EFFECT OF PROLACTIN ON THE TADPOLE TAIL FIN. I. STIMULATORY EFFECT OF PROLACTIN ON THE COLLAGEN SYNTHESIS OF THE TADPOLE TAIL FIN

Bovine prolactin stimulated the growth of connective tissues both in the tail fins and in other regions of the tadpole tail. Correlated with the morphological effect of the hormone on the tadpole tails, protein synthesis in tail fins was promoted about 2 times by prolactin. Experiments performed to determine the kind of protein, the synthesis of which was stimulated by prolactin, revealed that the hormone specifically enhanced collagen synthesis about 40 folds as compared to untreated animals.     

EFFECT OF PROLACTIN ON THE TADPOLE TAIL FIN. III. EFFECT OF PROLACTIN ON THE HYDROXYLATION OF PROTOCOLLAGEN-PROLINE OF THE TAIL FIN

The fact that bovine prolactin stimulates the collagen synthesis of the tadpole tail fin was confirmed by the present experiments, in which specific radioactivity of ¹⁴C-hydroxyproline hydroxylated from the incorporated ¹⁴C-proline was measured by the method different from that of the previous report (Y oshizato and Y asumasu , 1970). Stimulatory effect of prolactin on the incorporation of ¹⁴C-proline into the collagen fraction did not disappear even under the conditions, where the activity of protocollagen-proline hydroxylase was inhibited by α,α'-dipyridyl. In fact prolactin had not a significant effect on the activity of the emzyme. It, therefore, is concluded that the hormone promotes the incorporation of ¹⁴C-proline into collagen without affecting the hydroxylation step of the protein synthesis.     

EFFECT OF PROLACTIN ON THE TADPOLE TAIL FIN. V. STIMULATORY EFFECT OF PROLACTIN ON THE INCORPORATION OF 3H-THYMIDINE INTO DNA OF THE TADPOLE TAIL FIN

DNA content of the tadpole tail fin was increased appreciably by the treatment of animals with bovine prolactin. Incorporation of ³H-thymidine into DNA in the hormone-treated tail fins was remarkably stimulated as compared to the control ones. From the experiment on the effect of prolactin on the DNase activity, it is concluded that prolactin not only stimulates the synthetic parthway, but also suppresses significantly the catabolic one of the DNA metabolism.     

EFFECT OF PROLACTIN ON THE TADPOLE TAIL FIN. IV. EFFECT OF PROLACTIN ON THE METABOLIC FATE OF HYALURONIC ACID, COLLAGEN AND RNA WITH A SPECIAL REFERENCE TO CATABOLIC PROCESS

In the case of hyaluronic acid and collagen, treatment of tadpoles with bovine prolactin produced remarkable increase in the content of the two metabolites in the tail fin in accord with the stimulatory effect of the hormone on the incorporation of labeled precursors into hyaluronic acid and collagen. RNA content of the tissue was increased appreciably by the prolactin treatment, whereas the hormone had no effect on the incorporation of ¹⁴C-uridine into RNA. Prolactin had inhibitory effect on the activities of hyaluronidase and RNase of the tail fin. The experiments on the protein catabolism also revealed that prolactin inhibited the process of protein turn-over in the tissue.     

EFFECTS OF THYROXINE AND PROLACTIN ON COLLAGEN BREAKDOWN IN THE THIGH BONE AND TAIL FIN OF THE RANA CATESBEIANA TADPOLE

Injection of ¹⁴C-proline into the tadpole causes labeling of protein in the collagen fraction of the thigh bone and tail fin. The radioactivity of the ¹⁴C-hydroxyproline residue is about 26% of the total radioactivity in the ¹⁴C-labeled protein of the collagen fraction in the thigh bone as well as in the tail fin. In ¹⁴C-proline-loaded tadpoles into which prolactin has been injected, the radioactivity in the collagen fraction in these tissues is markedly higher than that in control animals. In thyroxine-treated tadpoles, the ¹⁴C-radioactivity of the collagen fraction in the thigh bone is always higher than that of the controls, but it is markedly low in the tail fin. During the incubation of thigh bone and tail fin isolated from ¹⁴C-proline-loaded tadpoles, low molecular weight materials containing ¹⁴C-hydroxyproline are released from the ¹⁴C-labeled protein of these tissues. The rate of ¹⁴C-hydroxyproline release, which represents the rate of collagen breakdown, is higher in thigh bone and tail fin isolated from thyroxine-treated tadpoles and is markedly lower in these tissues isolated from prolactin-treated tadpoles than in those isolated from controls. In these tissues, the high rate of collagen breakdown in thyroxine-treated tadpoles is reduced by prolactin injection.     

EFFECTS OF THYROXINE AND PROLACTIN ON THE RATES OF PROTEIN SYNTHESIS IN THE THIGH BONES OF THE TADPOLE OF RANA CATESBEIANA

In thigh bones isolated from a Rana catesbeiana tadpole which has been kept in a 5 × 10⁻⁸ M thyroxine solution for several days, the rate of ¹⁴C-leucine incorporation into protein becomes higher than that in the thigh bones of control animals. Intraperitoneal injection of prolactin also results in an increase in the rate of ¹⁴C-leucine incorporation into protein in the thigh bones at a rate very similar to that in thyroxine-treated animals. In the thigh bones of the thyroxine-treated tadpoles, the rate of ¹⁴C-proline incorporation into protein is markedly higher than that of control animals. Prolactin treatment of the tadpoles also causes an increase in the rate of ¹⁴C-proline incorporation, but the rate is lower than that found in thyroxine-treated animals. The injection of prolactin into thyroxine-treated tadpoles fails to cause further increase in the rates of incorporation of these amino acids into protein. In the thigh bones of tadpoles at the climax of metamorphosis, prolactin injection does not cause any increase in the rates of ¹⁴C-labeled proline and leucine incorporation, whereas both rates become slightly higher in the thigh bones of thyroxine-treated tadpoles at this stage. The thigh bones probably become insensitive to prolactin when they are exposed to thyroxine.     

早泥盆世原始胴甲鱼类的胸鳍及躯甲之后的结构

记述了产自云南曲靖翠峰山早泥盆世无肢突型云南鱼类一新的属种——西屯副云南鱼（Ｐａｒａｙｕｎｎａｎｏｌｅｐｉｓｘｉｔｕｎｅｎｓｉｓ ｇｅｎ． ｅｔ ｓｐ． ｎｏｖ．）。化石保存相当完好,一件是头、胸、尾自然相连的个体,另一件保存了与躯甲相连的左胸鳍甲的腹壁和一件完整的左前背侧片。因而,对迄今知之甚少的早期原始无肢突型胴甲鱼类的胸鳍甲和尾柄有了具体了解。新属一般特征与云南鱼属（Ｙｕｎｎａｎｏｌｅｐｉｓ）和长瘤鱼属（Ｐｈｙｍｏｌｅｐｉｓ）最为接近,不同之处在于鳞片厚、呈疣突状,彼此互不覆压,无尾鳍叶;鳍甲外侧缘高,内（中）缘低,由５列纵向鳍列、每列不少于１０块菱形小鳍片组成。此外,对同层另一类早期具有原始肢突的曲靖鱼（Ｃｈｕｃｈｉｎｏｌｅｐｉｓ）的胸鳍甲着生方位和鳍甲与肩带间的关接方式也进行了讨论。     

人参茎叶皂甙对大鼠垂体催乳素分泌的影响及其机制的探讨

本实验观察了人参茎叶皂甙(GSLS)对雄性大鼠血浆催乳素水平、垂体催乳素细胞超微结构和下丘脑中枢神经递质的影响。结果表明:5～100mg/kg的GSLS可刺激催乳素的释放,剂量加大反而无效;GSLS还可拮抗急性饥饿所致的大鼠垂体催乳素细胞超微结构的损伤;GSLS能分别使大鼠下丘脑中多巴胺和5-羟色胺含量增高和降低。结果表明,GSLS有刺激垂体催乳素分泌的作用,其机制可能与其直接作用于垂体细胞和/或经下丘脑中多巴胺和5-羟色胺含量的变化有关。     

冷冻液温和季节对鼠尾过冷点的影响

为研究动物对寒冷的适应性,将鼠尾置于冷液浸冻,发现在一定条件下鼠尾组织可发生过冷现象。实验表明,鼠尾组织的过冷点和冷冻液温有关,同一季节冷冻液温越低过冷点越高;而不同季节相同冷冻条件下,冬季鼠尾组织的过冷点明显低于春季。 动物肢体组织的过冷特性是动物的抗寒冷特性,它和组织自身的物理化学性质有关。理沦证明,过冷度(△T)和表面张力(O)、摩尔质量(M),冰点(Ti)、密度(p)、摩尔凝固热(△H)及冰胚临界半径(rk)有关,其关系式为△T=26MTi/p△Hrk.     

几种农药对黑斑蛙胚胎及蝌蚪的毒性

本文报道了常用的几种农药对黑斑蛙胚胎及蝌蚪发育的毒性影响。结果表明：农药对黑斑蛙胚胎、蝌蚪期的毒性大小依次为使它隆＞多效唑＞多菌灵＞异丙隆＞甲胺磷。胚胎期死亡时表现为胚体腐烂;蝌蚪期死亡时则表现为头部膨大,虱部缩小,弯曲。畸形在两个时期都表现为腹部膨大呈透明状和尾部弯曲。     

几种农药对黑斑蛙黑斑蛙胚胎及蝌蚪的毒性

本文报道了常用的几种农药对黑斑蛙胚胎及蝌蚪发育的毒性影响。结果表明 :农药对黑斑蛙胚胎、蝌蚪期的毒性大小依次为使它隆 >多效唑 >多菌灵 >异丙隆 >甲胺磷。胚胎期死亡时表现为胚体腐烂 ;蝌蚪期死亡时则表现为头部膨大 ,尾部缩小 ,弯曲。畸形在两个时期都表现为腹部膨大呈透明状和尾部弯曲     

TISSUE DEGRADATION PATTERNS OF AMPHIBIAN TADPOLE TAIL: HISTOLOGICAL AND BIOCHEMICAL STUDIES

The pattern of tissue degradation in the tadpole tail of the bullfrog, Rana catesbeiana , was studied histologically and biochemically. Tadpoles at four metamorphic stages (premetamorphic stage, stage XIII; prometamorphic stage, stage XVIII; early to middle climax stage, stage XXII; late climax stage, stage XXIII) were examined. In the histological study, tissues were stained by two different methods, i.e., Masson's trichrome stain and Van Gieson's stain. The results are summarized as follows: 1) Muscle tissues degenerated earlier thatn connective tissues; 2) Collagen density increased as tissue degraded; 3) At stage XXIII, degenerating and fragmented muscle tissues, surrounded by connective tissues, were seen, and 4) At the late climax stage, cell density was greatly increased as compared to preceding stages.
The biochemical studies are summarized as follows; 1) The general catabolic pattern of tail proteins seems to differ between the premetamorphic and late climax stages; 2) The total hydroxyproline content per unit wet weight of the tail increased significantly at the late climax stage as compared to the premetamorphic stage, supporting the histological observations, and 3) Collagen degradation products were obtained at the late climax stage on Sephadex G-75 columns.     

INHIBITION OF THYROXINE-INDUCED RESORPTION OF TADPOLE TAIL BY ADENOSINE 3', 5'-CYCLIC MONOPHOSPHATE

Small segments of tail of Bufo bufo japonicus tadpoles were cultured in medium containing thyroxine (T₄) and dibutyryl cyclic AMP (dbcAMP). Like prolactin, the cyclic nucleotide blocked T₄-induced shrinkage or tail pieces. Histological study of the segments after 4-days culture revealed that dbcAMP suppressed degenerative changes induced by T₄. The inhibitory effect of prolactin on T₄-induced tail regression was promoted by caffeine, an inhibitor of adenosine 3', 5'-cyclic monophosphate (cyclic AMP)-phosphodiesterase.
The effect of prolactin on the level of cyclic AMP in the tail was also studied in vivo . Sixty min after prolactin injection, the cyclic AMP level was 2–3 times the control value. Possible involvement of cyclic AMP in the action of prolactin, which blocks tail resorption induced by T₄, was discussed.     

催乳素对培养的绵羊睾丸间质细胞睾酮分泌的影响

在绵羊睾丸间质细胞体外无血清长期培养的条件下,研究了催乳素对睾丸间质细胞睾酮分泌的调节作用。实验结果表明,催乳素可增强细胞对人绒毛膜促性腺激素(hCG)刺激的反应。催乳素的这种作用呈双相调节。睾酮分泌量显著高于hCG和催乳素单独作用时的总和。在hCG存在下,不同的底物转化为睾酮的量不同。其中雄烯二酮和孕酮转化为睾酮的方式存在着双相性。脱氢表雄酮转为睾酮的量少,不存在双相性,而与其剂量成正比。催乳素在hCG存在下可调节底物转化为睾酮。低剂量的催乳素(1ng/ml)可使一定剂量的孕酮(10～30ng/ml)转化为睾酮的量明显增加,而高剂量的催乳素(>10ng/ml)却明显地抑制孕酮转化为睾酮。催乳素可明显地抑制雄烯二酮转化为睾酮,与剂量无关。可见催乳素对于孕酮和雄烯二酮这两个关键底物转化为睾酮的调节是不同的。催乳素增强hCG刺激睾酮分泌的作用可能部分是通过其促进孕酮转化为睾酮来实现的。     

污水和污水土地处理系统中各种水质对华西蟾蜍蝌蚪红细胞微核率的影响

本文使用蝌蚪红细胞微核率作为指示器研究明通河污水和用污水土地处理系统处理后水质的致突变性。蝌蚪在各种水样品中暴露7天。采心脏血制片。在对照组中,微核率分别为4.40‰和4.68‰。1/4明通河污水组诱发蝌蚪的微核率是17.01‰。同对照组相比有明显的差异。     

促乳素对促性腺激素诱导小鼠卵巢雌激素和孕酮形成的影响

给幼龄小鼠（２１－２３日龄）注射８ＩＵＰＭＳＧ促滤泡生长。４８ｈ后给一组动物只注射８ＩＵｈＣＧ,另一组注射８ＩＵｈＣＧ加１００μｇ促乳素（ＰＲＬ）。３,１２和２４ｈ后杀死动物,取血和卵巢,从后者分离颗粒细胞（ＧＣ）作离体培养。测定血清和培液中雌激素和孕激素含量表明,ＰＲＬ显著增强ｈＣＧ所致血中孕酮含量上升,但抑制ｈＣＧ所致雌激素的产生;对ＧＣ离体培养的测定结果也完全相同,上述结果表明,ＰＲＬ抑制Ｈ     

催乳素对大鼠前列腺细胞合成酸性磷酸酶的作用及其机制的研究

本文利用无血清培养的末成年大鼠前列腺上皮细胞模型研究了催乳素(PRL)和性激素对前列腺细胞分泌前列腺特异的酸性磷酸酶(PAP)功能的作用,并对其作用途径进行了探讨。结果表明:PRL 显著促进前列腺细胞PAP的合成和分泌,但与双氢睾酮(DHT)或雌二醇(E_2)无协同作用,单独的DHT 或E_2对PAP 的合成和分泌也无显著作用。在PRL 的作用过程中,腺苷酸环化酶未活化;PRL 和前列腺素E_2或F_(2α)有协同作用,消炎痛能阻断PRL 的作用。综合实验结果,本实验证明了PRL 对前列腺细胞的分泌功能有直接的刺激作用,在PRL 的作用过程中,可能有前列腺素的参与。     

竹笋脚料综合利用的研究

竹笋经加工成罐头后,有40％～45％脚料被丢弃。本文报道根据生物化学离子效应,对其脚料进行处理并生产酶制剂、食用蛋白、纸张、食用菌等多级产品,使原材料达到充分利用,减少环境污染,降低生产成本,提高经济效益。     

REMARKS ON THE VERTEBRAL COLUMN AND CAUDAL FIN OF ACANTHODIAN FISHES

The vertebral column and caudal fin are described from species of Acanthodes. Less-specialized acanthodians are briefly noted and shown to resemble Acanthodes spp. closely in these structures. The anterior extent of the notochord and the nature of acanthodian fin-rays are also considered. The phylogenetic significance of all these structures is discussed, and acanthodians are found to resemble the early members of other groups of gnathostome fishes mainly in primitive characters.     

甲壳胺影响变形链球菌粘附力的研究

目的：研究甲壳胺对变形链球菌的附着力的影响。方法：通过变链菌粘附实验和细菌平皿计数法,观察变链菌在有或无甲壳胺的培养基中的粘附和生长情况,结果：1．甲壳胺对变链菌的附着有抑制作用。2．甲壳胺能使已附着的变链菌脱落。0．5％浓度的甲壳胺作用强于0．25％。3．甲壳胺对变链菌的生长数量及形态无影响。结论：甲壳胺的防龋性是由于它减弱了变链菌的粘附力,而不是通过减少变链菌的数量来实现的。