| receptors, glucagon | Cell surface receptors that bind glucagon with high affinity and trigger intracellular changes which influence the behaviour of cells. Activation of glucagon receptors causes a variety of effects; the best understood is the initiation of a complex enzymatic cascade in the liver which ultimately increases the availability of glucose to body organs. (12 Dec 1998) |
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| glucagon | A polypeptide hormone (3485 D) secreted by the cells of the Islets of Langerhans in response to a fall in blood sugar levels. Induces hyperglycaemia. A family of structurally related peptides includes glucagon like peptides 1 & 2 (encoded by the same gene), gastric inhibitory polypeptide, secretin, vasoactive intestinal peptide, growth hormone releasing factor, pituitary adenylate cyclase activating polypeptide, exendins. (18 Nov 1997) |
| glands of internal secretion | Ductless glands that secrete substances which are released directly into the circulation and which influence metabolism and other body functions. (12 Dec 1998) |
| cytocrine secretion | The transfer of secretory material from one cell to another, such as the transfer of melanin granules from melanocytes to epidermal cells. (05 Mar 2000) |
| secretion | 1. <physiology> The process of elaborating a specific product as a result of the activity of a gland, this activity may range from separating a specific substance of the blood to the elaboration of a new chemical substance. 2. Any substance produced by secretion. Origin: L. Secretio, from secernere = to secrete (09 Oct 1997) |
| secretion vector | <molecular biology> A DNA vector in which the protein product is both expressed and secreted (excreted) from the cell. (09 Oct 1997) |
| stimulus secretion coupling | A term used to describe the events that link receipt of a stimulus with the release of materials from membrane bounded vesicles (the analogy is with excitation contraction coupling in the control of muscle contraction). A classical example is the link between membrane depolarisation at the presynaptic terminal and the release of neurotransmitter into the synaptic cleft. (18 Nov 1997) |
| neurohumoral secretion | Transmission of a nerve impulse across a synapse or to an end-organ by secretion of a minute amount of a chemical transmitter such as acetylcholine. (05 Mar 2000) |
| syndrome of inappropriate secretion of antidiuretic hormone | Continued secretion of antidiuretic hormone despite low serum osmolality and expanded extracellular volume. (05 Mar 2000) |
| external secretion | A substance formed by a cell and transported outside the cell walls as a means of ridding the cell of the substance or as a messenger to affect the function of other cells. (05 Mar 2000) |