Meal-synchronized CEA in rats: effects of meal size, intragastric feeding, and subdiaphragmatic vagotomy

1999 ◽  
Vol 276 (5) ◽  
pp. R1276-R1288 ◽  
Author(s):  
Wesley White ◽  
Gary J. Schwartz ◽  
Timothy H. Moran
Keyword(s):  
Meal Size ◽  
Vagal Activity ◽  
Subdiaphragmatic Vagotomy ◽  
Feeding Cycle ◽  
Induce Activity ◽  
Before And After ◽  
Afferent Vagal ◽  
G 34 ◽  
Nutrient Infusion ◽  
Intact Rats

Within a feeding schedule of intermittent food access, large meals have the ability to induce activity at the same time the next day [circadian ensuing activity (CEA)]. In these experiments, we evaluated the minimum meal size necessary to induce CEA and whether oral-pharyngeal factors and afferent vagal activity played necessary roles in the induction of the underlying process. In experiment 1, every 33 h rats were given two meals separated by a 2-h interval. The size of the first meal was varied, while total intake every feeding cycle was held constant. When the initial meal was <10 g (34 kcal) CEA occurred later, indicating that such a meal size was subthreshold for inducing CEA. In experiment 2, rats were given intragastric (IG) meals every 33 h, before and after complete subdiaphragmatic vagotomy. IG nutrient meals induced CEA, indicating that extensive oral-pharyngeal experience was not necessary for CEA induction. CEA occurred in vagotomized rats but, compared with intact rats, appeared to occur later relative to nutrient infusion, indicating that afferent vagal activity may be sufficient but not necessary to induce CEA.

A new approach to treatment of stomatitis in experiments on white rats (experimental research)

2018 ◽  
pp. 168-173
Author(s):  
Е.Б. Ганина ◽  
Ю.В. Червинец ◽  
Н.В. Грудинин ◽  
В.Г. Шестакова ◽  
В.М. Червинец ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Oral Cavity ◽  
Experimental Research ◽  
Quantitative Composition ◽  
Oral Diseases ◽  
New Approach ◽  
Highly Active ◽  
White Rats ◽  
Before And After ◽  
Intact Rats

Цель исследования - охарактеризовать микробиологическую картину стоматита до и после его лечения высокоактивными культурами лактобацилл, дать оценку эффективности их применения при экспериментальном стоматите. Методика. Опыты проводились на 32 самках беспородных белых крыс массой 230 г. Моделирование стоматита включало 2 этапа: моделирование травматического стоматита и воспроизведение бактериального стоматита на базе травматического. У крыс контрольной и опытных серий на всех этапах эксперимента брали мазки с поверхности десен для характеристики микробиоценоза ротовой полости. Результаты. После обработки слизистой оболочки полости рта (СОПР) культурой патогенного штамма Staphylococcus aureus существенно снизились частота встречаемости и количество условно-патогенных микроорганизмов. Лечение стоматита у крыс культурами лактобацилл ( Lactobacillus 11 зв., Lactobacillus 2 п.рта, Lactobacillus 24 д.ст.) и их комбинацией приводило к снижению распространенности S. aureus вплоть до его исчезновения, а также к нормализации количества условно-патогенной микробиоты. Заключение. Исследования показали эффективность использования отдельных высокоактивных штаммов лактобацилл или их комбинации при лечении заболеваний СОПР, в частности бактериального стоматита. Aim. To characterize the microbiological picture of stomatitis in intact rats before and after the treatment with highly active cultured lactobacilli and to evaluate the effectiveness of this treatment in experiments on white rats. Methods. Experiments were carried out on 32 mongrel female white rats weighing 230 g. Smears were taken from the gum surface of control and experimental rats at all stages of the experiment to characterize the oral cavity microbiocenosis. Results. After treatment of the oral cavity with cultured Staphylococcus aureus , the occurrence and quantity of opportunistic microorganisms significantly decreased. The treatment of stomatitis in rats with cultured lactobacillus ( Lactobacillus 11 zv., Lactobacillus 2 p.r., Lactobacillus 24 d.st. and their combination) led to a decrease in S. aureus prevalence up to its extinction and to normalization of the quantitative composition of opportunistic microbiota. Conclusions. The study showed the effieacy of highly active lactobacillus strains individually or their combinations in the treatment of oral diseases, in particular, bacterial stomatitis.

Does cuticular elasticity regulate the size of the blood meal imbibed by female Glossina austeni?

1983 ◽  
Vol 61 (8) ◽  
pp. 1888-1891 ◽  
Author(s):  
C. B. Carruthers ◽  
K. G. Davey
Keyword(s):  
Direct Measurement ◽  
Blood Meal ◽  
Meal Size ◽  
Tsetse Flies ◽  
Glossina Austeni ◽  
Before And After

In tsetse flies, a larva grows to maturity inside the uterus of the female. The size of the blood meal imbibed by females is known to increase at ovulation and decrease as the larva gets larger, so that the total volume of the fly remains constant. This has led to the hypothesis that meal size is determined by cuticular elasticity. Direct measurement of the elasticity of abdominal cuticle in mated females, before and after ovulation, and in virgin females, which do not ovulate, demonstrates that cuticular elasticity is unrelated to ovulation. Further, meal size is not closely correlated with cuticular elasticity. The hypothesis is therefore rejected.

Role of vagal afferents in the control of abdominal expiratory muscle activity in the dog

1991 ◽  
Vol 71 (5) ◽  
pp. 1795-1800 ◽  
Author(s):  
S. B. Hollstien ◽  
M. L. Carl ◽  
E. S. Schelegle ◽  
J. F. Green
Keyword(s):  
Muscle Activity ◽  
Vagal Afferents ◽  
Oblique Muscle ◽  
Vagus Nerves ◽  
Expiratory Muscle ◽  
C Fibers ◽  
C Fiber ◽  
Before And After ◽  
Afferent Vagal ◽  
Alpha Chloralose

We examined the contribution of afferent vagal A- and C-fibers on abdominal expiratory muscle activity (EMA). In seven spontaneously breathing supine dogs anesthetized with alpha-chloralose we recorded the electromyogram of the external oblique muscle at various vagal temperatures before and after the induction of a pneumothorax. When myelinated fibers were blocked selectively by cooling the vagus nerves to 7 degrees C, EMA decreased to 40% of control (EMA at 39 degrees C). With further cooling to 0 degrees C, removing afferent vagal C-fiber activity, EMA returned to 72% of control. On rewarming the vagus nerves to 39 degrees C, we then induced a pneumothorax (27 ml/kg) that eliminated the EMA in all the dogs studied. Cooling the vagus nerves to 7 degrees C, during the pneumothorax, produced a slight though not significant increase in EMA. However, further cooling of the vagus nerves to 0 degrees C caused the EMA to return vigorously to 116% of control. In three dogs, intravenous infusion of a constant incrementally increasing dose of capsaicin, a C-fiber stimulant, decreased EMA in proportion to the dose delivered. These results suggest that EMA is modulated by a balance between excitatory vagal A-fiber activity, most likely from slowly adapting pulmonary stretch receptors, and inhibitory C-fiber activity, most likely from lung C-fibers.

Increase in vagal activity during hypotensive lower-body negative pressure in humans

1988 ◽  
Vol 255 (1) ◽  
pp. R149-R156 ◽  
Author(s):  
K. Sander-Jensen ◽  
J. Mehlsen ◽  
C. Stadeager ◽  
N. J. Christensen ◽  
J. Fahrenkrug ◽  
...  
Keyword(s):  
Heart Rate ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Venous Pressure ◽  
Initial Increase ◽  
Vagal Activity ◽  
Lower Body ◽  
Central Venous ◽  
Subsequent Decrease ◽  
Before And After

Progressive central hypovolemia is characterized by a normotensive, tachycardic stage followed by a reversible, hypotensive stage with slowing of the heart rate (HR). We investigated circulatory changes and arterial hormone concentrations in response to lower-body negative pressure (LBNP) in six volunteers before and after atropine administration. LBNP of 55 mmHg initially resulted in an increase in HR from 55 +/- 4 to 90 +/- 5 beats/min and decreases in mean arterial pressure (MAP) from 94 +/- 4 to 81 +/- 5 mmHg, in central venous pressure from 7 +/- 1 to -3 +/- 1 mmHg, and in cardiac output from 6.1 +/- 0.5 to 3.7 +/- 0.11/min. Concomitantly, epinephrine and norepinephrine levels increased. After 8.2 +/- 2.3 min of LBNP, the MAP had decreased to 41 +/- 7 mmHg and HR had decreased to 57 +/- 3 beats/min. Vasopressin increased from 1.2 +/- 0.3 to 137 +/- 45 pg/ml and renin activity increased from 1.45 +/- 4.0 to 3.80 +/- 1.0 ng.ml-1.h-1 with no further changes in epinephrine, norepinephrine, and vasoactive intestinal polypeptide. A tardy rise in pancreatic polypeptide indicated increased vagal activity. After atropine. LBNP also caused an initial increase in HR, which, however, remained elevated during the subsequent decrease in MAP to 45 +/- 6 mmHg occurring after 8.1 +/- 2.4 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Leuprolide acetate affects intestinal motility in female rats before and after ovariectomy

1992 ◽  
Vol 262 (1) ◽  
pp. G185-G190
Author(s):  
R. Khanna ◽  
R. M. Browne ◽  
A. D. Heiner ◽  
M. H. Clench ◽  
J. R. Mathias
Keyword(s):  
Gastrointestinal Motility ◽  
Low Dose ◽  
Reproductive Hormones ◽  
Leuprolide Acetate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Gnrh Analogue ◽  
Fed State ◽  
Before And After ◽  
Intact Rats

Leuprolide acetate, a gonadotropin-releasing hormone (GnRH) analogue, is currently being proposed to control debilitating symptoms in women with functional bowel disease. Whether leuprolide alters gastrointestinal motility as part of its actions is unknown. This study was designed to assess, using myoelectric techniques in an animal model, the effects of leuprolide on potential mechanisms of neuromuscular function of small intestine. Female rats with (n = 6) or without (n = 8) bilateral ovariectomy were used to study jejunal motility before and after leuprolide therapy. Throughout the study, daily leuprolide dosages of 0.02, 0.2, or 0.4 micrograms/kg were injected into intact rats and 0.02, 0.2, 0.4, 1.0, or 2.5 micrograms/kg into ovariectomized rats. Recordings were made while the rats were fasted and postprandial and before and after leuprolide administration. Under control conditions, migrating myoelectric complexes (MMCs) were found in intact female rats, whether fasted or postprandial. After ovariectomy, postprandial controls and those treated with low-dose leuprolide (0.02, 0.2, and 0.4 micrograms) had typical fed-state patterns and no MMCs, but at 1.0 and 2.5 micrograms the fed state was inhibited and cycling MMCs occurred at a frequency similar to that of fasted controls. Reproductive hormones thus have a significant effect on gastrointestinal motility.

Receptive-field properties of rat ventral posterior medial neurons before and after selective kainic acid lesions of the trigeminal brain stem complex

1987 ◽  
Vol 57 (5) ◽  
pp. 1577-1600 ◽  
Author(s):  
R. W. Rhoades ◽  
G. R. Belford ◽  
H. P. Killackey
Keyword(s):  
Receptive Field ◽  
Kainic Acid ◽  
Appreciable Effect ◽  
Guard Hair ◽  
Peripheral Stimulation ◽  
Receptive Field Properties ◽  
Before And After ◽  
Mystacial Vibrissae ◽  
Nucleus Principalis ◽  
Intact Rats

Single neurons were recorded from the ventral posteromedial thalamic nucleus (VPM) of urethan-anesthetized rats. Six of these animals were intact, 28 sustained kainic acid (KA) lesions of trigeminal nucleus principalis (PrV), and 9 received similar lesions of trigeminal subnucleus interpolaris (SpVi). Four animals sustained PrV lesions that were followed, at an interval of 1-3 mo, by KA injections into SpVi. Special attention was paid to the receptive-field characteristics of neurons that were sensitive to deflection of the mystacial vibrissae. In normal animals, we recorded a total of 167 VPM neurons, 85% (n = 142) of which were vibrissa sensitive. The remaining VPM cells were excited by either guard hair deflection (8.4%), indentation of the skin (0.6%), or deflection of either vibrissae or guard hairs (1.8%). Seven cells (4.2%) were unresponsive. The topography of the trigeminal representation in VPM was similar to that reported previously by Waite (59). Vibrissa-sensitive neurons in intact rats generally gave rapidly adapting responses (84.5%), and only 16.2% were directionally selective. The vast majority (80.3%) of the vibrissa-sensitive cells were activated by deflection of only one whisker (1.2 +/- 0.5, mean +/- SD); none were excited by deflection of more than four vibrissae. Injections of KA into SpVi of otherwise intact rats (n = 9) had no appreciable effect on the receptive-field characteristics of vibrissa-sensitive VPM neurons. Injections of KA into PrV markedly altered the receptive-field properties of VPM cells. Recordings were made from 45 VPM neurons over a period extending from 0 to 10 h after KA injections into PrV in five rats. Of these cells, 4.4% were excited by vibrissa deflection and the remainder were unresponsive. Additional recordings from SpVi and the superior colliculus of these same animals indicated that the neurotoxin probably did not damage interpolaris neurons or their axons. Recordings were made from 394 VPM cells in 22 rats that survived 1-6 days after KA lesions of PrV. These experiments demonstrated an increase in the number of thalamic cells that were responsive to peripheral stimulation over this period. By 6 days after the lesion (4 animals), 52.8% of the 73 VPM neurons we recorded were excited by somatosensory stimuli. Of these, 89.5% were activated by deflection of one or more mystacial vibrissae. The average number of whiskers that excited a given VPM cell in these rats was 6.3 +/- 2.0 (SD). Recordings were made from VPM in five rats that survived 30-90 days after KA injections in PrV.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of oestradiol-17β on testicular microcirculation in rats

1987 ◽  
Vol 115 (3) ◽  
pp. 489-495 ◽  
Author(s):  
A. Widmark ◽  
J. E. Damber ◽  
A. Bergh
Keyword(s):  
Blood Vessels ◽  
Interstitial Fluid ◽  
Fluid Volume ◽  
Polymorphonuclear Leucocytes ◽  
Testosterone Production ◽  
Interstitial Fluid Volume ◽  
Before And After ◽  
Testicular Steroidogenesis ◽  
Hypophysectomized Rats ◽  
Intact Rats

ABSTRACT The effect of oestradiol-17β on testicular micro-circulation in intact and hypophysectomized rats was studied before and after treatment with human chorionic gonadotrophin (hCG). Treatment of intact rats with oestradiol-17β for 5 days did not influence vasomotion but decreased testicular interstitial fluid volume (IFV). Treatment of intact rats with 50 IU hCG 8 h before the experiment began induced an increase in testicular IFV, abolished vasomotion and increased the accumulation of polymorphonuclear leucocytes in the testicular venules and interstitium. These changes were unaffected by pretreatment with oestradiol-17β, despite the decreased testosterone production. However, pretreatment with oestradiol-17β potentiated the hCG-induced migration of polymorphonuclear leucocytes to the interstitium. The interstitial fluid volume and number of polymor phonuclear leucocytes in blood vessels were decreased in hypophysectomized rats, and vasomotion was abolished. Daily treatment with 5 IU hCG increased the IFV and the number of polymorphonuclear leucocytes in blood vessels, and preserved vasomotion. Treatment of hypophysectomized rats with oestradiol-17β decreased testosterone production but did not influence basal IFV, vasomotion or the changes in IFV and vasomotion induced by 5 IU hCG. The present study shows that the regulation of testicular vascular permeability and vasomotion may not be directly related to testicular steroidogenesis, and that oestrogens are probably not involved as a mediator of the hCG-induced changes in testicular microcirculation. J. Endocr. (1987) 115, 489–495

scholarly journals Improvement of Circadian Rhythm of Heart Rate Variability by Eurythmy Therapy Training

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Georg Seifert ◽  
Jenny-Lena Kanitz ◽  
Kim Pretzer ◽  
Günter Henze ◽  
Katharina Witt ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Negative Impact ◽  
Vagal Activity ◽  
Nonlinear Parameters ◽  
Low Frequencies ◽  
Before And After ◽  
Time Domains

Background. Impairment of circadian rhythm is associated with various clinical problems. It not only has a negative impact on quality of life but can also be associated with a significantly poorer prognosis. Eurythmy therapy (EYT) is an anthroposophic movement therapy aimed at reducing fatigue symptoms and stress levels.Objective. This analysis of healthy subjects was conducted to examine whether the improvement in fatigue symptoms was accompanied by improvements in the circadian rhythm of heart rate variability (HRV).Design. Twenty-three women performed 10 hours of EYT over six weeks. Electrocardiograms (ECGs) were recorded before and after the EYT trial. HRV was quantified by parameters of the frequency and time domains and the nonlinear parameters of symbolic dynamics.Results. The day-night contrast with predominance of vagal activity at night becomes more pronounced after the EYT training, and with decreased Ultralow and very low frequencies, the HRV shows evidence of calmer sleep. During the night, the complexity of the HRV is significantly increased indicated by nonlinear parameters.Conclusion. The analysis of the circadian patterns of cardiophysiological parameters before and after EYT shows significant improvements in HRV in terms of greater day-night contrast caused by an increase of vagal activity and calmer and more complex HRV patterns during sleep.

Glucagon acts in the liver to control spontaneous meal size in rats

1993 ◽  
Vol 264 (1) ◽  
pp. R116-R122 ◽  
Author(s):  
N. Geary ◽  
J. Le Sauter ◽  
U. Noh
Keyword(s):  
Vena Cava ◽  
Inhibitory Effect ◽  
Meal Size ◽  
Dark Phase ◽  
Glucagon Receptor ◽  
Hepatic Portal ◽  
Hepatic Branch ◽  
Portal Infusion ◽  
Intact Rats

To determine the site of origin of pancreatic glucagon's inhibitory effect on spontaneous feeding in rats, glucagon was infused into either the hepatic portal vein or the inferior vena cava during spontaneous meals late in the dark phase. Hepatic portal infusion of 1.7-13.6 micrograms glucagon/meal reduced spontaneous meal size. In contrast, these doses did not significantly affect meal size when delivered via vena caval catheters that ended near the junction of the hepatic vein. This difference indicates that glucagon receptor sites in the liver initiate the satiating action of glucagon during spontaneous meals. The vagal dependency of glucagon satiety was also tested. Hepatic portal infusion of 13.6 micrograms glucagon/meal reduced the size of spontaneous meals both early and late in the dark in neurally intact rats, but not in hepatic-vagotomized rats. Finally, antagonism of endogenous glucagon with hepatic portal infusion of glucagon antibodies in a dose sufficient to neutralize 1 ng glucagon in vitro increased spontaneous meal size in intact rats, but not in hepatic-vagotomized rats. Thus the satiating effects of both exogenous and endogenous glucagon on spontaneous food intake appear to depend on the hepatic branch of the vagus. Taken together, these results are consistent with the hypothesis that glucagon acts in the liver to produce a satiety signal that is transmitted to the brain by the hepatic branch of the abdominal vagus.

Spontaneous renal blood flow autoregulation curves in conscious sinoaortic baroreceptor-denervated rats

2002 ◽  
Vol 282 (1) ◽  
pp. F51-F58 ◽  
Author(s):  
Silene L. S. Pires ◽  
Claude Julien ◽  
Bruno Chapuis ◽  
Jean Sassard ◽  
Christian Barrès
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Renal Blood Flow ◽  
Coefficient Of Variation ◽  
Tubuloglomerular Feedback ◽  
Before And After ◽  
Renal Blood Flow Autoregulation ◽  
Limited Accuracy ◽  
Weibull Equation ◽  
Intact Rats

These experiments examined whether the conscious sinoaortic baroreceptor-denervated (SAD) rat, owing to its high spontaneous arterial pressure (AP) variability, might represent a model for renal blood flow (RBF) autoregulation studies. In eight SAD and six baroreceptor-intact rats, AP and RBF were recorded (1-h periods) before and after furosemide (10 mg/kg followed by 10 mg · kg−1 · h−1 iv)administration. In control conditions, AP variability was markedly enhanced in SAD rats (coefficient of variation: 16.0 ± 1.2 vs. 5.4 ± 0.5% in intact rats), whereas RBF variability was only slightly increased (8.7 ± 0.6 vs. 6.1 ± 0.5% in intact rats), suggesting buffering by autoregulatory mechanisms. In SAD rats, but not in intact rats, the AP-RBF relationships could be modeled with a four-parameter sigmoid Weibull equation ( r 2 = 0.24 ± 0.07, 3,600 data pairs/rat), allowing for estimation of an autoregulatory plateau (10.1 ± 0.7 ml/min) and a lower limit of RBF autoregulation (PLL = 93 ± 6 mmHg, defined as AP at RBF 5% below the plateau). After furosemide treatment, autoregulation curves ( r 2 = 0.49 ± 0.07) in SAD rats were shifted downward (plateau = 8.6 ± 0.8 ml/min) and rightward (PLL = 102 ± 5 mmHg). In five of six intact rats, PLL became measurable (104 ± 1 mmHg), albeit with limited accuracy ( r 2 = 0.09 ± 0.03). In conclusion, the conscious SAD rat offers the possibility of describing RBF autoregulation curves under dynamic, unforced conditions. The tubuloglomerular feedback and myogenic mechanisms cooperate in setting PLL and thus in stabilizing RBF during spontaneous depressor episodes.

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