Postnatal Development of the Dog Pineal Gland: Electron Microscopy

Calvo, J.; Boya, J; García-Mauriño, José Enrique; Lopez-Carbonell, A.

doi:10.1111/j.1600-079x.1990.tb00684.x

Cited by 35 publications

(53 citation statements)

References 14 publications

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“…The pineal size was generally larger in puppies after eyelids separation with more developed cell processes. In support to our results, a gradual increase in the pineal gland size was noticed in neonatal puppies (Calvo et al, 1988(Calvo et al, , 1990. Fig.…”

Section: Discussionsupporting

confidence: 91%

“…accordance, it has previously been shown that before eyelids separation, the puppies pinealocytes in the first 14 days of the postnatal life and those of rabbit in the first 24 h of postnatal life were immature cells (Calvo et al, 1988(Calvo et al, , 1990. On the other hand, after eyelids separation at the age of 25 days in puppies, the pineal cells become differentiated into mature pinealocytes and astrocytes.…”

Section: Discussionmentioning

confidence: 93%

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Pineal Gland Plays a Role in Gonadal Development after Eyelids Separation in Puppies

et al. 2015

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SUMMARY: Several functional and morphological studies have been conducted on the pineal gland in many mammalian species; however, no published reports are available on the role of pineal gland on the gonadal development before and after eyelids separation in puppies. Therefore, this study aimed to trace the postnatal histo-morphological changes in the pineal gland and gonads of puppies before (2, 10 and 11 days old) and after (25, 35 and 40 days old) eyelids separation in an attempt to investigate the possible role of pineal gland on the gonadal development. In general, the differentiation of pineal cells, interstitial endocrine cells of testes and stromal ovarian cells coincides with the start of eyelids separation in puppies. Histological examination of stained pineal and gonadal slices of puppies after eyelids separation revealed a remarkable differentiation of pinealocytes and testicular interstitial endocrine cells, as well as presence of some evidence of folliculogenesis in ovary. Surprisingly, melatonin receptor (MT1) protein expression levels were significantly increased in the ovaries and testes of puppies after eyelids separation. Moreover, the mRNA and protein expression of AANAT, a ratelimiting enzyme in melatonin biosynthesis, was notably increased in the pineal gland of opened eyes puppies. Our results suggest an increase of melatonin production from the pineal gland of opened eyes puppies and this could play a vital role in the developmental changes observed in the gonads of these puppies.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 93%

Pineal Gland Plays a Role in Gonadal Development after Eyelids Separation in Puppies

et al. 2015

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“…The human embryonic pineal gland exhibits two distinctive types of cells, a photoreceptor cell and a neuroendocrine cell eventually transforming into a melatonin-secreting pinealocyte (5). At the end of the third month of life, the photoreceptor cell type begins to lose its structure and finally vanishes during the fifth month (25). The size of the pineal gland is also affected by the season.…”

Section: Discussionmentioning

confidence: 99%

Melatonin Production in Healthy Infants: Evidence for Seasonal Variations

Sivan¹,

Laudon

Tauman³

et al. 2001

Pediatr Res

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The objective of this study was to determine the normal range of nocturnal urinary excretion of the major melatonin metabolite, 6-sulfatoxymelatonin (6SMT) in a large sample of healthy fullterm infants (8 and 16 wk old) and assess whether the endogenous production of melatonin changes with season. 6SMT was assessed in urine samples extracted from disposable diapers removed from full-term, 8-(n ϭ 317) and 16-wk-old (n ϭ 93) infants over the nocturnal period (19:00 -08:00 h). In addition, 6SMT was assessed in 8-wk-old (n ϭ 35) healthy infants over the entire 24-h period. 6SMT was determined by an ELISA assay. 6SMT excretion at 8 wk of age exhibited diurnal variations with (mean Ϯ SD) 61 Ϯ 18% of the daily production excreted during the nocturnal period regardless of season. The nocturnal 6SMT values in the entire cohort (at 8 as well as 16 wk of age) were found to significantly depart from normal distribution (Kolmogorov-Smirnov test). A normal distribution was obtained using a natural base logarithmic (ln) transformation of the data. The normal range (2.5-97.5 percentile of the ln 6SMT excretion per night) was thus defined as 4.66 -8.64 (106 -5646 ng/night) for 8-wk-old and 5.19 -9.67 (180 -15,820 ng/night) for 16-wk-old infants. A significant effect of the month of birth on 6SMT production at the age of 8 wk was found (ANOVA, p Ͻ 0.002) with maximal levels produced by infants born in June (summer solstice) and minimal excretion in infants born in December (winter solstice). Short-photoperiod-born infants excreted on average about threefold less 6SMT compared with long-photoperiod-born infants (t test, p ϭ 0.01). The seasonal variations were no longer present at 16 wk of age. No effect of breast-feeding at the time of sampling on seasonality of 6SMT was found. Normal ranges for the nocturnal urinary excretion of 6SMT in full-term infants at 8 and 16 wk of age are defined. This enables the evaluation of nocturnal 6SMT excretion as a prognostic and diagnostic factor for child development. The strong effect of season on the normal excretion of nocturnal 6SMT at 8 but not 16 wk of age suggests prenatal influence of the photoperiod on the ontogeny of melatonin. The changes in photoperiod are major environmental cues for initiating seasonal acclimatization of thermoregulatory mechanisms and reproduction. In all mammals studied to date, including humans, the nocturnal production of melatonin by the pineal gland reflects the photoperiod (1, 2) and plays a key role in seasonal acclimation. Humans are not considered photoperiod sensitive, although some disorders such as seasonal affective disorders (3) and cluster headache (4) have been associated with a particular season.Sudden infant death syndrome (SIDS) was shown to occur more frequently during the winter months, during the night, and during the first months of life (5). Some evidence links pineal dysfunction and impaired development with increased prevalence of SIDS (6, 7). A delayed melatonin production was found in infants who had experienced an apparent lifethreate...

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“…Características muy semejantes en cuanto a organización arquitectural observaron Calvo et al (1990) en la pineal de perro adulto, a la cual describieron en forma de pera con una amplia zona proximal y una delgada parte distal. La parte dorsal de la glándula también aparece revestida por una capa de células ciliadas.…”

Section: Histología De La Glándula Pinealunclassified

Morfología de la Glándula Pineal: Revisión de la Literatura

Roa

Sol

2014

Int. J. Morphol.

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ROA, I. & DEL SOL, M.Morfología de la glándula pineal -Revisión de la literatura. Int. J. Morphol., 32(2):515-521, 2014. RESUMEN:La glándula pineal es una pequeña estructura ubicada en el techo del diencéfalo, su principal función es la de regular los ritmos circadianos, tales como sueño-vigilia, secretar melatonina, hormona con fuerte efecto sobre la acción gonadal, además de oncostática, geroprotectora y antioxidante. La presente revisión tiene por objetivo conocer los aspectos morfológicos de la glándula pineal, desde su desarrollo a nivel embriológico como su descripción anatómica e histológica con el fin de comprender su función desde un punto de vista integral. INTRODUCCIÓNLa glándula pineal es una pequeña estructura que en la gran mayoría de los vertebrados se encuentra ubicada en el techo del diencéfalo, su principal función es regular los ritmos circadianos (sueño-vigilia), secretar melatonina, hormona con fuerte efecto sobre la acción gonadal, además de efectos oncostático, geroprotector, antioxidante (Stehle et al., 2011), así como un importante rol inmunoprotector (Arias et al., 2003), también ha sido descrita en el tratamiento de enfermedades degenerativas, tales como la enfermedad de Alzheimer (Zhu et al., 2004).Para realizar este estudio se consultaron artículos publicados en inglés y disponibles en las bases de datos PubMed y ScienceDirect. La búsqueda se realizó utilizando términos como "glándula pineal" y "melatonina". Textos de Anatomía e Histología fueron también consultados para esta revisión. ClasificaciónLa glándula pineal en el ser humano está situada en el techo del diencéfalo, encima de los colículos superiores y posterior al tercer ventrículo, dentro de la clasificación propuesta por Vollrath (1981), basada en la relación entre la glándula y el tercer ventrículo así como, la forma y distribución del tejido que conforma a la glándula, ésta entraría en la categoría de tipo A o proximal, las que se caracterizan por ser gruesas, poco elongadas y estar en una ubicación próxima al tercer ventrículo. Dentro de esta clasificación también están la pineal ovina y la del orangután.Por otra parte Cutore (1909) propuso una clasificación de la glándula pineal en mamíferos con respecto a la relación de esta con el cuerpo calloso, en ésta se relata que existen tres variedades: Subcallosa como las encontradas en marsupiales, algunos artiodáctilos, insectívoros, carní-voros y primates, en estos últimos incluyendo a los humanos. Retrocallosa como en la mayoría de los artiodáctilos y perisodáctilos. Supracallosa como la encontrada en roedores (Herring, 1927). Embriología de la glándula pinealLa glándula pineal es una estructura encefálica derivada de la porción caudal del diencéfalo dorsal embrionario, el cual posteriormente conformará el epitálamo (Moore, 1996).Con respecto al desarrollo de la glándula pineal durante el estado embrionario, Quay (1974) propuso que la glándula pineal durante su desarrollo pasaba por tres fases bien marcadas:Fase Morfogenética: ésta comienza aproximadamente en el día 30 de...

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Postnatal Development of the Dog Pineal Gland: Electron Microscopy

Cited by 35 publications

References 14 publications

Pineal Gland Plays a Role in Gonadal Development after Eyelids Separation in Puppies

Pineal Gland Plays a Role in Gonadal Development after Eyelids Separation in Puppies

Melatonin Production in Healthy Infants: Evidence for Seasonal Variations

Morfología de la Glándula Pineal: Revisión de la Literatura

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