Biomaterial Database

The effect of carbonic anhydrase inhibition on breathing movements and electrocortical activity in fetal sheep. 1985

A R Hohimer, and J M Bissonnette, and C M Machida, and B Horowitz

Fetal breathing movements (FBM) indicated by repetitive negative intrathoracic pressures and biparietal electrocorticograms (ECoG) were recorded from 8 fetal sheep for 3 h before (control) and 3 h after the administration of a carbonic anhydrase inhibitor, acetazolamide. FBM and the low voltage (LV) ECoG state occurred 36 +/- 5% (SEM) and 60 +/- 3% of the control period, respectively. Virtually no FBM occurred during high voltage (HV) ECoG while in 57 +/- 6% of the LV state the fetuses were making FBM. The peak magnitude of the negative intrathoracic (tracheal) pressure deflections was 4 +/- 1 Torr. Following acetazolamide the incidence of FBM rose to 53 +/- 4% (P less than 0.01) but there was no significant change in the incidence of the LV state (58 +/- 3%). Most of the increase in the incidence of FBM remained confined to periods of LV ECoG activity so that an increased proportion of this state (88 +/- 2%, P less than 0.001) was occupied with respiratory efforts. The amplitude of the FBM also increased to 8 +/- 1 Torr (P less than 0.05). The increased incidence and depth of FBM is most likely due to an elevated hydrogen ion concentration and differs from a fetal respiratory acidosis induced by increasing the inspired CO2 fraction to the ewe in that the respiratory stimulation induced by acetazolamide is not associated with an increased incidence of the permissive LV ECoG state.

UI	MeSH Term	Description	Entries
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
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
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D002257	Carbonic Anhydrase Inhibitors	A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES.	Carbonate Dehydratase Inhibitor,Carbonate Dehydratase Inhibitors,Carbonic Anhydrase Inhibitor,Carboxyanhydrase Inhibitor,Carboxyanhydrase Inhibitors,Anhydrase Inhibitor, Carbonic,Dehydratase Inhibitor, Carbonate,Inhibitor, Carbonate Dehydratase,Inhibitor, Carbonic Anhydrase,Inhibitor, Carboxyanhydrase,Inhibitors, Carbonate Dehydratase,Inhibitors, Carbonic Anhydrase,Inhibitors, Carboxyanhydrase
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005260	Female		Females