Carotid Chemosensory Response to Doxapram in the Newborn Kitten

Author(s):  
A. Bairam ◽  
F. Marchal ◽  
B. Hannhart ◽  
J.-P. Crance ◽  
S. Lahiri
1988 ◽  
Vol 64 (6) ◽  
pp. 2544-2551 ◽  
Author(s):  
H. Rigatto ◽  
C. Wiebe ◽  
C. Rigatto ◽  
D. S. Lee ◽  
D. Cates

We studied the ventilatory response to hypoxia in 11 unanesthetized newborn kittens (n = 54) between 2 and 36 days of age by use of a flow-through system. During quiet sleep, with a decrease in inspired O2 fraction from 21 to 10%, minute ventilation increased from 0.828 +/- 0.029 to 1.166 +/- 0.047 l.min-1.kg-1 (P less than 0.001) and then decreased to 0.929 +/- 0.043 by 10 min of hypoxia. The late decrease in ventilation during hypoxia was related to a decrease in tidal volume (P less than 0.001). Respiratory frequency increased from 47 +/- 1 to 56 +/- 2 breaths/min, and integrated diaphragmatic activity increased from 14.9 +/- 0.9 to 20.2 +/- 1.4 arbitrary units; both remained elevated during hypoxia (P less than 0.001). Younger kittens (less than 10 days) had a greater decrease in ventilation than older kittens. These results suggest that the late decrease in ventilation during hypoxia in the newborn kitten is not central but is due to a peripheral mechanism located in the lungs or respiratory pump and affecting tidal volume primarily. We speculate that either pulmonary bronchoconstriction or mechanical uncoupling of diaphragm and chest wall may be involved.


EvoDevo ◽  
2013 ◽  
Vol 4 (1) ◽  
pp. 25 ◽  
Author(s):  
Jonathan Bibliowicz ◽  
Alexandre Alié ◽  
Luis Espinasa ◽  
Masato Yoshizawa ◽  
Maryline Blin ◽  
...  

2020 ◽  
Vol 30 (2) ◽  
pp. 145-152
Author(s):  
Kapria-Jad Josaphat ◽  
Vicky Drapeau ◽  
David Thivel ◽  
Marie-Eve Mathieu

Background: High-intensity exercise can have an anorectic impact, leading to negative energy balance. Several studies have reported that the practice of physical activity could also cause a shift in perceptions and preferences, causing a change in food intakes. Objective: This study aimed to question to what extent the timing of exercise in relation to a meal could have an impact on olfaction and gustation, appetite, and food choices. Methods: Twelve males aged 25 (4) years with a body mass index of 22.4 (2.0) kg/m2 attended two experimental visits in a counterbalanced fashion. The participants consumed a standardized breakfast between 7:00 and 7:30 a.m. and were subjected to smell and taste tests upon arrival at the laboratory (8:30 a.m.). In the EX9:40 visit, the participants performed a 30-min exercise session (70% of maximum oxygen uptake) at 9:40 a.m., followed by a 90-min sedentary break. In EX10:30, the participants first took part in the 90-min sedentary break and then performed the 30-min exercise session at 10:30 a.m. Taste and smell tests were performed again at 11:40 a.m., immediately followed by an ad libitum buffet-style meal. Visual analog scales were used to report appetite sensations during the session and satiety quotients around the lunch. Results: There was no difference in energy intakes between the EX9:40 (596 [302] kcal) and EX10:30 (682 [263] kcal) conditions (p = .459). There was no condition effect for the taste and smell sensations (all ps > .05), appetite sensation, or satiety quotients around the meal (all ps > .05). Conclusion: Exercise timing in the morning had no effect on taste and smell perceptions, appetite sensations, or energy intakes.


1983 ◽  
Vol 245 (5) ◽  
pp. R678-R683 ◽  
Author(s):  
S. Lahiri ◽  
N. Smatresk ◽  
M. Pokorski ◽  
P. Barnard ◽  
A. Mokashi

The effects of chronic hypoxia on carotid chemoreceptor afferent activity before and after sectioning the carotid sinus nerves (CSN) were studied in cats exposed to 10% O2 for 21–49 days in a chamber at sea level. For comparison, chronically normoxic cats at sea level were also studied. The cats were anesthetized, paucifiber preparation for the measurement of carotid chemosensory activity from a small slip of CSN was made, and their steady-state responses to 4–5 levels of arterial pressure of O2 (PaO2) at a constant PaCO2 and to 3–4 levels of PaCO2 in hyperoxia were measured before and after sectioning the CSN. The chemosensory response to hypoxia in the cats with intact CSN after chronic exposure to hypoxia was not reduced relative to the cats that breathed room air at sea level. Sectioning the CSN significantly augmented the chemosensory responses to hypoxia in all the chronically hypoxic but not significantly in the normoxic cats. The responses to moderate hypercapnia during hyperoxia were not significantly changed by cutting the CSN in either group. We conclude that there is a significant CSN efferent inhibition of chemosensory activity due to chronic hypoxia in the cat. This implies that without the efferent inhibition the hypoxic chemosensitivity is increased by chronic hypoxia.


1991 ◽  
Vol 30 (1) ◽  
pp. 95???99
Author(s):  
MARK D. PARRISH ◽  
JANEEN M. HILL ◽  
MARC P. KAUFMAN

1989 ◽  
Vol 86 (20) ◽  
pp. 8118-8122 ◽  
Author(s):  
M. McKenna ◽  
P. Monte ◽  
S. L. Helfand ◽  
C. Woodard ◽  
J. Carlson

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