Distribution and metabolism of corticotropin-releasing factor in the rat

1986 ◽  
Vol 64 (6) ◽  
pp. 683-688 ◽  
Author(s):  
Bernard Candas ◽  
Josée Lalonde ◽  
Maurice Normand
Keyword(s):  
Time Course ◽  
Corticotropin Releasing Factor ◽  
Metabolic Clearance ◽  
Sprague Dawley ◽  
Rapid Injection ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
The Mean ◽  
The Moment ◽  
The One

To develop a mathematical model of the distribution and metabolism of rat corticotropin-releasing factor (rCRF), the time course of 125I-labelled rCRF in plasma was measured in male Sprague–Dawley rats (i) following a rapid injection of 24 ng rCRF/100 g body weight (BW), or (ii) following a rapid injection of 424 ng rCRF/100 g BW, or (iii) during an infusion at a rate ranging from 0.28 to0.73 ng rCRF∙min−1∙100 g BW−1. The comparison of the one-, two-, and three-compartment models shows that the two-pool structure fits better to the dynamics of CRF in plasma as measured in each rat. Following a rapid injection the decay curve occurs in a biphasic manner; the early phase of disappearance is 25 times faster than the late one. There is no significant difference between the estimates of the metabolic clearance rate following both amplitudes of injection (0.40 ± 0.06 and 0.48 ± 0.05 mL∙min−1∙100 g BW−1). The volume of the first pool, 16.8 ± 1.1 mL/100 g BW, is four times larger than the plasma volume. It would thus appear that CRF is rapidly distributed from plasma into several tissues which are represented in the first pool of the model. The mean residence time of every CRF molecule in the second compartment, from the moment of secretion to its elimination, is from three to four times longer than in the first one. It stays, on average, between 140 min and 3 h in the system before an irreversible exit. At steady state, the disposal rate represents only 3% of the CRF mass of the first compartment every minute. These results could explain the prolonged effects of CRF on pituitary-adrenocortical secretion.

Distribution and metabolism of adrenocorticotropin in the rat

1979 ◽  
Vol 57 (9) ◽  
pp. 1024-1027 ◽  
Author(s):  
Maurice Normand ◽  
Josee Lalonde
Keyword(s):  
Standard Error ◽  
Time Course ◽  
Compartment Model ◽  
Sprague Dawley ◽  
Mean Values ◽  
Sprague Dawley Rats ◽  
Two Compartment Model ◽  
Rapid Fall ◽  
Significant Difference ◽  
Endogenous Release

The time course of plasma bioactive adrenocorticotropin (ACTH) concentrations measured following two rapid injections of the hormone at doses of 7.5 and 22.5 mU/100 g, iv, and one infusion over a period of 80 min at a rate of 1.3 mU/min per 100 g, to male Sprague–Dawley rats whose endogenous release of ACTH had been blocked, leads to the conclusion that the hormone is distributed in two compartments. Indeed, the rapid fall of plasma ACTH concentrations in the early minutes following either the injections or the stop of the infusion is followed by a much slower phase. There is no significant difference between the measurements and the two-compartment model outputs. The model represents, on the average, the mean values of the measurements plus or minus 1 standard error for the single injections and plus or minus 1.2 standard error for the infusion.

Adrenocortical responses to corticotropin-releasing factor in the rat

1986 ◽  
Vol 64 (3) ◽  
pp. 269-272 ◽  
Author(s):  
Maurice Normand ◽  
Josée Lalonde
Keyword(s):  
Body Weight ◽  
Continuous Infusion ◽  
Time Course ◽  
Plasma Corticosterone ◽  
Corticotropin Releasing Factor ◽  
Delayed Response ◽  
Sprague Dawley ◽  
Rapid Injection ◽  
Long Time ◽  
Endogenous Release

The time course of plasma corticosterone was measured in male Sprague–Dawley rats whose endogenous release of ACTH had been blocked following rapid i.v. injections of doses ranging from 0.003 to 10 μg corticotropin-releasing factor (CRF) per rat and during i.v. infusions at rates ranging from 0.001 to 20 μg CRF∙min−1∙100 g body weight−1. The range of the dose–response curve, following rapid injection, extends from 0.01 to 0.37 μg CRF, whereas it extends over a 20 000-fold range from 0.001 to 20 ng CRF∙min−1∙100 g body weight−1 during a continuous infusion. The delayed response to a small rate of CRF could be ascribed to a relatively long time of residence of CRF in the plasma which implies that a relatively long period of time is required until a minimal plasma CRF concentration is reached after the onset of a continuous infusion of CRF at a small rate. When presented with a prolonged infusion of CRF at a large rate, the pituitary secretion of ACTH is rapidly turned on at a rate which exhibits the characteristics of a prolonged secretion at a constant large magnitude.

Spatiotemporal electrophysiology of cerebral ischemia observed using chronic electrode array in auditory cortex

2008 ◽  
Vol 2 (1) ◽  
Author(s):  
M.T. Huberty ◽  
P. Tek ◽  
P.J. Rousche
Keyword(s):  
Auditory Cortex ◽  
Time Course ◽  
Electrode Array ◽  
The United States ◽  
Stroke Recovery ◽  
Sprague Dawley ◽  
Stroke Research ◽  
Sprague Dawley Rats ◽  
The Mean

Stroke research is of considerable societal value in an age in which the scourge is a leading cause of disability and the third-leading cause of death in the United States. While previous studies investigate the electrophysiology of stroke, none examine the long-term time-course of stroke recovery in the auditory cortex, the objective of this study. An electrode was implanted in the auditory cortex of two anesthetized Sprague-Dawley rats, stroke was induced in one of the subjects using photothrombosis, and daily electrical recordings were made while each subject was presented with a click stimulus every 500 ms. Peri-stimulus time histograms reveal that in the control subject, the second stimulus-evoked bursts peak decreased the day following implantation (Day 1) but returned almost to its Day 0 (day of surgery) value by Day 5, representing recovery from implantation trauma. The mean firing rate decreased logarithmically from its Day 0 value of 90 Hz to 10 Hz by Day 8, revealing decreasing electrode viability. In the stroke subject, the second stimulus-evoked bursts peak was undetected Day 1, but was detected again on Day 4, elucidating that the rat auditory cortex regains function as stroke recovery progresses.

scholarly journals Curcumin Minimises Histopathological and Immunological Progression in the Ankle Joints of Collagen-Induced Arthritis Rats

2020 ◽  
Vol 15 (2) ◽  
pp. 26-36
Author(s):  
Taty Anna Kamarudin. ◽  
Keyword(s):  
Olive Oil ◽  
Inflammatory Diseases ◽  
Negative Control ◽  
Sprague Dawley ◽  
Collagen Induced Arthritis ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Ankle Joints ◽  
The Mean ◽  
Random Groups

Curcumin is a traditionally used spice with a potential to treat various inflammatory diseases including arthritis. This study was aimed at observing curcumin’s effects on the histopathological progression and interleukin-1β (IL-1β) levels in collageninduced arthritis (CIA). Thirty male Sprague-Dawley rats (150+50 g) were divided into five random groups. A group was assigned as the normal control (CTRL), while the remaining were subcutaneously immunised with 150 μg of collagen emulsion on day 0. CTRL and CIA-Curcumin-d0 groups were supplemented daily with olive oil (1 ml/kg) and curcumin (110 mg/ml/kg) from day 0, respectively. The CIA-OV (negative control), CIA-Beta and CIA-Curcumin-d14 groups were given daily supplementation of olive oil (1 ml/kg), Betamethasone (0.5 mg/ml/kg), and curcumin (110 mg/ml/kg) from day 14, respectively. The daily oral supplementations continued until day 42. The study showed that CIA-Beta (**P<0.05) and CIACurcumin- d0 (**P=0.01) groups had significantly lower mean histological scores compared to CIA-OV, respectively. Serum IL-1β levels for CIA-Beta and CIACurcumin- d0 were not significantly raised on day 42 as to compared to day 0, and the mean increment of IL-1β levels from day 0 to day 42 were significantly lower (**P≤0.01) for all the CIA groups compared to CIA-OV. There was no significant difference in both mean histological scores and IL-1β levels of CIA-Curcumin-d0 compared to CIA-Beta. Early supplementation of curcumin could potentially minimise disease progression of CIA in rats.

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

scholarly journals THE EFFECTS OF LEVELS OF ISOLATION, OR VARIETAL DIFFERENCES IN, HIGH FIBRE HULL FRACTION OF LOW GLUCOSINOLATE RAPESEED MEALS ON RAT OR PIG PERFORMANCE

1978 ◽  
Vol 58 (4) ◽  
pp. 743-752 ◽  
Author(s):  
J. J. KENNELLY ◽  
F. X. AHERNE ◽  
A. J. LEWIS
Keyword(s):  
Feed Intake ◽  
Average Daily Gain ◽  
Rapeseed Meal ◽  
Sprague Dawley ◽  
Crude Fibre ◽  
Gain Ratio ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Pig Performance ◽  
Daily Gain

Forty-eight crossbred pigs of average initial weight 21 kg were fed 10% Tower rapeseed meal (RSM) and 10% Candle RSM as partial replacements for soybean meal (SBM). Diets were formulated to be isocaloric. Pigs fed the SBM diet consumed less feed, gained significantly (P < 0.01) faster and were more efficient at converting feed to gain than those fed the RSM diets. Performance of pigs fed Candle RSM was not significantly different to that obtained with Tower RSM. In a second experiment, dehulled Tower RSM and Tower RSM hulls were mixed in amounts to produce RSM with crude fibre levels of 6.8, 10.8, 13.5 and 15.8%. The simulated RSM and Tower and Candle RSM were used to completely replace SBM in the diets of weanling (75 g) Sprague-Dawley rats. Rats fed SBM had significantly (P < 0.05) higher average daily gain (ADG) than those fed Tower or Candle RSM, or diets containing the rapeseed meats. There was no significant (P < 0.05) difference in ADG, feed intake or feed to gain ratio of rats fed either Tower or Candle RSM. Feed intake, feed to gain ratio and fecal volatile fatty acid concentrations increased while average daily gain decreased with increasing level of hulls in simulated RSM diets. There was no significant difference (P < 0.05) in thyroid weight between rats fed SBM, Tower RSM or Candle RSM.

Physiological and biophysical limits to work in the heat for clothed men and women

1978 ◽  
Vol 44 (6) ◽  
pp. 918-925 ◽  
Author(s):  
E. Kamon ◽  
B. Avellini ◽  
J. Krajewski
Keyword(s):  
Steady State ◽  
Vapor Pressure ◽  
Physiological Responses ◽  
Men And Women ◽  
Mean Values ◽  
Air Temperatures ◽  
Significant Difference ◽  
The Mean ◽  
Evaporative Heat Transfer ◽  
The One

Heat-acclimated, lightly clothed men and women (four of each) walked on a treadmill at 25% and 43% VO2 max, respectively, (M =194 W.m-2), under seven air temperatures (Ta) ranging from 36 to 52 degrees C. Each experiment involved 1 h of fixed and a 2nd h of progressively increasing ambient vapor pressure (Pa). The relative steady state of rectal temperature (Tre), mean skin temperature (Tsk), and heart rate (HR) reached in the 1st h were forced upward during the 2nd h by the rising Pa. The critical air vapor pressure (Pcrit) was identified by the Tre point of inflection for each Ta. One man did not fully reach steady state, but inflection could be determined for his physiological responses. The mean values of all points of inflection were calculated for Tre, Tsk, and HR. Significant sex difference in HR was found only by excluding the results of the one man. Tre and Tsk showed no significant difference between men and women. The coefficient for evaporative heat transfer (he), which could be derived using the Pcrit for the low Ta range, was 14.5 +/- 2.2 W.m-1 Torr-1.

scholarly journals Oral administration of Lactobacillus casei Shirota can ameliorate the adverse effect of an acute aflatoxin exposure in Sprague Dawley rats

2018 ◽  
Vol 88 (3-4) ◽  
pp. 199-208
Author(s):  
Elham Nikbakht ◽  
Rosita Jamaluddin ◽  
S. Mohd Redzwan ◽  
Saman Khalesi
Keyword(s):  
Adverse Effect ◽  
Lactobacillus Casei ◽  
Health Effect ◽  
Acute Exposure ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Lactobacillus Casei Shirota ◽  
Probiotic Treatment ◽  
Significant Difference ◽  
Aflatoxin B

Abstract. Aflatoxin B1 (AFB1) is a toxic compound commonly found in some crops with an adverse health effect on human and animals. Some beneficial microorganisms (or probiotics) such as lactic acid bacteria have shown the ability to reduce the bioavailability of aflatoxins and its intestinal absorption. However, the dose and duration of aflatoxins exposure and probiotic treatment can influence the ability of probiotics to remove aflatoxins. Therefore, this research aimed to investigate the efficacy of oral probiotic Lactobacillus casei Shirota strain (LcS) induction in an acute exposure to AFB1 in rats. Experimentally, Sprague Dawley rats were divided into three groups: AFB1 only (n = 9); AFB1 treated with LcS (n = 9); and control (no AFB1 exposure) (n = 6) groups. The blood AFB1 level of rats treated with LcS was slightly lower than the untreated AFB1 induced rats (11.12 ± 0.71 vs 10.93 ± 0.69 ng g–1). Also, LcS treatment slightly moderated the liver and kidney biomarkers in AFB1 induced rats. However, a trend for a significant difference was only observed in ALT of AFB1 induced rats treated with LcS compared to their counterparts (126.11 ± 36.90 vs 157.36 ± 15.46, p = 0.06). Rats’ body weight decreased in all animals force-fed with AFB1 with no significant difference between LcS treatment compared to the counterpart. In conclusion, this experiment indicated that probiotic LsC was able to slightly ameliorate the adverse effect of an acute exposure to AFB1 in rats. However, future studies with longer probiotics treatment or higher probiotics dose is required to confirm these findings.

scholarly journals Pengaruh Pemberian Kurma Muda (Phoenix dactylifera) Terhadap Kadar FSH dan Reseptor FSH Ovarium Tikus Putih (Rattus norvegicus)

2019 ◽  
Vol 7 (1) ◽  
pp. 117-121
Author(s):  
Herlambang Herlambang ◽  
Ave Olivia Rahman ◽  
Erny Kusdiyah
Keyword(s):  
Ovarian Tissue ◽  
Scientific Evidence ◽  
Phoenix Dactylifera ◽  
Group Iv ◽  
Sprague Dawley ◽  
Female Reproduction ◽  
Group I ◽  
Sprague Dawley Rats ◽  
Vaginal Swabs ◽  
The Mean

ABSTRACT Background: Infertility may give an impact on psychosocial. In Indonesia, the habit of consuming young dates is often done by couples to increase fertility. FSH is one of the factors that play a role in folliculogenesis. The lack of scientific evidence of young dates consumption effects on female reproduction has led to this study. This study aims to determine the levels of FSH hormone and the picture of ovarian tissue in mice after administration of young dates. Method: This study used an experimental design using 28 female Sprague-Dawley rats which were randomly divided into 4 groups. Group I to III was given young dates in successive doses: 17 mg, 34 mg, 68 mg per 200 grams of body weight and group IV was given distilled water. The treatment was carried out for 28 days. FSH levels were examined before treatment during the proestrus phase which was known from microscopic examination of rat vaginal swabs. The treatment begins during the proestrus phase. Result: The mean baseline and post-treatment FSH levels were 0.08 and 0.09 respectively Conclusion: There is no significant increase of FSH levels and FSH receptors as the effect of giving young dates (Phoenix Dactylifera) to female Sprague-Dawley rats Keywords: Dates, FSH, FSH receptors, Rats   ABSTRAK Latar Belakang: Infertilitas dapat memberikan dampak psikososial. Di Indonesia, kebiasaan mengkonsumsi kurma muda sering dilakukan oleh pasangan untuk meningkatkan kesuburan. Hormon FSH merupakan salah satu faktor yang berperan dalam folikelgenesis.  Belum adanya bukti ilmiah efek konsumsi buah kurma muda terhadap reproduksi wanita mendorong dilakukannya studi ini. Studi ini bertujuan mengetahui kadar hormon FSH dan gambaran jaringan ovarium pada tikus setelah pemberian kurma muda. Metode: Penelitian ini menggunakan desain ekperimental menggunakan tikus Sprague dawney betina sebanyak 28 ekor yang dibagi secara acak menjadi 4 kelompok. Kelompok I-III diberikan kurma muda dosis berturut -turut 17 mg, 34 mg, 68 mg per 200 gram BB dan kelompok IV diberikan aquadest. Perlakuan dilakukan selama 28 hari. Kadar hormon FSH diperiksa sebelum perlakuan saat fase proestrus yang diketahui dari pemeriksaan mikroskopis swab vagina tikus. Perlakuan dimulai saat fase proestrus. Hasil: Rerata kadar FSH baseline dan paska perlakuan adalah 0,08 dan 0,09 Kesimpulan: Tidak terdapat peningkatan yang signifikan kadar FSH dan reseptor FSH terhadap efek pemberian buah kurma muda (Phoenix Dactylifera) pada uterus tikus Spague Dawney Kata kunci : kurma, FSH, Reseptor FSH, tikus

scholarly journals Structural Alteration in Dermal Vessels and Collagen Bundles following Exposure of Skin Wound to Zeolite–Bentonite Compound

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Shahram Paydar ◽  
Ali Noorafshan ◽  
Behnam Dalfardi ◽  
Shahram Jahanabadi ◽  
Seyed Mohammad Javad Mortazavi ◽  
...  
Keyword(s):  
Healing Process ◽  
Volume Density ◽  
Skin Wound ◽  
Sprague Dawley ◽  
Small Vessels ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Sterile Normal Saline ◽  
Animal Skin ◽  
The Impact

Background. This study examines the impact of one-time direct application of haemostatic agent zeolite–bentonite powder to wounded skin on the healing process in rats. Materials and Methods. 24 male Sprague-Dawley rats were randomly allocated into two groups (n=12): (1) the rats whose wounds were washed only with sterile normal saline (NS-treated) and (2) those treated with zeolite–bentonite compound (ZEO-treated). The wound was circular, full-thickness, and 2 cm in diameter. At the end of the 12th day, six animals from each group were randomly selected and terminated. The remaining rats were terminated after 21 days. Just after scarification, skin samples were excised and sent for stereological evaluation. Results. The results showed a significant difference between the two groups regarding the length density of the blood vessels and diameter of the large and small vessels on the 12th day after the wound was inflicted. Besides, volume density of both the dermis and collagen bundles was reduced by 25% in the ZEO-treated rats in comparison to the NS-treated animals after 21 days. Conclusions. One-time topical usage of zeolite–bentonite haemostatic powder on an animal skin wound might negatively affect the healing process through vasoconstriction and inhibition of neoangiogenesis.

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