摘要:

Molina‐Carballo A, Acuna‐Castroviejo D, Rodriguez‐Cabezas T, Munoz‐Hoyos A. Effects of febrile and epileptic convulsions on daily variations in plasma melatonin concentration in children. J. Pineal Res. 1994: 16: 1–9.AbstractPlasma melatonin was measured in 118 infants and children (39 controls, 28 with epileptic convulsions, and 51 with febrile convulsions). The control group displayed a typical circadian rhythm, with melatonin peaking between 0200 and 0400. This normal daily variation significantly changed in the epileptic group, which showed a characteristic phase‐advance, with the nocturnal melatonin peak appearing between 2400 and 0200. Febrile convulsions were associated with the disappearance of the normal circadian rhythm of melatonin, which was replaced by melatonin bursts throughout the light: dark cycle. In both febrile and epileptic children, melatonin levels were significantly increased in comparison with norm

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00075.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Recio J, Mediavilla MD, Cardinali DP, Sánchez‐Barceló EJ. Pharmacological profile and diurnal rhythmicity of 2‐[125I]‐iodomelatonin binding sites in murine mammary tissue. J. Pineal Res. 1994: 16: 10–17.AbstractRecent studies demonstrated that melatonin treatment decreased the growth of mammary glands in pubertal and pregnant mice. In vitro, melatonin inhibited murine mammary gland growth at μM concentrations and increased it at pM concentrations. Melatonin‐induced changes of cyclic nucleotide synthesis was also demonstrated in mammary gland slices in vitro. The objective of the present study was to assess the possible existence of specific binding sites for melatonin in murine mammary gland by using 2‐[125I]‐iodomelatonin as a probe. The specific binding of 2‐[125I]‐iodomelatonin to murine mammary gland membranes was rapid, saturable, and reversible, showed an affinity in the low nM range, and displayed time, temperature, and pH dependence. Scatchard analysis indicated the existence of a single class of binding sites that exhibited a diurnal rhythmicity in affinity (Kd) and receptor density (Bmax). A maximum in Bmax(267 ± 42 fmol/mg protein) was found at the light period, while affinity was maximal during darkness (Kd= 1.33 ± 0.22 nM). In competition studies dopamine and dopamine‐related agents, as well as 6‐hydroxymelatonin and serotonin, but not melatonin, effectively displaced 2‐[125I]‐iodomelatonin from mammary binding sites. The results demonstrated a specific binding of 2‐[125I]‐iodomelatonin to murine mammary glands, with affinity in the low nM range, and a pharmacological profile that differed from that reported for 2‐[125I]‐iodomel

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00076.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

NToumi F, Martinet L, Mondain‐Monval M. Effects of melatonin treatment on the gonadotropin‐releasing hormone neuronal system and on gonadotropin secretion in male mink, Mustela vison, in the presence or absence of testosterone feedback. J. Pineal Res. 1994: 16: 18–25.AbstractThe effects of subcutaneous melatonin capsules on the gonadotropin‐releasing hormone (GnRH) immunoreactive (ir) system and the secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH) have been tested in intact, castrated, and castrated adult male mink supplemented with testosterone. Animals were transferred in July, i.e., during the period of sexual rest, under a daily light: dark cycle of 16‐hr light and 8‐hr darkness and studied over 13 weeks. GnRH (ir) perikarya, visualized by immunocytochemistry, were counted on serial coronal sections from the diagonal band of Broca to the infundibulum. Serum FSH and LH concentrations were measured by radioimmunoassay. In intact mink, melatonin induced a significant increase in the number of (ir) perikarya and in FSH and LH concentrations 3 and 8 weeks, respectively, after melatonin capsule implantation. In castrated mink, the number of perikarya and the concentrations of FSH, which had increased within 2 weeks after castration, did not change during melatonin treatment. In contrast, the concentrations of LH, which were not altered by castration, increased 3–6 weeks after the onset of melatonin administration, suggesting a stimulation of GnRH release. In castrated testosterone‐treated mink, the number of perikarya was increased as in castrated males, but the elevation of FSH in response to castration was prevented. Within 2 weeks after melatonin capsule implantation, the concentrations of FSH decreased while those of LH remained low, indicating an inhibition of GnRH release. These results show that testosterone modulates the effect of melatonin on the activity of the GnRH–go

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00077.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Tobler I, Jaggi K, Borbély AA. Effects of melatonin and the melatonin receptor agonist S‐20098 on the vigilance states, EEG spectra, and cortical temperature in the rat. J. Pineal Res. 1994: 16: 26–32.AbstractThe effects of melatonin (3 mg/kg i.p.) and the melatonin receptor agonist S‐20098 (3 mg/kg i.p.) on the vigilance states, electroencephalogram power spectra (0.25–25.0 Hz), and cortical temperature were determined in eight rats in the first 6‐hr interval of the 12‐hr light period. Compared to the vehicle injection both compounds reduced the power density in non‐rapid eye movement sleep in the low frequency range (1–8 Hz) but did not affect the vigilance states and brain temperature. The present findings do not indicate that the stimulation of the melatonin receptor exerts a hypnotic effect at doses that had been shown to affect the circadian rest

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00078.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Stokkan K‐A, Reiter RJ. Melatonin rhythms in Arctic urban residents. J. Pineal Res. 1994: 16: 33–36.AbstractThe 24‐hr rhythm of salivary melatonin was measured in persons living in the city of Tromsø (70°N) at the following times of the year: in January at a day length of 2 hr of twilight, in June under continuous sunshine, and in March and September at about 12 hr light and 12 hr darkness. The hormone patterns varied widely between individuals, but, in general, they were consistent within most individuals between the seasons. Highest peak values occurred in January when the mean level was also significantly higher than at any other time of year. The lowest mean levels occurred in June. Although individual rhythms were not always apparent, the mean patterns showed significantly elevated melatonin concentrations during the night at all seasons. The June melatonin peak was similar to that in March and September, but appeared to be phase‐delayed with increased melatonin concentrations from midnight until 0900. It is assumed that the delayed melatonin peak in June may be associated with a tendency among people to shift their activity/rest rhythm and that the pineal sensitivity to light is reduced in the morning

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00079.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Samejima M, Happe HK, Murrin LC, Pfeiffer RE, Ebadi M. Distribution of cholinergic and dopaminergic receptors in rainbow trout pineal gland. J. Pineal Res. 1994: 16: 37–43.AbstractThe involvement of multiple receptors in modulating the function of the pineal gland was investigated by searching for dopaminergic and cholinergic receptors in trout pineal gland. Dopamine D1and D2receptors were measured using [3H]SCH23390 and [3H]spiperone, respectively. Muscarinic and nicotinic cholinergic receptors were measured using quinuclidinyl benzilate ([3H]QNB) and [3H]methylcarbamyl choline, respectively. High‐affinity choline uptake sites were measured using [3H]hemicholinium‐3. The distribution of dopaminergic receptors varied throughout the pineal gland in that the density of D2receptors, which was higher than that of D1receptors, was most abundant in the distal region, exhibiting a value of 112 ± 17 fmol/mg tissue. The distribution of both muscarinic and nicotinic receptors was uniform throughout the pineal gland. However, the highest value for the high‐affinity choline transporter (106 ± 17 fmol/mg tissue) occurred in the proximal portion of the trout pineal gland. The results of these studies indicate that the pineal gland should not be viewed as a homogenous tissue possessing identical density of various receptors. Furthermore, these results, along with previous data, are interpreted to suggest that different regions of pineal gland may indeed possess unique

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00080.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Marín F, Boya J, Calvo JL, López‐Muñoz F, García‐Mauriño JE. Immunocytochemical localization of basic fibroblast growth factor in the rat pineal gland. J. Pineal Res. 1994: 16: 44–49.AbstractThe immunocytochemical localization of basic fibroblast growth factor (b‐FGF) during the postnatal development of the rat pineal gland was studied using a polyclonal antibody against the fraction 1–24 of bovine recombinant b‐FGF. Basic FGF immunoreactivity was evident from day 20 after birth in the endothelial cells and perivascular spaces of the gland. Although b‐FGF immunostaining showed its maximal expression at 30–45 days, it was maintained throughout the entire study period (up to 6 months), mainly in the distal zone of the gland. Pinealocytes did not show b‐FGF immunoreactivity at any time. There were no differences in the localization patterns or the intensity of b‐FGF immunostaining after the prenatal denervation with DSP‐4, a neurotoxic amine. The physiological role of b‐FGF in the adult pineal gland remains unknown; however, it does not seem to play a major role during the cytodifferentiation period of the parenchymal cells, or during the neovascularization in the early postnatal days. Furthermore, its immunocytochemical expression is not affected by the prenatal sympathetic denervation with DSP‐4, in contrast

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00081.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Mikkelsen JD, Møller M, Larsen PJ, Fahrenkrug J. The presence of nerve fibers immunoreactive for vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), and preproVIP(111‐l22) in the mouse pineal gland. J. Pineal Res. 1994: 16: 50–56.AbstractA low to moderate number of vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI)‐immunoreactive nerve fibers with prominent boutons‐en‐passage were demonstrated in the pineal gland of the mouse. The two peptides, which are parts of the same precursor molecule, were distributed identically in the gland. Positive fibers were present in the connective tissue septae in the gland, in the pineal capsule, and in the pineal parenchyma. No VIP‐PHI‐immunoreactive elements were found in the deep pineal gland, in the pineal stalk, or in habenular and posterior commissures. This morphological distribution of immunoreactive nerve fibers, which is similar to the distribution in other mammals, indicates that the VIP/PHI fibers of the mouse pineal gland originate exclusively from perikarya in a peripheral ganglion, presumably one of the cholinergic ganglia of the head. No evidence for a VIPergic central innervation was found. VIP and PHI are connected via a bridging peptide equivalent to amino acids 111‐122 of the precursor (preproVIP(111‐122)). In order to demonstrate the possible existence of this peptide in intra‐pineal nerve fibers, antisera directed against a synthetic sequence identical to pre‐proVIP(111–122) and immunohistochemistry were applied.AbstractPreproVIP(111‐122)‐immunoreactive nerve fibers were observed in the mouse pineal gland, with the same distribution pattern and morphology as those immunoreactive for VIP and PHI. To quantify the peptide‐immunoreactivities, 50 mice pineals were pooled, extracted, and the concentrations were measured radioimmunologically. The concentrations of the VIP and preproVIP(111–122) immunoreactivities were 1.7 and 2.0 pmol/g, respectively, whereas the concentration of PHI was 0.9 pmol/g. This indicates that not only VIP and PHI, but also other fragments of preproVIP are present in the mammalian pineal gland. Whereas the stimulatory role of VIP is well documented, the effect of other fragments processed from preproVIP on pineal

ISSN:0742-3098    

DOI:10.1111/j.1600-079X.1994.tb00082.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY