Circannual variations in serum concentrations of pituitary, thyroid, parathyroid, gonadal and adrenal hormones in male laboratory rats

1983 ◽  
Vol 97 (2) ◽  
pp. 179-185 ◽  
Author(s):  
C. C. Wong ◽  
K.-D. Döhler ◽  
M. J. Atkinson ◽  
H. Geerlings ◽  
R.-D. Hesch ◽  
...  

Seasonal effects were studied on basal levels of hormones in the serum of adult male Sprague–Dawley rats, which were born and raised under rigorously controlled laboratory conditions. Groups of 90-day-old rats were killed at monthly intervals by rapid decapitation. Significant fluctuations were observed throughout the observation period of 19 months in serum levels of TSH, prolactin, androgens, tri-iodothyronine and LH. Minor fluctuations were observed in serum levels of FSH, corticosterone, parathyroid hormone and thyroxine. The results indicate that male laboratory rats exhibit circannual and semi-annual fluctuations in serum levels of several hormones even though the animals were born, raised and maintained in constant laboratory conditions.

Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.


Endocrine ◽  
2013 ◽  
Vol 44 (3) ◽  
pp. 809-811 ◽  
Author(s):  
Brielle V. Rosa ◽  
Hugh T. Blair ◽  
Mark H. Vickers ◽  
Cameron G. Knight ◽  
Patrick C. H. Morel ◽  
...  

1974 ◽  
Vol 75 (3) ◽  
pp. 491-496 ◽  
Author(s):  
Junichi Mori ◽  
Hiroshi Nagasawa ◽  
Reiko Yanai ◽  
Junji Masaki

ABSTRACT The sequence of changes in the serum levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from 2 days before to 24 h after parturition of primiparous Sprague-Dawley rats was investigated by radioimmunoassay. No appreciable change in average serum FSH levels was observed during 2 days before and 1 h after parturition. After this the levels increased gradually to show a peak at 7 h after parturition and then declined gradually until 24 h after parturition. However, the level at 24 h after parturition was still twice as high as that at parturition (0 h). The average serum LH levels which were low between 2 days before and 1 h after parturition, showed a peak at 7 h and decreased toward 13 h after parturition. The same levels as at parturition were maintained between 13 and 24 h after parturition. The time of surge of either FSH or LH was closely related to the time after parturition. There were some differences between FSH and LH in the patterns of sequence of changes in the serum levels near parturition.


1999 ◽  
Vol 276 (3) ◽  
pp. E558-E564 ◽  
Author(s):  
Regine Minet-Quinard ◽  
Christophe Moinard ◽  
Françoise Villie ◽  
Stephane Walrand ◽  
Marie-Paule Vasson ◽  
...  

Aged rats are more sensitive to injury, possibly through an impairment of nitrogen and glutamine (Gln) metabolisms mediated by glucocorticoids. We studied the metabolic kinetic response of adult and old rats during glucocorticoid treatment. The male Sprague-Dawley rats were 24 or 3 mo old. Both adult and old rats were divided into 7 groups. Groups labeled G3, G5, and G7 received, by intraperitoneal injection, 1.50 mg/kg of dexamethasone (Dex) for 3, 5, and 7 days, respectively. Groups labeled G3PF, G5PF, and G7PF were pair fed to the G3, G5, or G7 groups and were injected with an isovolumic solution of NaCl. One control group comprised healthy rats fed ad libitum. The response to aggression induced specifically by Dex (i.e., allowing for variations in pair-fed controls) appeared later in the aged rats (decrease in nitrogen balance from day 1 in adults but only from day 4 in old rats). The adult rats rapidly adapted to Dex treatment, whereas the catabolic state worsened until the end of treatment in the old rats. Gln homeostasis was not maintained in the aged rats; despite an early increase in muscular Gln synthetase activity, the Gln pool was depleted. These results suggest a kinetic impairment of both nitrogen and muscle Gln metabolisms in response to Dex with aging.


MicroRNA ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 224-231
Author(s):  
Amin Derakhshanfar ◽  
Javad Moayedi ◽  
Mahjoob Vahedi ◽  
Abouzar Valizadeh

Background: Arum conophalloides (A. conophalloides) is a wild edible delicate plant, widely used in traditional medicine. Objective: This study aimed to examine the effects of A. conophalloides extracts on biochemical, molecular, and histopathological changes in the rat. Methods: Fifty adult male Sprague-Dawley rats were divided into 5 groups (10 each) as follows: G1 or control, received distilled water; G2 and G3, treated with the aqueous extract at doses of 200 and 400 mg/kg; G4 and G5, treated with the hydroalcoholic extract at doses of 200 and 400 mg/kg. Prior to and at the end of the experiments, the serum levels of biochemistry parameters and the relative expression of miR-122 were assessed. Moreover, the liver and kidney tissues were examined microscopically. Results: Liver and kidney tissues showed normal structure in all groups. There were no significant changes in biochemical indices or the expression of miR-122 in the extract-treated groups at the dose of 200 mg/kg. However, the group that received the aqueous extract at the dose of 400 mg/kg exhibited a significantly lower level of HDL, LDL, ALT, and ALP in comparison to the control. Additionally, miR-122 expression in this group exhibited a 10-fold increase (P=0.009). Conclusion: The serum level of hepatocyte-specific miR-122 will be more helpful in detecting hepatic changes in early stages than ALT and AST activity or histopathological evaluations of liver sections. Our findings highlight the potential hepatotoxicity of A. conophalloides aqueous extract in a rat model.


2010 ◽  
Vol 29 (4) ◽  
pp. 358-371 ◽  
Author(s):  
Jozef J. W. M. Mertens ◽  
Daniel W. Sved ◽  
Gary B. Marit ◽  
Nichole R. Myers ◽  
Phil L. Stetson ◽  
...  

S-111-S-WB, a mixture of perfluoro fatty acid ammonium salts (C6-C13), was administered orally to Crl:CD (SD)IGS-BR rats. Higher hepatic β-oxidation and liver weights with hepatocellular hypertrophy were present at the 0.125 and 0.6 mg/kg/d dosage. The 0.6 mg/kg/d males developed hepatocellular degeneration and necrosis. Lower serum protein and higher bilirubin and BUN were seen in the 0.6 mg/kg/d males and lower globulin and higher alkaline phosphatase in the 0.125 mg/kg/d males and 0.6 mg/kg/d animals. After 2 weeks, serum concentrations of pentadecafluorooctanoic acid (C8), heptadecafluorononanoic acid (C9), perfluoroundecanoic acid (C11), and perfluorotridecanoic acid (C13) were constant for at least 8 hours. After 90 days, only C9 in the 0.025 mg/kg/d females had reached steady state. Serum C8 and C9 concentrations in the males were 10-fold higher than in the females, whereas C11 and C13 were similar for both genders. The main elimination was via the urine for C8 (males) and C9 (females), and via the feces for C11 and C13. The no-observed-effect level (NOEL) was 0.025 mg/kg/d for the males and 0.125 mg/kg/d for the females.


1964 ◽  
Vol 42 (4) ◽  
pp. 567-577 ◽  
Author(s):  
Lorraine C. Smith ◽  
L.-P. Dugal

Exposure of white rats to 2 °C for 20 weeks caused an immediate and sustained increase in the excretion of catechol amines as compared to controls kept at 23 °C. Adrenaline excretion increased approximately three to four times while noradrenaline excretion increased about eight times. There were no marked differences between Wistar and Sprague–Dawley rats in the amounts of adrenaline and noradrenaline excreted at 23 °C or 2 °C. 'Old' rats kept in activity cages excreted much more of the catechol amines both at 23 °C and 2 °C than did the other rats and they showed a peak for adrenaline excretion after 1 week and for noradrenaline excretion after 3 to 4 weeks in the cold.


2000 ◽  
Vol 88 (6) ◽  
pp. 2023-2030 ◽  
Author(s):  
S. A. Shore ◽  
J. H. Abraham ◽  
I. N. Schwartzman ◽  
G. G. Krishna Murthy ◽  
J. D. Laporte

During ozone (O3) exposure, adult rats decrease their minute ventilation (V˙e). To determine whether such changes are also observed in immature animals, Sprague-Dawley rats, aged 2, 4, 6, 8, or 12 wk, were exposed to O3(2 ppm) in nose-only-exposure plethysmographs. BaselineV˙e normalized for body weight decreased with age from 2.1 ± 0.1 ml ⋅ min−1⋅ g−1in 2-wk-old rats to 0.72 ± 0.03 ml ⋅ min−1⋅ g−1in 12-wk-old rats, consistent with the higher metabolic rates of younger animals. In adult (8- and 12-wk-old) rats, O3caused 40–50% decreases in V˙e that occurred primarily as the result of a decrease in tidal volume. In 6-wk-old rats, O3-induced changes inV˙e were significantly less, and in 2- and 4-wk-old rats, no significant changes inV˙e were observed during O3exposure. The increased baseline V˙e and the smaller decrements in V˙e induced by O3in the immature rats imply that their delivered dose of O3is much higher than in adult rats. To determine whether these differences in O3dose influence the extent of injury, we measured bronchoalveolar lavage protein concentrations. The magnitude of the changes in bronchoalveolar lavage induced by O3was significantly greater in 2- than in 8-wk-old rats (267 ± 47 vs. 165 ± 22%, respectively, P < 0.05). O3exposure also caused a significant increase in PGE2in 2-wk-old but not in adult rats. The results indicate that the ventilatory response to O3is absent in 2-wk-old rats and that lack of this response, in conjunction with a greater specific ventilation, leads to greater lung injury.


2017 ◽  
Vol 35 (3) ◽  
pp. 208-214 ◽  
Author(s):  
Shulan Ma ◽  
Dongju Li ◽  
Yi Feng ◽  
Jianwei Jiang ◽  
Bo Shen

Aim To observe the effects of electroacupuncture (EA) on uterine morphology and expression of oestrogen receptor (ER) α and β in ovariectomised (OVX) rats. Methods Thirty female Sprague-Dawley rats with regular 4-day oestrus cycles were divided into a sham operation group (Control, n=10) and two OVX groups that remained untreated (OVX group, n=10) or received EA treatment (OVX+EA group, n=10). In the latter group, EA was applied at CV4, CV3, SP6 and bilateral Zigong (30 min per day) for 3 days. The effects of EA on uterine morphology were observed by H&E staining. Quantitative real-time reverse transcription-PCR (qRT-PCR) and Western blotting were used to measure ERα and ERβ mRNA and protein expression, respectively. Results Relative to the (untreated) OVX group, EA treatment significantly increased the uterine wet weight to body weight (UWW/BW) ratio (0.47±0.04 vs 0.31±0.03 g/kg, p=0.04), and myometrial thickness (109.39±10.71 vs 60.81±8.1 μm, p=0.016) of OVX rats. Similarly, the total number of endometrial glands per cross section and endometrial thickness in the OVX +EA group was significantly increased compared to the (untreated) OVX group. EA treatment also increased protein (but not mRNA) expression of both ERα and ERβ in the uteri of OVX rats. Conclusions This study has demonstrated that EA treatment decreases uterine atrophy in OVX rats. This unique effect of EA on the uterus may be due to upregulation of serum levels of E2 and differential regulation of sex steroid receptors ERα and ERβ.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Nima Tirgan ◽  
Gabriela A. Kulp ◽  
Praveena Gupta ◽  
Adam Boretsky ◽  
Tomasz A. Wiraszka ◽  
...  

Diabetes and smoking are known risk factors for cataract development. In this study, we evaluated the effect of nicotine on the progression of cataracts in a type 1 diabetic rat model. Diabetes was induced in Sprague-Dawley rats by a single injection of 65 mg/kg streptozotocin. Daily nicotine injections were administered subcutaneously. Forty-five rats were divided into groups of diabetics with and without nicotine treatment and controls with and without nicotine treatment. Progression of lens opacity was monitored using a slit lamp biomicroscope and scores were assigned. To assess whether systemic inflammation played a role in mediating cataractogenesis, we studied serum levels of eotaxin, IL-6, and IL-4. The levels of the measured cytokines increased significantly in nicotine-treated and untreated diabetic animals versus controls and demonstrated a positive trend in the nicotine-treated diabetic rats. Our data suggest the presence of a synergistic relationship between nicotine and diabetes that accelerated cataract formation via inflammatory mediators.


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