scholarly journals MORPHOLOGICAL AND BIOCHEMICAL CHANGES IN RAT SYNAPTOSOME FRACTIONS DURING NEONATAL DEVELOPMENT

1971 ◽  
Vol 51 (2) ◽  
pp. 484-498 ◽  
Author(s):  
Nicholas K. Gonatas ◽  
Lucila Autilio-Gambetti ◽  
Pierluigi Gambetti ◽  
Brenda Shafer
Keyword(s):  
Postnatal Development ◽  
Adult Animal ◽  
Specific Activity ◽  
Brain Homogenate ◽  
Subcellular Fractions ◽  
Presynaptic Terminals ◽  
Adult Rats ◽  
Total Brain ◽  
Mitochondrial Fractions ◽  
Rate Of Increase

A biochemical and quantitative morphologic study of presynaptic endings during postnatal development was carried out in subcellular fractions from cerebral cortex of 1, 4, 8, 12, and 18 day old and adult rats. Crude mitochondrial fractions were subfractionated in Ficoll gradients and all resulting fractions were examined in the electron microscope. Presynaptic terminals and other intact processes were counted. Protein content and enzyme activities were assayed in the fractions and in total brain homogenate. In the first and fourth day of life, most of the presynaptic terminals were found in two "light" fractions, between supernatant and 7.5% Ficoll, where they accounted, respectively, for 6 and 22% of all the processes. Progressively with age, more presynaptic terminals were found in the traditional "synaptosomal" fractions between 7.5 and 13% Ficoll. In that region of the gradient, 40, 54, 75, and 89% of the processes were presynaptic endings at 8, 12, and 18 postnatal days and in the adult animal, respectively. A similar shift from the lighter to the heavier fractions was observed in the distribution of choline acetyltransferase and acetylcholinesterase between days 8 and 12. The rate of increase of the specific activity of these two enzymes paralleled that of the percentage of the presynaptic endings after day 8. This study indicates that subcellular fractions can be used to study formation and maturation of synapses during postnatal development.

scholarly journals Specific expression of lactase in the jejunum and colon during postnatal development and hormone treatments in the rat

1990 ◽  
Vol 268 (1) ◽  
pp. 99-103 ◽  
Author(s):  
J N Freund ◽  
I Duluc ◽  
C Foltzer-Jourdainne ◽  
F Gosse ◽  
F Raul
Keyword(s):  
Postnatal Development ◽  
Specific Activity ◽  
Single Gene ◽  
Enzymic Activity ◽  
Transcriptional Level ◽  
Adult Rats ◽  
Specific Expression ◽  
Early Postnatal Development ◽  
Epidermal Growth ◽  
Large Decline

The expression of lactase was compared in the jejunum and colon of the rat at the levels of enzyme activity and protein and RNA content. We found that the enzyme proteins and the corresponding mRNAs share common features and are encoded by a single gene in both intestinal segments. In the jejunum, large amounts of lactase mRNA and proteins were detected during postnatal development as well as in adult rats, despite the 10-fold decline in lactase specific activity which occurs at weaning. In contrast, in the colon the expression of lactase was restricted to early postnatal development. In the colon, the enzymic activity of lactase and the amounts of protein and mRNA followed parallel development profiles with a peak at day 4 after birth. Injections of thryoxine or epidermal growth factor into neonates led to small modifications in the expression of lactase in the jejunum. On the other hand, these treatments caused a large decline in lactase activity in the colon that paralleled a decrease in the amount of lactase protein and mRNA. These data indicate that the expression of lactase is mainly regulated at the post-transcriptional level in the jejunum, whereas it is controlled at the pretranslational level in the colon.

Mitochondrial number, cytochrome oxidase and succinic dehydrogenase activity in Xenopus laevis oocytes

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 395-409
Author(s):  
E. Marinos ◽  
F. S. Billett
Keyword(s):  
Xenopus Laevis ◽  
Cytochrome Oxidase ◽  
Specific Activity ◽  
Succinic Dehydrogenase ◽  
Mitochondrial Fraction ◽  
Xenopus Laevis Oocytes ◽  
Mitochondrial Fractions ◽  
Rate Of Increase ◽  
Mitochondrial Cloud ◽  
Mitochondrial Number

An estimate has been made of the numbers of mitochondria in the mitochondrial cloud (Balbiani body) of Xenopus laevis oocytes ranging in size from 50 to 250 μm. The mitochondrial number is expressed in terms of a ‘standard ’ organelle measuring 2 μm in length and 0·2 μm in diameter and is derived by measurements on electron micrographs of sections through the cloud. It is found that the amount of mitochondrial material rises very rapidly as the oocyte grows in size. At the time the cloud disperses, in oocytes of about 300 μm in diameter, it is estimated that there are the equivalent of over 500000 mitochondria in each cell. The rate of increase is very similar to the rate of accumulation of mitochondrial DNA during the same period of growth. Using a polarographic technique the specific activity of cytochrome oxidase and succinic dehydrogenase was determined in mitochondrial fractions isolated from oocytes over a size range of 80–1200 μm in diameter. Although the specific activity of succinic dehydrogenase remains constant that of cytochrome oxidase falls sharply during the period when the mitochondria are replicating rapidly, i.e. up to about 300 μm diameter. In larger oocytes the specific activity of enzymes appears to remain constant but increasing contamination of the isolated mitochondrial fraction does not allow conclusions to be drawn from the enzyme loading of the mitochondria once they have dispersed from the cloud. The results are discussed in relation to the possibility that mitochondrial replication preceeds, or at least outpaces, mitochondrial differentiation during the course of oogenesis.

Oxygen tolerance in neonatal rats: role of subcellular superoxide generation

1989 ◽  
Vol 257 (6) ◽  
pp. L411-L420 ◽  
Author(s):  
H. Ischiropoulos ◽  
C. E. Nadziejko ◽  
T. Kumae ◽  
Y. Kikkawa
Keyword(s):  
Superoxide Anion ◽  
Subcellular Fractions ◽  
Antioxidant Defenses ◽  
Neonatal Rats ◽  
Sod Activity ◽  
Adult Rats ◽  
Hyperoxic Exposure ◽  
Mitochondrial Fractions ◽  
Generating Capacity

We compared the superoxide anion generating capacity of subcellular fractions from the lungs of neonatal and adult rats. Microsomal and mitochondrial fractions from adult rats produced approximately three times more superoxide (nanomoles per minute per milligram protein) than fractions from neonatal rats in the presence of 100% O2. Subcellular superoxide anion generating capacity was also examined in adult and neonatal rats exposed to greater than 95% fractional concentration of O2 in inspired gas. The O2- produced by mitochondrial and microsomal fractions of adult and neonatal rats increased above control levels for the first 24 h and declined below control values after 48 h of exposure in adults, whereas the elevated O2- production was sustained in microsomal fractions of neonates through 60 h. During the course of hyperoxic exposure, the largest difference in the superoxide generating capacity between adult and neonate was observed after 8-24 h of hyperoxia. The microsomal and mitochondrial fractions from adult rats produced three to seven times more O2- compared with neonatal rats. Cu,Zn superoxide dismutase (SOD) increased during the course of hyperoxia only in neonates at 8, 24, and 48 h of exposure. No change was observed in the activity of Mn SOD. The ratio of SOD activity (units per lung) to subcellular superoxide generating capacity (nanomoles per minute per lung) was calculated for the normal adults and neonates. The ratio for adult rats averaged 23 and 17 for mitochondrial and microsomal fractions, respectively, and 51 for neonatal rats for both subcellular fractions under normoxic conditions. These results suggest that O2- tolerance of neonates may be explained by the favorable balance between antioxidant defenses and subcellular superoxide generating capacity. The role of increased activity of Cu,Zn SOD as an accompanying or a causative phenomenon in O2 tolerance of neonates could not be determined from these experiments.

scholarly journals Impact of repeated co-treatment with escitalopram and aripiprazole on the schizophrenia-like behaviors and BDNF mRNA expression in the adult Sprague–Dawley rats exposed to glutathione deficit during early postnatal development of the brain

2021 ◽  
Author(s):  
Marta A. Lech ◽  
Kinga Kamińska ◽  
Monika Leśkiewicz ◽  
Elżbieta Lorenc-Koci ◽  
Zofia Rogóż
Keyword(s):  
Mrna Expression ◽  
Postnatal Development ◽  
Repeated Treatment ◽  
Sprague Dawley ◽  
Biochemical Tests ◽  
Bdnf Mrna ◽  
Adult Rats ◽  
Behavioral Deficits ◽  
Glutathione Synthesis ◽  
Early Postnatal Development

Abstract Background Preclinical and clinical studies have indicated that impaired endogenous synthesis of glutathione during early postnatal development plays a significant role in the pathophysiology of schizophrenia. Moreover, some studies have suggested that antidepressants are able to increase the activity of atypical antipsychotics which may efficiently improve the treatment of negative and cognitive symptoms of schizophrenia. Methods In the present study, we investigated the influence of repeated co-treatment with escitalopram and aripiprazole on the schizophrenia-like behavior and BDNF mRNA expression in adult rats exposed to glutathione deficit during early postnatal development. Male pups between the postnatal days p5–p16 were treated with the inhibitor of glutathione synthesis, BSO (L-buthionine-(S,R)-sulfoximine) and the dopamine uptake inhibitor, GBR 12,909 alone or in combination. Escitalopram and aripiprazole were given repeatedly for 21 days before the tests. On p90–92 rats were evaluated in the behavioral and biochemical tests. Results BSO given alone and together with GBR 12,909 induced deficits in the studied behavioral tests and decreased the expression of BDNF mRNA. Repeated aripiprazole administration at a higher dose reversed these behavioral deficits. Co-treatment with aripiprazole and an ineffective dose of escitalopram also abolished the behavioral deficits in the studied tests. Conclusion The obtained data indicated that the inhibition of glutathione synthesis in early postnatal development induced long-term deficits corresponding to schizophrenia-like behavior and decreased the BDNF mRNA expression in adult rats, and these behavioral deficits were reversed by repeated treatment with a higher dose of aripiprazole and also by co-treatment with aripiprazole and ineffective dose of escitalopram.

Characterization of positive inotropic effect of colforsin dapropate hydrochloride, a water-soluble forskolin derivative, in isolated adult rat cardiomyocytes

1999 ◽  
Vol 77 (4) ◽  
pp. 225-234 ◽  
Author(s):  
Rikako Miyake ◽  
Hiroyuki Yoshida ◽  
Kouichi Tanonaka ◽  
Yuki Miyamoto ◽  
Hideharu Hayashi ◽  
...  
Keyword(s):  
Calcium Transient ◽  
Water Soluble ◽  
Inotropic Action ◽  
Shortening Velocity ◽  
Adult Rats ◽  
Camp Content ◽  
Rat Cardiomyocytes ◽  
Positive Inotropic Action ◽  
Time To Peak ◽  
Rate Of Increase

The present study was undertaken to characterize the positive inotropic action of colforsin dapropate hydrochloride (NKH477), a novel water-soluble forskolin derivative, on isolated cardiomyocytes of adult rats. Simultaneous measurements of cellular contraction and intracellular calcium concentration ([Ca2+]i) were carried out. The effects of isoprenaline and ouabain on these parameters were also determined for comparison. The contraction and maximum [Ca2+]i of NKH477-, isoprenaline-, or ouabain-treated cells were increased concentration dependently. Peak shortening of NKH477-treated cells was positively correlated with the shortening velocity and inversely with the time to peak shortening. Maximum, but not minimum, [Ca2+]i in NKH477-treated cells was correlated with the rate of increase in [Ca2+]i and inversely with the time to maximum [Ca2+]i. Similar results were obtained with isoprenaline. In contrast, ouabain increased both maximum and minimum [Ca2+]i. Treatment with either NKH477 or isoprenaline increased cellular cAMP content, but treatment with ouabain did not. These results suggest that the positive inotropic action of NKH477 is associated with an increase in [Ca2+]i and acceleration of its kinetics.Key words: adenylate cyclase, calcium transient, colforsin dapropate, isoprenaline, ouabain.

Postnatal development of myogenic contractile activity and excitatory innervation of rat urinary bladder

1984 ◽  
Vol 247 (6) ◽  
pp. R972-R978 ◽  
Author(s):  
C. A. Maggi ◽  
P. Santicioli ◽  
A. Meli
Keyword(s):  
Urinary Bladder ◽  
Postnatal Development ◽  
Contractile Activity ◽  
Quiescent State ◽  
Stages Of Development ◽  
Adult Rats ◽  
Rat Urinary Bladder ◽  
Muscarinic Cholinoceptors ◽  
Newborn Animals

Bladder strips from newborn compared with adult rats exhibited marked differences in both myogenic properties and postganglionic excitatory innervation. In the first 2-wk of life myogenic contractile activity progressively changed from a quiescent state (at birth) to the asynchronous contractile activity typical of bladder strips from adult animals. After birth activation of muscarinic cholinoceptors changed the myogenic contractile activity in a manner similar to that observed at later stages of development. Neurogenic contractions of bladders from newborn animals were atropine sensitive in the whole range of frequencies studied. During the first 2 wk the atropine-resistant component of these contractions increased progressively to reach an adult-like condition, i.e., atropine-resistant contractions account for over 90% and approximately 60% of contractions elicited at 0.1 and 1–20 Hz, respectively.

FACTORS INFLUENCING THE EXCRETION OF A FAT-MOBILIZING SUBSTANCE IN THE URINE OF RATS

1966 ◽  
Vol 44 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. R. Beaton ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Body Weight ◽  
Sex Difference ◽  
Specific Activity ◽  
Young Male ◽  
Total Activity ◽  
Female Rats ◽  
Male Rats ◽  
Diabetic Rat ◽  
Adult Rats ◽  
Factors Influencing

The effect of various factors on excretion of a lipid-mobilizing activity in FMS IA (anorexigenic) and in FMS IB (fat-mobilizing) by the fasting rat has been investigated. During fasting, the greatest excretion of such activity in FMS IA and FMS IB occurred in the first 24 hours and diminished thereafter up to 72 hours; and the specific activity of FMS IB was greatest in the first 24 hours whereas that of FMS IA was constant throughout. The hypothalamicobese rat excretes FMS IA and FMS IB in greater than normal amounts. The alloxan-diabetic rat excretes less total activity of FMS IA and IB than do control animals. Young male rats excrete greater amounts of FMS IB, but not of FMS IA, than do adult rats, the greatest excretion per 100 g body weight being observed at approximately 37 days of age. At 27 days of age (prepuberty), male rats excreted a greater total activity of FMS IB but not of FMS IA than did female rats. At 90 days of age (post-puberty), there was no apparent sex difference in the amount of total activity of FMS IB excreted per rat, but when expressed per 100 g body weight, females excreted more FMS IB than did males.

Proteinsynthese in grünen Blättern

1964 ◽  
Vol 19 (3) ◽  
pp. 235-248 ◽  
Author(s):  
Benno Parthier
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Subcellular Fractions ◽  
Mechanical Destruction ◽  
Cell Organization ◽  
Specific Activities ◽  
Short Time ◽  
Natural Cell

In the green leaves of Nicotiana rustica, protein synthesis of various subcellular fractions has been investigated in vivo after 14CO2-photosynthesis and also in vitro by incorporation of radioactive amino acids. Following photosynthesis, homogenization of the tissues, and differential centrifugation of the homogenates, the results show that all structural particles of the cell are able to use photosynthetically formed amino acids for the incorporation into their proteins. The proteins with the highest specific activities are found in the mitochondria-rich fractions, and with the lowest in the soluble cytoplasma supernatant. High specific activities are also observed in the ribosomal-rich fraction in short-time experiments, and also in the chloroplasts after exposure of the leaves to light. After an osmotic-mechanical destruction of the isolated 14C-labelled chloroplasts, the specific activities of lamellar proteins exceed the colourless soluble proteins of the chloroplasts. A green fraction, sedimented at 1,000 g, and perhaps mainly consisting of broken and leached chloroplasts, shows the highest specific activity of all chloroplast fractions. Obviously, due to the destruction of the natural cell organization, in vitro experiments give not only drastically decreased specific activities but also another distribution of the incorporated amino acids between the subcellular fractions, compared with experiments in vivo.

A model of ventilatory instability induced in the unrestrained rat

1992 ◽  
Vol 73 (4) ◽  
pp. 1530-1536 ◽  
Author(s):  
A. J. Thomas ◽  
W. Austin ◽  
L. Friedman ◽  
K. P. Strohl
Keyword(s):  
Unconditioned Stimulus ◽  
Adult Animal ◽  
Routine Care ◽  
Auditory Stimuli ◽  
Adult Rats ◽  
Conditioning Paradigm ◽  
Sleep Period ◽  
Neonatal Life ◽  
Neonate Rat ◽  
Classic Conditioning

A classic conditioning paradigm was used to examine the hypothesis that perturbations during sleep in the neonate rat can have a lasting impact on breathing. During the first 4 wk of life, stimuli were presented to rats during behaviorally defined sleep. In a conditioned hypoxic (CH) group, brief periods of hypoxic gas were used as the unconditioned stimulus. Tactile and auditory stimuli were used as the conditioned stimuli. In a conditioned control (CC) group, air was used as the unconditioned stimulus. A third group of unconditioned control (UC) rats was not exposed to the conditioning paradigm. Animals were provided routine care for 3.5 mo; ventilation was then assessed using plethysmography. Conditioning during neonatal life produced increased ventilatory irregularities and apnea during behaviorally defined sleep in adult rats. Both CH and CC rats showed a significantly greater number of apneic events compared with UC rats. Over a 2-h sleep period, CH rats exhibited a total of 105.1 +/- 9.4 (SE) apneic events, CC rats 69.4 +/- 4.2 events, and UC rats 42.1 +/- 3.1 events [F(2,18) = 25.568; P < 0.0001]. These findings suggest that experiences in the first few weeks of life will alter ventilatory patterning in the adult animal.

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