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1.
2.
NADPH2 and ATP competitively inhibit sweet potato glucose 6-phosphatedehydrogenase with NADP and glucose 6-phosphate (G6P), respectively.At pH 8.0, a Lineweaver-Burk plot of the reciprocal rate againstreciprocal G6P concentration was concave downwards in the presenceand absence of ATP, whereas a double reciprocal plot followedthe Michaelis-Menten relationship at pH 7.0, irrespective ofthe presence of ATP. Many of the other metabolic intermediatestested had no effects on the enzyme reaction.
1 This paper constitutes Part 96 of the Phytopathological Chemistryof Sweet Potato with Black Rot and Injury.
2 Present address: Institute of Applied Microbiology, Universityof Tokyo Bunkyo-ku, Tokyo 113. (Received October 20, 1971; ) 相似文献
3.
Manabu Sakakibara Carlos Collin Alan Kuzirian Daniel L. Alkon Eliahu Heldman Shigetaka Naito Izja Lederhendler 《Journal of neurochemistry》1987,48(2):405-416
Type B photoreceptors of the nudibranch mollusc Hermissenda crassicornis receive excitatory synaptic potentials (EPSPs) whose frequency is controlled by potential changes of a neighboring cell known as the S optic ganglion cell which is thought to be electrically coupled to the presynaptic source of these EPSPs, the E optic ganglion cell. The frequency of the EPSPs increases when a conditioned stimulus (light) is paired with an unconditioned stimulus (rotation) during acquisition of a Pavlovian conditioned response. The results of the present study are consistent with an adrenergic origin for these EPSPs. Noradrenergic agonists (greater than 100 microM), norepinephrine and clonidine, only slightly depolarize the type B cell but clearly prolong its depolarizing response to light. Serotonin, by contrast, causes hyperpolarization of the type B cell's resting potential as well as after a light step. Clonidine reduces voltage-dependent outward K+ currents (IA, an early current, ICa2+-K+, a late Ca2+-dependent current) that control the type B cell's excitability (and thus its light response and membrane potential). These effects of clonidine are reduced or blocked by the alpha 2-receptor antagonist, yohimbine (0.5 microM), but not the alpha 1-blocker, prazosin. The same yohimbine concentration also blocked depolarizing synaptic excitation of the type B cell in response to depolarization of a simultaneously impaled S optic ganglion cell. Histochemical techniques (both the glyoxylic acid method of de la Torre and Surgeon and the formaldehyde-induced fluorescence or Falck-Hillarp method) demonstrated the presence of a biogenic amine(s) within a single neuron in each optic ganglion as well as three or four cells within the vicinity of previously identified visual interneurons. No serotonergic neurons were found within the optic ganglion or in proximity to visual interneurons. A clonidine-like synaptic effect on type B cells, therefore, could amplify conditioning-specific changes of membrane currents by increasing type B depolarization and possibly, as well, by elevating intracellular second messengers. 相似文献
4.
Behavioral endocrinology of male rats with periodic sexual contacts with exclusive or varied females
G T Taylor D Komitowski S Muto J Weiss 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1989,192(3):236-241
Sexual contact keys a profound series of acute and chronic changes in males that, presumably, are orchestrated by acute pulsatile release of hormones. An experimental paradigm is reported in which male rats were paired periodically with either the same or different estrous females to receive identical amounts of copulatory experiences. Results confirmed the hypothesis that exposure to an unfamiliar female would induce a different endocrine response which would be reflected in various androgen-sensitive systems. The "successively polygynous" males showed more sexual behavior than "monogamous" males, and their respective females solicited the males differently, as well. Circulating levels of testosterone were higher immediately after sexual contact with an unfamiliar than with a familiar female partner. There were no differences in testosterone titers among the groups when the animals were killed at either 2 or 7 weeks after the final copulatory experiences. Yet, necropsies at 2 weeks postcopulation revealed that primary and secondary sex structures from polygynous males clearly were larger. Differences between the two experimental groups were reduced after 7 weeks of sexual rest, yet, polygnous males continued to show a different structural profile than the other groups. Conclusions were that males may experience greater activation of androgen-sensitive behavior and physiology following qualitatively different sexual contacts. 相似文献
5.
In the proximal end of the navicular fossa, the stratified columnar epithelium lining the spongy part of the urethra abruptly changes into the stratified squamous one, presenting a sharp demarcation. It is considered that the junction between these 2 epithelia corresponds to the former site of the junction of the entoderm and ectoderm. The width of the microridges in the distal part of the navicular fossa was about doubled compared to that in the proximal part. It is suggested that the epithelium in the distal part is keratinized, while that in the proximal part is nonkeratinized. 相似文献
6.
Takashi Ooba Hideyuki Hayashi Sachiko Karaki Manabu Tanabe Kyoichi Kano Masafumi Takiguchi 《Immunogenetics》1989,30(2):76-80
The primary structure ofHLA-B51 andHLA-Bw52 suggested thatHLA-B51 was derived fromHLA-Bw52 by the combination of a genetic exchange withHLA-B8 and a point mutation. To investigate the evolution of theHLA-B5 cross reactive group, theHLA-B35 gene was cloned and the primary structure was determined.HLA-B35 is identical toHLA-Bw58 except in the α1 domain. The α1 domain ofHLA-B35 except Bw4/Bw6-associated amino acids is identical to that ofHLA-B51
*, which was suspected to be an intermediate gene betweenHLA-B51 andHLA-Bw52. These data suggest thatHLA-B35 has evolved fromHLA-Bw58 in two steps; an in vivo replacement of the α1 domain withHLA-B51 and genetic exchange with one of theHLA-Bw6 genes. These three genes andHLA-Bw58 are postulated to share a common ancestor. 相似文献
7.
Yoshinao Nakagawa Manabu Totsuka Tomoaki Sato Yoshiro Fukuda Koichi Hirota 《European journal of applied physiology and occupational physiology》1989,59(3):239-242
We examined the influence exerted, through disuse of the hindlimb, on the collagen fibres of the achilles tendon in rats. With disuse the body mass decreased by 28%, and the mass of soleus muscle decreased by 20%. A decrease in the surface area and diameter was observed in the experimental group when compared to the control group. A histogram of the collagen fibres showed a decrease of the thick fibres in the experimental group. The maximum surface area of collagen fibres in the experimental group was seen to be only 43% of that of the control group. These results showed a decrease in the thickness of the collagen fibres of the achilles tendon through disuse. This seemed to suggest that resistance to tension is decreased by disuse. 相似文献
8.
9.
Yoshinori Nio MD Takahiro Shiraishi Michihiko Tsubono Hideki Morimoto Chen-Chiu Tseng Kazuya Kawabata Yoshikazu Masai Manabu Fukumoto Takayoshi Tobe 《Biotherapy》1992,4(2):81-86
The present study was designed to evaluate the effects of a recombinant human G-CSF (rhG-CSF) and a mutein G-CSF(KW-2228) on leucopenia and tumor growth in mice treated with 5-fluorouracil (5-FU). In normal mice, the number of leucocytes (white blood cell, WBC) reached the peak 12 hours after a single injection of either type of G-CSF and decreased to the normal level after 24 hours. Daily administration induced a continuous increase in the WBC count, however, administrations at intervals did not. Meth-A fibrosarcoma was subcutaneously inoculated into the backs of syngeneic BALB/c mice. The mice were treated with 5-FU alone or with G-CSFs. Chemotherapy with 5-FU alone resulted in leucopenia and an insignificant inhibition of tumor growth. The conjunctive administration of G-CSFs with 5-FU resulted in a significantly augmented inhibition of tumor growth, and leukopenia was not seen. This augmenting effect was more prominent with KW-2228.These results suggest that in 5-FU chemotherapy G-CSFs may be beneficial in restoring the number of leucocytes from leucopenic state and in augmenting the tumor inhibitory effect. Furthermore, KW-2228 may be more beneficial than the natural type rhG-CSF. 相似文献
10.
Solubilization and reconstitution of ca pump from corn leaf plasma membrane 总被引:1,自引:0,他引:1
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The Ca2+ transport system of corn (Zea mays) leaf plasma membrane is composed of Ca2+ pump and Ca2+/H+ antiporter driven by H+ gradient imposed by a H+ pump (M Kasai, S Muto [1990] J Membr Biol 114: 133-142). It is necessary for characterization of these Ca2+ transporters to establish the procedure for their solubilization, isolation, and reconstitution into liposomes. We attempted to solubilize and reconstitute the Ca2+ pump in the present study. A nonionic detergent octaethyleneglycol monododecyl ether (C12E8) was the most effective detergent for a series of extraction and functional reconstitution of the Ca2+ pump among seven detergents examined. This was judged from activities of ATP-dependent 45Ca2+ uptake into liposomes reconstituted with the respective detergent-extract of the plasma membrane by the detergent dilution method. C12E8-extract of the plasma membrane was subjected to high performance liquid chromatography using a DEAE anion exchange column. Ca2+-ATPase was separated from VO43−-sensitive Mg2+-ATPase. These ATPases were separately reconstituted into liposomes, and their ATP-dependent Ca2+ uptake was measured. The liposomes reconstituted with the Ca2+-ATPase, but not with the VO43−-sensitive Mg2+-ATPase, showed ATP-dependent Ca2+ uptake. Nigericin-induced pH gradient (acid inside) caused only a little Ca2+ uptake into liposomes reconstituted with the Ca2+-ATPase, suggesting that the Ca2+/H+ antiporter was not present in the preparation. These results indicate that the Ca2+-ATPase actually functions as Ca2+ pump in the corn leaf plasma membrane. 相似文献