Biomaterial Database

Fetal breathing movement, sleep state and cardiovascular responses to an inhibitor of mitochondrial ATPase in sheep. 1986

B J Koos, and H Sameshima, and G G Power

Hypoxia abolishes breathing movements in fetal sheep, perhaps by reducing ATP synthesis within regulatory brain cells. This possibility was examined by administering to 13 chronically catheterized fetal sheep oligomycin B, a mitochondrial ATPase inhibitor. Injections into the left external carotid artery of oligomycin B (170 +/- 19 micrograms/kg in 9 fetuses) reduced significantly (P less than 0.01) the incidence of fetal breathing movements from a control mean of 52 +/- 6.3% to 6 +/- 2.2 and 9 +/- 4.4% during the first and second hours after drug injection. Oligomycin did not decrease significantly the incidence of low voltage electrocortical activity or reduce the average duration of a cycle of low and high voltage electrocortical states. Nor did it decrease significantly the incidence of rapid eye movements. Fetal heart rate and mean arterial pressure were not significantly affected, and the arterial blood gases and pH did not significantly differ from control values. However, a large dose of the drug (700 micrograms/kg) produced an isoelectric electrocorticogram, hypertension, and bradycardia associated with a rise in arterial PO2 and a severe metabolic acidosis. In 3 fetal sheep oligomycin also inhibited continuous breathing induced by indomethacin. Injection of the vehicle (ethanol) alone did not alter the incidence of breathing movements, electrocortical activity, eye movements or blood gases. These results suggest that reduced mitochondrial production of ATP may be a mechanism by which hypoxia abolishes fetal breathing activity.

UI	MeSH Term	Description	Entries
D009840	Oligomycins	A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).	Oligomycin
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
D001933	Brain Stem	The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.	Brainstem,Truncus Cerebri,Brain Stems,Brainstems,Cerebri, Truncus,Cerebrus, Truncus,Truncus Cerebrus
D005333	Fetus	The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.	Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D012890	Sleep	A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.	Sleep Habits,Sleeping Habit,Sleeping Habits,Habit, Sleep,Habit, Sleeping,Habits, Sleep,Habits, Sleeping,Sleep Habit