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Pinealectomy

About: Pinealectomy is a research topic. Over the lifetime, 1317 publications have been published within this topic receiving 37187 citations.


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Journal ArticleDOI
TL;DR: The pineal gland might be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ that is particularly apparent in immunodepressive states.
Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MIIO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as gamma-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.

480 citations

Journal ArticleDOI
18 Jun 1965-Science
TL;DR: Data emphasize the importance of the pineal gland in the regulation of photoperiodic influences on the gonads in hamsters exposed to light-dark cycles.
Abstract: Exposure of male hamsters to cycles of 1 hour of light and 23 hours of darkness causes atrophy of the gonads. Pinealectomy prevents this atrophy, but has no effect on animals exposed to light-dark cycles of 16 : 8. Likewise, removal of both eyes induces gonad atrophy which is prevented by pinealectomy. These data emphasize the importance of the pineal gland in the regulation of photoperiodic influences on the gonads.

427 citations

Journal ArticleDOI
07 Jun 1968-Science
TL;DR: The data demonstrate that the pineal organ is a crucial component of the endogenous time-measuring system of the sparrow, and does not abolish the rhythm of locomotor activity in birds exposed to light-dark cycles.
Abstract: The pineal organ of the house sparrow, Passer domesticus, is essential for persistence of the circadian locomotor rhythm in constant conditions. Upon removal of the pineal body, activity becomes arrhythmic. However, pinealectomy does not abolish the rhythm of locomotor activity in birds exposed to light-dark cycles. Pinealectomized birds are entrained by light cycles in much the same manner as are normal birds. Our data demonstrate that the pineal organ is a crucial component of the endogenous time-measuring system of the sparrow.

357 citations

Journal ArticleDOI
TL;DR: The results of these studies suggest that melatonin may interact with nuclear proteins and that the indole may have an important function at the nuclear level in a variety of mammalian tissues.
Abstract: Melatonin was detected by an improved immunocytochemical technique in the cell nuclei of most tissues studied including several brain areas, pineal gland, Harderian gland, gut, liver, kidney, and spleen from rodents and primates. Cryostat sections from tissues fixed in Bouin's fluid, formalin, or acetone/ethanol were used. The nuclear staining appeared primarily associated with the chromatin. The nucleoli did not exhibit a positive reaction. The melatonin antiserum was used in the range of 1:500 to 1:5,000. Incubation of the antibody with an excess of melatonin resulted in the complete blockade of nuclear staining. Pretreatment of the sections with proteinase K (200-1,000 ng/ml) prevented the positive immunoreaction. In a second aspect of the study, we estimated the concentration of melatonin by means of radioimmunoassay in the nuclear fraction of several tissues including cerebral cortex, liver, and gut. The subcutaneous injection of melatonin (500 micrograms/kg) to rats resulted, after 30 min, in a rapid increase in the nuclear concentration of immunoreactive melatonin which varied in a tissue-dependent manner. However, samples collected 3 h after the injection showed that melatonin levels had decreased to control values. Pinealectomy in rats resulted in a clear reduction in the nuclear content of melatonin in the cerebral cortex and liver but not in the gut. The results of these studies suggest that melatonin may interact with nuclear proteins and that the indole may have an important function at the nuclear level in a variety of mammalian tissues.

333 citations

Journal ArticleDOI
TL;DR: Removal of the pineal organ from small rodents may be rapidly accomplished by immobilizing the skull in a head mounting device and by cutting and removing a circular disc of bone overlying the Pineal area with the use of a dental machine and a specially designed circle cutter.
Abstract: Removal of the pineal organ from small rodents may be rapidly accomplished by (1) immobilizing the skull in a head mounting device and (2) by cutting and removing a circular disc of bone overlying the pineal area with the use of a dental machine and a specially designed circle cutter.

309 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20233
202220
20213
202010
20197
20185