Profound hypothermia in golden hamsters (Mesocricetus auratus) induced by serotonergic potentiating and noradrenergic inhibiting drugs

Profound hypothermia (6 degrees C) was induced in cold exposed golden hamsters (Mesocricetus auratus) by a combination of drugs that potentiate brain serotonergic activity (fluoxetine and pargyline) and inhibit noradrenergic activity (alpha-methyl-p-tyrosine). Individual drugs and combinations of 2 were ineffective.     

Complete development ofAncylostoma ceylanicum (Looss, 1911) in golden hamsters,Mesocricetus auratus

Zusammenfassung Es gelang, den HakenwurmAncylostoma ceylanicum an den Goldhamster zu adaptieren, was zur Vereinfachung chemotherapeutischer Versuche bei der Bekämpfung dieses tierischen und menschlichen Parasiten im Laboratorium beitrug.     

Aneuploidy as a consequence of senescence and ovariectomy in the golden hamster (Mesocricetus auratus)

The hypothesis of the preferred X-chromosome loss in elder human females was reevaluated in the golden hamster: early castration of females proved that the increase of aneuploid cells is correlated with the loss of the ovaries. But here, and in old females, aneuploidy consisted of random loss of excess of chromosomes, in no case an X-chromosome.     

Aneuploidy as a consequence of senescence and ovariectomy in the golden hamster (Mesocricetus auratus)

Summary The hypothesis of the preferred X-chromosome loss in elder human females was reevaluated in the golden hamster: early castration of females proved that the increase of aneuploid cells is correlated with the loss of the ovaries. But here, and in old females, aneuploidy consisted of random loss or excess of chromosomes, in no case an X-chromosome.     

The activation of membrane ATPase by ouabain in several tissues of the golden hamster (Mesocricetus auratus) in the absence of potassium

Summary The activity of the membrane ATPase of 5 organs of the golden hamster was increased by 10^–7–10^–3 moles/l ouabain in K⁺-free medium. In similar experiments on rats no increase was observed.     

Carcinogenic activation of benzo(a)pyrene by iodine and ferric chloride in the respiratory tract of Syrian golden hamsters

Summary Benzo(a)pyrene (0.5 mg), in itself weakly carcinogenic, when given in combination with ferric chloride (0,16 mg) or iodine (0,2 mg), alone noncarcinogenic, induced a number of tumors of different parts of the respiratory tract of Syrian golden hamsters.Partially supported by Public Health Service contracts PHS 43-68-959 and NO1 CP33278 from the Division of Cancer Cause and Prevention. The authors wish to thank Mrs Virginia Ooten for her technical assistance.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

Summary We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O₂ uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O2 uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Oxidative activity during the sexual cycle of the central nervous system,adrenal glands and ovaries in the hamster (Mesocricetus auratus)

Summary The results indicate significant increases of the oxidative metabolism in the oestrus of the ovaries, hypothalamus and the posterior cortex, while in the amygdala this increase occurs in the phase of diestrus.     

Pituitary gonadotropin releasing hormone (GnRH) receptor levels in intact and ovariectomized-adrenalectomized female golden hamsters on a short photoperiod

Both intact and ovariectomized + adrenalectomized hamsters on a short photoperiod, had a daily surge in plasma LH at approximately 16.00-18.00 h. The number of pituitary GnRH receptors was generally lower in ovariectomized + adrenalectomized hamsters than in intact animals, but both intact and ovariectomized + adrenalectomized hamsters had a decrease in the number of receptors just prior to the LH surge. These results show that gonadal steroids are not involved in regulating the pre-LH surge fall in the number of GnRH receptors.     

Pituitary gonadotropin releasing hormone (GnRH) receptor levels in intact and ovariectomized-adrenalectomized female golden hamsters on a short photoperiod

Summary Both intact and ovariectomized+adrenalectomized hamsters on a short photoperiod, had a daily surge in plasma LH at approximately 16.00–18.00 h. The number of pituitary GnRH receptors was generally lower in ovariectomized+adrenalectomized hamsters than in intact animals, but both intact and ovariectomized+adrenalectomized hamsters had a decrease in the number of receptors just prior to the LH surge. These results show that gonadal steroids are not involved in regulating the pre-LH surge fall in the number of GnRH receptors.     

Potentiation of bradykinin and eledoisin by BPF (bradykinin potentiating factor) fromBothrops jararaca venom

Zusammenfassung Nachweis der pharmakologischen Wirkung des Bradykinins am isolierten Meerschweinchenileum und am deutlichen Blutdruckanstieg bei Hund und Katze nach Vorbehandlung mit BPF (Bradykinin-potenzierender Faktor aus Jararcagift). Unter diesen Bedingungen werden mit Bradykinin gleich intensive Effekte wie mit Eldoisin erhalten.

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This work was aided by research grants from the Fundação de Amparo à Pesquisa and from the Public Health Service, National Institute of Health, Bethesda (Md. USA) (NB. 02953-03).