Dose Dependent Degeneration of Leydig Cells Following Kisspeptin-10 Administration: An Ultrastructural Study

2021 ◽  
Vol 28 ◽  
Author(s):  
Faiqah Ramzan ◽  
Irfan Zia Qureshi ◽  
Muhammad Haris Ramzan
Keyword(s):  
Leydig Cells ◽  
Plasma Concentrations ◽  
Physiological Saline ◽  
Testicular Tissue ◽  
Male Rats ◽  
Ultrastructural Changes ◽  
Plasma Testosterone ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Dose Dependent

Background: The discovery of kisspeptin signaling as a key regulator of gonadotropin releasing hormone (GnRH) secretion from the hypothalamus enhanced our understanding of the neuroendocrine regulation of mammalian reproduction. Effects of central and peripheral administration of kisspeptin on plasma gonadotropins, testosterone and spermatogenesis are studied in detail. Objective: The present study was conducted to check the ultrastructure of Leydig cells in prepubertal male rats in response to the administration of a range of kisspeptin doses. Method: To this end, we administered a range of kisspeptin-10 doses (1µg, 1ηg and 10ρg) intraperitoneally, to prepubertal male Sprague-Dawley rats (PND 35) twice daily after every 12 hours. Control rats were injected with physiological saline in parallel. Results: At the end of the treatment, plasma concentrations of testosterone was measured by competitive binding radioimmunoassay and small pieces of rat testicular tissue were processed for electron microscopy to examine the ultrastructure of Leydig cells. Plasma testosterone concentration was reduced significantly at 1ηg (P<0.05) and 1μg (P<0.01) doses as compared to control. Distinct ultrastructural changes categorized as dilatation of cytoplasmic organelles, irregular shaped nuclei with nuclear membrane invaginations, reduced nuclear sizes, degeneration and vacuolation were observed in the kisspeptin-10 treated Leydig cells as compared to control. Quantification of the data showed reduced Leydig cell indices and hyperplasia of the interstitial cells. Conclusion: It is concluded that chronic intermittent administration of kisspeptin-10 has a dose dependent degenerative effect on the plasma testosterone levels and Leydig cells ultrastructure in prepubertal male rats.

STUDIES ON THE BIOSYNTHESIS OF TESTOSTERONE IN THE RAT

1971 ◽  
Vol 68 (3) ◽  
pp. 614-624 ◽  
Author(s):  
Z. Kniewald ◽  
M. Zanisi ◽  
L. Martini
Keyword(s):  
Adrenal Gland ◽  
Sharp Decrease ◽  
Plasma Corticosterone ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Normal Male ◽  
Sprague Dawley ◽  
Unilateral Adrenalectomy ◽  
Sprague Dawley Rats ◽  
Chromatographic Procedure

ABSTRACT Plasma levels of testosterone have been measured in adult male Sprague-Dawley rats using a gas-chromatographic procedure. Immediately after castration, the concentrations of testosterone in the plasma increase to reach a maximum one hour after orchidectomy; after this time a progressive decrease in plasma testosterone is observed. The concentration of testosterone then returns to levels close to those found before the operation two hours after castration; four hours after orchidectomy plasma testosterone begins to decrease to values lower than in the intact controls. Adrenalectomized animals with their testes in situ show a sharp decrease in plasma testosterone which begins immediately after the operation; the plasma testosterone reaches levels significantly lower than those in the intact control one hour after adrenalectomy; a greater decrease is observed four hours after the operation. Twenty-four hours after unilateral adrenalectomy the remaining gland significantly increases in weight; at this time, the plasma corticosterone and plasma testosterone levels of unilaterally adrenalectomized rats are normal. These results are interpreted as indicating that the adrenal gland of normal male rats is capable of producing testosterone, and that the synthesis of testosterone at the adrenal level is increased immediately after castration. Moreover it is suggested that the adrenal gland also contributes to the biosynthesis of testosterone in an indirect fashion, i. e. by providing the testes with an essential precursor. It has been tentatively proposed that progesterone might be such a precursor.

scholarly journals A Fracture Pain Model in the Rat

2008 ◽  
Vol 108 (3) ◽  
pp. 473-483 ◽  
Author(s):  
Katie T. Freeman ◽  
Nathan J. Koewler ◽  
Juan M. Jimenez-Andrade ◽  
Ryan J. Buus ◽  
Monica B. Herrera ◽  
...  
Keyword(s):  
Femur Fracture ◽  
Weight Bearing ◽  
Male Rats ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Left Femur ◽  
Pain Model ◽  
Sprague Dawley Rats ◽  
Skeletal Pain ◽  
Dose Dependent

Background Because of the relative lack of understanding of the mechanisms that drive skeletal pain, the purpose of this study was to adapt a previously validated closed femur fracture model to quantitatively evaluate skeletal pain in female and male rats. Methods Three-month-old female and male Sprague-Dawley rats were anesthetized, and a stainless steel pin was inserted into the intramedullary space of the left femur. Three weeks later, the rats were reanesthetized, and left femoral diaphyses were fractured using a standardized impactor device. At 1-21 days after fracture, skeletal pain was measured by quantitatively assessing spontaneous guarding, spontaneous flinching, and weight bearing of the fractured hind limb. Results Females and males showed highly robust pain behaviors that were maximal at day 1 after fracture and returned gradually to normal nonfractured levels at days 14-21 after fracture. The magnitude of fracture pain was not significantly different at most time points between female and male rats. In both females and males, the pain-related behaviors were attenuated by subcutaneous morphine in a dose-dependent manner. Conclusions This model may help in developing a mechanism-based understanding of the factors that generate and maintain fracture pain in both females and males and in translating these findings into new therapies for treating fracture pain.

Ultrastructural Effects of Acute Kepone Treatment in Rats

1976 ◽  
Vol 34 ◽  
pp. 286-287
Author(s):  
Richard L. Klein ◽  
Åsa K. Thureson-Klein ◽  
Harihara M. Mehendale
Keyword(s):  
Neurological Disorders ◽  
Corn Oil ◽  
Preliminary Investigation ◽  
Reproductive Capacity ◽  
Ultrastructural Changes ◽  
Lipid Deposition ◽  
Severe Toxicity ◽  
Sprague Dawley ◽  
Ether Anesthesia ◽  
Sprague Dawley Rats

KeponeR (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one) is an insecticide effective against ants and roaches. It can cause severe toxicity in fishes, birds, rodents and man. Prominent effects include hepatic lipid deposition and hypertrophy, impairment of reproductive capacity and neurological disorders. Mitochondrial oligomycin-sensitive Mg2+-ATPase is also inhibited. The present study is a preliminary investigation of tissue ultrastructural changes accompanying physiological signs of acute toxicity, which after two days treatment include: pronounced hypersensitivity and tremor, various degrees of anorexia and adipsia, and decreased weight gain.Three different series of adult male Sprague-Dawley rats (Charles River or CD-I) were treated by intubation with Kepone in corn oil at a dose of 50 mg per kg for 3 successive days or at 200 ppm in food for 8 days. After ether anesthesia, rats were immediately perfused via a cannula in the left ventricle with 4% p-formaldehyde and 0.5% glutaraldehyde in Millonig's phosphate buffer at pH 7.2 for 20-30 min at 22°C.

Ultrastructural changes in isolated rat liver perfused with cyclic heptapeptide toxins from norwegian freshwater cyanobacteria (blue-green algae)

1987 ◽  
Vol 45 ◽  
pp. 858-859
Author(s):  
A.S. Dabholkar ◽  
W.W. Carmichael ◽  
K. Berg ◽  
J. Wyman
Keyword(s):  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Isolated Rat Liver ◽  
Blue Green Algae ◽  
Sprague Dawley Rats ◽  
Cyclic Heptapeptide ◽  
Intracellular Changes ◽  
Oscillatoria Agardhii ◽  
Rat Livers ◽  
Isolated Rat

Intracellular changes in the hepatocytes of isolated rat livers perfused with cyclic heptapeptide toxins are described. The toxins used are 1) -Ala-Leu- β-methyl isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 944) from Microcystis aeruginosa- Lake Akersvatn, Norway; 2) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 1023) from Oscillatoria agardhii var. - Lake Kolbatnvatn, Norway; 3) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-dha (M.W. 1009) from Oscillatoria agardhii var. isothrix - Lake Froylandsvatn, Norway. Approximate LD intraperitoneal mouse for the toxins is 50, 500 and 1000 μg/kg respectively.Livers were removed from male Sprague Dawley rats and perfused for 15 min with a blood-free perfusate (50 ml) followed by 60 min with perfusate containing i) 25, 50, or 200 μg of M. aeruginosa toxin ii) 50, 250, 500 or 1000 μg of O. agardhii var. toxin and iii) 1000, 2000, 2500 or 5000 μg of O. agardhii var. isothrix toxin. Control livers were perfused for 75 min with the blood-free perfusate.

scholarly journals Oral absorption and drug interaction kinetics of moxifloxacin in an animal model of weightlessness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong Liang ◽  
Jing Ma ◽  
Bo Wei
Keyword(s):  
Oral Dose ◽  
Oral Absorption ◽  
Jugular Vein ◽  
Plasma Concentrations ◽  
Pharmacokinetic Data ◽  
Simulated Weightlessness ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Interaction Kinetics ◽  
Kinetics Of

AbstractTo investigate the effect of simulated weightlessness on the pharmacokinetics of orally administered moxifloxacin and the antacid Maalox or the antidiarrheal Pepto-Bismol using a tail-suspended (TS) rat model of microgravity. Fasted control and TS, jugular-vein-cannulated, male Sprague-Dawley rats received either a single 5 mg/kg intravenous dose or a single 10 mg/kg oral dose of moxifloxacin alone or with a 0.625 mL/kg oral dose of Maalox or a 1.43 mL/kg oral dose of Pepto-Bismol. Plasma concentrations of moxifloxacin were measured by HPLC. Pharmacokinetic data were analyzed using WinNonlin. Simulated weightlessness had no effect on moxifloxacin disposition after intravenous administration but significantly decreased the extent of moxifloxacin oral absorption. The coadministration of moxifloxacin with Maalox to either control or TS rats caused significant reductions in the rate and extent of moxifloxacin absorption. In contrast, the coadministration of moxifloxacin with Pepto-Bismol to TS rats had no significant effect on either the rate or the extent of moxifloxacin absorption. These interactions showed dose staggering when oral administrations of Pepto-Bismol and moxifloxacin were separated by 60 min in control rats but not in TS rats. Dose staggering was more apparent after the coadministration of Maalox and moxifloxacin in TS rats.

Ultrastructural changes of Basolateral Amygdaloid nuclei in the Sprague Dawley rats brain following exposure to naphthalene balls

2021 ◽  
Vol 12 (2) ◽  
pp. 1272-1275
Author(s):  
Angu Bala Ganesh K S V ◽  
Sujeet Shekhar Sinha ◽  
Kesavi Durairaj ◽  
Abdul Sahabudeen K
Keyword(s):  
Structural Changes ◽  
Corn Oil ◽  
Chromatin Condensation ◽  
Ultrastructural Changes ◽  
High Dose ◽  
Model Group ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
The Brain ◽  
Amygdaloid Nuclei

Naphthalene is a bicyclic aromatic constituent commonly used in different domestic and marketable applications comprising soil fumigants, lavatory scent disks and mothballs. Accidentally, workers, children and animals are exposed to naphthalene mothballs, so there is a need to study the pathology behind this chemical toxicity. The current study was carried out to assess the ultra structural changes of basolateral amygdaloid nuclei in the Sprague Dawley rats brain in association to naphthalene toxicity. The toxicity model group was administered with naphthalene (200 and 400mg) using corn oil as a vehicle for 28 days. The post delayed toxicity of naphthalene high dose ingestion was also assessed in rats. After the experimental period, the brain tissue was processed to observe the ultra structural changes using a transmission electron microscope. The alterations in cell organelles, nuclei damage, mitochondrial swelling, chromatin condensation suggested naphthalene induced damage in the neurons of the basolateral amygdala of the brain in the toxicity model group. These experimental trials provide information about the alert of mothball usage in the home and identify risks linked with accidental exposure and misuse.

Effect of fluoride on the proteomic profile of the hippocampus in rats

2015 ◽  
Vol 70 (5-6) ◽  
pp. 151-157 ◽  
Author(s):  
Ye Pan ◽  
Peng Lü ◽  
Lijing Yin ◽  
Keping Chen ◽  
Yuanqing He
Keyword(s):  
Body Weight ◽  
Spectroscopic Analysis ◽  
Physiological Saline ◽  
Treated Group ◽  
The Body ◽  
Learning Ability ◽  
Sprague Dawley ◽  
Acid Biosynthesis ◽  
Two Dimensional Gel Electrophoresis ◽  
Sprague Dawley Rats

Abstract Two-dimensional gel electrophoresis (2-DE) was used to detect fluoride-induced alterations in the proteome of the rat hippocampus. Male Sprague-Dawley rats (n=30) were subjected to treatments three weeks after weaning. Animals of the first group were injected intraperitoneally (i.p.) with aqueous NaF (20 mg/kg/body weight/day), the second group, injected with physiological saline, served as the control. After 30 days, the body weight of the fluoride-treated rats was lower than that of the control, and F– levels in serum were higher than in the control. The hippocampus was subjected to proteomic analysis, and the fluoride-treated group was found to contain 19 up-regulated and eight down-regulated proteins. The proteins, identified by mass-spectroscopic analysis of their fragments obtained after digestion, were found to be involved in amino acid biosynthesis, the insulin signaling pathway and various other crucial functions. Our results also provide useful information on the mechanism of the reduction of the learning ability and memory induced by F.

scholarly journals Erythropoietin Produces a Dual Effect on Carotid Body Chemoreception in Male Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Christian Arias-Reyes ◽  
Sofien Laouafa ◽  
Natalia Zubieta-DeUrioste ◽  
Vincent Joseph ◽  
Aida Bairam ◽  
...  
Keyword(s):  
Carotid Body ◽  
No Synthase ◽  
Male Rats ◽  
High Dose ◽  
No Production ◽  
Sprague Dawley ◽  
En Bloc ◽  
No Synthase Inhibitor ◽  
Sprague Dawley Rats ◽  
Synthase Inhibitor

Erythropoietin (EPO) regulates respiration under conditions of normoxia and hypoxia through interaction with the respiratory centers of the brainstem. Here we investigate the dose-dependent impact of EPO in the CB response to hypoxia and hypercapnia. We show, in isolated “en bloc” carotid body (CB) preparations containing the carotid sinus nerve (CSN) from adult male Sprague Dawley rats, that EPO acts as a stimulator of CSN activity in response to hypoxia at concentrations below 0.5 IU/ml. Under hypercapnic conditions, EPO did not influence the CSN response. EPO concentrations above 0.5 IU/ml decreased the response of the CSN to both hypoxia and hypercapnia, reaching complete inhibition at 2 IU/ml. The inhibitory action of high-dose EPO on the CSN activity might result from an increase in nitric oxide (NO) production. Accordingly, CB preparations were incubated with 2 IU/ml EPO and the unspecific NO synthase inhibitor (L-NAME), or the neuronal-specific NO synthase inhibitor (7NI). Both NO inhibitors fully restored the CSN activity in response to hypoxia and hypercapnia in presence of EPO. Our results show that EPO activates the CB response to hypoxia when its concentration does not exceed the threshold at which NO inhibitors masks EPO’s action.

Effects of androgens on bioactivity and immunoreactivity of pituitary FSH in GnRH antagonist-treated male rats

1990 ◽  
Vol 122 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Om P. Sharma ◽  
Shafiq A. Khan ◽  
Gerhard F. Weinbauer ◽  
Mohammed Arslan ◽  
Eberhard Nieschlag
Keyword(s):  
Isoelectric Focusing ◽  
Gnrh Antagonist ◽  
Molecular Composition ◽  
Male Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Combined Administration ◽  
Ph Range ◽  
Fsh Bioactivity

Abstract The effects of androgens on the bioactivity and molecular composition of pituitary FSH were examined in intact and GnRH antagonist-suppressed male rats. Eight groups of adult Sprague-Dawley rats were subjected to the following treatments: antagonist (75 μg/day by osmotic minipumps; sc), testosterone-filled Silastic implants (3×5 cm, sc), dihydrotestosterone-filled Silastic implants (3×5 cm, sc), E2 benzoate (15 μg/day, sc), and combined administration of antagonist with either steroid for 3 weeks. At the end of the treatment period, pituitaries were dissected out and homogenised. FSH content was determined in the pituitary extracts by an in vitro bioassay and a radioimmunoassay. Individual pituitary extracts from rats treated with vehicle, testosterone and testosterone + antagonist were subjected to isoelectric-focusing on sucrose density gradients performed in the pH range from 3.5 to 7.0. Individual isoelectric-focusing fractions (100-120) were analysed for bioactive and immunoreactive FSH. Treatment with antagonist, E2 or antagonist + E2 caused a significant decrease in pituitary FSH, whereas testosterone and dihydrotesterone alone or in combination with antagonist prevented the decrease in pituitary FSH. The effects of all treatments on both bioactive and immunoreactive FSH were similar. Testosterone treatment not only maintained FSH synthesis but also altered the molecular composition of pituitary FSH. Following treatment with testosterone there was a shift of maximal FSH bioactivity to the more acidic pH range. On the other hand, less bioactivity was recovered than corresponding immunoreactivity in the higher pH region, resulting in significantly reduced ratios of bioactivity to immunoreactivity of FSH. No significant differences were found in the isoelectric-focusing profiles or bioactivity to immunoreactivity ratios of pituitary FSH in animals treated with testosterone alone or in combination with antagonist. The results demonstrate that testosterone not only maintained the synthesis of both bioactive and immunoreactive FSH in male rats, but also influences the molecular composition of pituitary FSH. These effects of testosterone on pituitary FSH appear not to be mediated through hypothalamic GnRH.

THE EFFECT OF STILBOESTROL ANALOGUES ON THE METABOLISM OF STEROIDS BY THE TESTIS AND PROSTATE OF THE RAT IN VITRO

1973 ◽  
Vol 59 (3) ◽  
pp. 539-544 ◽  
Author(s):  
VARAPAN DANUTRA ◽  
MAUREEN E. HARPER ◽  
K. GRIFFITHS
Keyword(s):  
Marked Effect ◽  
Enzyme System ◽  
Testicular Tissue ◽  
Sesame Oil ◽  
Prostatic Tissue ◽  
Synthetic Activity ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Testosterone Administration

SUMMARY Male Sprague—Dawley rats were injected (i.m.) daily for 10 days with 100 μg of either oestradiol-17β, diethylstilboestrol (DES), dl-dihydrodibutylstilboestrol (dl-DHBS) or meso-dihydrodibutylstilboestrol (meso-DHBS) in 0·2 ml sesame oil. After 10 days, the testicular tissue was removed and incubated simultaneously with [7α-3H]dehydroepiandrosterone and [4-14C]17α-hydroxyprogesterone. Less testosterone was synthesized by the testicular tissue from animals treated with oestradiol-17β, DES and meso-DHBS than by the controls or animals treated with dl-DHBS. The decreased synthetic activity was related to the decreased activity of both the 17β-hydroxysteroid dehydrogenase and 17α-pregnene-C17, 20-lyase enzyme systems. Prostatic tissue was also incubated with [7α-3H]testosterone. Administration of DES, oestradiol-17β or meso-DHBS increased the metabolism of testosterone by the prostatic tissue with a marked effect on the 5α-reductase enzyme system.

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