Immune-mediated denervation of the pineal gland underlies sleep disturbance in cardiac disease

Disruption of the physiologic sleep-wake cycle and low melatonin levels frequently accompany cardiac disease, yet the underlying mechanism has remained enigmatic. Immunostaining of sympathetic axons in optically cleared pineal glands from humans and mice with cardiac disease revealed their substantial denervation compared with controls. Spatial, single-cell, nuclear, and bulk RNA sequencing traced this defect back to the superior cervical ganglia (SCG), which responded to cardiac disease with accumulation of inflammatory macrophages, fibrosis, and the selective loss of pineal gland-innervating neurons. Depletion of macrophages in the SCG prevented disease-associated denervation of the pineal gland and restored physiological melatonin secretion. Our data identify the mechanism by which diurnal rhythmicity in cardiac disease is disturbed and suggest a target for therapeutic intervention.

Mass-spectrometry analysis of the human pineal proteome during night and day and in autism

The human pineal gland regulates day-night dynamics of multiple physiological processes, especially through the secretion of melatonin. Using mass-spectrometry-based proteomics and dedicated analysis tools, we identify proteins in the human pineal gland and analyze systematically their variation throughout the day and compare these changes in the pineal proteome between control specimens and donors diagnosed with autism. Results reveal diverse regulated clusters of proteins with, among others, catabolic carbohydrate process and cytoplasmic membrane-bounded vesicle-related proteins differing between day and night and/or control versus autism pineal glands. These data show novel and unexpected processes happening in the human pineal gland during the day/night rhythm as well as specific differences between autism donor pineal glands and those from controls.

Disrupted nocturnal melatonin in autism: Association with tumor necrosis factor and sleep disturbances

Sleep disturbances, abnormal melatonin secretion, and increased inflammation are aspects of autism spectrum disorder (ASD) pathophysiology. The present study evaluated the daily urinary 6-sulfatoxymelatonin (aMT6s) excretion profile and the salivary levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6) in 20 controls and 20 ASD participants, as well as correlating these measures with sleep disturbances. Although 60% of ASD participants showed a significant night-time rise in aMT6s excretion, this rise was significantly attenuated, compared to controls (P < .05). The remaining 40% of ASD individuals showed no significant increase in nocturnal aMT6s. ASD individuals showed higher nocturnal levels of saliva TNF, but not IL-6. Dysfunction in the initiation and maintenance of sleep, as indicated by the Sleep Disturbance Scale for Children, correlated with night-time aMT6s excretion (r = -.28, P < .05). Dysfunction in sleep breathing was inversely correlated with aMT6s (r = -.31, P < .05) and positively associated with TNF level (r = .42, P < .01). Overall such data indicate immune-pineal axis activation, with elevated TNF but not IL-6 levels associated with disrupted pineal melatonin release and sleep dysfunction in ASD. It is proposed that circadian dysregulation in ASD is intimately linked to heightened immune-inflammatory activity. Such two-way interactions of the immune-pineal axis may underpin many aspects of ASD pathophysiology, including sleep disturbances, as well as cognitive and behavioral alterations.

Arecoline inhibits pineal-testis function in experimentally induced hypothyroid rats

Arecoline is known to cause endocrine dysfunction. In the current article role of arecoline on pineal-testis activity was investigated in hypothyroid rats induced by propylthiouracil (PTU). PTU treatment caused thyroid dysfunction ultrastructurally with a fall in T₃ and T₄ levels followed by a rise of thyroid stimulating hormone (TSH) level. Pineal activity was impaired by PTU treatment, as evident from degenerated synaptic ribbons and mitochondria of the pinealocytes with depletion of pineal and serum N-acetyl serotonin and melatonin levels. Leydig cell function was suppressed, evident from reduced smooth endoplasmic reticulum and depletion of testosterone level. Sex accessories function was impaired by showing scanty rough endoplasmic reticulum with depletion of fructose and sialic acid levels. Arecoline treatment that caused pineal dysfunction and testicular stimulation in control rats, suppressed both pineal and testis functions after PTU treatment. The findings suggest that arecoline inhibits pineal-testis function in experimentally induced hypothyroid rats.

The absence of maternal pineal melatonin rhythm during pregnancy and lactation impairs offspring physical growth, neurodevelopment, and behavior

Maternal melatonin provides photoperiodic information to the fetus and thus influences the regulation and timing of the offspring's internal rhythms and preparation for extra-uterine development. There is clinical evidence that melatonin deprivation of both mother and fetus during pregnancy, and of the neonate during lactation, results in negative long-term health outcomes. As a consequence, we hypothesized that the absence of maternal pineal melatonin might determine abnormal brain programming in the offspring, which would lead to long-lasting implications for behavior and brain function. To test our hypothesis, we investigated in rats the effects of maternal melatonin deprivation during gestation and lactation (MMD) to the offspring and the effects of its therapeutic replacement. The parameters evaluated were: (1) somatic, physical growth and neurobehavioral development of pups of both sexes; (2) hippocampal-dependent spatial learning and memory of the male offspring; (3) adult hippocampal neurogenesis of the male offspring. Our findings show that MMD significantly delayed male offspring's onset of fur development, pinna detachment, eyes opening, eruption of superior incisor teeth, testis descent and the time of maturation of palmar grasp, righting reflex, free-fall righting and walking. Conversely, female offspring neurodevelopment was not affected. Later on, male offspring show that MMD was able to disrupt both spatial reference and working memory in the Morris Water Maze paradigm and these deficits correlate with changes in the number of proliferative cells in the hippocampus. Importantly, all the observed impairments were reversed by maternal melatonin replacement therapy. In summary, we demonstrate that MMD delays the appearance of physical features, neurodevelopment and cognition in the male offspring, and points to putative public health implications for night shift working mothers.

[CME: Jet Lag Jetlag]

CME: Jet Lag Jetlag Abstract. Crossing several time zones by air travel leads to a temporary desynchronization of the internal clock with the external light/dark cycle. In the following jet lag occurs typically including difficulties falling asleep or waking up early as well as day-time sleepiness and significant reduction of wellbeing and fitness. To provide optimal medical advice, it is necessary to understand the human circadian rhythm and sleep-wake regulation. In consideration with additional information on travel plans, an approach to alleviate jet lag symptoms can be developed. This article addresses different supportive measures and advice on how to adjust to a new time zone and reduce jet lag symptoms.

The Pineal Gland and Breast Cancer: Serum Levels of Melatonin in Patients with Mammary Tumors and Their Relation to Clinical Characteristics

Several studies have suggested that the pineal gland hormone melatonin may influence the growth of breast cancer. The importance of melatonin blood concentrations in the clinical history of human breast cancer, however, has still to be defined. To further investigate this problem, we used a RIA method to assay serum levels of the pineal hormone in 74 untreated breast cancer patients, clinical stage T1–3 NO-2 MO, and in 46 age-matched healthy women as controls. Mean serum melatonin levels were significantly higher inpatients than in controls. Melatonin concentrations were highest in breast cancer patients with the best prognosis (i.e. estrogen receptor-positive/node-negative cases). Mean levels of melatonin were significantly higher in estrogen receptor-positive patients than in the negative ones. They were also higher in node-negative than in node-positive cases, and in progesterone receptor-positive patients than negative ones, but none of these differences was statistically significant. No difference was observed in relation to menopausal status and to tumor histotype. These results suggest that melatonin plays a role in the hormone-dependency of human breast cancer.

Peripheral Precocious Puberty Caused by Human Chorionic Gonadotropin Producing Pineal Gland Tumor

BACKGROUND

Pineal gland lesions usually present with central precocious puberty.

CASE CHARACTERISTICS

A 3½-yr-old boy presented with precocious puberty. Clinically and biochemically, it was gonadotropin releasing hormone (GnRH) independent. Serum and CSF beta-hCG levels were increased. Thin section magnetic resonance imaging of brain revealed a pineal gland tumor.

OUTCOME

He received chemotherapy followed by radiotherapy and responded well.

MESSAGE

CSF beta-hCG should be measured in all cases of peripheral precocity, and if CSF beta-hCG is elevated, thin section magnetic resonance imaging of brain should be considered.

Arecoline cannot alter testicular dysfunction and pineal activation caused by noise in wistar rat

Millions of people consume betel nut for increased capacity to work and for stress reduction. The nut contains arecoline, which has multiple side effects on endocrine functions. Objective of the work is to investigate pineal-testicular responses to noise and after arecoline treatment in noise in rats. Noise exposure (100 dB, 6 h daily, 10 days) caused pineal stimulation ultrastructurally and at indoleamines level. Leydig cell dysfunction with fall of testosterone level and suppression of sex accessories were noticed. In contrast, pineal activity was inhibited and reproductive functions were stimulated after arecoline administration, confirmed from reversed changes to those of noise. Arecoline treatment in noise exposure showed same results as in noise both in pineal and in reproductive functions. It is concluded that noise causes testicular dysfunction probably by gonadotropin suppression induced by pineal melatonin in noise. Furthermore, arecoline cannot prevent it in noise in rats.

Peculiairities of the influence nitrogen monoxide synthesis blockade on circadian organization of kidney acid-regulating function under conditions of pineal gland hyperfunction

OBJECTIVE

Introduction: In recent decades chronobiology - a science that studies the regularities of the functioning of the organism, especially biological rhythms is developing rapidly. Biorhythms are stable nonstopper lifetime fluctuations with individual amplitude-frequency characteristics. Kidneys are characterized by a clear time organization of functions too, however, the peculiarities of circadian organization and the mechanisms of the participation of intracellular messengers in particular nitrogen monoxide (NО) in biorhythmic regulation of renal functions, remain insufficiently studied The aim of our work was to investigate the peculiairities of the influence nitrogen monoxide synthesis blockade on circadian organization of kidney acid-regulating function under conditions of pineal gland hyperfunction.

PATIENTS AND METHODS

Materials and methods: The experiments were conducted on 72 mature non-linear albino male rats with their body mass 0,15-0,18 kg. The animals were kept under vivarium conditions at a stable temperature and air humidity fed on a standard dietary intake. The control group included animals (n=36) kept under conditions of usual light regimen (12.00L:12.00D) during 7 days. The experimental group included animals (n=36) injected with N-nitro-L-arginine (L-NNA) in the dose of 20 mg/kg during 7 days under conditions of continuous absolute darkness (12.00D:12.00D). On the 8th day the animals were exposed to 5& water load with heated to room temperature water supplied and the parameters of the kidney acid-regulating function under conditions of forced diuresis were investigated.

RESULTS

Results: The inhibition of the monoxide synthesis (NО) in conditions of pineal gland (PG) hyperfunction violated the structures of chronorhythms acid-regulating function of the kidneys. The decrease in urine pH at daytime intervals was due to a decrease in the level of hydrogen ion excretion during this period of the day. The introduction of the NО blocker against the background of the PG hyperfunction violated the structure of the acid esterification chronorhythms that are titrated. The maximum level of this indicator was recorded at 20.00 a.m. a day. The blockade of the synthesis NО on the background of the PG hyperfunction significantly reduced the level of excretion of ammonia.

CONCLUSION

Conclusions: The maximum level of excretion was 12.00 a.m., bathyphase - at 24.00 a.m. The average daily level was 1.5 mcmol/100 mcl GF and was lower relative to the control animals and animals that were in the conditions of PG hyperfunction.

PECULIAIRITIES OF MELATONIN EFFECT ON CHONORHYTMIC ORGANIZATION OF KIDNEY ACID-REGULATING FUNCTION INFLUENCED BY NITROGEN MONOXIDE SYNTHESIS BLOCKADE UNDER CONDITIONS OF PINEAL GLAND HYPOFUNCTION

The objective of research is to study the peculiarities of melatonin effect on chronorhythmic organization of the kidney acid-regulating function influenced by nitrogen monoxide (NO) synthesis blockade under conditions of pineal gland (PG) hypofunction. The experiments were conducted on 72 mature non-linear albino male rats with their body mass 0,15-0,18 kg. The animals were kept under vivarium conditions at a stable temperature and air humidity fed on a standard dietary intake. The control group included animals (n=36) kept under conditions of usual light regimen (12.00С:12.00Т) during 7 days. The experimental group included animals (n=36) injected with N-nitro-L-arginine (L-NNA) in the dose of 20 mg/kg during 7 days under conditions of continuous light (12.00С:12.00С) and melatonin in the dose of 0,5 mg/kg during 7 days simultaneously. On the 8th day the animals were exposed to 5% water load with heated to room temperature water supplied and the parameters of the kidney acid-regulating function under conditions of forced diuresis were investigated. Kidney functions in the control animals are subordinated to accurate circadian organization. Daily rhythms of the parameters of kidney acid-regulating functions reflect similar changes of the renal processes. Chronorhythmic transformations of the kidney acid-regulating functions in animals with blocked NO synthesis against continuous light and parallel injection of melatonin enable to suggest that NO synthesis blockade under conditions of melatonin correction reduces daily mean pH level as compared to the control. Although, it was higher than that in the animals with blocked NO synthesis against the ground of physiological function of the pineal gland, and animals with PG hypofunction under conditions of NO synthesis blockadeю Therefore, under conditions of L-NNA blockade of NO synthesis and injection of melatonin influenced by PG hypofunction chronorhythmic transformations of architectonics and phase structure of rhythms of the majority of parameters of the kidney acid-regulating function were found, which is an important diagnostic sign of exertion of adaptive possibilities on the border of transmission of adaptation into disadaptation, were detected.

The association of pineal gland volume and body mass in obese and normal weight individuals: a pilot study

BACKGROUND

In obese individuals impaired sleep and neuroendocrine alterations such as melatonin deficits are associated with circadian rhythm disruption, altered circadian clock gene expression, and bright light at night. While the relation of pineal gland volume (PGV) and melatonin levels has recently been documented in humans, surprisingly little is known about the possible interference of the PGV and the pathophysiology of obesity in humans.

SUBJECTS AND METHODS

We therefore compared the PGV of obese with non-obese individuals; both groups were matched by age and gender. Volumetric analyses were performed on the basis of 3 Tesla high resolution Magnetic Resonance Imaging (MRI).

RESULTS

We found, that the PGV was significantly smaller in obese individuals than in lean controls (P=0.036). Moreover, PGV and waist-hip ratio showed a significant negative association in controls (P=0.018, r^s=-0.602) whereas no association of both variables was found in obese individuals (P=0.856, r^s=-0.051).

CONCLUSIONS

Thus, the current pilot investigation suggests that pineal gland function, reflected by PGV might be involved in the energy homeostasis and pathophysiological mechanisms that contribute to the development and the maintenance of obesity in humans. Moreover, our data supports the notion that the replacement of melatonin deficits might be a novel strategy in the treatment of obesity.

SPECIFIC FEATURES OF CHRONORHYTH- MOLOGIC CHANGES OF THE ION-REGU- LATING FUNCTION OF THE KIDNEYS UN- DER THE HYPOFUNCTION OF THE PINEAL GLAND

The paper investigates the specific features of chronorhythmologic changes of the ion-regulating function of the kidneys under the hypofunction of the pineal gland. For the study of hypofunction of the pineal gland, animals were maintained under constant light stimulation during 7 days. It has been established that the hypofunction epiphysis point out disturbances of the phasic structure of the ion-regulating function in relation to chronograms of the intact group of rats. In terms of physiological pinealectomy observed in- crease in the excretion of sodium ions (6,11±0,81 mmol/h) and the concentration of this cation in the blood plasma remained elevated around the clock. The obtained results indicate significant changes of integral characteristics of the rhythms of electrolyte metabolism and the important role of the pineal gland in ensuring physiological homeostasis.

[Reproductive health disorders in night shift workers (review of literature)]

The review considers problems of reproductive health disorders in night shift workers. In materials of national and foreign authors, ambiguous opinions are presented on the influence, such as on reproductive sphere malignancies development in shift workers. Data of experimental and clnical laboratory studies are presented, that support reproductive pathologies connected with night shift work. The authors tackle a problem on role of epiphysis and circadian rhythms, that influence physiologic biologic rhythms.

[Dynamics of daily rhythm changes of arterial blood pressure in hypopinealism]

The article presents the original data on the character of the changes in arterial blood pressure (ABP) in rabbit with hypopinealism induced by long 24-hour lighting. In experimental animals registered leveling the daily rhythm of ABP primarily because of increase this value in dark time (night, evening) and formation of arterial hypertension by 'non-dipper".

Light exposure at night disrupts host/cancer circadian regulatory dynamics: impact on the Warburg effect, lipid signaling and tumor growth prevention

The central circadian clock within the suprachiasmatic nucleus (SCN) plays an important role in temporally organizing and coordinating many of the processes governing cancer cell proliferation and tumor growth in synchrony with the daily light/dark cycle which may contribute to endogenous cancer prevention. Bioenergetic substrates and molecular intermediates required for building tumor biomass each day are derived from both aerobic glycolysis (Warburg effect) and lipid metabolism. Using tissue-isolated human breast cancer xenografts grown in nude rats, we determined that circulating systemic factors in the host and the Warburg effect, linoleic acid uptake/metabolism and growth signaling activities in the tumor are dynamically regulated, coordinated and integrated within circadian time structure over a 24-hour light/dark cycle by SCN-driven nocturnal pineal production of the anticancer hormone melatonin. Dim light at night (LAN)-induced melatonin suppression disrupts this circadian-regulated host/cancer balance among several important cancer preventative signaling mechanisms, leading to hyperglycemia and hyperinsulinemia in the host and runaway aerobic glycolysis, lipid signaling and proliferative activity in the tumor.

[Chronobiological characteristics of stroke and poststroke cognitive impairment]

OBJECTIVE

To study chronobiological characteristics of ischemic stroke (II) and post stroke cognitive impairment (CI).

MATERIAL AND METHODS

We examined 80 patients with acute ischemic stroke. The cognitive status, sleep quality, chronobiological parameters and night urinary level of 6-sulfatoxymelatonin were assessed. The clinical observation of the efficacy of melaxen treatment in intensive care unit was performed.

RESULTS

The results of the study indicate the significance of social and environmental factors which determine the sleep-wake behavior in the development of pineal dysfunction. The pineal dysfunction probably underlies the development of stroke and accompanied neurodegenerative process.

CONCLUSION

The use of melaxen in hyperacute stroke was associated with better recovery of circadian rhythms and rehabilitation results.

Cancer and the endogenous "pineal clock": a means of early diagnosis and successful treatment as well as prevention of cancers

The majority of chronic diseases, most notably those accompanying aging, result from progressive deterioration of central neuroimmunoendocrine control, often referred to as immunological surveillance. This is as true of cancer as it is of the development of cardiovascular, autoimmune, and neurodegenerative disease, in all of these immunological surveillance break downs, leading to an unraveling of the neuroimmunoendocrine process that inhibits proliferation of preneoplastic and neoplastic cells already existing in the body. The onset of cancer is anticipated by changes in the hormonalimmune coordination resulting in chronic quantitative alterations in the synthesis and release of hormones and the loss of the natural synchronicity of that release, which occurs according to circadian rhythms in the healthy organism, principally under the control of the pineal network. Periodic circadian hormonal release is the source of immune system regulation, thus altering hormone rhythms impairs the immune system's ability to maintain control over emerging tumor cells, not necessarily to eliminate them, but to inhibit proliferation. Malignancy, then, is the result of suppression of or interference with the regular release of hormones that maintain strict regulation of the thymo-lymphatic immune system's maturation and activity. This understanding means that we can act to prevent cancer by means of efficiently monitoring and maintenance of physiological hormonal values. For the cyclic synthesis of malignancies that are metastasized, a means of xenogeneic bone marrow transplantation is proposed as an alternative therapeutic approach.

Morning and nocturnal serum melatonin rhythm levels in patients with major depressive disorder: an analytical cross-sectional study

CONTEXT AND OBJECTIVE

The pineal gland is an adaptive organ that precisely regulates the biological rhythms of melatonin brain hemostasis. Variation in the regulation of melatonin rhythms is a likely cause of depressive disorder. The purpose of this study was to measure serum melatonin levels in patients with major depressive disorder (MDD) and normal control subjects.

DESIGN AND SETTING

Analytical cross-sectional study at the industrial medical unit of the Iron Smelting Company of Isfahan, Iran.

METHODS

The morning and nocturnal serum melatonin levels of patients and controls were measured using the enzyme-linked immunosorbent assay (ELISA) method. All data were assessed using variance analysis.

RESULTS

The morning and nocturnal serum melatonin levels of depressed and healthy subjects differed (P < 0.05). The nocturnal serum melatonin levels of depressed women were lower than those of depressed men (P < 0.05).

CONCLUSIONS

The findings of this study showed that the nocturnal serum melatonin levels in the depressed patients were lower than in the controls. Thus, the peak melatonin phase in the depressed patients was reached with delay.

[Metabolic disorders in elderly patients with hypertension and their correction with melatonin]

The incidence of dysmetabolic factors in 100 elderly patients with hypertension stage II and the role of melatoninproducing function of epiphysis (pineal gland) in the development of these disorders were studied. It was found that the decrease of melatoninproducing function is one of the factors causing disorders of carbohydrate and lipid metabolism in elderly patients with hypertension. Simultaneous application of Melatonin with lisinopril or amlodipine have the normalizing effect on metabolic parameters affected in patients with arterial hypertension.

[Morphofunctional and molecular bases of pineal gland aging]

The review analyzed morphology, molecular and functional aspects of pineal gland aging and methods of it correction. The pineal gland is central organ, which regulates activity of neuroimmunoendocrine, antioxidant and other organisms systems. Functional activity of pineal gland is discreased at aging, which is the reason of melatonin level changing. The molecular and morphology research demonstrated, that pineal gland hadn't strongly pronounced atrophy at aging. Long-term experience showed, that peptides extract of pineal gland epithalamin and synthetic tetrapeptide on it base epithalon restored melatonin secretion in pineal gland and had strong regulatory activity at neuroimmunoendocrine and antioxidant organism systems.

Ethanol consumption and pineal melatonin daily profile in rats

It is well known that melatonin participates in the regulation of many important physiological functions such as sleep-wakefulness cycle, motor coordination and neural plasticity, and cognition. However, as there are contradictory results regarding the melatonin production diurnal profile under alcohol consumption, the aim of this paper was to study the phenomenology and mechanisms of the putative modifications on the daily profile of melatonin production in rats submitted to chronic alcohol intake. The present results show that rats receiving 10% ethanol in drinking water for 35 days display an altered daily profile of melatonin production, with a phase delay and a reduction in the nocturnal peak. This can be partially explained by a loss of the daily rhythm and the 25% reduction in tryptophan hydroxylase activity and, mainly, by a phase delay in arylalkylamine N-acetyltransferase gene expression and a 70% reduction in its peak activity. Upstream in the melatonin synthesis pathway, the results showed that noradrenergic signaling is impaired as well, with a decrease in β1 and α1 adrenergic receptors' mRNA contents and in vitro sustained loss of noradrenergic-stimulated melatonin production by glands from alcohol-treated rats. Together, these results confirm the alterations in the daily melatonin profile of alcoholic rats and suggest the possible mechanisms for the observed melatonin synthesis modification.

[Videooculography in evaluation of oculomotor function in patients with mass lesions of pineal region, midbrain and pons]

Aim of this study was to assess feasibility of videooculography in evaluation of oculomotor function and its dynamics in patients with mass lesions of pineal region, midbrain and pons. Computed videooculography was performed in 48 patients with tumors of pineal region and midbrain, 9 patients with pontine hematomas and 10 healthy volunteers. 25 patients with midbrain and pineal neoplasms were followed after tumor resection or open biopsy. We evaluated amplitude of eye movements in normal and impaired oculomotor function. 4 grades decreases of amplitude upwards, downwards, medially and laterally were emphasized. In early postoperative period statistically significant decrease of amplitude in patients with clinical deterioration was observed. Application of videooculography allows reliable quantitative assessment of oculomotor function, registration and storage of examination data and follow-up of oculomotor function for observation of tendencies in course of disease.

[A hormonal drug melatonin in the treatment of cognitive function disorders in parkinsonism]

Pineal hormone melatonin, which is known to possess neuroptotector and nootrope activity, also produces a significant therapeutic effect with respect to various brain pathologies. The review of original and published data suggests that it is expedient to use melatonin in the treatment of cognitive disorders accompanying Parkinson's disease.

[Morphological and chronoepidemiological motivation of lunasensory pineal gland function in the context of redumer hypothesis of aging]

Diurnal analysis of databases of deaths from myocardial infarction (n = 26133) in Moscow in 1995-1996 and the primary incidence of stroke (n = 396) in Dnepropetrovsk in 2007-2008 revealed the following regularities. The incidence both strokes and heart attacks reveals a trend of statistical dependence of these triggering agents fenoptosys from phase extremes of the Moon. Analysis of mortality from myocardial infarction in a representative sample demonstrates its expressed statistical dependence on gravity situation in times of new moon and full moon. For both sexes, the new moon is critical for death due to myocardial infarction. Favorable in this respect, especially for women, are the days of full moon. The obtained data prove the hypothesis of redusome aging and fenoptosys.

[Dependence of atropin-induced amnesia fluctuations on the state of pineal gland]

Atropin produces weakening of the memory on the model of passive avoidance reaction in rats, the effect being more pronounced in evening hours. The drug effect is increased in pinealectomized animals and attenuated by the pineal hormone melatonin, also differently in daytime.

Pinealectomy in the chicken: a good model of scoliosis?

The phenomenon of spinal deformity in the pinealectomized chicken has led researchers to postulate a disturbance of melatonin activity as a potential cause of adolescent idiopathic scoliosis (AIS). More recently, structural differences between curves seen in this model and those seen in scoliosis have been highlighted suggesting the deformities observed are not as similar as first thought. We examined melatonin levels, and the radiological and histological characteristics of scoliosis after pinealectomy in chickens. They underwent pinealectomy (P) at 2 days of age, sham surgery (S) or served as controls (C). Mean melatonin levels were 32.9 pmol/L (P), 175 pmol/L (S) and 227.3 pmol/L (C). Scoliosis developed in 75% of chickens after pinealectomy and 38% after a sham procedure. Nineteen percent of unoperated controls also developed scoliosis. A lower melatonin level was associated with the development of scoliosis (p < or = 0.001), but exceptions were seen with levels up to 265 pmol/L observed in one case. Most of the curves occurring spontaneously and after sham surgery and almost half after pinealectomy were short angular curves: distinct from those resembling idiopathic scoliosis. These occur over one or two segments and are characterized by marked apical wedging, frequently associated with subluxation or dislocation. The intervertebral joint in the chicken is more like a synovial joint histologically than an intervertebral disc. This study highlights important differences between the chicken and the human, and between their respective spinal deformities. Caution is advised when drawing conclusions regarding the pathogenesis of AIS from this model.

[Stroke and epiphysis]

The data on the role of epiphysis and its key hormone melatonin in the natural mechanisms of brain protection from stroke are reviewed. The authors consider chronobiological features of stroke with regard to the fact that epiphysis, which produces melatonin, is involved in the formation of oscillatory processes. Experimental evidences that cerebral ischemia depends on epiphysis activity and injection of exogenic melatonin are presented. Based on experimental data, the authors reveal the protective effect of epiphysis activity in stroke by means of the systemic and direct neuroprotective action of melatonin. It has been suggested that nontoxic preparations of melatonin may be needed in the complex prevention and treatment of stroke, especially in elderly patients with the natural involution of the pineal gland.

Melatonin, light and chronobiological disorders

Human plasma melatonin concentrations can be measured accurately and sensitively by gas chromatography-negative chemical ionization mass spectrometry. With this assay, we have shown that: in rats and in humans, plasma melatonin is exclusively derived from the pineal gland; propranolol and clonidine reduce melatonin levels in human; some blind people appear to have free-running melatonin secretory circadian rhythms; bright light can acutely suppress human melatonin production according to a linear fluence-response relationship; manic-depressive patients appear to be supersensitive to light, even when they are well; melatonin levels are greater in manic patients than in depressed patients; in experiments to test the clock-gate model and the hypothesized phase-response curve, two different effects of light appear to present in humans: an acute suppressant effect (mainly in the evening during long photoperiods) and an entrainment effect (particularly during the morning but also in the evening). When blood is sampled for measuring melatonin levels as a marker for circadian phase position, bright light should be avoided after 5 p.m. (the dim light melatonin onset). Bright-light exposure in the morning appears to advance circadian rhythms, whereas bright-light exposure in the evening appears to delay them. Once a patient has been 'phase typed' (phase-advanced vs. phase-delayed), predictions can be made about whether morning or evening light would be more effective in treating the sleep or mood disorder.

Asymptomatic and symptomatic glial cysts of the pineal gland

Glial cysts of the pineal gland are benign and mostly asymptomatic incidental lesions found in the brain MRI or at autopsy examinations. In rare cases pineal cysts become symptomatic and require surgical intervention. Symptomatic glial cysts may be clinically and radiologically indistinguishable from cystic neoplasms of the pineal region; therefore, histopathological diagnosis is critical for further prognosis and therapy in operated patients. In this paper we present detailed histopathological characteristics of symptomatic glial cysts in 2 surgical cases and of asymptomatic cysts of the pineal gland found at random in 3 autopsy cases. Both surgical patients, a 19-year-old girl and a 17-year-old boy, presented with severe headaches, associated with syncope in one case and insomnia in the second one. Preoperative MR imaging suggested tumour of the pineal gland in case no. 2. Histopathological and immunohistochemical examination of the specimens from both surgical and all autopsy cases revealed a characteristic pattern of cystic structures within the pineal gland, surrounded by layers of a dense fibrillar glial tissue and pineal parenchyma, consistent with non-neoplastic glial cysts. Although histopathological findings in asymptomatic and symptomatic cysts are essentially the same, the cyst in surgical case 1 was unilocular and partly lined with ependymal cells, whereas the cysts in other cases were multilocular, comprising cavities of various size, formed in the central part of gliotic tissue or directly within the pineal parenchyma, and lacked ependymal lining. Possible pathophysiological and clinicopathological significance of some morphological variants of pineal glial cysts is discussed.

Role of circadian rhythm and endogenous melatonin in pathogenesis of acute gastric bleeding erosions induced by stress

Stress that appears as a consequence of burns, surgical trauma and life threatening conditions is a serious clinical entity, can result in acute gastric mucosal lesions. Such stress lesions can develop in response to the imbalance between the aggressive factors promoting mucosal damage and the gastric mucosal defense mechanisms including predominantly gastric blood flow (GBF), biosynthesis of gastroprotective prostaglandins (PG) and enhanced mucus/bicarbonate secretion. Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Melatonin is released during the night but little is known about the effect of circadian rhythm and day/night alterations in melatonin secretion on the formation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. It was found that the gastric mucosa exposed to WRS of various time duration's lasting 1.5, 3 and 6 h, time-dependently increased the number of gastric lesions and this effect was accompanied by the time-dependent fall in the GBF and an increase in the plasma and luminal melatonin levels. Pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS lesions were significantly reduced at night hours and showed circadian variations in plasma levels melatonin with significantly higher plasma melatonin levels at night than in the day and with a greater magnitude of damage induced in the daily hours than at night hours. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels Stress that appears as a consequence of burns, surgical trauma and life threatening conditions is a serious clinical entity, can result in acute gastric mucosal lesions. Such stress lesions can develop in response to the imbalance between the aggressive factors promoting mucosal damage and the gastric mucosal defense mechanisms including predominantly gastric blood flow (GBF), biosynthesis of gastroprotective prostaglandins (PG) and enhanced mucus/bicarbonate secretion. Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Melatonin is released during the night but little is known about the effect of circadian rhythm and day/night alterations in melatonin secretion on the formation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. It was found that the gastric mucosa exposed to WRS of various time duration's lasting 1.5, 3 and 6 h, time-dependently increased the number of gastric lesions and this effect was accompanied by the time-dependent fall in the GBF and an increase in the plasma and luminal melatonin levels. Pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS lesions were significantly reduced at night hours and showed circadian variations in plasma levels melatonin with significantly higher plasma melatonin levels at night than in the day and with a greater magnitude of damage induced in the daily hours than at night hours. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels with a pronounced reduction in mucosal generation of PGE(2) and GBF and by a small increase in plasma melatonin levels during the dark phase. We conclude that 1) stress-induced gastric bleeding erosions exhibit circadian rhythm with an increase in the day and attenuation at night and that these fluctuations in the formation of stress-induced gastric damage may depend upon the melatonin synthesis 2) the progressive increase in plasma melatonin in pinealectomized animals exposed to various time intervals of WRS suggests that extra-pineal melatonin possibly that derived from gastrointestinal tract, play an important role in the gastric mucosal defense against stress-induced gastric damage.

[Melatoninergic receptor agonists and antagonists: therapeutic perspectives]

The chronobiotic neurohormone melatonin, synthetized in the pineal gland during darkness periods governs the circadian and seasonal biological rhythms. Physiologically, melatonin regulates the sleep/activity alternance, together with the circadian cycle of body temperature and cortisol secretion, and influences various immune, endocrine and metabolic functions. Dysfunction of the endogenous melatonin secretion is associated with mood and behavioral disorders including body weight. Patients with severe depression exhibit desynchronized and reduced melatonin secretion, in parallel with marked sleep disturbances whereas exogenous melatonin administration and antidepressive drugs restore melatonin secretion. A dysregulated melatonin secretion is also observed in obese subjects. Implication of melatonin in these disorders stimulated the search for melatonin analogues with enhanced antidepressive and body weight control effects. The melatoninergic agonist S 20098, or agomelatin, disclosed a potent antidepressive and anxiolytic activity in preclinical studies, which was confirmed in clinical trials in patients with major depression. The antagonist S 20928 was shown to limit seasonal weight gain in an hibernating rodent model. Thus, development of melatoninergic agonists and antagonists appear as an innovative approach in the treatment of depression and obesity, two major public health problems.

A promoter polymorphism in the monoamine oxidase A gene is associated with the pineal MAOA activity in Alzheimer's disease patients

BACKGROUND

Monoamine oxidase A (MAOA) is involved in the pathogenesis of mood disorders and Alzheimer's disease (AD). MAOA activity and gene expression have been found to be up-regulated in different brain areas of AD patients, including the pineal gland. Increased pineal MAOA activity might contribute to the reduced pineal melatonin production in AD. A promoter polymorphism of a variable number tandem repeats (VNTR) in the MAOA gene shows to affect MAOA transcriptional activity in vitro.

METHODS

Here we examined in 63 aged controls and 44 AD patients the effects of the MAOA-VNTR on MAOA gene expression and activity in the pineal gland as endophenotypes, and on melatonin production.

RESULTS

AD patients carrying long MAOA-VNTR genotype (consisting of 3.5- or 4-repeat alleles) showed higher MAOA gene expression and activity than the short-genotyped (i.e., 3-repeat allele) AD patients. Moreover, the AD-related up-regulation of MAOA showed up only among long-genotype bearing subjects. There was no significant effect of the MAOA-VNTR on MAOA activity or gene expression in controls, or on melatonin production in both controls and AD patients.

CONCLUSION

Our data suggest that the MAOA-VNTR affects the activity and gene expression of MAOA in the brain of AD patients, and is involved in the changes of monoamine metabolism.

Hypothesis: lifespan is regulated by chronomere DNA of the hypothalamus

As the basis for the lifelong clock and as a primary cause of aging, a process of shortening of hypothetical perichromosomal DNA structures termed chronomeres is proposed in the CNS. The lifelong clock is regulated by the shortening of chronomere DNA in postmitotic neurons of the hypothalamus. Shortening of these DNA sequences occurs in humans on a monthly basis through a lunasensory system and is controlled by release of growth hormone discharged from the anterior pituitary directly into the hypothalamus via local blood vessels. In adults, this process is under control of the pineal gland. It is further proposed that different forms of Alzheimer's disease (AD) are caused by somatic and inherited deletions of chronomeres followed by a further abnormally accelerated decrease in their activity, resulting in failures of neurotrophic and neuroendocrinal activities and in various cellular imbalances. In this model, AD is considered as a segmental progeria caused by shortening of anomalous chronomeres that are partially deleted in early development. It is proposed that a calorie-restricted diet retards chronomere shortening due to a local deficit of growth hormone in the surroundings of hypothalamic cells, thus slowing the lifelong clock and delaying aging. Calorie restriction increases lifespan by preserving mitochondrial and other organismal functions owing to the decreased chronomere shortening.

Increased vascular permeability and nitric oxide production in response to hypoxia in the pineal gland

This study examined the factors that may be involved in altering the function of pineal gland in hypoxic conditions. Adult Wistar rats were subjected to hypoxia and the pineal gland was examined for the mRNA and protein expression of hypoxia-inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), endothelial, neuronal and inducible nitric oxide synthase (eNOS, nNOS, iNOS) at 3 hr-14 days after hypoxic exposure by real time reverse transcription-polymerase chain reaction, Western blotting and immunohistochemistry. Upregulated mRNA and protein expression of HIF-1alpha, VEGF, eNOS, nNOS and iNOS was observed in response to hypoxia. VEGF concentrations as determined by enzyme immunoassay and nitric oxide (NO) production measured by colorimetric assay were significantly higher after hypoxic exposure when compared with the controls. Melatonin content of the pineal gland, as determined by ELISA, was significantly reduced after the hypoxic exposure. Dilated blood vessels expressing eNOS were observed in hypoxic rats. Cells immunoreactive for VEGF were identified as the astrocytes whereas those immunoreactive for iNOS were pinealocytes and macrophages. Our findings indicate that excess production of VEGF and NO in pineal gland in response to hypoxia may be involved in increased vascular permeability as evidenced by an enhanced leakage of rhodamine isothiocyanate (RhIC). The increased vascular permeability may allow free access of serum-derived substances in the pineal gland that may affect the secretory function of the pinealocytes. Administration of exogenous melatonin may be beneficial as it reduced VEGF concentration and NO production significantly in hypoxic rats, and leakage of RhIC was concomitantly reduced.

Disturbance and strategies for reactivation of the circadian rhythm system in aging and Alzheimer's disease

Circadian rhythm disturbances, such as sleep disorders, are frequently seen in aging and are even more pronounced in Alzheimer's disease (AD). Alterations in the biological clock, the suprachiasmatic nucleus (SCN), and the pineal gland during aging and AD are considered to be the biological basis for these circadian rhythm disturbances. Recently, our group found that pineal melatonin secretion and pineal clock gene oscillation were disrupted in AD patients, and surprisingly even in non-demented controls with the earliest signs of AD neuropathology (neuropathological Braak stages I-II), in contrast to non-demented controls without AD neuropathology. Furthermore, a functional disruption of the SCN was observed from the earliest AD stages onwards, as shown by decreased vasopressin mRNA, a clock-controlled major output of the SCN. The observed functional disconnection between the SCN and the pineal from the earliest AD stage onwards seems to account for the pineal clock gene and melatonin changes and underlies circadian rhythm disturbances in AD. This paper further discusses potential therapeutic strategies for reactivation of the circadian timing system, including melatonin and bright light therapy. As the presence of melatonin MT1 receptor in the SCN is extremely decreased in late AD patients, supplementary melatonin in the late AD stages may not lead to clear effects on circadian rhythm disorders.

Neuroendoscopic management of a solitary pineal region tumor. Case report of an adenocarcinoma metastasis

The present case describes a two-step endoscopic management of hydrocephalus and diagnosis of a single pineal region metastasis arising from a gastric adenocarcinoma. A 62-year-old man presenting with signs of subacute obstructive hydrocephalus from a pineal region mass had at first been treated with an endoscopic third ventriculostomy. As cerebrospinal fluid tumor markers (alpha-fetoprotein, beta-human chorionic gonadotropin) were negative, an endoscopic biopsy of the pineal region tumor was performed through a more anterior frontal burr hole. Pathology showed an adenocarcinoma and primary tumor work-up revealed an unsuspected gastric tumor, the pathology of which matched with the intracranial metastasis. The present report emphasizes the role of neuroendoscopy in pineal region tumors and reports a rare case of a solitary gastric adenocarcinoma metastasis in this location.

Aicardi syndrome: an unusual case associated with pineal gland cyst and ventricular septal defect

Aicardi syndrome is a cerebroretinal disorder consisting of a heterogeneous spectrum of clinical findings that includes the triad of infantile spasms, agenesis of the corpus callosum, and chorioretinal lacunae. This report describes a 6-month-old girl who has all of the essential features suggestive of Aicardi syndrome, as well as a pineal gland cyst and ventricular septal defect. Although the characteristic features of Aicardi syndrome have been described, its association with pineal gland cyst and ventricular septal defect has not been reported in the literature.

Neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle: indications, technique, complications, and results

OBJECTIVE

Evaluation of results of the neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle.

METHODS

From 2001 to 2004, 23 patients (mean age, 30.6 yr) with tumors located in the pineal region or posterior third ventricle underwent neurofiberscopic biopsy with simultaneous third ventriculostomy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by radiotherapy and/or chemotherapy without open surgery (eight patients), establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy (11 patients), differentiation of the recurrent neoplasm and radiation necrosis (two patients), and decompression of the large tumor-associated cyst (two patients). In six previously shunted patients, substitution of the ventriculoperitoneal shunt on the third ventricle stoma was performed.

RESULTS

There was no postoperative mortality or permanent morbidity. In all cases, the obtained tissue sample was sufficient for pathological diagnosis. Transient postoperative complications included fever (15 patients), nausea and vomiting (three patients), and diplopia (one patient). On the long-term follow-up, delayed third ventricular stoma failure caused by tumor regrowth and scar formation was found in one patient, and dissemination of the malignant glioma through the subarachnoid space was found in another patient.

CONCLUSION

Neurofiberscopic biopsy represents a useful method for sampling of tumors of the pineal region and posterior third ventricle, which can be effectively used in both previously shunted and shunt-free patients.

Pure pineal germinomas: analysis of gender incidence

OBJECTIVE

Pure pineal germinomas have been rarely reported in girls. Gender incidence and differences of pure pineal germinomas are not well known. The authors report a series of pure pineal germinoma and its gender characteristic is reviewed.

METHODS AND RESULTS

Of a total of 50 germ cell tumors operated on between 1988 and 2004 we found 26 cases (median age at diagnosis, 12 years) of pineal germ cell tumors. Of these, 14 cases (male/female ratio: 13/1) were pure pineal germinomas, and 12 cases (male/female ratio: 12/0) were non-germinoma germ cell tumors. In pure pineal germinomas, the main clinical presentations were intracranial hypertension and cranial nerve dysfunction. Imaging studies disclosed a homogeneous type of tumor (n = 10) and associated hydrocephalus (n = 6). Cases were managed with biopsy and subsequent radiation therapy and chemotherapy. After a follow up of 10 years, pure germinoma cases have no neurological deficits and tumor recurrence. The literature on gender incidence of pure pineal germinomas is analyzed and possible causes are discussed.

CONCLUSIONS

Although rare, pure pineal germinoma can be found in female subjects. On the basis of the literature review, the male/female ratio in cases of pure pineal germinoma is between 5:1 and 22:1 (mean 14:1). In our series, the male/female ratio was 13:1.

Pineal clock gene oscillation is disturbed in Alzheimer's disease, due to functional disconnection from the "master clock"

The suprachiasmatic nucleus (SCN) is the "master clock" of the mammalian brain. It coordinates the peripheral clocks in the body, including the pineal clock that receives SCN input via a multisynaptic noradrenergic pathway. Rhythmic pineal melatonin production is disrupted in Alzheimer's disease (AD). Here we show that the clock genes hBmal1, hCry1, and hPer1 were rhythmically expressed in the pineal of controls (Braak 0). Moreover, hPer1 and hbeta1-adrenergic receptor (hbeta1-ADR) mRNA were positively correlated and showed a similar daily pattern. In contrast, in both preclinical (Braak I-II) and clinical AD patients (Braak V-VI), the rhythmic expression of clock genes was lost as well as the correlation between hPer1 and hbeta1-ADR mRNA. Intriguingly, hCry1 mRNA was increased in clinical AD. These changes are probably due to a disruption of the SCN control, as they were mirrored in the rat pineal deprived of SCN control. Indeed, a functional disruption of the SCN was observed from the earliest AD stages onward, as shown by decreased vasopressin mRNA, a clock-controlled major output of the SCN. Thus, a functional disconnection between the SCN and the pineal from the earliest AD stage onward could account for the pineal clock gene changes and underlie the circadian rhythm disturbances in AD.

Circadian rhythm disorder in a rare disease: Smith-Magenis syndrome

Smith-Magenis syndrome (SMS) is a clinically recognizable contiguous gene syndrome, caused by interstitial deletion of chromosome 17p11.2. The SMS phenotype include distinctive facial features, developmental delay and neurobehavioral abnormalities. The patients present major sleep disturbances ascribed to a phase shift of their circadian rhythm of melatonin with a paradoxical diurnal secretion of the hormone. Treatment with morning beta-blockers and evening melatonin reinstated a normally timed melatonin circadian rhythm, improved daytime behavior and restored normal sleep habits, resulting in a greatly improved quality of life for both SMS patients and their family. SMS is the demonstration of biological basis for sleep disorder in a genetic disease. Considering that clock genes mediate generation of circadian rhythms, we suggest that haploinsufficiency for a circadian system gene mapping to chromosome 17p11.2 may cause the inversion of circadian rhythm in SMS.

[A chronobiological approach in treatment of sleep disturbances in Alzheimer's dementia patients]

Alzheimer's dementia (AD) is a neurodegenerative disease that is often accompanied by severe sleep disturbances. The manifestation of the sleep disturbances is twofold: nighttime hyperarousal sometimes accompanied by irritability and agitation, and daytime excessive sleepiness. Thus, although treatment with sedatives or hypnotics may offer some relief to the nighttime hyperarousal, the daytime excessive sleepiness remains mostly unresolved. Recently, however, more promising results in relief of excessive daytime sleepiness, as well as nighttime hyperarousal, are offered by the chronobiological approach. This approach attributes the sleep problems of AD patients to a dysfunction in a broader neuronal mechanism, namely the biological clock, that paces various physiological functions, among which is the sleep-wake cycle. The biological clock, situated in the suprachiasmatic nuclei (SCN) of the hypothalamus, receives environmental light input via neuronal signals from the retina. The SCN, in turn, innervates the pineal gland, that is responsible for the production and release of melatonin. Light stimulus causes the attenuation of melatonin secretion from the pineal gland; whereas the cessation of light increases melatonin secretion. In diurnal mammals, the dim light melatonin onset (DLMO) is in accordance with sleep onset. The chronobiological approach offers two main treatments to the sleep problems in AD patients: morning exposure to bright light and evening administration of melatonin, both of which show at least moderate success in restoring the sleep-wake cycle in AD patients, that is more marked in the early stages of the disease.

Surgical pinealectomy accelerates intervertebral disc degeneration process in chicken

Despite the importance of intervertebral disc (IVD) degeneration both in research and clinical practice, the underlying biological mechanism of this phenomenon remains obscure. The current study investigated the effects of neonatal pinealectomy on the development of IVD degeneration process in chicken. Thirty chicks (3 days of age) were divided into two equal groups: unoperated controls (Group X) and pinealectomized chicks (Group Y). Pinealectomies were performed at the age of 3 days. At the age of 8 weeks, magnetic resonance imaging examination of one animal in each experimental group was taken. At the end of the study, serum melatonin level was determined by using ELISA method and histopathological or biochemical examination of specimens from all subjects was done. The results of biochemical analyses were compared using Mann-Whitney U test, whereas The Chi-square test was adopted for the histological findings. In this study, the serum melatonin levels in Group Y were significantly lower than those in Group X (P < 0.001). Similarly, scoliosis was developed in 14 out of 15 (93%) in Group Y. Hydroxyproline content of IVD tissue was high in Group Y compared with the values in Group X, although there was no significant difference. Histologically, an appearance of normal IVD was observed in Group X, while the presence of a degenerated IVD was observed in Group Y. From the results of the current study, it is evident that surgical pinealectomy in new-hatched Hybro Broiler chicks has a significant effect on serum melatonin level as well as on the development of IVD degeneration and spinal malformation. In the light of these results from present animal study, melatonin may play a role in the development of IVD degeneration in human beings, but this suggestion need to be validated in the human setting.