Prof. Segal is a Fellow at The John B. Pierce Laboratory

We focus on microcirculation in skeletal muscle and cellular mechanisms of blood flow control.

Our goal is to understand the nature of cell-to-cell communication that underlies the ability of microvessels to control tissue blood flow and oxygen delivery.

Physiological stimuli (e.g., muscle contraction, neurotransmission) generate electrical signals in smooth muscle and endothelial cells that can travel rapidly from cell-to-cell and coordinate vasomotor responses (dilation, constriction) within and among branches of microvascular resistance networks. Our experiments are designed to reveal the cellular and molecular pathways which underlie the initiation and spread of electrical signals in microvessels, how these pathways are governed by the nervous system, and how they are affected by aging.

Intravital video microscopy provides direct insight into blood flow control processes in vivo. Electrophysiological recordings reveal key signaling events that determine the contractile status of smooth muscle and its regulation by endothelium.

Complementary studies using molecular, pharmacological, and immunolabeling techniques resolve regulatory proteins that mediate cell-to-cell coupling (e.g., through gap junctions) and electrical signaling (e.g., through ion channels) in respective cell layers. Parallel experiments based upon genetic engineering reveal how targeted disruption of signaling pathways affects tissue blood flow through changes in microvascular structure and function.

Motor innervation of skeletal muscle fibers between an arteriole
and venule in the hamster retractor muscle

Selected Publications

"Histamine inhibits conducted vasodilation through endothelium-derived NO production in arterioles of mouse skeletal muscle," Payne, G.W., J.A. Madri, W.C. Sessa, and S.S. Segal, FASEB J., 18, 280-286 (2004).

 

"Connexin expression and conducted vasodilation along arteriolar endothelium in mouse skeletal muscle," Looft-Wilson, R.C., G.W. Payne, and S.S. Segal, J. Appl. Physiol., 97, 1152-1158 (2004).

 

"Interaction between sympathetic nerve activation and muscle fibre contraction in resistance vessels of hamster retractor muscle," VanTeeffelen, J.W.G.E. and S. S. Segal, J. Physiol., 550(2) 563-574 (2003).

 

"Homocellular conduction along endothelium and smooth muscle of arterioles in hamster cheek pouch: unmasking an NO wave," Budel, S., I.S. Bartlett, and S.S. Segal, Circ. Res., 93, 61-68 (2003).