Acute hypoxia causes pulmonary vasoconstriction and coronary vasodilation. The divergent effects of hypoxia on pulmonary and coronary vascular smooth muscle cells suggest that the mechanisms involved in oxygen sensing and downstream effectors are different in these two types of cells. Since production of reactive oxygen species (ROS) is regulated by oxygen tension, ROS have been hypothesized to...

KAY, JOHN MICHAEL, JACK C. WAYMIRE, AND ROBERT F. GROVER. -Lung mast cell h..perplasia and pulmonary histamine-forming capacity in hypoxic rats. Am. J. Physiol. 226(l): 178-184. 1974.We have studied lung mast cells (MC), histamine, and pulmonary histamine-forming capacity (PHFC) in acute and chronic hypoxic pulmonary hypertension in rats. Histochemical examination of lung tissue showed no evide...

OBJECTIVE We have previously found that chronic hypoxia inhibited thyrotropin-releasing hormone (TRH) mRNA expression in rat paraventricular nucleus (PVN). This study presented the effects of hypoxia on TRH secretion in rat hypothalamus, and the norepinephrine (NE) involvement in the modulation of TRH secretion during acute hypoxia exposure. SETTING AND DESIGN Hypoxia was simulated at altitud...

The respiratory response to hypoxia in mammals develops from an inhibition of breathing movements in utero into a sustained increase in ventilation in the adult. This ventilatory response to hypoxia (HVR) in mammals is the subject of this review. The period immediately after birth contains a critical time window in which environmental factors can cause long-term changes in the structural and fu...

Aguirre, J. I., N. W. Morrell, L. Long, P. Clift, P. D. Upton, J. M. Polak, and M. R. Wilkins. Vascular remodeling and ET-1 expression in rat strains with different responses to chronic hypoxia. Am J Physiol Lung Cell Mol Physiol 278: L981–L987, 2000.—Chronic hypoxia leads to a greater degree of pulmonary hypertension in the WistarKyoto (WKY) rat than in the Fischer 344 (F-344) rat. We question...

The effect of chronic hypobaric hypoxia (28 days, 455 Torr) on the organization of brain vessels was studied in Balb/c mice. In comparison to age-matched controls kept at sea level, emulsion-perfused capillaries in hypoxic mice showed marked dilation in all brain areas studied. Capillary length per unit volume of tissue (Lv) was increased in the cerebellar granular layer, the caudate nucleus, t...

Lung disease with chronic hypoxia has been associated with cognitive impairment of the subcortical type. Objectives To review the cognitive effects of chronic hypoxia in patients with lung disease and its pathophysiology in brain metabolism. Methods A literature search of Pubmed data was performed. The words and expressions from the text subitems including "pathophysiology of brain hypoxia"...

We examined the effect of MCC-134, a novel inhibitor of mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels and activator of sarcolemmal ATP-sensitive K(+) (sarcK(ATP)) channels, on cardioprotection conferred by adaptation to chronic hypoxia. Adult male Wistar rats were exposed to intermittent hypobaric hypoxia (7000 m, 8 h/day, 5-6 weeks) and susceptibility of their hearts to ventricular ar...

The effect of chronic hypercapnia on cardioprotection induced by chronic hypoxia was investigated in adult male Wistar rats exposed to isobaric hypoxia (10 % O(2)) for three weeks. In the first experimental group, CO(2) in the chamber was fully absorbed; in the second group, its level was increased to 4.1 %. Normoxic controls were kept in atmospheric air. Anesthetized open-chest animals were su...

Sleep-disordered breathing is associated with pulmonary hypertension and raised haematocrit. The multiple episodes of apnoea in this condition cause chronic intermittent hypoxia and hypercapnia but the effects of such blood gas changes on pulmonary pressure or haematocrit are unknown. The present investigation tests the hypothesis that chronic intermittent hypercapnic hypoxia causes increased p...