Anomaly of the nuclear maturation in vitro of golden hamster oocytes]

Nuclear anomalies were observed during maturation in vitro of golden hamster oocytes, as follows: 1) In 33 p. cent of oocytes, the axis of the first meiotic division spindle was oriented incorrectly. This leads either to the formation of "large" polar bodies or to non-expulsion of the polar body if the spindle occupied a central instead of peripherical position. 2) Triploidy was observed in 0.3 p. cent of the oocytes which accomplished their maturation and fertilization in vitro. 3) Two rare anomalies--reconstitution of the nucleus after expulsion of the first polar body and formation of two second division spindles--appeared to be due to degenerescence of the oocytes in culture.     

Ultrastructural study of cardiotoxicity and skin alterations in the golden hamster after treatment with 8 different anthracyclines]

Golden hamsters were submitted to i.p. administration during 4 weeks of 8 anthracyclines, adriamycin (ADM), detorubicin (DTR), daunorubicin (DNR), 4'-epi-adriamycin (eADM), adriamycin hydrochloride (ADMh), rubidazon (RBZ), aclacinomycin (ACM) and AD32, at doses equivalent to 3/4 of those which are optimally oncostatic on murine L1210 leukemia. The comparative study of the mortality, the electron microscopic (EM) alterations of the myocardium, and the light microscopic (EM) alterations of the myocardium, and the light microscopic (LM) lesions of the skin, show that ACM and AD32 are the least toxic drugs. EM detected almost no early lesions of myocardium in ACM treated animals, but, after 4 week's treatment, severe cardiac alterations appeared which, like those after AD32 treatment, are non lethal and reversible. Similarly. LM revealed no histologic changes in the skin following ACM and AD32 administrations, but pathologic alterations, atrophy and alopecia, were observed in animals receiving all other drugs.     

LHRH-systems in the brain of the golden hamster

Summary Vibra tome sections of male hamster brains were treated immunohistochemically with LHRH antiserum, and the anatomical distribution of LHRH immunoreactive cells and nerve fibers was assessed. LHRH-cell bodies are found in the ventral hypothalamus that includes its preoptic, anterior and central parts, in the septum, the olfactory tubercle, the main and accessory olfactory bulb, and the prepiriform cortex. In addition, extracerebral LHRH-neurons and ganglia exist in LHRH-positive nerves at the ventromedial surface of the olfactory tubercle and bulb as well as in olfactory nerves. Dense networks of LHRH-immunoreactive fibers are found in all regions where LHRH-cell bodies exist. Intraseptal connections reach the organum vasculosum of the lamina terminalis, the subfornical organ, and the lateral ventricle. Dorsolateral projections from the septum can be traced via the fimbria hippocampi and alveus to the ventral hippocampus, via the stria terminalis to the amygdala and piriform cortex. Ventrolateral projections extend from the level of the olfactory tubercle and preoptic-anterior hypothalamic area via the ventral amygdalofugal pathway to the prepiriform and piriform cortex as well as the amygdala. Dorsal supracallosal projections via the stria longitudinalis are seen in the induseum griseum and the cingulate cortex. Caudal efferents reach the habenula, interpeduncular nucleus, midbrain raphe, and central gray of the rostral fourth ventricle via the stria medullaris and fasciculus retroflexus and by a ventral projection via the periventricular and subventricular hypothalamus. A major portion of this ventrocaudal projection gives rise to a dense network in the median eminence. Anatomical relationships of LHRH-fibers to certain regions of the inner ventricular and outer brain surface are noted.Postdoctoral fellow of the Deutsche ForschungsgemeinschaftSupported by US PHS grant NS09914 and NRCHD grant HD03110     

Compensatory hypertrophy of golden hamster ovaries during early postnatal ontogenesis]

The right-side ovariectomy in the golden hamster females during the prepubertate period resulted in the compensatory hypertrophy of the rest paired organ. The morphological rearrangement of the hypertrophied ovary represented the shift in the quantitative distribution of follicles by the maturation stages towards the predominance of mature forms. The accelerated growth and differentiation along the path of normal postnatal ontogenesis led to the earlier ovulations in the hypertrophied ovary.