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1.
Thyrotopin releasing hormone (TRH) produces “wet dog shakes” in rats similar to those observed during morphine withdrawal. The shaking behavior precipitated by morphine abstinence can be exacerbated by TRH administration while the other components of the morphine withdrawal syndrome remain unchanged. Morphine, chlorpromazine, apomorphine, and Δ9-tetrahydrocannabinol effectively block shakes induced by either TRH administration or morphine withdrawal. These results suggest the possibility that endogenous TRH may be associated with the “wet dog shakes” observed as a portion of morphine's abstinence syndrome in rats. However, TRH is unable to alter the stereospecific binding of morphine invivo or invitro, and naloxone fails to potentiate the number of TRH-induced shakes. TRH has no antinociceptive properties, and it cannot alter those of morphine. These data suggest that more than one neuromechanism may be responsible for shaking behavior in rats.  相似文献   

2.
1) Ambient temperature (Ta) significantly influenced the display of 4 of the 14 naloxone-precipitated withdrawal signs (nesting, flat posture, vocalization, dyspnea) in morphine-dependent, non-hibernating ground squirrels (Citelluslateralis).2) Analysis of variance performed on the six quantified signs revealed that Ta during withdrawal, but not during the development of physical dependence, was a significant factor in determining the expression of two signs (nesting and vocalization).3) The interaction between the influence of Ta during the periods of morphine administration and abstinence was a significant factor in determining the expression of nesting behavior, a finding that is consistent with the natural role of nesting as a behavioral thermoregulatory response.4) We conclude that environmental temperature modulates the expression of selected components of the naloxone-precipitated abstinence syndrome in C. lateralis without exerting a measurable influence on the development of morphine physical dependence itself.  相似文献   

3.
4.
Seven patients entering an alcoholic detoxification and treatment unit exhibited elevated levels of plasma high density lipoprotein cholesterol (HDLC) and enhanced metabolic disposal of antipyrine. Followig a 2-week abstinence treatment, the HDLC levels were reduced by 28% (from 64 to 47 mg/100 ml) and the t12 of antipyrine was extended from 12.4 to 13.7 hours. The extent of the HDLC reduction correlated with the antipyrine t12 changes (r = ?0.753, P = 0.05).  相似文献   

5.
The time at which dosage compensation of an X-linked gene in the mouse is established has been estimated by measuring the activity levels of two glycolytic enzymes, phosphoglycerate kinase (EC 2.7.2.3) and triosephosphate isomerase (EC 5.3.1.1), during early development of embryos from XX and XO mice. During preimplantation development the level of phosphoglycerate kinase in embryos from XX mice was constant for the first 48 hr of development (2.55–2.71 nmoles/hr/embryo) and then dropped to one-half the earlier level (1.44 nmoles/hr/embryo) by 72 hr of development. The general developmental profile of phosphoglycerate kinase was similar in embryos from XO mice; however, the absolute level of enzyme activity was reduced to approximately 1.4 nmoles/hr/embryo during the first 48 hr of development and to 0.9 nmoles/hr/embryo by 72 hr of development. These differences in phosphoglycerate kinase levels between embryos from XX and XO mice disappeared between the blastocyst and egg cylinder stages (150 hr postplug) during which time the activity levels had increased to 183 and 193 nmoles/hr/egg cylinder for embryos from XO and XX mice, respectively.The activity level for triosephosphate isomerase in embryos from XX and XO mothers did not differ at any stage of development; this suggests that the gene coding for triosephosphate isomerase is autosomal. In addition the level of activity remained constant during preimplantation development (approximately 3 nmoles/hr/embryo) and then, like phosphoglycerate kinase, increased 100-fold between the blastocyst and egg cylinder stages.The frequency distribution of the activity ratio (triosephosphate isomerase to phosphoglycerate kinase) in the egg cylinder of individual embryos from both XX and XO mothers was determined in order to detect differences among XX, XO and XY embryos. These frequency distributions were unimodal, and hence these results coupled with the gene dosage differences observed during preimplantation development indicate that dosage compensation for an X-linked gene has been established in the 6-day mouse embryo.  相似文献   

6.
Progesterone concentrations were determined by radioimmunoassay in the plasma of heifers of German Brown Swiss, Holstein-Friesian and White Fulani cattle during two consecutive estrous cycles in the dry and wet seasons in a tropical climate. Seasonal differences in the levels were not significant but peak levels were significantly higher in the Bostaurus than in the Bosindicus heifers. The low levels at estrus and the gradual rise five days after estrus were similar among the heifers. The levels on the 1st and 2nd days preceding estrus were significantly higher in the Bostaurus than in the Bosindicus heifers, and suggest a possible tendency for the former to be more susceptible to infertility arising from high progesterone levels 1 and 2 days preceding estrus and insemination. The genital tract and ovaries at the mature luteal phase were generally smaller in the Bosindicus than in the Bostaurus heifers.  相似文献   

7.
The courses of infection in inbred mouse strains were compared following infection with three Stabilates of high, intermediate, and low virulence of Trypanosoma vivax stock Zaria Y486. Mouse strains could only be shown to differ in their resistance to T. vivax infections as judged by the height of the initial parasitemia and survival times when a trypanosome population of low or intermediate virulence was used. A T. vivax population of high virulence was uniformly lethal. Comparison of lytic antibody titers between groups of resistant (C57B16) and susceptible (Balbc) mice did not show any significant differences in titers of the surviving mice but the mice in either group which did not control the initial parasitemia had lower lytic antibody titers than those which did. A significantly larger number of Balbc mice failed to control the initial infection as compared to the C57B16. Treatment with cyclophosphamide did not ablate differences in susceptibility between the two strains. The use of congenic mice showed that these differences in susceptibility were not related to differences in the major histocompatibility complex between these strains.  相似文献   

8.
Animal models make it possible to perform studies that normally can not be done in human beings. In the present work, the cellular response pattern of the lungs both to the environment and to a challenger strain of bacteria were analyzed in two mouse mutations-cribriform degeneration (cri) and motheaten (me)-. The mice were submitted to an infective aerosol containing Staphylococcus aureus and were killed either immediately or 4 h after exposure; pulmonary washings were performed in these animals as well as in non-infected controls. The results showed neither quantitative differences in the total cell count nor in cell viability between the different groups. However, there were qualitative changes in the differential cell content characterized by a neutrophilic response in cri/cri mice and a giant cell response in me/me mice. Since most of the cystic fibrosis patients suffer from chronic lung infection, with a persistently high proportion of neutrophils, these findings point to the cri/cri mouse as a promising animal model for cystic fibrosis studies.  相似文献   

9.
Male rats received Silastic implants of the aromatase inhibitor, 1,4,6-androstatriene-3, 17-dione (ATD), on days 2–10 of life. Controls received blank implants. There were no differences in the masculine sexual behavior of ATD and control males when they were tested as gonadally intact adults. In contrast, even without exogenous hormone treatment, nine of 14 ATD males exhibited lordosis behavior, whereas only one of 12 controls did so. In addition, during a sexual preference test in which access was provided to both a sexually receptive female and to a stud male, there was no difference in the proportions of ATD (1114) and control (712) males that copulated with the stimulus female; however, seven of the ATD males also exhibited feminine sexual behavior including some instances of solicitation. Only one of the control males showed any lordosis behavior. In general, all animals spent more time with the stimulus female than with the stud male. At the termination of preference testing, all animals were castrated and then tested twice for feminine sexual behavior under exogenous estradiol benzoate and progesterone. All of the ATD males showed lordosis behavior with a mean lordosis quotient (LQ) of 85; and 11 of the 14 also showed solicitation behavior. Only five of 12 control males exhibited lordosis (X?LQ = 59) and only one showed solicitation behavior. These results indicate that the propensity of males to show feminine sexual behavior can be manipulated independently of the capacity for masculine sexual behavior. Moreover, our results suggest that the process of defeminization may occur primarily postnatally in rats since treatment during that period results in substantial increments in later feminine sexual behavior including solicitation behaviors.  相似文献   

10.
Ultraviolet difference spectroscopy was used to study the interaction of peanut (Arachis hypogaea) lectin with complementary carbohydrates. A correlation was observed between variations of ultraviolet spectra during the binding of sugars to the lectin and the specificity and the strength of the binding. The association constant, free energy, enthalpy and entropy for peanut lectin-lactose interactions were calculated over the temperature range 10–30°C. The binding constants for 10 mono- and disaccharides containing a D-galactopyranosyl or a D-talopyranosyl residue were calculated. Comparing their effectiveness to interact with peanut lectin, methyl α-D-galactopyranoside appeared to have a more marked affinity than lactose; D-galacturonic acid and methyl 7-deoxy-D-glycero-β-D-galacto-heptopyranoside had no measurable affinity; the other sugars showed a lower affinity than lactose. The correlations between these differences and the conformations of the sugars obtained by X-ray analysis are discussed.  相似文献   

11.
Sulfated gastrins were quantitated in sera from 15 patients with the Zollinger-Ellison syndrome (ZES) by specific radioimmunoassays. The total concentration of gastrin varied from 174 to 285000 pmol/1. Sulfated gastrins constituted 44.8±5.5% (mean ± S.E.M.) of the gastrins in ZES sera compared with 37.7±1.9% in sera from 100 control subjects (P>0.1). There was no correlation between gastrin concentration and sulfation (r=0.40). Gel and ion-exchange chromatography showed that up to 90% of the gastrins could be in the sulfated form. The highest degree of sulfation was found in sera where the small gastrin components dominated. Thus, the percentage of small gastrins (G-17 and G-14) correlated with the degree of sulfation (N = 15, r=0.75, P<0.01). We suggest therefore that proteolytic processing of the gastrin precursor and sulfation of tyrosyl are associated.  相似文献   

12.
The mitochondrial phenotype of poky and other extra-nuclear Neurospora mutants is known to predominate over that of wild type in heteroplasms. This phenomenon was investigated in heterokaryons using normally occurring strain differences in restriction enzyme patterns to distinguish wild-type and poky mitochondrial DNAs. Each of ten independent heterokaryons eventually showed the poky phenotype as judged by slow growth rate and deficiency of 19 S RNA. Six heterokaryons contained mitochondrial DNAs with restriction enzyme patterns of the poky parent whereas four contained DNAs which lacked restriction enzyme fragments characteristic of the poky parent. The latter may be recombinants of wild-type and poky mitochondrial DNA.  相似文献   

13.
Rat hearts were perfused in vitro using a modified Langendorff technique, allowing the separate collection of coronary- and interstitial effluents. When heparin was added to the perfusion medium lipoprotein lipase was found in the coronary, as well as in the interstitial effluents. The relative amounts of lipase activity in both effluents varied with the feeding conditions of the animals, being high in the coronary effluent during fasting and high in the interstitial effluent during feeding. When glucagon (2.10?7 M) was included in the perfusion medium, no differences between fasted and fed animals were obtained. The apparent Km of the interstitial lipase was lower than that of the lipase found in the coronary effluent. The results are discussed in the light of the localization of lipoprotein lipase in rat hearts in situ.  相似文献   

14.
Transport of thiomethyl-β-D-galactoside (TMG) via the melibiose permease system (TMG permease II) in Salmonella typhimurium is known to be a sodium-dependent co-transport system. We have shown that this co-transport of sodium and TMG is associated with extrusion of protons from the cells. The rate and extent of proton extrusion during TMG uptake were measured in wild-type cells and mutants containing internal and extended deletions in the pts locus. No differences between these various strains were noted.  相似文献   

15.
Three phosphorylated dinucleosides designated HS1, HS2, and HS3, isolated from the water-mould Achlya, were shown to significantly inhibit ribonucleotide reductase activity from Achlya. All three compounds decreased CDP reduction in fungal extracts by 50% at concentrations of 0.1mM. At the same concentration HS3 also inhibited partially purified CDP reductase from Chinese hamster ovary cells by at least 80% but showed only 10% inhibition with enzyme from E.coli. ADP reductase activity from Achlya was inhibited 50% by both HS1 and HS3 at 0.1mM. HS2 however, showed no inhibitory effect on purine reduction. The levels of ribonucleotide reductase during the asexual growth cycle of Achlya correlated with thymidine uptake into DNA and with the synthesis of HS compounds.  相似文献   

16.
α-Glucosidase was membrane bound during exponential growth of Bacilluslicheniformis but was released into the medium during stationary phase. It could be partially removed from exponential phase cells by washing with NaCl (0.5 M). α-Amylase was exclusively extracellular and could not be detected in cells. Polysomes were prepared from exponential phase cells and separated into membrane bound and soluble fractions. Invitro chain completion and immunoprecipitation showed that α-glucosidase and α-amylase were synthesized by membrane bound and not by soluble ribosomes.  相似文献   

17.
An earlier study showed that pregnant rats given ethanol in drinking water exhibited a significant degree of dehydration. The objective of the present study was to determine whether dehydration alone contributes to fetal growth retardation in alcohol treated rats. Female Sprague-Dawley rats were divided into 4 dietary groups. Group 1 (alcohol) received 20% ethanol in drinking water for four weeks prior to mating and 30% alcohol in drinking water throughout pregnancy and a stock diet ad libitum. Group 2 (pair-fed) was given an amount of food equal to that consumed by the alcohol group with the alcohol isocalorically substituted by corn starch. Water was available ad libitum. Group 3 (pair-water) was given an amount of food and water equal to that consumed by the alcohol animals. Group 4 (ad libitum) was given food and water ad libitum. On day 21 of gestation body weights of the alcohol exposed fetuses were significantly lower than those of the other three treatment groups. The difference in fetal body weights between the pair-fed and pair-water groups was not significant. Placentas were significantly heavier in the alcohol group than in the pair-fed and pair-water groups. Maternal plasma osmolality was significantly higher in the alcohol treated rats when compared to the pair-fed and ad libitum controls but not the pair-water group. No significant differences were seen in fetal plasma osmolality among the four treatment groups. It is concluded that dehydration does not contribute significantly to retarded fetal growth in rats given alcohol in drinking water as the sole source of fluid prior to and during gestation.  相似文献   

18.
Fetal rat lungs placed in invitro organ culture at 15.5 days gestation grow significantly based on accumulation of DNA and protein. In the experimental system described, DNA accumulated rapidly during the first three days in culture and increased from 4.8 to 15.6 micrograms per lung culture. Protein content increased more slowly and reached a value more than double the initial value after six days in the culture system. Glycogen accumulated in the tissue during the first six days in culture and was depleted during the subsequent culture period, a pattern strikingly similar to that observed during lung development invivo. Phospholipid accumulation was biphasic with respect to time with an inflection point at about the sixth day of culture. The phosphatidylcholine species synthesized in the culture system invitro were similar to those produced invivo in fetal lung at 21 days gestation.  相似文献   

19.
The effects of estradiol-17β treatment on plasma lipid levels, liver lipid and glycogen reserves were examined during different phases of the reproductive cycle in goldfish, Carassiusauratus. Estrogen therapy resulted in increased plasma and hepatic lipid levels except during the spawning season. Hepatic glycogen deposits were depleted by estradiol injections during all seasons. Treatment of fish with the estrogen antagonist, CI-628, during the spawning season caused a reduction in plasma and liver lipid levels. Electrophoretic studies conducted during the post-spawning season showed that estrogen induces the appearance of a specific lipoprotein, probably a yolk precursor, in the serum and liver of goldfish.  相似文献   

20.
Chemically synthesized 1-O-hexadecyl-2-O-acetyl-sn-glycero-3-phosphocholine possessed the most potent hypotensive activity compared with bradykinin, prostagrandin E2 and I2 when 5 nano moles/kg body weight of each drug were administered intravenously in spontaneously hypertensive rat. The potency and the duration of hypotensive activity of 1-O-hexadecyl-2-O-acetyl-sn-glycero-3-phosphocholine were dose dependent. Exogenous norepinephrine or angiotensin II showed pressor activity during the hypotensive action of 1-O-hexadecyl-2-O-acetyl-sn-glycero-3-phosphocholine, but did not disturb the hypotensive pattern of this ether lipid. These may suggest that 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholine plays an important role for the regulation of blood pressure.  相似文献   

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