Biomaterial Database

Carotid chemoreceptors and respiratory adaptations to dead space loading during incremental exercise. 1993

N C Syabbalo, and T Zintel, and R Watts, and C G Gallagher

Division of Respiratory Medicine, Royal University Hospital, Saskatoon, Saskatchewan, Canada.

Dead space (VD) loading has been shown to cause an increase in tidal volume and a decrease in respiratory frequency at moderate to high levels of ventilation (VI) during exercise (J. Appl. Physiol. 70: 55-62, 1991). This study examined the role of carotid chemoreceptors (CC) in the breathing pattern response to added VD during maximal incremental exercise; we used hyperoxia to silence the CC. Nine healthy subjects exercised on a bicycle ergometer on 4 different days while inspiring air with VD (AVD) and without VD [air control (AC)] and while inspiring 100% O2 with VD (O2VD) and without VD (O2C). Equipment resistance for VD and control studies was identical, and the exercise tests were done in a randomized order. At a matched level of VI equivalent to 75% VI at the end of the AC experiments (102 l/min), the breathing pattern in the AVD and O2VD tests was significantly deeper and slower (P < 0.05) than that in the AC and O2C tests. The difference in tidal volume between AVD and AC tests (delta = 0.26 +/- 0.16 liter) was not significantly different from that between O2VD and O2C tests (delta = 0.23 +/- 0.23 liter). The breathing pattern was the same in the AC and O2C tests. It is concluded that the altered breathing pattern with VD loading is not mediated by the CC.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D012126	Respiratory Dead Space	That part of the RESPIRATORY TRACT or the air within the respiratory tract that does not exchange OXYGEN and CARBON DIOXIDE with pulmonary capillary blood.	Dead Space, Respiratory,Dead Spaces, Respiratory,Respiratory Dead Spaces,Space, Respiratory Dead,Spaces, Respiratory Dead
D002344	Carotid Body	A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.	Glomus Caroticum,Bodies, Carotid,Body, Carotid,Caroticum, Glomus,Carotid Bodies
D002628	Chemoreceptor Cells	Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.	Chemoreceptive Cells,Cell, Chemoreceptive,Cell, Chemoreceptor,Cells, Chemoreceptive,Cells, Chemoreceptor,Chemoreceptive Cell,Chemoreceptor Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000222	Adaptation, Physiological	The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.	Adaptation, Physiologic,Adaptations, Physiologic,Adaptations, Physiological,Adaptive Plasticity,Phenotypic Plasticity,Physiological Adaptation,Physiologic Adaptation,Physiologic Adaptations,Physiological Adaptations,Plasticity, Adaptive,Plasticity, Phenotypic
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D015444	Exercise	Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.	Aerobic Exercise,Exercise, Aerobic,Exercise, Isometric,Exercise, Physical,Isometric Exercise,Physical Activity,Acute Exercise,Exercise Training,Activities, Physical,Activity, Physical,Acute Exercises,Aerobic Exercises,Exercise Trainings,Exercise, Acute,Exercises,Exercises, Acute,Exercises, Aerobic,Exercises, Isometric,Exercises, Physical,Isometric Exercises,Physical Activities,Physical Exercise,Physical Exercises,Training, Exercise,Trainings, Exercise