Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered.The chemical symbol for prothoracicotropic hormone is (C64H102N16O19S2). It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922)[1] and Vincent Wigglesworth (1934),[2] who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause[3][4] would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.
Later it was established that the insect brain produces a number of hormones, but the hormone which was the cause of the observations made by Kopeć and Wigglesworth was prothoracicotropic hormone. PTTH is secreted by a neurohemal organ, the corpus cardiacum (in some insects the corpus allatum secretes PTTH) which is actually a discrete structure posterior to the brain. PTTH is released in response to environmental stimuli and as its name implies PTTH acts on the prothoracic glands, which respond by releasing molting hormone (an ecdysteroid) into the haemolymph. Molting hormone stimulates the molting process.[5][6]
Referencesedit
^KOPEć, Stefan (1922-06-01). "Studies on the Necessity of the Brain for the Inception of Insect Metamorphosis". The Biological Bulletin. 42 (6): 323–342. doi:10.2307/1536759. ISSN 0006-3185. JSTOR 1536759. Retrieved 2012-02-26.
^Wigglesworth, V.B. (1934). "The physiology of ecdysis in Rhodnius prolixus (Hemiptera). II Factors controlling moulting and metamorphosis". Q. J. Microsc. Sci. 77: 191–223.
^Williams, Carroll M. (1947-10-01). "Physiology of Insect Diapause. II. Interaction between the Pupal Brain and Prothoracic Glands in the Metamorphosis of the Giant Silkworm, Platysamia cecropia" (PDF). Biological Bulletin. 93 (2): 89–98. doi:10.2307/1538279. ISSN 0006-3185. JSTOR 1538279. PMID 20268135. Retrieved 2012-02-26.
^Williams, Carroll M. (1952). "Physiology of Insect Diapause. IV. The Brain and Prothoracic Glands as an Endocrine System in the Cecropia Silkworm" (PDF). Biological Bulletin. 103 (1): 120–138. doi:10.2307/1538411. ISSN 0006-3185. JSTOR 1538411. Retrieved 2012-02-26.
^Chapman, R.F. 1998. The Insects: Structure and Function. 4th edition, Cambridge University Press.
^Klowden, M.J. 2007. Physiological Systems in Insects. 2nd edition, Academic Press.
November 29, 2023
prothoracicotropic, hormone, ptth, first, insect, hormone, discovered, chemical, symbol, prothoracicotropic, hormone, c64h102n16o19s2, originally, described, simply, brain, hormone, early, workers, such, stefan, kopeć, 1922, vincent, wigglesworth, 1934, realiz. Prothoracicotropic hormone PTTH was the first insect hormone to be discovered The chemical symbol for prothoracicotropic hormone is C64H102N16O19S2 It was originally described simply as brain hormone by early workers such as Stefan Kopec 1922 1 and Vincent Wigglesworth 1934 2 who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached After a certain point the ligation had no effect and both sections of the insect would molt or pupate However implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause 3 4 would induce molting or pupation Thus the brain was originally thought to be the source of the hormone that induces molting in insects Later it was established that the insect brain produces a number of hormones but the hormone which was the cause of the observations made by Kopec and Wigglesworth was prothoracicotropic hormone PTTH is secreted by a neurohemal organ the corpus cardiacum in some insects the corpus allatum secretes PTTH which is actually a discrete structure posterior to the brain PTTH is released in response to environmental stimuli and as its name implies PTTH acts on the prothoracic glands which respond by releasing molting hormone an ecdysteroid into the haemolymph Molting hormone stimulates the molting process 5 6 References edit KOPEc Stefan 1922 06 01 Studies on the Necessity of the Brain for the Inception of Insect Metamorphosis The Biological Bulletin 42 6 323 342 doi 10 2307 1536759 ISSN 0006 3185 JSTOR 1536759 Retrieved 2012 02 26 Wigglesworth V B 1934 The physiology of ecdysis in Rhodnius prolixus Hemiptera II Factors controlling moulting and metamorphosis Q J Microsc Sci 77 191 223 Williams Carroll M 1947 10 01 Physiology of Insect Diapause II Interaction between the Pupal Brain and Prothoracic Glands in the Metamorphosis of the Giant Silkworm Platysamia cecropia PDF Biological Bulletin 93 2 89 98 doi 10 2307 1538279 ISSN 0006 3185 JSTOR 1538279 PMID 20268135 Retrieved 2012 02 26 Williams Carroll M 1952 Physiology of Insect Diapause IV The Brain and Prothoracic Glands as an Endocrine System in the Cecropia Silkworm PDF Biological Bulletin 103 1 120 138 doi 10 2307 1538411 ISSN 0006 3185 JSTOR 1538411 Retrieved 2012 02 26 Chapman R F 1998 The Insects Structure and Function 4th edition Cambridge University Press Klowden M J 2007 Physiological Systems in Insects 2nd edition Academic Press Retrieved from https en wikipedia org w index php title Prothoracicotropic hormone amp oldid 1171092080, wikipedia, wiki, book, books, library,
