Effects of Changes in Environmental Lighting Upon Levels of Hydroxyindole O-Methyltransferase Activity in the Developing-Chick Pineal Gland

1975 ◽  
Vol 53 (4) ◽  
pp. 438-443 ◽  
Author(s):  
S. D. Wainwright
Keyword(s):  
Enzyme Activity ◽  
Pineal Gland ◽  
Diurnal Cycle ◽  
Enzymic Activity ◽  
Constant Light ◽  
Constant Darkness ◽  
Methyltransferase Activity ◽  
Constant Illumination ◽  
Lighting Conditions ◽  
Environmental Lighting

The level of hydroxyindole O-methyltransferase (HIOMT) activity in the pineal gland of developing chicks raised under constant illumination rose more rapidly and to higher values than in the gland of birds maintained in constant darkness. Rates of net increase in activity, and levels of activity attained, for birds raised under a diurnal cycle of illumination were intermediate between those maintained in constant light or darkness. Under each of the lighting conditions, the course of increase in enzymic activity was markedly affected by variations in an unidentified factor, the source of which appeared to be the hatching eggs.Birds transferred from constant light to the dark showed either an arrest of increase in enzyme activity or a loss of activity until the level equalled that observed for chicks of the same age raised in constant darkness. Chicks transferred from constant darkness to constant illumination showed marked increases in levels of enzyme activity at rates comparable with the maximal values observed with birds maintained under constant illumination, regardless of age and without delay. No diurnal cycle in level of HIOMT activity was observed in the pineals of 15-day birds.

scholarly journals Transcriptional regulation of hydroxyindole O-methyltransferase in the chicken pineal gland: day/night changes and long-term effects of light and darkness

1993 ◽  
Vol 290 (3) ◽  
pp. 661-664 ◽  
Author(s):  
M Bernard ◽  
J Guerlotte ◽  
M Cogne ◽  
P Greve ◽  
J P Collin ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Gene Transcription ◽  
Cdna Probe ◽  
Constant Light ◽  
Constant Darkness ◽  
Mrna Levels ◽  
Long Term Effects ◽  
Night Time ◽  
Environmental Lighting ◽  
Time Fall

The indolic hormone melatonin is produced by the pineal gland according to a daily rhythm. The terminal step of melatonin synthesis is catalysed by hydroxyindole O-methyltransferase (HIOMT, EC 2.1.1.4). Adaptation to constant light or darkness modifies HIOMT activity and concentration. Using a cDNA probe encoding HIOMT, we investigated the effect of environmental lighting on HIOMT gene expression in the chicken pineal gland. HIOMT mRNA levels increased by 100% in constant light as compared with constant darkness. In addition, the present study disclosed the existence of a day/night rhythm of HIOMT gene transcription, with 3-fold higher mRNA levels at midday than at midnight. This transcriptional rhythm was not accompanied by day/night changes in HIOMT concentration, probably due to a slow turnover of this protein. Unexpected darkness did not prevent the daytime rise in HIOMT mRNA levels, whereas unexpected light prevented the night-time fall in HIOMT mRNA levels. Together, the data would suggest that the day/night rhythm of HIOMT gene transcription in the chicken pineal gland involves both a response to light and the activity of a biological oscillator.

Chick pineal serotonin acetyltransferase: a diurnal cycle maintained in vitro and its regulation by light

1979 ◽  
Vol 57 (6) ◽  
pp. 700-709 ◽  
Author(s):  
S. D. Wainwright ◽  
Lillian K. Wainwright
Keyword(s):  
Enzyme Activity ◽  
Diurnal Cycle ◽  
Prolonged Exposure ◽  
Continuous Illumination ◽  
Constant Darkness ◽  
Light Cycle ◽  
Acetyltransferase Activity ◽  
Lighting Conditions

We have reproduced in vitro the diurnal cycles in levels of serotonin acetyltransferase activity found in the chick pineal gland in vivo. The more closely the lighting conditions of culture matched those under which the birds were raised, the closer was the similarity between cycles in levels of enzyme activity in vitro and in vivo. Repetitive cycles in levels of acetyltransferase activity persisted in culture for at least 4 days under a diurnal cycle of illumination, and at least 2 days in continuous darkness. When glands were explanted into culture in the light phase of a cycle, short periods of further exposure to light markedly stimulated subsequent increase of acetyltransferase in the dark (after a short lag). Prolonged exposure to light in culture markedly inhibited increase of enzyme activity. Cycles in the levels of enzyme activity in glands cultured under altered light cycles were regulated primarily by changes in illumination. However, the endogenous biological 'clock' remained at least partly entrained to the original light cycle. Increase of acetyltransferase activity in vitro was markedly stimulated by theophylline plus compound Ro. 20.1724 (4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone) under all lighting conditions. Kinetics (to the time of attaining maximum levels in situ) of the increase under diurnal lighting and in constant darkness were indistinguishable from those in vivo. A high concentration of dl-propranolol markedly stimulated an increase in acetyltransferase activity in glands cultured in constant darkness but had little effect on glands under diurnal lighting or continuous illumination.

The relationship between variations in levels of serotonin acetyltransferase activity and cGMP content in cultured chick pineal glands

1981 ◽  
Vol 59 (8) ◽  
pp. 593-601 ◽  
Author(s):  
S. D. Wainwright ◽  
Lillian K. Wainwright
Keyword(s):  
Enzyme Activity ◽  
Circadian Rhythm ◽  
Cyclic Amp ◽  
Diurnal Cycle ◽  
Constant Darkness ◽  
Continuous Darkness ◽  
Camp Content ◽  
Lighting Conditions ◽  
Subsequent Loss ◽  
The Relationship

Chick pineal glands cultured in continuous darkness exhibited a circadian rhythm in 3′,5′-cyclic GMP (cGMP) content. cGMP content increased earlier and fell later than in glands incubated under diurnal lighting. A "spike" of further increase in cGMP content preceded start of decline in acetyl-CoA:arylamine N-acetyltransferase (NAT) activity.Theophylline or 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (compound Ro 20.1724) alone markedly stimulated increase of NAT activity in the dark, and retarded subsequent loss of activity either in the dark or in the photoperiod of a diurnal cycle of illumination. In constant darkness a combination of the two agents elicited greater increases of NAT than either alone and suppressed subsequent loss of activity for several hours. Under diurnal lighting conditions the combination was only slightly more effective than either alone. Compound Ro 20.1724 suppressed the precipitous loss of NAT activity seen when glands are transferred prematurely to the light. However, neither the rate or extent of loss of activity was greatly affected by theophylline.Effects of theophylline and compound Ro 20.1724 upon levels of NAT activity appeared to be due primarily to effects upon the process(es) by which enzyme activity is lost. They could not be attributed solely to effects upon pineal contents of cGMP and (or) 3',5'-cyclic AMP (cAMP). Theophylline alone was as effective as the drug combination in eliciting and maintaining elevated pineal content of cGMP, but had little effect upon cAMP content. Compound Ro 20.1724 alone elicited large increases in pineal contents of both nucleotides but did not sustain them.

EFFECTS OF SEX HORMONES AND ENVIRONMENTAL LIGHTING ON RAT HARDERIAN GLAND PORPHYRIN

1974 ◽  
Vol 63 (1) ◽  
pp. 99-102 ◽  
Author(s):  
RENÉE ULRICH ◽  
ARTHUR YUWILER ◽  
EDWARD GELLER ◽  
LENNART WETTERBERG
Keyword(s):  
Harderian Gland ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Constant Light ◽  
Constant Darkness ◽  
Intact Control ◽  
Gland Weight ◽  
Lighting Conditions ◽  
Harderian Glands ◽  
Environmental Lighting

SUMMARY Ovariectomy of adult female rats significantly decreased the porphyrin content of the Harderian glands compared with intact control rats. Treatment of ovariectomized rats for 5 days with testosterone propionate, progesterone or oestradiol did not alter porphyrin content or concentration; however, administration of oestradiol plus progesterone significantly increased Harderian gland porphyrin content to values indistinguishable from those of intact controls. Additionally, oestradiol treatment lowered the weight of the Harderian glands. Constant light or constant darkness for 35 days significantly decreased Harderian gland porphyrins compared with those of rats kept in diurnal lighting conditions. Constant light significantly lowered porphyrin values compared with those obtained from rats maintained in constant darkness. The effects of constant light were not altered by either ovariectomy or enucleation. Harderian gland weight was reduced in all groups kept in constant light.

scholarly journals The Excitatory Effects of GABA within the Suprachiasmatic Nucleus: Regulation of Na-K-2Cl Cotransporters (NKCCs) by Environmental Lighting Conditions

2020 ◽  
Vol 35 (3) ◽  
pp. 275-286 ◽  
Author(s):  
John K. McNeill ◽  
James C. Walton ◽  
Vitaly Ryu ◽  
H. Elliott Albers
Keyword(s):  
Protein Expression ◽  
Suprachiasmatic Nucleus ◽  
Critical Role ◽  
Time Of Day ◽  
Adult Brain ◽  
Constant Darkness ◽  
Inhibitory Neurotransmitter ◽  
Lighting Conditions ◽  
Environmental Lighting ◽  
The Brain

The suprachiasmatic nucleus (SCN) contains a pacemaker that generates circadian rhythms and entrains them with the 24-h light-dark cycle (LD). The SCN is composed of 16,000 to 20,000 heterogeneous neurons in bilaterally paired nuclei. γ-amino butyric acid (GABA) is the primary neurochemical signal within the SCN and plays a key role in regulating circadian function. While GABA is the primary inhibitory neurotransmitter in the brain, there is now evidence that GABA can also exert excitatory effects in the adult brain. Cation chloride cotransporters determine the effects of GABA on chloride equilibrium, thereby determining whether GABA produces hyperpolarizing or depolarizing actions following activation of GABAA receptors. The activity of Na-K-2Cl cotransporter1 (NKCC1), the most prevalent chloride influx cotransporter isoform in the brain, plays a critical role in determining whether GABA has depolarizing effects. In the present study, we tested the hypothesis that NKCC1 protein expression in the SCN is regulated by environmental lighting and displays daily and circadian changes in the intact circadian system of the Syrian hamster. In hamsters housed in constant light (LL), the overall NKCC1 immunoreactivity (NKCC1-ir) in the SCN was significantly greater than in hamsters housed in LD or constant darkness (DD), although NKCC1 protein levels in the SCN were not different between hamsters housed in LD and DD. In hamsters housed in LD cycles, no differences in NKCC1-ir within the SCN were observed over the 24-h cycle. NKCC1 protein in the SCN was found to vary significantly over the circadian cycle in hamsters housed in free-running conditions. Overall, NKCC1 protein was greater in the ventral SCN than in the dorsal SCN, although no significant differences were observed across lighting conditions or time of day in either subregion. These data support the hypothesis that NKCC1 protein expression can be regulated by environmental lighting and circadian mechanisms within the SCN.

Impact of photoperiodic exposures during late gestation and lactation periods on the pineal and reproductive physiology of the Indian palm squirrel, Funambulus pennanti

Reproduction ◽  
2000 ◽  
pp. 295-301 ◽  
Author(s):  
KS Bishnupuri ◽  
C Haldar
Keyword(s):  
Pineal Gland ◽  
Recovery Process ◽  
Reproductive Physiology ◽  
Late Gestation ◽  
Constant Light ◽  
Constant Darkness ◽  
Lactation Period ◽  
Postpartum Recovery ◽  
The Impact ◽  
Constant Dark

Studies on the maternal transfer of photoperiodic information in mammals indicate that the daily photoperiod perceived by the mother during the gestation-lactation period is communicated to the fetus either through the placenta or via the milk. However, the impact of photoperiodic exposures during gestation and lactation on the maternal pineal and reproductive physiology has not been reported for any tropical rodent. The exposure of pregnant female Indian palm squirrels (Funambulus pennanti) to constant light (24 h light:0 h dark), constant dark (0 h light:24 h dark), long daylength (14 h light:10 h dark) or short daylength (10 h light:14 h dark) during early gestation (< 30 days) resulted in the resorption of pregnancy, while during late gestation (> 30 days), it did not interfere with the maintenance of pregnancy. Alterations in photoperiodic condition during late gestation and lactation altered the postpartum recovery process. Pineal gland activity, as assessed by pineal mass, protein content and plasma melatonin, was lowest during the breeding phase, but increased gradually after parturition until the next breeding phase. During gestation and lactation, constant light, long daylength and short daylength conditions were less effective, while constant dark condition had a profound effect in depressing pineal gland activity, which subsequently advanced postpartum recovery. Hence, lactating females under constant darkness prepare themselves for next mating much earlier than females under natural daylength (12 h light:12 h dark) conditions. Therefore, photoperiodic information, mediated via the pineal gland, may be important for maintaining gestation physiology as well as postpartum recovery in female rodents.

The influence of lighting conditions upon the level and course of increase in specific activity of serotonin N-acetyltransferase in the developing chick pineal gland

1976 ◽  
Vol 54 (2) ◽  
pp. 103-109 ◽  
Author(s):  
I. H. Fraser ◽  
S. D. Wainwright
Keyword(s):  
Pineal Gland ◽  
Specific Activity ◽  
Major Product ◽  
Constant Darkness ◽  
Dark Phase ◽  
Light Phase ◽  
Normal Cycle ◽  
Lighting Conditions ◽  
Hydroxyindoleacetic Acid ◽  
Unidentified Metabolite

A diurnal cycle in level of serotonin acetyltransferase (acetyl-CoA: arylamine N-acetyltransferase (EC 2.3.1.5)) activity was found in the pineal gland of chicks aged 16 to 20 days maintained under diurnal lighting conditions. Diurnal variation in levels of activity was markedly reduced in the pineal gland of birds kept in constant darkness, and suppressed in the gland of chicks under constant illumination. High levels of activity attained during the dark phase of the normal cycle rapidly declined when the birds were transferred to the light. The light phase level of serotonin acetyltransferase of the pineal increased progressively from the 11th day of incubation to about 1 week post-hatch. This course of increase in enzyme activity was largely unaffected by lighting conditions. Under conditions for assay of serotonin acetyltransferase activity in the chick pineal gland and brain, radioactive serotonin gave rise to N-acetylserotonin, 5-hydroxyindoleacetic acid and a further unidentified metabolite, which was quantitatively the major product.

5-Methoxytryptophol rhythms in the chick pineal gland: effect of environmental lighting conditions

1998 ◽  
Vol 251 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Jolanta B Zawilska ◽  
Debra J Skene ◽  
Jerzy Z Nowak
Keyword(s):  
Pineal Gland ◽  
Lighting Conditions ◽  
Environmental Lighting

Regulation of the diurnal cycle in activity of serotonin acetyltransferase in the chick pineal gland

1978 ◽  
Vol 56 (7) ◽  
pp. 685-690 ◽  
Author(s):  
S. D. Wainwright ◽  
Lillian K. Wainwright
Keyword(s):  
Enzyme Activity ◽  
Organ Culture ◽  
Pineal Gland ◽  
Diurnal Cycle ◽  
Adenosine Receptor ◽  
Control Mechanism ◽  
Negative Control ◽  
Acetyltransferase Activity ◽  
In Vivo Effects

When chick pineal glands were explanted into organ culture at midlight phase of a diurnal cycle of illumination and incubated in the dark, they developed marked increases in serotonin acetyltransferase (acetyl coA:arylamine N-acetyltransferase; EC 2.3.1.5) activity. Either this increase in activity was inhibited or its onset was retarded in glands incubated under constant illumination.Supplements of theophylline, isobutylmethylxanthine, quinidine, and compound Ro 20-1724 (4-(3-butoxyl-4-methoxybenzyl)-2-imidazolidinone) elicited very marked increases in serotonin acetyltransferase activity in glands cultured in the dark. Levels of activity attained after 6 h in culture approached or exceeded the maximum levels attained at middark phase of the diurnal cycle in vivo. Effects of theophylline and compound Ro 20-1724 were additive.Supplements of dibutryl cAMP had little or no effect upon levels of serotonin acetyltransferase activity when tested alone or in combination with theophylline but further enhanced the increase in the level of enzyme activity elicited by Ro 20-1724. Adenosine and cAMP had little or no effect upon levels of serotonin acetyltransferase activity.It is concluded that levels of serotonin acetyltransferase activity in the chick pineal gland are regulated by a repressive, negative-control mechanism, which probably involves a membranous adenosine receptor.

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