aquaporins

DEFINITION:

A family of membrane channel proteins that serve as selective pores through which water crosses the plasma membranes of many human tissues and cell types.

AQPs

DEFINITION:

Aquaporins.

water channel proteins

DEFINITION:

See aquaporins.

cell

DEFINITION:

1. Any one of the minute protoplasmic masses that make up organized tissue, consisting of a nucleus which is surrounded by cytoplasm which contains the various organelles and is enclosed in the cell or plasma membrane. A cell is the fundamental, structural, and functional unit of living organisms.

2. A small, more or less closed space.

neuroglial cells - The cells of the supportive tissue of the central nervous system (neuroglia); these non-neural cells are of three kinds: astrocytes, oligodendrocytes (collectively termed macroglia) and microglia.

reticular cells - The cells forming the reticular fibers of connective tissue; those forming the framework of lymph nodes, bone marrow, and spleen are part of the reticuloendothelial system and under appropriate stimulation may differentiate into macrophages.

stem cell - 1. Any precursor cell.

2. A blood cell progenitor, or mother cell, having the capacity for both replication and differentiation, and giving rise to various morphologically recognizable precursors of different blood cell lines, such as the proerythrocyte and myeloblast, which cannot self-replicate and must differentiate into more mature daughter cells.

intracellular

DEFINITION:

Situated or occurring within a cell or cells.

trafficking

DEFINITION:

Acting as a transporter.

properties

DEFINITION:

Properties are characteristic qualities, abilities, capabilities, or functions.

AQPs

DEFINITION:

Aquaporins.

cells

DEFINITION:

See definitions for "cell."

tissues

DEFINITION:

See definitions under "tissue."

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard.
2. In biology, the adaptation of form or behavior of an organism to changed conditions.
3. The power to form a whole embryo from stages before the gastrula.

AQP2

DEFINITION:

Aquaporin-2.

trafficking

DEFINITION:

Acting as a transporter.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

permission

DEFINITION:

Formal consent; authorization.

physiology

DEFINITION:

1. The science which treats of the functions of the living organism and its parts, and of the physical and chemical factors and processes involved.

2. The basic processes underlying the functioning of a species or class of organism, or any of its parts or processes.