Pineal gland changes of rats exposed to heat

Zusammenfassung Ratten, die 20 oder mehr Tage bei 33°C gehalten werden, weisen — absolut gemessen — erniedrigten RNS- und Gesamtprotein-Gehalt der Pineals auf, während DNS und Drüsengewicht konstant bleiben. Da die Tiere durch die Hitzeexplosion an Gewicht verlieren, wird der RNS- und Proteingehalt-Abfall pro Körpergewicht nicht wahrnehmbar.

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Acknowledgment. The authors are indebted to MissUte Schmidt andMiss Jeanine Dorf for their excellent technical assistance.     

Night pineal N-acetyltransferase activity in rats exposed to white or red light pulses of various intensity and duration

Summary Night N-acetyltransferase activity is suppressed by red and white light; the red light intensity, however, must be 10 times higher. Short light pulses also suppress night N-acetyltransferase; the higher the light intensity, the shorter the pulse is effective.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Metabolism of alcohol in partially hepatectomized rats exposed to cold

Résumé Le taux de conversion de¹⁴C de l'alcool au¹⁴CO₂ respiratoire aussi bien que l'activité spécifique du¹⁴CO₂ fut différent entre des rats partiellement hépatectomisés, des opérés à blanc et des témoins absolus exposés au froid et leurs témoins maintenus à la température du laboratoire. Toutefois, aucune différence ne fut observée à l'intérieur même des groupes exposés au froid, ni chez ceux maintenus à la température du laboratoire.     

Synaptic development in brains of rats exposed perinatally to ethanol

Summary Development of brain synaptosomal uptakes of³H-norepinephrine and³H-dopamine in pups whose mothers received ethanol were nearly normal. However, development of synaptosomal uptake of³H-serotonin was significantly lower than in controls, while uptake of³H-norepinephrine into synaptic storage vesicles was increased.The authors thank F.J. Seidler and W.L. Whitmore for their technical assistance. Research was supported by U.S. Public Health Service grants AA-02935 and DA-00465. TAS is recipient of Research Scientist Development Award DA-00006 from the National Institute on Drug Abuse, and SMS is recipient of Research Scientist Award MH-06489 from the National Institute of Mental Health.     

Isoprotenerol induction of pineal serotonin N-acetyltransferase in normotensive and spontaneously hypertensive rats

Zusammenfassung Verabreichung von Isoprotenerol, eines -adrenergen Agonisten, induziert einen signifikant höheren Anstieg der Aktivität der Serotonin-N-Acetyltransferase in der Epiphyse von spontan hypertensiven, im Vergleich mit normotensiven, Rattenmännchen. Derselbe Unterschied wurde auch bei Weibchen beobachtet, jedoch liegen die Aktivitätswerte bei spontan hypertensiven Männchen allgemein höher. Die durch Isoprotenerol erhöhte Induktion der Serotonin-N-Acetyltransferase erzeugt hinsichtlich der Catecholamine in den Pinealozyten von spontan hypertensiven Ratten eine veränderte Reaktivität der Achse -Rezeptor-Adenylzyklasesystem-Serotonin-N-Acetyl transferase.     

Pineal indols and testosterone affect exploratory activity of male rats

The testosterone level has an inverse relation to activity in the open-field test. This is more important in red light than in white light. Pineal indols do not disturb this action. Some of these results are consistent with the assumption that androgens play a role on the exploratory activity of adult subjects.     

Pineal function cannot prevent the occurrence of castration cells in male rats

Summary The relationship between the pineal gland and the pituitary gland was investigated in male rats. The results indicate that the hypothalamo-adenohypophysial-gonadal axis is affected by the pineal gland, but the appearance of castration cells following gonal ablation may be only slightly modified by alterations in pineal gland function.     

Pineal function cannot prevent the occurrence of castration cells in male rats

The relationship between the pineal gland and the pituitary gland was investigated in male rats. The results indicate that the hypothalamo-adenohypophysial-gonadal axis is affected by the pineal gland, but the appearance of castration cells following gonad ablation may be only slightly modified by alterations in pineal gland function.     

Pineal indols and testosterone affect exploratory activity of male rats

Summary The testosterone level has an inverse relation to activity in the open-field test. This is more important in red light than in white light. Pineal indols do not disturb this action. Some of these results are consistent with the assumption that androgens play a role on the exploratory activity of adult subjects.     

Protracted analgesia in young and adult rats maternally exposed to methadone

Summary The analgesic response to the hot-plate test was studied in 21-, 45-, 60-, 120- and 300-day-old rats maternally exposed to methadone (5 mg/kg). An elevation in nociceptive threshold, in the absence of further exposure to methadone, was observed in young and adult rats perinatally subjected to methadone.This research was supported by grant DA 01618.     

Mitogenic effect of the serum of rats exposed to cold

Summary Serum from rats exposed for 3 days to 5 °C stimulated the multiplication of mouse heteroploid and human and rat diploid cells in culture. The response of the cells to this unspecific growth stimulation was related to the growth capacities of the different cell types.     

Surface morphological study of ehrlich ascites tumor cells exposed to microware irradiation and heat

Summary Microwave irradiation of EAT cells caused an increase in length and number of surface microvilli. The tumor cells tend to form large aggregates by means of extensive interdigitation of surface microvilli. On the other hand, heat hyperthermia caused a decrease of surface microvilli but an increase of surface blebs. Hence the surface morphology of EAT cells after in vitro exposure to microwave irradiation differs markedly from that after heat hyperthermia.Part of the results was presented a the Fifth meeting of the European Co-operative Hyperthermia Group, Essen, July 1983.     

Pineal weight response to a dietary variable inMicrotus montanus

Résumé Le régime de contrôle (alimentation de laboratoire des lapins) deMicrotus montanus a été augmenté de plantes vertes. La glande pinéale des animaux recevant le supplément eut un poids inférieur à celui de la glande des témoins (p<0,01).

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This project was supported by the Atomic Energy Commission, contract No. AT-(40-1)-3946, the United States Public Health Service No. NIH-GM 00669-MBS and a Biomedical Sciences Support Grant from Tulane University.     

Liver regeneration after partial hepatectomy in rats exposed before the operation to the stress stimulus

Zusammenfassung Es wird nachgewiesen, dass bei Ratten, die 8 h vor partieller Hepatektomie einer Stress-Stimulation ausgesetzt wurden, die Intensität der DNS-Synthese postoperativ im Vergleich mit den Kontrolltieren grösser war. Ebenso waren Veränderungen des Lebergewichtes und des Triglyzeridinhaltes in der Leber nach der partiellen Hepatektomie dieser Ratten stärker ausgeprägt. Vergleichbare Resultate wurden auch bei Ratten gefunden, die in der gleichen Zeit vor der partiellen Hepatekto'mie eine ACTH-Injektion erhielten.     

Individually housed rats exceed group-housed animals in rotational movements when exposed to a novel environment

Individually and group-housed rats of both sexes were compared in respect to spontaneous rotational movements when exposed to a novel environment. Thereby, individually housed animals showed a higher number of rotational movements than group-housed controls. During an L12:D12 cycle, such movements occurred most frequently at the beginning of the dark phase, when locomotor activity was highest. It is assumed that these rotations are part of the hyperreactivity toward a novel environment induced by long-term individual housing.     

Neither prolactin nor growth hormone restore the nocturnal rise in pineal N-acetyltransferase activity or melatonin content in hypophysectomized rats

Hypophysectomy in adult male rats greatly attenuated the nocturnal rise in both pineal N-acetyltransferase (NAT) activity and melatonin content. High nighttime levels of NAT and melatonin were not restored by treating the animals with either prolactin or growth hormone, alone or in combination. Treating intact rats with bromocriptine, which depresses circulating prolactin levels, also was without effect on pineal melatonin synthesis. It appears that neither prolactin nor growth hormone are of major importance in determining pineal melatonin production.