞体积增大，数量增多；给药6周后，空骨陷窝率增大；给药8周后，骨小梁稀疏变细、结构紊乱，软骨区可见死骨形成及部分性坏死和软骨面塌陷。说明单纯注射低剂量激素可以复制出典型的激素性股骨头缺血性坏死模型。     

淫羊藿提取液对激素性股骨头坏死的作用

背景：研究表明中药淫羊藿可以改善激素性股骨头坏死的症状,但具体的作用机制尚未阐明。 目的：探讨淫羊藿提取液治疗激素性股骨头坏死的初步效果。 方法：清洁级SD成年雄性大鼠建立激素性股骨头坏死大鼠模型后,分别给予0.4,0.2 g/mL淫羊藿提取液或生理盐水干预,并设立未造模的空白对照组。干预8周后,检测各组大鼠血液三酰甘油、总胆固醇的变化情况,解剖出股骨头并切片光镜下观察骨密度变化情况,计算空骨陷窝比率,进行组间比较。 结果与结论：与空白对照组相比,模型组股骨头疏松,易于凿切,血脂升高,骨小梁变细、稀疏,空骨陷窝率增高,髓腔脂肪细胞增多;而淫羊藿高、低剂量组的上述病变情况有不同程度减低,以淫羊藿高剂量组病变程度最低。结果表明,淫羊藿提取液能够改善激素性股骨头坏死血流变因素,改善脂肪代谢紊乱,促进堆积脂肪代谢的作用;还能够促进体外成骨细胞增殖及分化成熟,抑制破骨细胞活性、促进股骨头骨再生,改变股骨头内环境向好的方向转变,防治激素引起的骨质疏松,为淫羊藿治疗激素性股骨头坏死提供了初步理论依据。     

早期激素性股骨头缺血性坏死模型的建立及半胱天冬酶3活性测定

背景：有研究表明骨细胞凋亡与激素性股骨头缺血性坏死的发病机制密切相关，而活化的半胱天冬酶3可作用于其他半胱天冬酶家族成员，使蛋白酶级联反应放大，最终导致细胞凋亡。但半胱天冬酶3参与的骨细胞凋亡与早期激素性股骨头缺血性坏死的相关研究则罕见报道。 目的：采用大剂量激素联合强迫兔直立负重的方法建立早期激素性股骨头缺血性坏死模型并测定骨细胞半胱天冬酶3活性。 方法：将4月龄新西兰大白兔随机分成模型组和对照组。模型组每周3次臀肌注射地塞米松，每日强迫兔直立1 h，对照组注射等量生理盐水。分别于3，6，9和12周处死动物，取其双侧股骨头，光镜及电镜下观察组织病理学改变，应用对-硝基酰苯胺比色法测定骨细胞半胱天冬酶3活性。 结果与结论：给药3周后，模型组光镜下可见脂肪细胞肥大和增多，骨髓间充质干细胞及造血干细胞数量相对减少；给药6周后，模型组空骨陷凹率均大于对照组(P < 0.05)；给药9周后，模型组出现骨小梁变细、断裂，电镜下见模型组部分骨细胞体积缩小，染色质浓集，核固缩和碎裂等凋亡特征。给药6周后，模型组骨细胞半胱天冬酶3活性高于对照组(P < 0.05)。实验以此推论采用大剂量激素联合强迫兔直立负重可以诱导建立早期激素性股骨头缺血性坏死模型，半胱天冬酶3参与的骨细胞凋亡可能与早期激素性股骨头缺血性坏死发病过程有关。     

Mechanisms of the suppression of the nociceptive reflex of the opening of the mouth during stimulation of the structures of the limbic brain

The comparative effectiveness of the inhibitory influence of tetanic stimulation of hypothalamus, amygdala and limbic cortex on EMG-response of m. digastricus evoked by electrical stimulation of tooth pulp nociceptive afferents was studied in cats anesthetized with a mixture of chloralose and nembutal. It was found that inhibition of the EMG-component of the jaw-opening reflex is most pronounced in case of stimulation of medial and lateral region of the hypothalamus, the inhibitory effect of central and medial nuclei of the amygdala is less pronounced and the effect of the limbic cortex is the weakest. It was shown that the mechanism of the antinociceptive effect of tetanic stimulation of the hypothalamus is not related to the concomitant increase of the blood pressure. After stabilization of the blood pressure the suppressive effect of the hypothalamus remains without changes, that points out to a direct, primary, not baro-afferent mechanism of the inhibition of the activity of nociceptive neurons of the trigeminal sensory nuclei. Noradrenaline, injected intravenously, induced a large increase of the blood pressure accompanied by a pronounced inhibition of the pain reflex. Angiotensin causes the same degree of blood pressure elevation without changes in the amplitude of the EMG-response of the pain reflex. Hypothalamic and noradrenergic mechanisms for control of pain sensitivity are discussed.     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Summary Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves.Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue, whose activity was revealed after-receptor blockade, had a similar threshold to the vasoconstrictor fibres.Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa.The preganglionic compound nerve action potential had four major components, S₁–S₄. S₁, S₂ and usually S₃ fibres were associated with membrane contraction; S₂, S₃ and sometimes S₁ fibres were associated with nasal vasoconstriction; and S₃, usually S₂ and occasionally S₁ fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S₄ fibres, may include fibres associated functionally with the three effectors.There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Development of the projection from the nucleus of the brachium of the inferior colliculus to the superior colliculus in the ferret

Neurons in the deeper layers of the superior colliculus (SC) have spatially tuned receptive fields that are arranged to form a map of auditory space. The spatial tuning of these neurons emerges gradually in an experience-dependent manner after the onset of hearing, but the relative contributions of peripheral and central factors in this process of maturation are unknown. We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection. The pattern of retrograde labeling produced by injections of fluorescent microspheres in the SC on postnatal day (P) 0 and just after the age of hearing onset (P29), showed that the nBIC-SC projection is topographically organized in the rostrocaudal axis, along which sound azimuth is represented, from birth. Injections of biotinylated dextran amine-fluorescein into the nBIC at different ages (P30, 60, and 90) labeled axons with numerous terminals and en passant boutons throughout the deeper layers of the SC. This labeling covered the entire mediolateral extent of the SC, but, in keeping with the pattern of retrograde labeling following microsphere injections in the SC, was more restricted rostrocaudally. No systematic changes were observed with age. The stability of the nBIC-SC projection over this period suggests that developmental changes in auditory spatial tuning involve other processes, rather than a gross refinement of the projection from the nBIC.     

Origins of the sympathetic innervation of the cervical end of the uterus in the rat

A retrograde neuronal tracer (Fast Blue) was injected in the cervical end of the uterine horn of virgin rats. The majority of the retrogradely labeled post-ganglionic sympathetic neurons were found in the sympathetic chain (74%). The superior mesenteric ganglia, inferior mesenteric ganglia and suprarenal ganglia accounted for 22, 3 and <1%, respectively. The distribution of neurons in the sympathetic chain labeled from the uterus resembles that described for other pelvic organs.     

Sexual pheromones and the evolution of the reward system of the brain: the chemosensory function of the amygdala

The amygdala of all tetrapod vertebrates receives direct projections from the main and accessory olfactory bulbs, and the strong similarities in the organization of these projections suggest that they have undergone a very conservative evolution. However, current ideas about the function of the amygdala do not pay sufficient attention to its chemosensory role, but only view it as the core of the emotional brain. In this study, we propose that both roles of the amygdala are intimately linked since the amygdala is actually involved in mediating emotional responses to chemical signals. The amygdala is the only structure in the brain receiving pheromonal information directly from the accessory olfactory bulbs and we have shown in mice that males emit sexual pheromones that are innately attractive for females. In fact, sexual pheromones can be used as unconditioned stimuli to induce a conditioned attraction to previously neutral odorants as well as a conditioned place preference. Therefore, sexual pheromones should be regarded as natural reinforcers. Behavioural and pharmacological studies (reviewed here) have shown that the females' innate preference for sexual pheromones is not affected by lesions of the dopaminergic cells of the ventral tegmental area, and that the systemic administration of dopamine antagonists do not alter neither the attraction nor the reinforcing effects of these pheromones. Anatomical studies have shown that the vomeronasal amygdala gives rise to important projections to the olfactory tubercle and the islands of Calleja, suggesting that these amygdalo-striatal pathways might be involved in the reinforcing value of sexual pheromones.     

Topographical organization of the motoneuron pools that innervate the muscles of the pinna of the cat

The topographical organization of the 22 motoneuron pools that innervate the pinna muscles of the cat was examined by injecting the B-subunit of cholera toxin conjugated to horseradish peroxidase into individual muscles. All 22 pools are found in the facial nucleus, organized as rostro-caudally oriented columns, and arranged according to the action of the muscles they innervate. Pools innervating muscles that pull the pinna dorsally are located in the dorsal two thirds of the medio-dorsal subdivision, and those innervating muscles that pull the pinna ventrally are located in the ventral one half of the nucleus. Motoneurons innervating muscles that pull the pinna cranially are located laterally, those that pull the pinna caudally are located medio-ventrally, and those that change the shape of the pinna are located along the entire dorso-ventral extent in the center of the medio-dorsal subdivision. This topographical layout is consistent with the somatotopic organization of the entire facial nucleus as demonstrated in a variety of species. © 1995 Wiley-Liss, Inc.     

Histochemical methods for the further characterisation of the tumourettes of the posterior lobe of the pituitary

Summary The granular cell tumourettes of the posterior lobe of the pituitary possess neuraminic acid containing carbohydrate. After removal of neuraminic acid with neuraminidase and exposure to FITC (Fluorescein isothiocyanate) labelled peanut agglutinin (Arachis hypogaea) (PNA), intracellular receptor structures could be demonstrated. The significance of the findings is discussed.