小鼠颌下腺的交感神经支配的性差异

成年小鼠颌下腺的交感神经支配有显著的性差异:雄性小鼠颌下腺内的肾上腺能神经末梢基丛的荧光素较雌性小鼠的粗而明亮。用生化方法测定的颌下腺去甲肾上腺素含量,以整个腺体计,在雄性小鼠为225.39毫微克,在雌性小鼠为111.05毫微克;以每克腺体计,雄性为4.18微克,雌性为2.91微克。但成年小鼠虹膜内和幼年小鼠颌下腺内去甲肾上腺素含量无性差异。 多次注射丙酸睾酮后,雌性成年小鼠的颌下腺内去甲肾上腺素含量上升到同年龄的雄性小鼠的水平;多次注射异丙基肾上腺素后,雄性小鼠腺体内的去甲肾上腺素总量不变。 成年雄性小鼠的颌下腺内有较丰富的交感神经末梢,显然与成年雄性小鼠的颌下腺有高度分化的卷曲小管,产生大量的神经生长因子(NGF)有关。由于虹膜的去甲肾上腺素含量没有性差异,颌下腺NGF的作用途径看来是通过神经末梢摄取,经轴突逆向运输到达细胞体,而不是通过血液循环。     

切断颈上神经节的节前或节后神经对小鼠颌下腺蛋白代谢的影响

神经生长因子(NGF)的发现,推进了交感神经元和它们的靶器官之间的营养性关系的研究。最近,我们实验室观察到颌下腺的内源性NGF对支配腺体的交感神经元具有逆向的营养性影响。然而,支配颌下腺的交感神经元是否也对它的效应器官行使正向的营养性影响? 本工作比较切断颈上神经节(SCG)的节前和节后神经对小鼠颌下腺可溶性蛋白的~3H-亮氨酸参入的影响,试图观察交感神经元的非递质因子对颌下腺蛋白质代谢的效应。实验结果表明这种正向影响的存在。 实验选用年龄为2月左右的ICR/JCL品系雄性小白鼠,于双简立体显微镜下沿右侧颈动脉上行找到SCG及其节前神经,摘除SCG(去节后)或切断节前神经(去节前)或将SCG自身移植于同侧的颌     

小鼠颌下腺内交感神经末梢变性时程的性差异

外源性神经生长因子(NGF)对周边交感系统的营养性影响已有广泛的研究(Black,1978;Purves等,1978)。但是,内源性NGF是否同样行使这种影响,至今还没有被人证实(Nja等,1978)。1979年,Carstairs等人利用丙酸睾酮慢性处理,提高小鼠颌下腺内NGF含量以后,观察到颈上神经节(SCG)中有部分神经元肥大,但其它交感神经节不受影响。作者认为SCG内肥大的神经元就是支配颌下腺的那部分交感神经元。由于雄性小鼠颌下腺内的NGF含量是雌性小鼠的92倍(Hirata等,1979),我们实验室直接检查了小鼠颌下腺和虹膜的交感神经支配,发现成年雄性小鼠颌下腺的荧光基丛索远较雌性小鼠的     

神经节苷脂对6-OHDA损毁交感神经末梢的对抗作用

单次6-OHDA (15mg/kg.i.p.)注射后24h,可使雌性成年小鼠颌下腺内儿茶酚胺荧光神经末梢几乎完全消失;同时用 HPLC 测得腺体内去甲肾上腺素(NA)和多巴胺(DA)的含量下降至正常值的3—4%以下。随着受损交感神经末梢再生过程,NA 和 DA 水平有缓慢的恢复。在损毁2周时 NA 和 DA 含量分别达到正常水平的50%和28%,且在4周时完全恢复。在注射6-OHDA 的同时,和在损伤后12h 内给动物注射4次神经节苷脂(每次50mg/kg.i.p.)并在其后的一周內每天注射一次,可使颌下腺内 NA 含量维持在正常水平;在损毁后4h 及损毁前4d 开始施用神经节苷脂,也可不同程度地对抗交感神经末梢损伤,但作用强度不如前者。实验结果提示:(1)神经节苷脂通过减弱6-OHDA 及其代谢产物的损伤效应能够保护交感神经末梢膜,它可能还有促损伤末梢再生性长芽的作用;(2)损伤后神经节苷脂处理得越早,其效果越好。     

去交感后小鼠颌下腺总蛋白量变化时程的性差异

1.去交感后,成年小鼠颌下腺的总蛋白量的变化时程有显著的性差异:雌性小鼠在去交感后第6小时,腺体总蛋白量超过对照侧(P<0.001),此时雄性两侧腺体无明显区别(P>0.5)。但是,在去交感6小时以后,与雌性小鼠相比,雄性小鼠手术侧腺体的总蛋白量下降的幅度较大,下降所持续的时间较长。2.经丙酸睾酮慢性处理的成年雌性小鼠,去交感引起的颌下腺总蛋白量下降的时程类似于雄性小鼠。但是,去神经后6小时内出现的腺体总蛋白量升高不因雄激素处理而消失。3.去交感后,小鼠颌下腺总蛋白量的丧失不是由于蛋白合成速率的降低,而是由于腺体变性分泌的结果。4.小鼠颌下腺内卷曲小管细胞的蛋白分泌是受交感神经影响的。     

小鼠颌下腺粗提物中神经生长因子活力的测定

神经生长因子(Nerve Growth Factor,简称 NGF)系1951年 Levi-Montalcini 发现。大量的体内外实验证明,它对交感神经细胞和感觉神经细胞有促进成熟与分化的作用。NGF 广泛存在于动物体内,以成年雄性小鼠颌下腺中含量最高,其次是豚鼠前列腺和蛇毒中。它为一蛋白质,分子量130000,通常称为7S NGF,由5个亚基组成,只有β亚基具有促进神经生长的特性。用不同方法提取,可     

性别及日龄对转人神经生长因子基因小鼠唾液中蛋白分泌的影响

神经生长因子(Nerve growth factor,NGF)是一种能促进神经元发育、分化、再生的蛋白。为高效生产药效更佳的人源NGF (hNGF)药物,最近,笔者实验室构建出唾液腺特异表达hNGF的转基因小鼠,并从该转基因小鼠唾液中纯化获得具有高生物学活性的h NGF蛋白。为了选择性别和日龄最适宜的转hNGF基因小鼠用于收集纯化hNGF蛋白,文中比较了28日龄(性成熟前)雄性、雌性,63日龄(性成熟后)雄性、雌性转hNGF基因小鼠,共4组转hNGF基因小鼠分泌的唾液量、唾液总蛋白量、唾液鼠源NGF (mNGF)蛋白量和唾液h NGF蛋白量等指标。结果显示,63日龄的转hNGF基因小鼠分泌的唾液量、唾液总蛋白量、唾液mNGF蛋白量和唾液hNGF蛋白量显著高于28日龄同一性别的转hNGF基因小鼠,且63日龄的雄性转hNGF基因小鼠分泌的唾液hNGF蛋白量显著高于同一日龄的雌性转hNGF基因小鼠;在4组小鼠中,63日龄的雄性转hNGF基因小鼠分泌的唾液hNGF含量最高,比28日龄雌性转hNGF基因小鼠高出约46倍,最适宜用于收集唾液并从中纯化hNGF。     

层粘连蛋白、纤粘连蛋白及Ⅳ型胶原抗血清对小鼠胚泡着床的影响

文中报道了子宫角单次注射层粘连蛋白（ＬＮ）抗血清、纤粘连蛋白（ＦＮ）抗血清以及Ⅳ型胶原（ＣｏｌⅣ）抗血清对小鼠胚胎植入的作用。选用６０只３０ｇ左右的昆明品系雌性成年小鼠,与有生殖能力的雄性小鼠按１：１合笼,翌晨检查外阴,以出现阴栓为妊娠第１天。于妊娠第３天下午,给每个雌性小鼠 侧子宫角单次注射５μｌ ＬＮ抗血清ＮＦ抗血清或Ｃｏｌ Ⅳ抗血清作为实验组;给同一小鼠右侧子宫角注射５μｌ正常兔血清（Ｎｏｒ     

神经生长因子的研究

神经生长因子在雄性小鼠的颌下腺中含量最多,现已了解其分子结构。它对感觉神经与交感神经的生存、发育是必要的;在中枢神经系统(如海马等部位)也有较多的 NGF 和 NGFmRNA 存在,与胆碱能神经的功能关系密切。NGF 可抑制某些肿瘤细胞(如 PC12细胞)的有丝分裂;它还可能与促进脑的某些部位损伤、脊髓神经细胞损伤后的修复有关,并有促进创口愈合的作用。     

α-MMT及利血平对正常或苯乙肼化鼠脑去甲肾上腺素含量的影响

(一)注射α-MMT(50毫克/公斤)或利血平(1毫克/公斤),30分钟后大白鼠脑内NA 含量即明显下降,2小时到达最低水平,并维持于该水平24小时以上。两个药物都使大白鼠操作式条件反射受到抑制,但α-MMT 组条件反射恢复比 NA 含量的回升早得多。(二)单胺氧化酶抑制剂苯乙肼不能完全阻断利血平降低 NA 含量的作用,仅使之推迟,但可完全阻断α-MMT 的作用。苯乙肼处理的大白鼠,注α-MMT 后再给利血平,脑内 NA 含量仍下降,因此α-MMT 影响 NA 含量的机制和利血平是不同的。α-MMT 的翻转性兴奋较利血平更明显而恒定。     

肾上腺素能神经元在小鼠颌下腺内神经生长的性差异

利用移植技术,荧光组化与去甲肾上腺素的生化测定方法,在不同性別的成年小鼠颌下腺内,比较观察了颈上神经节的肾上腺素能神经纤维的生长。结果表明,神经生长因子含量较高的雄性腺体是神经纤维生长的较优越环境。     

Developmental changes of nerve growth factor levels in sympathetic ganglia and their target organs

The predominant source of nerve growth factor (NGF) used by mature sympathetic neurons originates in their target organs (Heumann, R., Korsching, S., Scott, J., and Thoenen, H. (1984), EMBO J. 3, 3183-3189; Korsching, S., and Thoenen, H. (1985), J. Neurosci. 5, 1058-1061). We have determined the NGF content of two sympathetically innervated mouse organs, submandibular gland and heart ventricle, and of sympathetic ganglia from mouse and rat between embryonic Day 12 (E12) and adulthood. NGF levels were measured by a two-site enzyme immunassay (Korsching, S., and Thoenen, H. (1983), Proc. Natl. Acad. Sci. USA 80, 3513-3516). In heart ventricle and submandibular gland, NGF first became detectable around the time of initial innervation by sympathetic neurons (E12 and E13, respectively) and increased respectively 14- and 7-fold in the following 2 days, to reach adult levels already at E14 for heart ventricle (1.4 +/- 0.2 ng NGF/g wet wt). NGF in the superior cervical ganglion (SCG) was first detected at the same time as in its target organ, the submandibular gland. NGF content in the SCG then increased 6-fold during the next 2 days and continued to increase until the end of the third postnatal week, when adult levels were reached. Although the levels of NGF in the adult mouse submandibular gland are sexually dimorphic and six orders of magnitude higher than those in other sympathetic target organs, no sex difference in the NGF content was found in either developing submandibular gland or SCG until the end of the third postnatal week. Moreover, the steep NGF increase observed in the male submandibular gland after postnatal Day 18 (250-fold within the following 3 days and up to the 55,000-fold in the next 7 days) was not reflected in a corresponding increase in the NGF content of the male SCG. These data indicate that, in accordance with earlier findings (see Levi-Montalcini, R., and Angeletti, P. U. (1968), Physiol. Rev. 48, 534-569), SCG neurons do not have access to the large amounts of NGF synthesized during and after adolescence in the mouse submandibular gland. Our results support the concept that initial fiber outgrowth of sympathetic neurons is neither dependent on NGF nor mediated by it. The time course of NGF levels in the SCG is consistent with the concept that sympathetic neurons are provided with NGF by means of retrograde axonal transport from the innervated organs already early in development.     

Immunocytochemical demonstration of nerve growth factor and histofluorescence of catecholaminergic nerves in the salivary glands of diabetic mice

Summary Nerve growth factor (NGF) was localized in the submandibular, sublingual, and parotid salivary glands of male and female diabetic mice and their normal littermates by immunoperoxidase staining usingp-phenylenediamine-pyrocatechol as a chromogen for the cytochemical demonstration of peroxidase activity. In the normal male submandibular gland, immunoreactive NGF was localized in the apical regions of granular, intercalated and collecting duct cells, while in the normal female submandibular gland, NGF was present throughout the cytoplasm of granular duct cells. The localization of NGF in the diabetic male and female submandibular glands was similar and resembled that of the normal female. NGF immunoreactivity was also observed in the striated duct cells in the sublingual and parotid glands of all four types of mice.The sympathetic innervation of the submandibular glands of normal and diabetic mice was demonstrated using glyoxylic acid-induced histofluorescence. The pattern of sympathetic innervation and the intensity of catecholamine fluorescence was consistently different in the four types of mice. In the normal male submandibular gland the fluorescence was very intense, particularly in nerves adjacent to the granular ducts. In the normal female submandibular gland, the fluorescence was weak, while in the diabetic male and female the fluorescence was moderate.The correlation between the intensity of the immunocytochemical staining for NGF and the catecholamine fluorescence adjacent to the granular ducts suggests a trophic influence of the NGF-containing granular ducts on their sympathetic innervation.     

Regulation of nerve growth factor synthesis in mouse submaxillary glands by testosterone.

—It has long been known that the activity of nerve growth factor (NGF) in extracts obtained from the male mouse submaxillary gland is higher than in extracts from the female gland, and that the activity present in female glands can be increased by testosterone treatment. This communication presents a study of the mechanism of the testosterone effect. Of several different steroids administered to female Swiss–Webster mice only testosterone propionate led to increased gland NGF activity. The increase did not appear to be due to an enhancement of the activity of pre-existing molecules on sympathetic nerve fiber outgrowth, or due to an altered affinity for the specific antibodies used in the estimation of NGF content, but appeared rather to be due to an accumulation of NFG molecules. The kinetics of change in the male gland NGF content upon castration and secondary testosterone propionate stimulation was analyzed by application of the plateau principle. The rate of loss of NGF from this organ was not measureably different between the castrate and testosterone propionate stimulated state. On the other hand, there was estimated to be a 10-fold difference in the rate of input between the basal and steroid stimulated state. Tracer amounts of radioiodine labelled NGF administered i.v. was not accumulated by the gland, and there is no evidence for uptake of this protein from the circulation. We, therefore, infer that the increased NGF concentration in male submaxillary glands is due to a 10-fold increase in the rate constant of synthesis.     

Mouse epidermal growth factor concentrations are altered by gonadectomy and treatments with estradiol and progesterone

In adult male and female mice we compared the epidermal growth factor (EGF) concentrations after gonadectomy and studied the effects of postgonadectomy treatments with estradiol and progesterone. In gonadectomized mice the mean concentration of EGF in the submandibular salivary gland (SMG) was (7-fold) higher in the females than the males. In the kidneys the males had (1.3-fold) higher levels of EGF than the females. Yet, gonadectomized males had higher plasma EGF levels and females higher urinary EGF concentrations. Estradiol treatment clearly decreased the EGF concentration in the SMG and increased it in urine and kidneys. Progesterone decreased male kidney EGF. Combined treatment with estradiol and progesterone increased the EGF concentration in the male urine and SMG, and decreased it in male kidneys.     

EFFECTS OF DEXAMETHASONE AND NERVE GROWTH FACTOR ON PHENYLETHANOLAMINE N-METHYLTRANSFERASE AND ADRENALINE IN ORGAN CULTURES OF NEWBORN RAT SUPERIOR CERVICAL GANGLION

Abstract— Phenylethanolamine N -methyltransferase (PNMT) and adrenaline (A) have been studied in organ cultures of neonatal rat sympathetic ganglia. Organ culture for 2 days without added nerve growth factor (NGF) caused a fall in noradrenaline (NA) and PNMT contents but there was no change in dopamine (DA) or A contents compared to controls. However, in the presence of dexamethasone, there was a marked increase in both PNMT activity and A content, but no change in NA or DA content. Addition of NGF to cultures stimulated with dexamethasone caused no further significant change in PNMT activity or A content, whereas both NA and DA were increased. Prolonged culture without NGF, in the presence of dexamethasone resulted in reductions in both NA and DA content, but the high levels of PNMT activity and A content were sustained. The results are consistent with the hypothesis that both PNMT and A are not contained in the noradrenergic cell bodies but are located chiefly within the small intensely fluorescent cells in sympathetic ganglia.