Separation of pineal extracts on Sephadex G-10. II. A spectrofluorimetric and thinlayer chromatographic study of indoles in a sheep pineal extract

Influence of temperature and photoperiod on plasma melatonin in the mudpuppy, Necturus maculosus

A melatonin (MEL) radioimmunoassay employed previously only in mammals was used to estimate plasma MEL in a salamander, Necturus maculosus. Validation procedures included thin-layer chromatography of plasma extracts, parallel inhibition curves of authentic MEL and serially diluted plasma and plasma extracts and quantitative recovery of authentic MEL added to pooled Necturus plasma. A diel cycle of plasma MEL was demonstrated in mudpuppies acclimatized for a minimum of 3 weeks under a 12L:12D photoperiod and 15 +/- 1 degrees and sampled in late March. The MEL cycle persisted under a reversed photoperiod (lights on, 1800 hr), but the amplitude of the MEL peak was diminished, and the peak was more than 180 degrees out of phase with the corresponding peak under a normal photoperiod. In animals acclimated to 5 degrees in mid-June under a 12L:12D photoperiod, the diel cycle of plasma MEL continued, but both midphotophase and midscotophase concentrations were reduced compared with 15 degrees controls. The diel cycle was also present in animals acclimated to 25 degrees, but the decrease in MEL concentrations was less marked than that in 5 degrees animals. Photoperiod is apparently the primary cue for cycles in plasma MEL in Necturus, but the cycle can be influenced by temperature.

A survey of the location, isolation and identification of indoles, pteridines and some unknown active substances in sheep pineals. The possible significance of pteridines for the neuroendocrine control of neoplastic growth

Several indoles with mass spectra identical to those of synthetic melatonin, 5-hydroxyindole-3-acetic acid (5-HIAA), 5-methoxyindole-3-acetic acid (5-MIAA), 5-hydroxytryptophol (5-HTL) and 5-methoxytryptophol (5-MTL) could be located, isolated and identified in sheep pineal extracts using rather simple and mild extraction and separation methods. An antigonadotropin, which differs from melatonin, was isolated and partially purified from sheep pineals, using compensatory ovarian hypertrophy after unilateral ovariectomy as a bioassay. Antigonadotropic and gonadotropic compounds which differ from the indoles above mentioned could be located with the same methods. In vitro, these fractions act either on the hypothalamus or on the anterior pituitary. From the paper chromatography fraction, acting on the anterior pituitary in vitro, a compound could be isolated which is most probably identical with biopterin. In our opinion, however, this compound is not responsible for the antigonadotropic activity of the fraction, observed in vitro. Some pineal fractions showing an effect on the activity of the hypothalamus or anterior pituitary of male rats and mice in vitro, may be also active in some experimental tumour models. A possible relationship between disorders in pteridine metabolism and neoplastic growth is discussed.

A survey of some active sheep pineal fractions and a discussion on the possible significance of pteridines in those fractions in in vitro and in vivo assays

Aqueous extracts of sheep pineals are separated on Sephadex G-25 fraction with antigonadotropic activity are ultrafiltered through the membrane UM 2. The UM 2 filtrate is subsequently filtered through the membrane UM 05. The actions of the different fractions on the anterior hypophysis and hypothalamus are discussed. The fractions which show an activity are further separated on Sephadex G-10. The active Sephadex G-10 fractions of the UM 05 filtrate acting on the anterior hypophysis in vitro are purified by electrophoresis and paper chromatography. After elution of different fluorescence bands the main inhibitory activity is found in a region, with the same Rf value as synthetic 6-biopterin. Gas liquid chromatography and mass spectrometry studies of the isolated fractions are carried out. The mass spectrum of an isolated compound from that fraction is identical with that of synthetic 6-biopterin. Thinlayer chromatography and the results of the Crithidia fasciculata test reveal that the isolated compound is probably identical with 6-L-erythrobiopterin. The activity of the active paper chromatography fraction (C4) is compared with the activity of three synthetic biopterin-preparations in vitro and in vivo.

Estimation of the methylating capacity of the pineal gland. With special reference to indole metabolism

In order to obtain more information on the methylating capacity of the pineal gland, a method determining the formation of different 5-methoxyindoles in the pineal gland was developed. The method depends on measuring the incorporation of labelled methyl groups into the various hydroxyindoles present in the pineal gland, after incorporation of pineal tissue with labelled S-adenosyl methionine. Hydroxyindoles were not added to the incubation medium. After incubation thin-layer chromatography was performed with pineal tissue together with the incubation medium; the spots were scraped and counted.

Separation of pineal extracts by gelfiltration. VI. Isolation and identification from sheep pineals of biopterin; comparison of the isolated compound with some synthetic pteridines and the biological activity in in vitro and in vivo bioassays

Aqueous extracts of sheep pineal bodies were separated on Sephadex G-25. Two low molecular weight Sephadex G-25 fractions, F2 and F3, were ultrafiltrated through the Amicon membrane UM-2. The UM-2 filtrate was subsequently filtrated through the ultramembrane UM-05 and the UM-05 filtrate was separated on Sephadex G-10 columns. After paper electrophoresis, preparative paper chromatography was carried out. The fluorescent band showing a Rf value identical with synthetic 6-biopterin was eluted; gas liquid chromatography and mass spectrometry of the isolated compound were carried out. The mass spectra of the isolated compound were shown to be identical with synthetic 6-biopterin. The results of the Crithidia fasciculata test and thinlayer chromatography study revealed that the isolated compound is identical with 6-L-erythro-biopterin. The activities of the isolated compound and of synthetic biopterin in in vitro and in vivo bioassays are demonstrated.

Separation of pineal extracts by gelfiltration. V. Location by paper chromatography of a sheep pineal principle inhibiting hypophyseal gonadotropic activity

Previously we were able to isolate by simple and mild methods from an aqueous sheep pineal extract an inhibiting principle action on the anterior hypophysis of male rats in vitro. This substance could be located by paper electrophoresis. In the present paper we describe the further purification of this active principle by paper chromatography in two different solvents. In two regions possessing a special fluorescence an inhibiting factor of the gonadotropic activity of the anterior pituitary was found in vitro.

Separation of pineal extracts by gelfiltration. IV. Isolation, location and identification from sheep pineals of three indoles, identical with 5-hydroxytryptophol, 5-methoxytryptophol and melatonin

Aqueous extracts of sheep pineal bodies were separated on Sephadex G-25. A low molecular Sephadex G-25 fraction F4 was filtrated on Sephadex G-10. Several distinct peaks could be detected showing excitation and fluorescence maxima resembling those of indoles. A thinlayer chromatography study revealed that one Sephadex G-10 peak contained a spot identical with that of synthetic 5-methoxytryptophol, another a spot with the same Rf-values in different solvents as synthetic 5-hydroxytryptophol, while from a third peak a substance was isolated identical with synthetic melatonin. Mass spectra of the isolated compounds were recorded. These results are compared with those of previous isolation studies.

Separation of pineal extracts by gelfiltration. III. Sheep pineal factors acting either on the hypothalamus, or on the anterior hypophysis of mice and rats in in vitro experiments

Some compounds, other than melatonin, can be detected in aqueous extracts of sheep pineals, using in vitro bioassays. Mild and simple separation methods are used such as gelfiltration on Sephadex G-25, ultrafiltration through Amicon ultramembranes UM-2and UM-05, followed by gelfiltration on Sephadex G-10 and paper electrophoresis. Some fractions are acting on the hypothalamus, others on the anterior hypophysis of mice and rats. The results are compared with those obtained previously with different extraction and separation methods. Key words: Pineal extract, pineal activities in vitro experiments, hypothalamus, anterior hypophysis, paper electrophoresis.

Separation of pineal extracts by gelfiltration. II. Identification and isolation of two indoles from sheep pineal glands

After separation of aqueous extracts of sheep pineal bodies and sheep cerebral cortex on Sephadex G-25, a high fluorescence peak showing an excitation maximum at 305 leads to 310 nm and a fluorescence maximum at 350 leads to 355 nm was observed in pineal extracts, which could not be detected in cerebral cortex extracts. Separation of this pineal fluorescence peak on Sephadix G-10 with water elution, followed by gradient elution of water and NaOH, gave rise to several highly fluorescent peaks. From one of these it was possible to isolate a substance with Rf-values, using thinlayer chromatographic, fluorescence and mass spectra studies, identical with synthetic 5-hydroxyindole-3-acetic acid. From another peak a substance, idential with synthetic 5-methoxyindole-3-acetic acid, could be isolated. The results are compared with those obtained in previous studies.