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The purpose of the present study was to determine the genetic control of baseline breathing pattern by examining the mode of inheritance between two inbred murine strains with differential breathing characteristics. Specifically, the rapid, shallow phenotype of the C57BL/6J (B6) strain is consistently distinct from the slow, deep phenotype of the C3H/HeJ(More)
The role genetic factors play in ventilatory control was examined by challenging eight inbred strains of mice to acute hypercapnia under normoxic and hypoxic conditions. Age-matched mice were exposed for 3-5 min to inspired gases of the following composition (FICO2:FIO2) 0.03:0.10, 2) 0.03:0.21, 3) 0.08:0.10, and 4) 0.08:0.21, with intermittent room air(More)
The carotid body (CB) is a sensor of oxygen, carbon dioxide, hydrogen ion, and glucose in the arterial blood. Many studies of the CB's responses to low oxygen (hypoxia) have been reported. Recently attention has been increasingly focused on its responses to elevated CO2 (hypercapnia). An increase in ventilation or carotid body neural output (CBNO) can(More)
The carotid body (CB) is a polymodal sensor which increases its neural output to the nucleus tractus solitarii with a subsequent activation of several reflex cardiopulmonary responses. Current reports identify acetylcholine (ACh) and adenosine triphosphate (ATP) as two essential excitatory neurotransmitters in the cat and rat CBs. This study explored the(More)
Oxygen can be said to be the most fundamentally necessary substrate for life. In those organisms having a cardiopulmonary system for delivering it in blood to the tissues the carotid body functions as the principal detector of decreases in arterial oxygen. Such a decrease stimulates an increase in neural output from the carotid body to the nucleus tractus(More)
With immunocytochemical techniques using a monoclonal antibody for alpha7 subunits of neuronal nicotinic acetylcholine receptors, we have found these subunits to be exclusively expressed in nerve fibers in the carotid body. Double-immunostaining showed that alpha7 subunit-positive nerve endings enveloped tyrosine hydroxylase-positive glomus cells. Some(More)
Hypoxia, hypercapnia and acidosis stimulate the carotid body (CB) sending increased neural activity via a branch of the glossopharyngeal nerve to nucleus tractus solitarius; this precipitates an impressive array of cardiopulmonary, endocrine and renal reflex responses. However, the cellular mechanisms by which these stimuli generate the increased CB neural(More)
From the 1930s into the 1970s, the role of acetylcholine (ACh) in the carotid body's chemotransduction of hypoxia was debated. Since the late 1970s, the issue has been pursued only intermittently or not at all. The purpose of this study was to test again with a new preparation the hypothesis that ACh is an excitatory neurotransmitter in the cat carotid(More)
To determine the role of endogenous ACTH and hyperventilation in the adrenocortical response to hypoxia, pentobarbital-anesthetized dogs equipped with left adrenal venous cannulas for measurement of cortisol secretion rate (CSR) and arterial cannulas for measurement of plasma ACTH were exposed to 20 min of normoxia (group I), spontaneous ventilation,(More)