Tumor microenvironments are disturbed with abnormal growth and remodeling of blood and lymphatic vessels. More effective targeting strategies for delivering anti-angiogenic and cytotoxic agents are being developed through advances in intravital imaging. Blood flow control requires both vasodilation and vasoconstriction
to be coordinated along and among arterioles and feed arteries. Evolving insights into signaling pathways between smooth muscle cells and endothelial cells illuminate how such processes can be affected in vasculopathies. These timely reviews provide a novel reference for advancing research frontiers in microcirculation. “
“The pulmonary circulation is a low-pressure, low-resistance vascular bed with little to no resting tone under normal conditions. IWR-1 mw An increase in the [Ca2+]i in PASMCs is an important determinant of contraction, migration, and proliferation. Both Ca2+ influx through plasma membrane Ca2+ channels and Ca2+ release from the SR contribute to a rise in [Ca2+]i. Additionally important in the pulmonary circulation are several kinase-mediated signaling pathways that act to increase the sensitivity of the contractile apparatus to [Ca2+]i. Similarly, cytoskeletal processes resulting in dynamic remodeling of the actin cytoskeleton can further contribute to contractility in the pulmonary circulation. In addition to endocrine, paracrine, and autocrine factors,
alveolar hypoxia is an important stimulus for pulmonary vasoconstriction. However, prolonged hypoxia is a critical pathological stimulus associated with the development of pulmonary hypertension and cor see more pulmonale. In this review, we will discuss recent advances in our understanding of how Ca2+ homeostasis and sensitization regulate PASMC contractility under both physiological and pathophysiological conditions. “
“Please cite this paper as: Drummond GB, Vowler SL. Variation: use it or misuse it
– replication and its variants. Microcirculation 19: 468–471, 2012. “
“The cerebral blood supply is delivered by a surface network of pial arteries and arterioles from which arise (parenchymal) arterioles that penetrate into the cortex and terminate in a rich capillary bed. The critical regulation of CBF, locally and globally, requires precise vasomotor regulation of the intracerebral microvasculature. This selleck vascular region is anatomically unique as illustrated by the presence of astrocytic processes that envelope almost the entire basolateral surface of PAs. There are, moreover, notable functional differences between pial arteries and PAs. For example, in pial VSMCs, local calcium release events (“calcium sparks”) through ryanodine receptor (RyR) channels in SR membrane activate large conductance, calcium-sensitive potassium channels to modulate vascular diameter. In contrast, VSMCs in PAs express functional RyR and BK channels, but under physiological conditions, these channels do not oppose pressure-induced vasoconstriction.