chalone Biochem.
(ˈkæləʊn, ˈkeɪləʊn)
[ad. Gr. χαλῶν, pres. pple. of χαλάω slacken, after hormone.]
An internal secretion that reduces or inhibits the action of certain organs and tissues, opp. hormone. Hence chaˈlonic a.
| 1914 E. Schäfer Introd. Study Endocrine Glands i. 11 Effects are either in the direction of excitation, in which case the endocrine substances producing them..would come under the expression ‘hormones’, or in the direction of restraint and inhibition, in which case they may be termed restraining or inhibiting autacoids and be classed as ‘chalones’. And the action of an autacoid may be described as hormonic or chalonic, according to the kind of effect it produces. 1923 Glasgow Herald 18 Jan. 12 Hormones and chalones (specific chemical messengers) produced by the ductless or endocrine glands. 1925 J. A. Thomson Gosp. Evol. ii. 59 Hormones, which stimulate organs and tissues to greater activity; others are called chalones, which put on a brake. 1962 Times 6 July 6/3 Substances, or active principles, known as chalones. |