BLOCKAGE OF THE ETHER-INDUCED SURGE OF PROLACTIN BY NALOXONE IN MALE RATS

1978 ◽  
Vol 79 (3) ◽  
pp. 397-398 ◽  
Author(s):  
S. H. SHIN
Keyword(s):  
Male Rats ◽  
Ether Anaesthesia ◽  
Queen's University ◽  
Endogenous Morphine

Department of Physiology, Abramsky Hall, Queen's University, Kingston, Ontario, Canada, K7L 3N6 (Received 17 July 1978) It is well established that the stress of ether anaesthesia raises the level of prolactin in the circulation of the rat (Wakabayashi, Arimura & Schally, 1971; Krulich, Hefco, Illner & Read, 1974). Morphine or the endogenous morphine-like peptides, endorphins and enkephalins, can stimulate the secretion of prolactin in vivo (Ojeda, Harms & McCann, 1974; Martin, Audet & Saunders, 1975; Bruni, Van Vugt, Marshall & Meites, 1977; Rivier, Vale, Ling, Brown & Guillemin, 1977; Chihara, Arimura, Coy & Schally, 1978); naloxone, however, blocks the stimulatory effects of these substances (Bruni et al. 1977; Rivier et al. 1977). It was recently demonstrated that naloxone inhibits the secretion of prolactin induced by stress due to heat or immobilization (Van Vugt, Bruni & Meites, 1978). The restraintinduced stress produced an immediate increase in the concentration of prolactin

Cardioprotective Effects of Diet with Different Grains on Lipid Profiles and Antioxidative System in Obesity-Induced Rats

2012 ◽  
Vol 82 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Y. Kim ◽  
H. Shin ◽  
S. Lee
Keyword(s):  
Aortic Wall ◽  
Plasma Lipids ◽  
Antioxidant Activities ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Thiobarbituric Acid ◽  
Lipid Profiles ◽  
Dietary Lipids ◽  
Male Rats

In the present study, the nutritional quality of four grains including adlay (AD), buckwheat (BW), glutinous barley (GB), and white rice (WR) were evaluated in terms of plasma lipid parameters, gut transit time, and thickness of the aortic wall in rats. The rats were then raised for 4 weeks on the high-fat diet based on the American Institute of Nutrition-93 (AIN-93 G) diets containing 1 % cholesterol and 20 % dietary lipids. Forty male rats were divided into 4 groups and raised for 4 weeks with a diet containing one of the following grains: WR, AD, BW, or WB. The level of thiobarbituric acid-reactive substances (TBARS) in liver was shown to be higher in rats by the order of those fed WR, AD, GB, and BW. This indicates that other grains decreased oxidative stress in vivo more than WR. The superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase levels in the AD, BW, and GB groups were significantly higher than those in the WR group (p < 0.05). Plasma lipid profiles differed significantly according to grain combination, and decreased aortic wall thickness was consistent with the finding of decreased plasma low-density lipoprotein cholesterol (LDL-C) (p < 0.05) and increased high-density lipoprotein (HDL-C) in rats fed AD, BW, and GB (p < 0.001). The antioxidant and hypolipidemic capacities of grains are quite high, especially those of adlay, buckwheat, and glutinous barley. In conclusion, this study has demonstrated that the whole grains had a cardioprotective effect. This effect was related to several mechanisms that corresponded to lowering plasma lipids, decreasing TBARS, and increasing antioxidant activities.

scholarly journals Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stem Cells ◽  
Locomotor Activity ◽  
Tissue Injury ◽  
Male Rats ◽  
Adipose Derived Stem Cells ◽  
Sprague Dawley ◽  
Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

scholarly journals Properties of a bovine collagen type I membrane for guided bone regeneration applications

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 210-221
Author(s):  
Igor S. Brum ◽  
Carlos N. Elias ◽  
Jorge J. de Carvalho ◽  
Jorge L. S. Pires ◽  
Mario J. S. Pereira ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Collagen Type ◽  
Mechanical Stability ◽  
Collagen Type I ◽  
Guided Bone Regeneration ◽  
Bone Volume ◽  
Male Rats ◽  
Toxicity Tests ◽  
Type I

Abstract Dental implant treatment requires an available bone volume in the implantation site to ensure the implant’s mechanical stability. When the bone volume is insufficient, one must resort to surgical means such as guided bone regeneration (GBR). In GBR surgery, bone grafts and membranes are used. The objective of this work is to manufacture and characterize the in vitro and in vivo properties of resorbable collagen type I membranes (Green Membrane®) for GBR. Membrane surface morphology was characterized by SEM and roughness was measured using an interferometric noncontact 3D system. In vivo skin sensitization and toxicity tests have been performed on Wistar rats. Bone defects were prepared in 24 adult male rats, filled with biomaterials (Blue Bone® and Bio Oss®) and covered with collagen membranes to maintain the mechanical stability of the site for bone regeneration. The incisions were closed with simple stitches; and 60 days after the surgery, the animals were euthanized. Results showed that the analyzed membrane was homogeneous, with collagen fiber webs and open pores. It had no sign of cytotoxicity and the cells at the insertion site showed no bone morphological changes. There was no tissue reaction and no statistical difference between Blue Bone® and Bio Oss® groups. The proposed membrane has no cytotoxicity and displays a biocompatibility profile that makes it suitable for GBR.

scholarly journals Boosting the Intra-Articular Efficacy of Low Dose Corticosteroid through a Biopolymeric Matrix: An In Vivo Model of Osteoarthritis

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1571
Author(s):  
Matilde Tschon ◽  
Francesca Salamanna ◽  
Lucia Martini ◽  
Gianluca Giavaresi ◽  
Luca Lorenzini ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Pain Sensitivity ◽  
Type Ii Collagen ◽  
Male Rats ◽  
In Vivo Model ◽  
Type Ii ◽  
Chemical Induction ◽  
Local Pain ◽  
Gait Parameters

The purpose of this study was to verify the efficacy of a single intra-articular (i.a.) injection of a hyaluronic acid-chitlac (HY-CTL) enriched with two low dosages of triamcinolone acetonide (TA, 2.0 mg/mL and 4.5 mg/mL), in comparison with HY-CTL alone, with a clinical control (TA 40 mg/mL) and with saline solution (NaCl) in an in vivo osteoarthritis (OA) model. Seven days after chemical induction of OA, 80 Sprague Dawley male rats were grouped into five arms (n = 16) and received a single i.a. injection of: 40 mg/mL TA, HY-CTL alone, HY-CTL with 2.0 mg/mL TA (RV2), HY-CTL with 4.5 mg/mL TA (RV4.5) and 0.9% NaCl. Pain sensitivity and Catwalk were performed at baseline and at 7, 14 and 21 days after the i.a. treatments. The histopathology of the joint, meniscus and synovial reaction, type II collagen expression and aggrecan expression were assessed 21 days after treatments. RV4.5 improved the local pain sensitivity in comparison with TA and NaCl. RV4.5 and TA exerted similar beneficial effects in all gait parameters. Histopathological analyses, measured by Osteoarthritis Research Society International (OARSI) and Kumar scores and by immunohistochemistry, evidenced that RV4.5 and TA reduced OA features in the same manner and showed a stronger type II collagen and aggrecan expression; both treatments reduced synovitis, as measured by Krenn score and, at the meniscus level, RV4.5 improved degenerative signs as evaluated by Pauli score. TA or RV4.5 treatments limited the local articular cartilage deterioration in knee OA with an improvement of the physical structure of articular cartilage, gait parameters, the sensitivity to local pain and a reduction of the synovial inflammation.

Effects of in vivo gonadal hormone environment on in vitro hGRF-40-stimulated GH release

1985 ◽  
Vol 249 (3) ◽  
pp. E276-E280 ◽  
Author(s):  
W. S. Evans ◽  
R. J. Krieg ◽  
E. R. Limber ◽  
D. L. Kaiser ◽  
M. O. Thorner
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Base Line ◽  
Pituitary Cells ◽  
Intact Male ◽  
Castrate Male ◽  
Basal Release

The effects of gender and the gonadal hormone environment on basal and stimulated growth hormone (GH) release by dispersed and continuously perifused rat anterior pituitary cells were examined. Cells from intact male and diestrus day 2 female rats and from castrate male rats either untreated or treated with testosterone (T) or 17 beta-estradiol (E2) were used. Basal GH release (ng/min per 10(7) cells; mean +/- SE) by cells from diestrus day 2 female rats was less than by cells from castrate rats treated with T (4.3 +/- 0.6 vs. 11.4 +/- 2.7, respectively; P less than 0.025). No other differences in basal release were detected. Concentration-response relationships were documented between human GH-releasing factor 40 (hGRF-40; 0.03-100 nM given as 2.5-min pulses every 27.5 min) and GH release. Mean (+/- SE) overall GH release (ng/min per 10(7) cells) above base line was greater by cells from intact male rats (496 +/- 92) than by cells from castrate (203 +/- 37.3; P less than 0.0001), castrate and T-treated (348 +/- 52.8; P = 0.008), or castrate and E2-treated (58.1 +/- 6.8; P less than 0.001) male rats or by diestrus day 2 rats (68.6 +/- 9.5; P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Differential regulation of insulin resistance and hypertension by sex hormones in fructose-fed male rats

2005 ◽  
Vol 289 (4) ◽  
pp. H1335-H1342 ◽  
Author(s):  
Harish Vasudevan ◽  
Hong Xiang ◽  
John H. McNeill
Keyword(s):  
Insulin Resistance ◽  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Sex Hormones ◽  
Threshold Value ◽  
Relative Increase ◽  
Estrogen Treatment ◽  
Male Rats ◽  
Normal Chow

Differences in gender are in part responsible for the development of insulin resistance (IR) and associated hypertension. Currently, it is unclear whether these differences are dictated by gender itself or by the relative changes in plasma estrogen and/or testosterone. We investigated the interrelationships between testosterone and estrogen in the progression of IR and hypertension in vivo in intact and gonadectomized fructose-fed male rats. Treatment with estrogen significantly reduced the testosterone levels in both normal chow-fed and fructose-fed rats. Interestingly, fructose feeding induced a relative increase in estradiol levels, which did not affect IR in both intact and gonadectomized fructose-fed rats. However, increasing the estrogen levels improved insulin sensitivity in both intact and gonadectomized fructose-fed rats. In intact males, fructose feeding increased the blood pressure (140 ± 2 mmHg), which was prevented by estrogen treatment. However, the blood pressure in the fructose-fed estrogen rats (125 ± 1 mmHg) was significantly higher than that of normal chow-fed (113 ± 1 mmHg) and fructose-fed gonadectomized rats. Estrogen treatment did not affect the blood pressure in gonadectomized fructose-fed rats (105 ± 2 mmHg). These data suggest the existence of a threshold value for estrogen below which insulin sensitivity is unaffected. The development of hypertension in this model is dictated solely by the presence or absence of testosterone. In summary, the development of IR and hypertension is governed not by gender per se but by the interactions of specific sex hormones such as estrogen and testosterone.

Differential effects of passive immunization with somatostatin antiserum on adenohypophysial hormone secretions in starved rats

1986 ◽  
Vol 109 (2) ◽  
pp. 169-174 ◽  
Author(s):  
J. N. Hugues ◽  
A. Enjalbert ◽  
E. Moyse ◽  
C. Shu ◽  
M. J. Voirol ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Hormone Secretion ◽  
Plasma Concentrations ◽  
Passive Immunization ◽  
Negative Control ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Minimal Effective Dose ◽  
Gh Secretion

ABSTRACT The role of somatostatin (SRIF) on adenohypophysial hormone secretion in starved rats was reassessed by passive immunization. Because of the absence of pulsatile GH secretion in starved rats, the effects of the injection of SRIF antiserum on GH levels can be clearly demonstrated. To determine whether starvation modifies the sensitivity of the adenohypophysis to SRIF, we measured 125I-labelled iodo-N-Tyr-SRIF binding. There was no difference in the dissociation constant (Kd) nor in the maximal binding capacity (Bmax) in fed (n = 15) and starved (n = 15) animals (Kd = 0·38 ± 0·09 (s.e.m.) and 0·45 ± 0·09 nmol; Bmax = 204 ± 39 and 205 ± 30 fmol/mg protein respectively). Administration of SRIF antiserum resulted in a dose-dependent increase in plasma concentrations of GH, TSH and prolactin. The minimal effective dose of SRIF antiserum was 50 μl for GH, 100 μl for TSH and 200 μl for prolactin. Our results show that: (1) starvation does not modify adenohypophysial SRIF-binding sites, (2) in starved male rats endogenous SRIF exerts a negative control on prolactin secretion in vivo and (3) sensitivity to endogenous SRIF seems to be different for each hypophysial cell type. J. Endocr. (1986) 109, 169–174

Genetic analysis of oxygen defense mechanisms in Drosophila melanogaster and identification of a novel behavioural mutant with a Shaker phenotype

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 749-757 ◽  
Author(s):  
James M. Humphreys ◽  
Brenda Duyf ◽  
Mei-Ling A. Joiner ◽  
John P. Phillips ◽  
Arthur J. Hilliker
Keyword(s):  
Drosophila Melanogaster ◽  
Defense Mechanisms ◽  
Chromosome Region ◽  
Recessive Mutation ◽  
Ether Anaesthesia ◽  
Ros Metabolism ◽  
Chromosome Mutations ◽  
New Gene ◽  
New Alleles

Mutants of Drosophila melanogaster that lack Cu/Zn superoxide dismutase or urate are hypersensitive to reactive oxygen species (ROS) generated in vivo by the redox-cycling agent paraquat. We have subsequently employed paraquat as a selective agent to identify adult viable mutants potentially defective in other, perhaps unknown, components of ROS metabolism. Paraquat screening of ethyl methanesulfonate-induced second- and third-chromosome mutations yielded 24 paraquat hypersensitive mutants. Two mutants were identified as being new alleles of the previously identified doublesex (dsx) and pink (p) genes. The remainder of the mutations identified previously undescribed genes, including one second chromosome paraquat hypersensitive mutant that was found to exhibit shaking legs, abdomen pulsations, and body shuddering under ether anaesthesia. This recessive mutation was mapped to the polytene chromosome region of 48A5–48B2 and defines a new gene we named quiver (qvr). This mutation is similar in phenotype to the Shaker (Sh), ether-a-gogo (eag), and Hyperkinetic (Hk) mutations, all of which affect potassium channel function in D. melanogaster. Key words : Drosophila, paraquat, EMS-mutagenesis, Shaker, oxidative-stress.

Ontogeny of Angiotensin-II-Induced Prolactin Release in vivo and in vitro in Female and Male Rats

1994 ◽  
Vol 59 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Graciela S. Díaz-Torga ◽  
Damasia Becú-Villalobos ◽  
Carlos Libertun
Keyword(s):  
Angiotensin Ii ◽  
Male Rats ◽  
Prolactin Release

scholarly journals Prolactin and Male Fertility: The Long and Short Feedback Regulation

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
M. K. Gill-Sharma
Keyword(s):  
Chromatin Condensation ◽  
Feedback Regulation ◽  
Pituitary Hormones ◽  
Feedback Mechanism ◽  
Reproductive Hormones ◽  
Male Rats ◽  
Normal Men

In the last 20 years, a pituitary-hypothalamus tissue culture system with intact neural and portal connections has been developed in our lab and used to understand the feedback mechanisms that regulate the secretions of adenohypophyseal hormones and fertility of male rats. In the last decade, several in vivo rat models have also been developed in our lab with a view to substantiate the in vitro findings, in order to delineate the role of pituitary hormones in the regulation of fertility of male rats. These studies have relied on both surgical and pharmacological interventions to modulate the secretions of gonadotropins and testosterone. The interrelationship between the circadian release of reproductive hormones has also been ascertained in normal men. Our studies suggest that testosterone regulates the secretion of prolactin through a long feedback mechanism, which appears to have been conserved from rats to humans. These studies have filled in a major lacuna pertaining to the role of prolactin in male reproductive physiology by demonstrating the interdependence between testosterone and prolactin. Systemic levels of prolactin play a deterministic role in the mechanism of chromatin condensation during spermiogenesis.

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