Recent Advances in Pineal Cytochemistry. Evidence of the Production of Indoleamines and Proteinaceous Substances by Rudimentary Photoreceptor Cells and Pinealocytes of Amniota
1979; Elsevier BV; Linguagem: Inglês
10.1016/s0079-6123(08)62933-7
ISSN1875-7855
Autores Tópico(s)Neurobiology and Insect Physiology Research
ResumoPineal cells produce rhythmic signals and appear very responsive. In the pineal organ of Amniota, several types of messages may be elaborated: (1) in some reptiles, lacertilians and probably chelonians, the input of photic information may be converted into electrical signals, which are conducted to other parts of the brain; (2) in all groups of Amniota (reptiles, birds and mammals) chemical (neurohormonal) signals seem to be produced. Mainly from biochemical and physiological data it is concluded that two different categories of active pineal constituents (chemical signals) responsible for endocrine capabilities are elaborated; indoleamines now discovered in all Amniota and also low molecular weight compounds (possibly peptidic or polypeptidic), are found only in mammals. Other groups have not been investigated in this respect. However, at present, no pineal compound fully satisfies the classical criteria for a candidate hormone. This chapter highlights recent advances in pineal cytochemistry and also provides evidence of the production of indoleamines and proteinaceous substances by rudimentary photoreceptor cells and pinealocytes of amniota.
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