Related Experiment Video
Updated: May 29, 2026

Real-time Evaluation of Absolute, Cytosolic, Free Ca2+ and Corresponding Contractility in Isolated, Pressurized Lymph Vessels
Published on: March 22, 2024
[Effects of histamine on contractile activity of lymphatic node capsules. The NO role]
Abstract:
Effects of histamine (10(-9)--5 x 10(-5) M) on the phase and tonic contractile activity of capsular smooth muscles of isolated bovine mesentery lymph node were investigated. Dual dose-depended effect of histamine was found. Low concentrations of histamine less than 10(-7) M caused a decrease of contractile activity, whereas higher concentrations of histamine (more than 5 x 10(-7) M) resulted in increase of the phase and tonic contractions. Both H1- and H2-receptors of smooth muscle cells are involved in the response. Much of the relaxing histamine-induced response is produced by the stimulation of the endothelial cells. We believe that activating effect of histamine is due to the excitation of H1-receptors located on the membrane of myocytes, whereas its inhibitory effect occurs in two ways: 1) via excitation of H2-receptors located on the membrane of myocytes; 2) via stimulation of the NO production by the endothelial cells of lymph node sinus.
Related Concept Videos
Detailed Structure and Function of Lymph Nodes
From a histological perspective, lymph nodes can be split into two main areas: the superficial cortex and the deep medulla. The outer cortex is populated by dendritic cells, macrophages, and B lymphocytes, which are densely packed into follicles. When these B-lymphocytes are presented...
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Parasympathetic Signaling
The effects of...
Nitric Oxide Signaling Pathway
Antihypertensive Drugs: Action of Calcium Channel Blockers
Sympathetic Signaling
Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the...

