Postnatal maturation of ventilation and breathing pattern in kittens: influence of sleep

Ventilation and breathing pattern were studied in kittens at 1, 2, 3, 4, and 8 wk of life during quiet wakefulness (W), quiet sleep (QS), and active sleep (AS) with the barometric method. Tidal volume (VT), respiratory frequency (f), ventilation (VE), inspiratory time (TI), expiratory time (TE), mean inspiratory flow (VT/TI), and respiratory “duty cycle” (TI/TT) were measured. VT, VE, TI, TE, and VT/TI increased; f decreased and TI/TT remained constant during postnatal development in wakefulness and in both sleep states. No significant difference was observed between AS and QS for all the ventilatory parameters except TI/TT, which was greater in QS than in AS at 2 wk. VE was larger in W than in both AS and QS at all ages. This was mainly due to a greater f, TI/TT remaining constant. VT/TI, which represents an index of the central inspiratory activity, was larger in W than in sleep, VT not being significantly different whatever the stage of consciousness. The results of this study show that in the kitten 1) unlike in the adult cat, ventilation and breathing pattern are similar in QS and in AS; 2) in sleep, the central inspiratory drive appears to be independent of the type of sleep; and 3) in wakefulness, the increase of the central inspiratory activity could be related to important excitatory inputs.

Download Full-text

Maturation of ventilation and ventilatory pattern in normal sleeping infants

Journal of Applied Physiology ◽

10.1152/jappl.1979.46.5.998 ◽

1979 ◽

Vol 46 (5) ◽

pp. 998-1002 ◽

Cited By ~ 38

Author(s):

G. G. Haddad ◽

R. A. Epstein ◽

M. A. Epstein ◽

H. L. Leistner ◽

P. A. Marino ◽

...

Keyword(s):

Duty Cycle ◽

Rem Sleep ◽

Cycle Time ◽

Age Groups ◽

Inspiratory Flow ◽

Inspiratory Time ◽

Sleep State ◽

Quiet Sleep ◽

Ventilatory Pattern ◽

Inspiratory Activity

Noninvasive studies of ventilation and ventilatory pattern were performed serially in 15 normal infants in the first 4 mo of life during REM and quiet sleep with the barometric method. We measured tidal volume (VT), total respiratory cycle time (Ttot), inspiratory time (Ti), expiratory time (TE), mean inspiratory flow (VT/TI), and respiratory “duty cycle” (TI/Ttot). Vt, Ttot, TI, TE, VT/TI, and VT/Ttot but not TI/Ttot increased with age. In all age groups, Ttot, TI, and TE but not VT/TI were greater in quiet than in REM sleep. In the first 2 mo of life, VT was greater in quiet than in REM sleep; in the older infants, VT/Ttot was smaller in quiet than in REM sleep. TI/Ttot was not dependent on sleep state. Thus, because VT/Ttot = VT/TI X TI/Ttot, the increase in VT/Ttot with age results from an increase in mean inspiratory flow rather than from changes in respiratory “duty cycle”. Further, the “on-switching” as well as the “off-switching” of inspiratory activity depends on sleep state.

Download Full-text

Postnatal maturation of laryngeal chemoreflexes in the preterm lamb

Journal of Applied Physiology ◽

10.1152/japplphysiol.00977.2006 ◽

2007 ◽

Vol 102 (4) ◽

pp. 1429-1438 ◽

Cited By ~ 29

Author(s):

Marie St-Hilaire ◽

Nathalie Samson ◽

Elise Nsegbe ◽

Charles Duvareille ◽

François Moreau-Bussière ◽

...

Keyword(s):

Heart Rate ◽

Lower Airway ◽

Distilled Water ◽

Active Sleep ◽

Sleep State ◽

Quiet Sleep ◽

General Belief ◽

Postnatal Maturation ◽

Laryngeal Mucosa ◽

Life Threatening

Laryngeal chemoreflexes (LCR) are triggered by the contact of liquids with the laryngeal mucosa. In the mature organism, LCR trigger lower airway protective responses (coughing, effective swallowing, and arousal) to prevent aspiration. General belief holds that LCR are responsible for apnea and bradycardia in the newborn mammal, including humans. Our laboratory has recently shown that LCR in full-term lambs are consistently analogous to the mature LCR reported in adult mammals, without significant apneas and bradycardias (St-Hilaire M, Nsegbe E, Gagnon-Gervais K, Samson N, Moreau-Bussiere F, Fortier PH, and Praud J-P. J Appl Physiol 98: 2197–2203, 2005). The aim of the present study was to assess LCR in nonsedated, newborn preterm lambs born at 132 days of gestation (term = 147 days). The preterm lambs were instrumented for recording glottal adductor electromyogram, electroencephalogram, eye movements, heart rate, respiration, and oximetry. A chronic supraglottal catheter was used for injecting 0.5 ml of saline, distilled water, and HCl (pH 2) during quiet sleep, active sleep, and wakefulness on postnatal days 7 (D7) and 14 (D14). Laryngeal stimulation by water or HCl on D7 induced significant apneas, bradycardia, and desaturation, which, at times, appeared potentially life-threatening. No significant apneas, bradycardias, or desaturation were observed on D14. No consistent effects of sleep state could be shown in the present study. In conclusion, laryngeal stimulation by liquids triggers potentially dangerous LCR in preterm lambs on D7, but not on D14. It is proposed that maturation of the LCR between D7 and D14 is partly involved in the disappearance of apneas/bradycardias of prematurity with postnatal age.

Download Full-text

Significance of airway resistance for the pattern of breathing and lung volumes in exercising humans

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.5.1875 ◽

1990 ◽

Vol 68 (5) ◽

pp. 1875-1882 ◽

Cited By ~ 10

Author(s):

C. M. Hesser ◽

F. Lind ◽

D. Linnarsson

Keyword(s):

Tidal Volume ◽

Airway Resistance ◽

Cycle Ergometer ◽

Inspiratory Time ◽

Lung Volumes ◽

Flow Rates ◽

Central Inspiratory Activity ◽

Leg Exercise ◽

Inspiratory Activity ◽

Exercise Induced

The effects of increased airway resistance on lung volumes and pattern of breathing were studied in eight subjects performing leg exercise on a cycle ergometer. Airway resistance was changed 1) by increasing the density (D) of the respired gas by a factor of 4.2 and changing the inspired gas from O2 at 1.3 bar to air at 6 bar and 2) by increasing airway flow rates by exposing the subjects to incremental work loads of 0-200 W. Increased gas D caused a slower and deeper respiration at rest and during exercise and, at work loads greater than 120 W, depressed the responses of ventilation and mean inspiratory flow. Raised airway resistance induced by increases in D and/or airway flow rates altered respiratory timing by increasing the ratio of inspiratory time (TI) to total breath duration. Furthermore, analyses of the relationships between tidal volume and TI and between end-inspiratory volume and TI revealed elevation of Hering-Breuer inspiratory volume thresholds. We propose that this elevation, and hence exercise-induced increases of tidal volume, can largely be explained by previous observations that the threshold of the inspiratory off-switch mechanisms depends on central inspiratory activity (cf. C. von Euler, J. Appl. Physiol. 55: 1647-1659, 1983), which in turn increases with airway resistance (Acta Physiol. Scand. 120: 557-565, 1984).

Download Full-text

Breath-to-breath variations in rate and depth of ventilation in sleeping infants

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1982.243.1.r164 ◽

1982 ◽

Vol 243 (1) ◽

pp. R164-R169

Author(s):

G. G. Haddad ◽

T. L. Lai ◽

M. A. Epstein ◽

R. A. Epstein ◽

K. F. Yu ◽

...

Keyword(s):

Tidal Volume ◽

Linear Relationship ◽

Eye Movement ◽

Rem Sleep ◽

Cycle Time ◽

Strong Correlation ◽

Inspiratory Time ◽

Quiet Sleep ◽

Positive Linear Relationship ◽

Inspiratory Activity

Ventilatory measurements were made noninvasively over 2- to 3-h periods during sleep in each of nine normal infants at 1 mo of age. To assess the changes that occur in ventilation on a breath-to-breath basis, we 1) examined the variations of each of tidal volume (VT), respiratory cycle time (Ttot), expiratory time (TE), and inspiratory time (TI) and 2) studied their interrelationships. We found that the variations of VT, Ttot, and TE but not of TI were significantly greater in rapid-eye-movement (REM) than in quiet sleep. In addition, on a breath-to-breath basis, VT had a positive linear relationship and strong correlation with TI; however, the correlation between VT and TE was weak in both sleep states. VT/Ttot was found to be moderately and negatively correlated with Ttot in both REM and quiet sleep. VT was weakly correlated with Ttot in REM sleep and was, on the average, more correlated with Ttot in quiet sleep. We suggest that in infants 1) on a breath-to-breath basis, VT/Ttot is likely to drop if respiratory frequency is decreased and 2) VT is nonlinearly related to Ttot during sleep; this lack of linearity depends on the lack of constancy of VT/Ttot, which is in turn closely related to the variability of the "on-switching" of inspiratory activity.

Download Full-text

Repetitive hypoxia rapidly depresses cardio-respiratory responses during active sleep but not quiet sleep in the newborn lamb

The Journal of Physiology ◽

10.1111/j.1469-7793.1999.0571m.x ◽

1999 ◽

Vol 519 (2) ◽

pp. 571-579 ◽

Cited By ~ 14

Author(s):

Renea V. Johnston ◽

Daniel A. Grant ◽

Malcolm H. Wilkinson ◽

Adrian M. Walker

Keyword(s):

Active Sleep ◽

Quiet Sleep ◽

Newborn Lamb ◽

Respiratory Responses

Download Full-text

The effect of inert gas choice on multiple breath washout in healthy infants: differences in lung function outcomes and breathing pattern

Journal of Applied Physiology ◽

10.1152/japplphysiol.00524.2017 ◽

2017 ◽

Vol 123 (6) ◽

pp. 1545-1554 ◽

Cited By ~ 7

Author(s):

Per M. Gustafsson ◽

Lovisa Bengtsson ◽

Anders Lindblad ◽

Paul D. Robinson

Keyword(s):

Functional Residual Capacity ◽

Sulfur Hexafluoride ◽

Breathing Pattern ◽

Inert Gas ◽

Respiratory Drive ◽

Quiet Sleep ◽

Lung Clearance ◽

Healthy Infants ◽

Lung Clearance Index ◽

Residual Capacity

The detrimental effects on breathing pattern during multiple breath inert gas washout (MBW) have been described with different inhaled gases [100% oxygen (O2) and sulfur hexafluoride (SF6)] but detailed comparisons are lacking. N2- and SF6-based tests were performed during spontaneous quiet sleep in 10 healthy infants aged 0.7–1.3 yr using identical hardware. Differences in breathing pattern pre and post 100% O2 and 4% SF6 exposure were investigated, and the results obtained were compared [functional residual capacity (FRC) and lung clearance index (LCI)]. During 100% O2 exposure. mean inspiratory flow (“respiratory drive”) decreased transiently by mean (SD) 28 (9)% ( P < 0.001), and end-tidal CO2 (carbon dioxide) increased by mean (SD) 0.3 (0.4)% units ( P < 0.05) vs. air breathing prephase. During subsequent N2 washin (i.e., recovery phase), the pattern of change reversed. No significant effect on breathing pattern was observed during SF6 testing. In vitro testing confirmed that technical artifacts did not explain these changes. Mean (SD) FRC and LCI in vivo were significantly higher with N2 vs. SF6 washout: 216 (33) vs. 186 (22) ml ( P < 0.001) and 8.25 (0.85) vs. 7.55 (0.57) turnovers ( P = 0.021). Based on these results, SF6 based MBW is the preferred methodology for tests in this age range. NEW & NOTEWORTHY Inert gas choice for multiple breath inert gas washout (MBW) in infants has important consequences on both breathing pattern during test performance and the functional residual capacity and lung clearance index values obtained. Data suggest the detrimental effect of breathing pattern of 100% O2 and movement of O2 across the alveolar capillary membrane, with direct effects on MBW outcomes. SF6 MBW during infancy avoids this and can be further optimized by addressing the sources of technical artifact identified in this work.

Download Full-text

Seropathological Diagnosis of Toxoplasma gondii in Stray Cats in Baghdad Province

The Iraqi Journal of Veterinary Medicine ◽

10.30539/iraqijvm.v38i1.260 ◽

2014 ◽

Vol 38 (1) ◽

pp. 92-98

Author(s):

Mohammed J. Alwan

Keyword(s):

Toxoplasma Gondii ◽

Alveolar Space ◽

Internal Organs ◽

Blood Samples ◽

Pathological Lesions ◽

Stray Cats ◽

Significant Difference ◽

Adult Cat ◽

The Brain ◽

Local Necrosis

The current study was performed an investigation in seropositive stray cats with Toxoplasma gondii and to correlate the results of pathological lesions with seropositive results of the cats. To achieve these goals, fifty blood samples and specimens from internal organs (liver, spleen, brain, kidney, intestine and lung) of stray cats were collected from different area of Baghdad Province during the period 1.10.2011-1.10.2012. Seropositive ELISA-IgG was demonstrated that 66 % of stray cats while female expressed (75 %) of seropositive ELISA-IgG were higher than male (30% ) and animals with average age 2months showed high percentage of seropositive ELISA-IgG (100%) as compared with age (adult cat) that expressed( 63.82 %) of seropositive. There was a significant difference (P≤0.01) among positive cases to anti-Toxoplasma ELISA-IgG. Severe pathological lesions were noticed in the lungs ,livers and intestines of animals that expressed high (optical density) (OD) of anti-Toxoplasma IgG ,in addition ,tachyzoits intracytoplasm of alveolar macrophages and hepatocytes as well as free zoites in alveolar space of the lung, were reported. Local necrosis with tachyzoites was seen in the brain of the cats, in addition to mineralization. On bases of the presence of pathological lesions in cats that expressed seropositive anti-Toxoplasma antibodies, it can be conclude that T.gondii is responsible for the appearance of inflammatory reaction in the internal organs of cats and there is a correlation between seropositive and pathological lesions of T.gondii infection and this parasite is highly distributed in Baghdad stray cats and it may be an important cause of abortion in the women.

Download Full-text

Evaluation of Raw Yeast Extract (Saccharomyces cerevisiae) as an Ingredient, Additive or Palatability Agent in Wet Diet for Cats

International Journal of Biology ◽

10.5539/ijb.v8n1p1 ◽

2015 ◽

Vol 8 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Lidia M. Lima ◽

Jose Walter Silva Jr ◽

Rosana C. S. Ogoshi ◽

Jessica S. dos Reis ◽

Janine Franca ◽

...

Keyword(s):

Yeast Extract ◽

Control Diet ◽

Latin Squares ◽

Metabolizable Energy ◽

Energy Utilization ◽

Functional Additive ◽

Apparent Digestibility Coefficient ◽

Significant Difference ◽

Adult Cat ◽

And Control

Three experiments were performed to evaluate the effects of strain-specific yeast extract (SSYE) as an ingredient, functional additive or palatability agent when supplemented in its raw form in wet cat food. SSYE as ingredient – SSYE was chemically characterized and its use evaluated through fourteen cats divided into two treatments: control diet (complete wet adult cat food) and control diet with 30 % replacement by SSYE. The results of apparent digestibility coefficient of SSYE were 71.64 % for dry matter, 72.55 % for organic matter, 50.78 % for ashes, 78.59 % for crude protein, 84.33 % for the energy gross and digestible and metabolizable energy value, respectively, of 4,247 and 4,163 kcal/kg, these results indicated that SSYE is comparable to other protein sources for cat’s food. SSYE as a functional additive - twelve cats were distributed into two 6x6 latin squares (treatments; experimental periods), and the treatments were control diet and replacement levels ranged from 2 % to 10 % SSYE. The following parameters were evaluated: digestibility, energy utilization, nitrogen balance, serum urea and creatinine levels. No differences were found. SSYE as palatability agent – Were used twenty cats by comparing the control diet with 2 % replacement by SSYE. A significant difference (P < 0.01) was observed with a preference for control diet. SSYE is a potential protein source for cats; however, it is not effective as additive and may compromise palatability when supplemented in its raw form in complete wet cat food.

Download Full-text

Naloxone attenuates poststimulatory respiratory depression of laryngeal origin in the adult cat

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1995.269.1.r113 ◽

1995 ◽

Vol 269 (1) ◽

pp. R113-R123 ◽

Cited By ~ 4

Author(s):

D. Mutolo ◽

F. Bongianni ◽

M. Corda ◽

G. A. Fontana ◽

T. Pantaleo

Keyword(s):

Respiratory Depression ◽

Time Course ◽

Superior Laryngeal Nerve ◽

Endogenous Opioids ◽

Respiratory Frequency ◽

Inspiratory Activity ◽

Stimulation Period ◽

Adult Cat ◽

Adult Cats ◽

Alpha Chloralose

Poststimulatory depression in respiratory activity induced by superior laryngeal nerve (SLN) stimulation was quantitatively investigated in 20 adult cats. The role played in this phenomenon by endogenous opioids was studied using the opiate antagonist naloxone. The effects of hypercapnia on the same phenomenon were also investigated for comparison. Experiments were performed on cats anesthetized with pentobarbitone or alpha-chloralose, vagotomized, paralyzed, and artificially ventilated with 100% O2. Some animals were also carotid sinus denervated. Respiratory output was monitored as integrated phrenic nerve activity. SLN stimulation produced apnea, which outlasted the stimulation period; when respiration resumed, it was markedly depressed as revealed mainly by a decrease in phrenic minute output, respiratory frequency, and rate of rise of inspiratory activity. Phrenic output recovered gradually to control levels following an exponential time course. These effects varied as a function of the duration of SLN stimulation. Naloxone administration (0.8 mg/kg iv) significantly reduced the duration of poststimulatory apnea and attenuated the depression of phrenic minute output of the first recovery breath as a result of changes in peak phrenic activity; it also accelerated the time course of recovery. Hypercapnia did not affect the duration of poststimulatory apnea, but attenuated the initial poststimulatory depression because of changes in respiratory frequency; the rate of recovery was reduced. The results provide characterization of poststimulatory respiratory depression of laryngeal origin in the adult cat and suggest a role of endogenous opioids in its genesis or modulation.

Download Full-text