Correlations linking hypophysis and epiphysis volumes to body weight and brain weight in Simian and in man]

The human hypophyseal and epiphyseal volumes are quantitatively conformable to those of the simians studied. In simians and man, the hypophysis is better correlated to body weight and to brain weight than the epiphysis, as already observed by us in other Mammals (Insectivora, Prosimiano, Rodents and Chiroptera). The pineal gland must be correlated to a non essential somatic function that varies from one species to another at constant somatic weight.     

Comparative morphometric data on the epiphysis, the subfornical organ, and the anterior pituitary gland in 2 groups of pure strain Wistar female rats, SPF or conventional]

In SPF female rats, the pineal gland is less voluminous and its cell-nuclei are smaller than those of conventionnal female rats. This confirms (with the voluminous adrenals previously reported) the stressing action of the absence of pathogenic germs on these animals. The anterior lobe of the hypophysis is slightly smaller and subfornical organ a little larger than in conventionnal female rats.     

Demonstration of pineal gland and pituitary involution in mice poisoned with carbon tetrachloride]

Ingestion of carbone tetrachloride by male C3H Orleans mice determines an involution of the pineal gland and of the hypophysis, as well as extensive lesions of the hepatic parenchyma. There may exist in these animals a higher blood-level of glucocorticoids, as this has been shown to be the case in men suffering from cirrhosis or hepatitis. Involution of the pineal gland in cases of stress, as has been shown by various authors, would result from an entirely different mechanism, that is by increased secretion of corticoadrenal hormones.     

川金丝猴内分泌腺的大体解剖

对3例川金丝猴的内分泌腺作了观察。位于垂体窝内的垂体呈扁圆球形,前后径平均为8．0mm,横径为9．0mm,垂直径为4．5mm;松果体呈扁圆锥形,松果体脚很短,松果体隐窝很小;左肾上腺呈等腰三角形,右肾上腺呈直角三角形;连接甲状腺左、右叶的峡为纤维峡,仅1mm宽;1例川金丝猴有3个甲状旁腺(左侧1个,右侧2个);胸腺右叶较长,伸至颈部形成颈叶。此外,对右肾上腺方位、形态特征的形成也作了讨论。作者认为疣猴类右肾上腺这一特征与它们胃的膨大有关。     

Gas chromatographic analysis of free amino acids in the hyaloplasm of the hypophysis, pineal gland, thyroid gland, spinal cord, thymus and lymph nodes of the cow

Studies of the qualitative and quantitative composition of free amino acids in the hyaloplasm of the hypophysis, pineal gland, thyroid gland, spinal cord, thymus and lymph nodes of the cow are described. The following findings are reported: the highest levels of alanine, valine, glycine, isoleucine, histidine, leucine, threonine, serine, phenylalanine, tyrosine and lysine are found in the thyroid gland, methionine and aspartic acid in the spinal cord, tryptophan and hydroxyproline in the pineal gland, and proline and glutamic acid in the thymus gland. The highest level by weight is that of glutamic acid in all tissues. The presence of α-aminobutyric acid combined with sarcosine and 4-aminoisobutyric acid with 2-AOA and citrulline with cystine was demonstrated. α-Aminoisobutyric acid and isovaline were found in the spinal cord.     

Morphometric data on pineal gland of loir (Glis glis) and lerot (Elioyms quercinus) during the annual cycle]

The important involution of the pineal gland of Glis glis and Eliomys quercinus during the months of july and august belongs to a polyglandular involution (anterior lobe of the hypophysis, male and female genital glands) characteristic of estivation.     

Problems of body structure and size of the hypophysis.

The size of the hypophysis, especially of the anterior lobe, is related to body size while the nervous lobe is related to the brain weight. The anterior lobe of the hypophysis in domestic animals is smaller than that of their ancestors in the wild. The proportions of the body, the distribution of bulk, as they appear in different races--whippets and bulldogs--are related to the size of the anterior lobe. Same body weight implies that the anterior lobe is nearly twice as large in animals with a compact body structure. These intraspecific results can also be shown interspecificly by comparing the species of African Bovidae. Independent of the influence of body size, the subfamilies Alcelaphinae and Hippotraginae possess a larger anterior lobe. A tendency can be shown for a relation to body structure as short-legged species living on marshy grounds (Kobus) or soft sands (Addax) have larger anterior lobes.     

The pineal gland of the gerbil,Meriones unguiculatus

Morphometric analytical procedures were employed to study the pineal gland of the Mongolian gerbil following superior cervical ganglionectomy (SCGX). The purpose of this study was to define the effects of sympathetic denervation on the morphology of the gland at two time periods, 0500 and 1900 h (one hour before lights-on and lights-off, respectively). Fluorescence histochemistry was employed to determine catecholamine and indoleamine content in intact and denervated pineal glands. After SCGX, the pinealocytes decrease in size, concretions are prevented from forming, and the yellow fluorescence in the gland is lost. Following denervation a depression in the volume of most of the pinealocyte organelles, i.e., SER, RER/ribosomes, free cytoplasm, mitochondria and presumptive secretory vesicles, was also observed. However, synaptic ribbons increased in volume in the gerbils that had been killed at 1900 h. It appears that the sympathetic innervation to the pineal gland is a requirement for the presumptive secretory activity of the pinealocytes.     

Ultrastructural characteristics of the differentiation of glandular cells in the anterior pituitary gland of collared lemmings (Dicrostonyx) from the Vrangel Island

In 15.5-, 16-, 17.5-, 18.5-, 20-day-old fetuses and newborn lemmings, the ultrastructure of the anterior lobe of the hypophysis has been studied. In the parenchyma of the 15.5-day-old fetus gland, some cells containing secretory material are revealed, but they are difficult for identification, since differentiation of their organellas is not completed and polymorphism of their granules is strongly manifested. On the 17.5th day of the prenatal development TTH-, ACTH-, LH-, STH-secreting adenocytes are detected; they include secretory granules having diameters 70--100 nm, 80--150 nm, 60--140 nm and 200--400 nm, respectively. On the 18.5th day FSH-secreting cells are identified. Lactotropocytes appear on the 20th day. The anterior lobe of the hypophysis of 17.5--18.5-day-old fetuses are characterized by a high level of the secretory activity which decreases to some extent before birth. Ultrastructure of the cellular organellas in the newborn hypophysis is similar to that in a mature animal, nevertheless, the diameter of the secretory granules does not reach the size of these elements in mature individuals.     

The ultrastructure of the human fetal pineal gland

Summary The ultrastructure of the pineal gland of 18 human fetuses (crown-rump lengths 30–178 mm) was investigated.The pineal gland exhibits a pyramidal shape and consists of an anterior and posterior lobe. Only one parenchymal cell type, the pinealocyte, was observed. Few neuroblasts were seen between the pinealocytes and in the extended perivascular space. The pinealocytes possess all the organelles necessary for hormone synthesis. No specific secretory granule could be observed. The organ is abundantly vascularized and richly innervated. The morphology of the capillaries indicates the existence of a blood-brain barrier.The ultrastructure of the human fetal pineal gland suggests that the gland has a secretory function in early intrauterine life. Acknowledgements. The author is grateful to Mrs. Yael Balslev and Miss Inger Ægidius for their able technical assistance. This investigation was supported in part by The Carl and Ellen Hertz's foundation and the Johann and Hanne Weimann foundation.     

Expression of neural cell adhesion molecules,NCAMs, and their polysialylated forms,PSA-NCAMs,in the developing rat pituitary gland

Neural cell adhesion molecules (NCAMs) can undergo post-translational modifications, such as the addition of polysialic acid chains, thus generating PSANCAMs, which are expressed mainly during development. Since polysialylation considerably modifies NCAM adhesivity, expression of NCAMs and PSANCAMs has been investigated in the developing hypophysis by immunohistochemistry. At embryonic day 13 (E13), an antibody against NCAM outlined all cellular profiles in the entire Rathke's pouch; this labelling persisted until adulthood. NCAM expression increased in all lobes during development and concerned all pituitary cell types. In contrast, at E13, PSA-NCAMs were only detected in the neural lobe, solely constituted of pituicytes at this stage, and the tuberal lobe, the only lobe expressing hormonal mRNA at the same stage. PSA-NCAMs expression increased in the neural lobe at E17 with the arrival of the neurosecretory fibres and persisted into adulthood. In the anterior lobe, PSA-NCAMs appeared at E15 where their distribution was similar to that of the differentiating corticotrophic cells; at subsequent stages, their expression extended to the whole anterior lobe. Only two cell types, corticotrophic and somatotrophic cells, remained labelled in the adult gland. In the intermediate lobe, melanotrophic cells never expressed PSA-NCAMs but these were expressed on folliculo-stellate cells at birth, preceding the onset of innervation. These results suggest that NCAMs and PSA-NCAMs play a role in pituitary histogenesis, cell differentiation and neurointermediate lobe innervation.     

Studies on the development of growth hormone and prolactin cells in the rat pituitary gland by in situ hybridization

Summary An antiserum raised against N-amino-3-propyl melatonin bound to a protein carrier was used to visualize melatonin by immunohistochemistry and to measure melatonin concentration by radioimmunoassay in the pineal gland of intact mink females killed throughout the 24 h cycle and females killed after a bilateral ablation of the cervical superior ganglion. Melatonin immunoreactivity revealed by immunofluorescence or by the peroxidase-antiperoxidase complex was observed in the cytoplasm of presumed pinealocytes of all the females. Circadian changes in pineal melatonin content were not visualized by immunohistochemistry; furthermore, immunoreactivity was also present in the pineal gland of the ganglionectomized females. However, the melatonin content measured by radioimmunoassay was significantly higher in the pineal gland from intact females killed during the night compared with that of intact females killed during the day or of ganglionectomized females. The discrepancy between the results obtained using the two methods may arise because immunohistochemistry can detect very small amounts of melatonin.     

Material translations in the Cartesian brain

This article reexamines the controversial doctrine of the pineal gland in Cartesian psychophysiology. It argues initially that Descartes' combined metaphysics and natural philosophy yield a distinctly human subject who is rational, willful, but also a living and embodied being in the world, formed in the union and through the dynamics of the interaction between the soul and the body. However, Descartes only identified one site at which this union was staged: the brain, and more precisely, the pineal gland, the small bulb of nervous tissue at the brain's center. The pineal gland was charged with the incredible task of ensuring the interactive mutuality between the soul and body, while also maintaining the necessary ontological incommensurability between them. This article reconsiders the theoretical obligations placed on the pineal gland as the site of the soul-body union, and looks at how the gland was consequently forced to adopt a very precarious ontological status. The article ultimately questions how successfully the Cartesian human could be localized in the pineal gland, while briefly considering the broader historical consequences of the ensuing equivalence of the self and brain.     

Role of the pineal gland in the body protection from injury

Pineal gland phylogenic antiquity, its involvement in the stress reaction and many-sided activity of its compounds permit to consider the gland to be the organ taking an active part in the body protection against injury, which is essential for everyone since its appearance on the planet. The available data prove that almost all the reactions developing in the organism from the moment of trauma up to the complete wound reparation are under the pineal control. Being always an urgent one the problem of traumatism increased nowadays because of pineal dysfunction. It makes the premises to apply pineal secret products in traumatic disease as a kind of replace therapy that is suggested to be not less successful than glucocorticoid administration in shock.     

Independent differentiation of mammotropes and somatotropes in the chicken embryonic pituitary gland

It has been reported that mammotropes in a rodent pituitary gland are derived from somatotropes via somatomammotropes (SMTs), cells that produce both growth hormone (GH) and prolactin (Prl). However, no studies have been done on the transdifferentiation of somatotropes in the chicken pituitary gland. In this study, in order to determine the origin of mammotropes, we studied detail property of appearance of chicken somatotropes, mammotropes and pit-1 cells and then evaluated the existence of SMTs in the chicken embryonic pituitary gland. Immunohistochemical analysis revealed that GH-immunopositive (GH-ip) cells appeared on embryonic day (E) 14 and were mainly distributed in the caudal lobe, while Prl-immunopositive (Prl-ip) cells appeared in the cephalic lobe of the pituitary gland on E16. In situ hybridization (ISH) and RT-PCR analysis showed that expression of GH and Prl mRNA starts at E12 in the caudal lobe and at E14 in the cephalic lobe respectively. Pit-1 mRNA was first detected on E5 by RT-PCR, and pit-1 mRNA-expressing cells were found in the cephalic lobe on E8. Then with the ontogeny of the chicken, these cells spread into both lobes. Using a double staining method with ISH and immunohistochemistry, we could not detect the existence of SMTs in the chicken embryonic pituitary gland even in the marginal region of either lobe. These results suggest that chicken somatotropes and mammotropes independently appear in different lobes of pituitary gland and that transdifferentiation from somatotropes to mammotropes is not the central route for differentiation of mammotropes in the embryonic chicken pituitary gland.     

Multiple redundant circadian oscillators within the isolated avian pineal gland

Summary The avian pineal gland contains a circadian pacemaker that oscillates in vitro. Using a flow-through culture system it is possible to measure melatonin production from very small subsections of an individual gland. We have used this technique to attempt to localize the oscillators in the pineal. Progressive tissue reduction did not affect the rhythmicity of cultured pineals. Multiple pieces (up to eight) from a single pineal all were capable of circadian oscillation — establishing directly that a pineal gland contains at least eight oscillators. All pineal pieces were responsive to light, and single light pulses shifted the phase of the melatonin rhythm. Because pieces equivalent to less than one per cent of the whole gland were rhythmic and because the capacity for oscillation was distributed throughout the gland, an individual pineal appears to be composed of a population of circadian oscillators.     

Effect of photoperiod on pineal gland volume and pinealocyte size in the Chinese hamster, Cricetulus griseus

Male adult (200-day-old) Chinese hamsters (Cricetulus griseus) raised from weaning under either LD 16:8 or LD 8:16 were used. The pineal gland of the Chinese hamster consists of superficial (major) and deep (minor) components and a continuous, or interrupted, narrow parenchymal stalk interposed between them. The volume of the superficial pineal including the parenchymal stalk is greater under LD 16:8 than under LD 8:16. Under both photoperiods, pinealocytes in the superficial pineal have larger nuclei and more abundant cytoplasm than those in the deep pineal. Nuclei in the superficial pineal appear pale and usually have irregular profiles, whereas those in the deep pineal appear dark and have round profiles. In the superficial pineal, pinealocyte nuclei are larger, paler, and more irregular; and, in addition, nuclear density is lower under LD 16:8 than under LD 8:16. Similar, but less prominent, photoperiod-induced changes occur in the volume of the deep pineal, the size of pinealocytes, and pinealocyte nuclear morphology in the deep pineal. The results indicate that the development and differentiation of pinealocytes in both pineal portions may be advanced under long photoperiods and delayed under short photoperiods, although pinealocytes in the deep pineal may remain not fully differentiated even in adults. Since testicular weights and body weights are similar under both photoperiods, the photoperiod may exert marked influences on the development of the pineal gland without affecting reproductive activity and growth rates of animals.     

Cytochemical localization of type-A and -B monoamine oxidase in the rat pineal gland

Summary In the mammalian pineal gland, serotonin (5-HT) is located both in the pinealocytes and in the noradrenergic nerve terminals. Pineal 5-HT can be metabolized by three different routes, one of these being its deamination, catalized by monoamine oxidase (MAO). MAO is known to exist as two isozymes, MAO-A and MAO-B. Using two different cytochemical methods at the ultrastructural level, we have localized the presence of MAO in the pineal gland of the rat. The use of selective inhibitors of A-type (clorgyline) and B-type (deprenyl) has shown that MAO-A is localized in the noradrenergic nerve terminals, while pinealocytes contain MAO-B. Taking into account that 5-HT is only deaminated by MAO-A, the specific association of each MAO isozyme with a defined cell type implicates that two cellular compartments are needed in the pineal gland for the biosynthesis of 5-methoxytryptophol and 5-methoxyindole acetic acid, while for the synthesis of melatonin and 5-methoxytryptamine just one cellular compartment, the pinealocyte, is appropriate.     

Functional lymphocytes in the chicken pineal gland

The primary antibody response of lymphoid tissue occupying the pineal gland of 6-wk-old chickens was studied subsequent to injection of the carotid artery with sheep red blood cells (SRBC) or bovine serum albumin (BSA). Injection of SRBC did not produce plaque-forming cells (PFC) among pineal lymphocytes whereas BSA stimulated synthesis of anti-BSA immunoglobulin in pineal lymphoid tissue. A cytotoxic assay using appropriate anti-lymphocyte sera indicated that single-cell suspensions of pineal lymphocytes were composed of 42% B lymphocytes and 51% T lymphocytes. Bursal and thymic lymphocytes labeled with tritiated thymidine migrated into pineal lymphoid tissue when injected into 4- and 5-wk-old naive chicks. These observations indicate that the bursa and thymus make equivalent contributions to the lymphoid mass in the chicken pineal gland. Challenge of pineal-established lymphocytes by antigen introduced via the blood vascular system suggests that soluble antigens--rather than particulate ones--stimulate antibody production in the pineal gland. Collectively, these studies indicate that the pineal gland should be considered as a functional component of the chicken's lymphomyeloid system.