摘要:

Abstract:By means of teledischarge techniques from the database MEDLINE we selected those documents that contained in their title one or several of the following descriptors:pineal*,epiphys* ormelatonin*, in addition to the descriptorpineal‐bodyin the MESH (Medical Subject Headings) section. A total of 7,617 original documents published between 1966 and 1994 were extracted that dealt with any aspect related with the pineal gland or its main secretary product, melatonin. The main bibliometric laws were applied: Price's Law on the increase in scientific literature, Bradford's Law on the dispersion of the scientific literature, and Lotka's Law on the author's productivity. Furthermore, we have analyzed the participation index (PaI) of the main countries within the global production, the productivity index of the authors (PI), and the number of authors/paper index. Our results demonstrate an exponential increase of the scientific literature on the pineal gland (“r” value = 0.983, in contrast with a “r” value = 0.966 after the linear adjustment). The number of publications on melatonin was less than those on other aspects of pineal research until 1991, when this situation was reversed. The journal with the largest number of original papers isJournal of Pineal Research(1st Bradford's zone) with 533 articles, followed byJournal of Neural Transmision(258) andNeuroendocrinology(221), which constituted the 2nd Bradford's zone. The total number of authors is 9,140, responsible for 23,524 authorships. 3.8% of the authors present a PI>1 (large producers), and 64.9% a PI=0 (occasional authors). Lotka's Law was widely fulfilled in this material since 10.3% of the authors are responsible of 50.2% of all the papers. The average number of authors per paper has changed from 2.29 in 1966 to 3.85 in 1994. The most productive country (during the interval between 1988–1994) was USA (PaI = 30.6), followed by Japan (7.15), United Kingdom (6.45), Germany (6.37), France (6.26), Italy (6.15) and Spain (5.34). Of the total number articles published, 86.9% are

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00247.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Light microscopic, electron microscopic and immunohistochemical observations of the various portions of the pineal gland of the cotton rat (Sigmodon hispidus) were made. The volume of the proximal half occupied about 30% of the whole organ, and pinealocytes were slightly smaller in size in the proximal portion than elsewhere. The distal and intermediate portions contained few interstitial cells and numerous astrocytes, but the proximal portion lacked interstitial cells and had more abundant astrocytes than elsewhere. Astrocytes, which were immunoreactive for glial fibrillary acidic protein, mainly lined the pericapillary spaces in the distal and intermediate portions, but in the proximal portion these cells often surrounded isolated or groups of pinealocytes. In the distal and intermediate portions, abundant sympathetic fibers and less numerous non‐sympathetic, peptidergic fibers were mainly localized in the pericapillary spaces; these fibers were sparsely distributed in the parenchyma close to interstitial cells or astrocytes. In the proximal portion, non‐sympathetic fibers were scarce and sympathetic fibers were distributed abundantly and almost exclusively in the parenchyma. Most of the sympathetic fibers were adjacent to astrocytes and, occasionally, made specialized contact with them. Fenestrae in the capillary endothelium were numerous in the distal portion but absent in the proximal portion. Thus, marked differences in structure existed between the distal and proximal portions of the pineal gland of the cotton rat, suggesting that both portions are functionally dissimilar. In addition, the present study indicates that the proximal portion of the cotton rat was well developed and showed morphological features similar to the deeply situated pineal glands of other mamm

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00248.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Production of melatonin in the pineal gland of inbred mice such as C57B1/6J, B ALB/c and AKR strains is still a matter of debate. In previous studies, we and other authors showed that these strains of inbred mice have a clear‐cut circadian rhythm of serum melatonin and urinary 6‐hydroxy‐melatonin‐sulphate. In contrast, other groups claimed these mice are unable to synthesize melatonin. These studies were based on RIA measurements and/or estimates of N‐acetyltransferase (NAT) and hydroxyindole‐O‐methyltransferase (HIOMT) activities. In the present study we validate the presence of melatonin in the pineal gland of C57B1/6, BALB/c, and AKR mice by HPLC determinations. We found a short‐term melatonin peak in the middle of the dark period with a pattern which mirrors that found previously in the serum. The possibility remains, although it seems unlikely, that the pineal melatonin rhythm measured here represents melatonin produced elsewhere which then was subsequently taken up by t

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:The pineal hormone melatonin showed no effect on voltage‐gated calcium channels in cultured human aortic smooth muscle cells. In combination with estradiol, which blocked calcium channels, melatonin did not antagonize the effect of estradiol. It is concluded that melatonin seems to have different effects on voltage‐gated calcium channels of divergent cell types since the positive action of melatonin previously observed on rat cardiac membranes by other authors could not be seen in the present investigations with human vascular smooth muscle ce

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00250.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:The effects of melatonin implants were investigated on winter fur growth, monitored by counting growing and mature hairs per bundle and testicular recrudescence, judged by testis width, score count of spermatogenesis, and serum testosterone in the adult male raccoon dogs. Melatonin administration in July highly elevated melatonin concentrations in serum and urine and induced an earlier decrease in prolactin secretion (August in the treated group vs September in the control group), winter fur growth (July‐beginning of November in the treated group vs. August‐end of November in the control group) and testicular recrudescence (October in the treated group vs. November in the control group). In the control animals, urinary excretion of melatonin between 1500–0900 hr increased during autumn followed by a rapid fall in winter. The increase from July (1.8 ± 0.4 ng) to August (3.9 ± 0.5 ng) and the subsequent unchanged levels until October coincided with the period of winter fur growth. The further increase in November (6.5 ± 1.2 ng) coincided with the significant elevation in both testis width and score count of spermatogenesis. These results suggest a role of the increase in endogenous melatonin secretion during autumn in the growth of winter fur and testicular recrudescence in this species under natural conditions. Relatively high serum concentrations of prolactin were shown in two animals, one in the control group and another in the treated group. However, the parameters for testis and winter fur growth in the two cases were similar to those in the remainder of the animals. Thereby, the role of prolactin in the winter fur growth and the initiation of testicular recrudescence, if it is truly involved, is manifested through its decreasing secretion rather than the actual blood concen

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00251.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:We have used the NADPH‐diaphorase enzyme histochemical technique to localize the enzyme nitric oxide synthase in the rat pineal gland. Some scattered NADPH‐diaphorase positive pineal cells were present, mostly in the rostral part of the gland close to the pineal stalk. In addition, NADPH‐diaphorase positive nerve fibers were located in the pineal capsule, in the connective tissue septae of the gland, and also intraparenchymally between the pinealocytes. Most nerve fibers were endowed with boutons en passage. These nerve fibers remained in the gland after bilateral removal of the superior cervical ganglia verifying a non‐sympathetic nature of the NADPH‐diaphorase positive nerve fibers. Pineal blood vessels also exhibited NADPH‐diaphorase activity. The number and distribution of NADPH‐diaphorase containing cells and nerve fibers were not affected by bilateral superior cervical ganglionectomy. Furthermore, animals sacrificed during day or night exhibited the same NADPH‐diaphorase pattern. The present investigation provides the first morphological evidence for the presence of NADPH‐diaphorase activity in rat pineal cells, suggesting an influence of nitric oxide on pineal metabolism. Furthermore, the presence of NADPH‐diaphorase activity in the pineal blood vessels as well as in the perivascular nerve fibers suggests an influence of nitric oxide on the blood flow to the gland and/or the metabolism of the pineal cells adjacent t

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00252.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Abstract:Earlier studies on the immunoregulatory role of the pineal gland and melatonin revealed that melatonin counteracts immunosuppression and thymus atrophy induced by stress or corticosteroid treatment. Moreover, melatonin protects mice injected with encephalitogenic virsuses, synergizes with interleukin‐2 (IL‐2) in cancer immunotherapy and rescues hematopoiesis from cancer chemotherapy toxicity. In regard to the mechanism of action, melatonin seems to act directly on CD4+lymphocytes which release opioid peptides with immunoenhancing properties along with other cytokines. Because of these findings, we investigated the role of the pineal gland and melatonin in autoimmune diabetes mellitus type I using, as an experimental model, female non‐obese diabetic (NOD) mice. Mice were pinealectomized or treated chronically with melatonin (injected subcutaneously or administered via drinking water). This paper shows that neonatal pinealectomy accelerates the development of the disease in female NOD mice while exogenous melatonin protects the animals. This in spite of the fact that melatonin increased the production of insulin autoantibodies (IAA). We conclude that the pineal gland and melatonin influence the development of autoimmune diabetes although the mechanism of action that needs further investig

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00253.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00254.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1996.tb00255.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY