Is any of various structurally related polypeptides, such as bradykinin, that act locally to induce vasodilation and contraction of smooth muscle.

Hormones involved in cell division and other processes.

A polypeptide that makes blood vessels widen and smooth muscles contract.

Group of large protein molecules that influence the contraction of smooth muscle. The result may be low blood pressure, pain, or changes in normal blood flow.

One of a group of naturally occurring polypeptides that are powerful vasodilators, which lower blood pressure, and cause contraction of smooth muscle. The kinins bradykinin and kallidin are formed in the blood by the action of proteolytic enzymes {kallikreins) on certain plasma globulins (kininogens). Kinins are not normally present in the blood, but are formed under certain conditions; for example when tissue is damaged or when there are changes in the pH and temperature of the blood. They are thought to play a role in inflammatory response.

Substances present in the body which are powerful vasodilators. They also induce pain, and are probably involved in the production of the headache of migraine. In addition, they play a part in the production of allergy and anaphylaxis.

A general term for a group of polypeptides that have considerable biological activity. They are capable of influencing smooth muscle contraction, inducing hypotension, increasing the blood flow and permeability (vasodilation) of small blood capillaries, and inciting pain.

The initial classification of elements that stimulate cellular proliferation in various plant types, customarily cultivated as callus within a sanitized medium. The prefix cyto- (cytokinins) has been attached to prevent ambiguity with a collection of polypeptides, alternatively named kinins, that elicit muscle contractions in organisms of the animal kingdom.