Biomaterial Database

Changes in tyrosine hydroxylase and substance P immunoreactivity in the cat carotid body following chronic hypoxia and denervation. 1998

Z Z Wang, and B Dinger, and S J Fidone, and L J Stensaas

Department of Physiology, University of Utah School of Medicine, Salt Lake City 84108, USA.

Long-term hypoxia elicits functional changes in the cat carotid body which are manifest as altered chemosensitivity in response to hypoxia. Previous studies have suggested that these functional adjustments may be mediated by changes in neurotransmitter levels in chemosensory type I cells. Neurotransmitter metabolism in the carotid body has also been shown to be regulated by the neural innervation to the organ. The present study using the cat carotid body demonstrates profound changes in the levels of immunoreactivity of the catecholamine-synthesizing enzyme, tyrosine hydroxylase, and the neuropeptide, substance P, in response to a two-week exposure to hypoxia (10% O2 in 90% N2). Furthermore, these changes were modulated both by sensory and sympathetic denervation of the organ. For TH, the intensity of immunostaining in type I cells was markedly increased by long-term hypoxia in both normal and chronic carotid sinus nerve-denervated carotid bodies, but this effect was blocked following chronic sympathectomy. Substance P immunoreactivity in type I cells was dramatically attenuated by hypoxia in both intact and chronic carotid sinus nerve-denervated preparations, but this effect was reduced following chronic sympathectomy. Tyrosine hydroxylase- and substance P-positive axon terminals were observed to innervate type I cells. These axons were also present in chronically sympathectomized preparations, but they disappeared following chronic carotid sinus nerve-denervation suggesting that they very likely arise from sensory neurons in the petrosal ganglion. Our data indicate that chronic chemoreceptor stimulation by hypoxia elicits multiple neurochemical adjustments in the cat carotid body. These changes suggest that catecholaminergic enzymes and neuropeptides play a significant role in the adaptive mechanisms of chemoreceptor function which occur in response to chronic physiological stimulation. Furthermore, the data suggest that neurotrophic mechanisms may influence neurotransmitter metabolism in chemosensory type I cells.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008297	Male		Males
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
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
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003714	Denervation	The resection or removal of the nerve to an organ or part.	Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
D005260	Female		Females
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
D000860	Hypoxia	Sub-optimal OXYGEN levels in the ambient air of living organisms.	Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon