摘要:

The effects of unilateral adrenalectomy on the contralateral adrenal gland in rats form the basis of the present communication. The project has been undertaken in an attempt to establish on ultrastructural grounds the stage at which an animal is stabilized on a solitary adrenal gland. The work is chiefly based on electron microscopy, supplemented by gross morphological and light microscopic investigations. Morphological changes in the adrenal gland after removal of the contralateral one were confined exclusively to the cortex and did not involve the medulla. The changes in the fine structure involved most of the organelles that are known to play vital roles in the biosyntheseis of corticosteroid hormones, namely, mitochondria, smooth endoplasmic reticulum (SER) and lipid droplets. The ultra-structural alterations showed remarkably wide variations at different time periods after the operation. The organelles eventually reverted to normal appearances after the 2nd postoperative week. These results have been correlated with the observations of previous workers, and the significance of the present findings, particularly in relation to the functional activity of the adrenal cortex, has been discussed.

ISSN:1422-6405    

DOI:10.1159/000145302

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

When whole viper (Vipera aspis) venom is injected into pregnant mice at various times during gestation, several anomalies occur in the fetuses and offspring. The teratogenic targets of the venom include the brain, heart, limbs and face, depending on the day of the injection. In the present study, the various constituents of whole venom were separated by gradient chromatography and the lethal and teratogenic properties of each fraction were determined and compared to the activity of whole and reconstituted venom. Our results imply that a synergy or potentiation exists between the fractions, the overall properties of whole venom being more teratogenic than the sum of its parts.

ISSN:1422-6405    

DOI:10.1159/000145303

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The guinea pig is a nest-quitter or nidifugous mammal which develops almost to the weaning stage before birth. Myocardial cells of the bilateral atria and ventricles of guinea pigs were examined for comparison with the rat by an ultrastructural quantitative method during the pre- and postnatal developmental periods, at copulation ages of 50, 57, 64 (term), 73 and 80 days. Throughout the developmental stages, no clear differences between the right and left sides were found in the characteristics of the myocardial cells. At the stage of day 57, T-tubules were first recognized in the ventricular muscle cells, and at the same time the fiber thickness of the ventricular muscle cells (8–9 µm) became greater than that of the atrial cells (6–7 µm). At this stage, the fraction of mitochondria was also found to differ between the atrial and ventricular muscle cells. The general cellular features appeared to change more greatly during the last prenatal week from copulation day 57 to day 64 (term) than during the first postnatal week. Thus, the last prenatal week in the ontogeny of the guinea pig may be interpreted as corresponding to the postnatal period from the 10th to the 20th day in the ontogeny of th

ISSN:1422-6405    

DOI:10.1159/000145304

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000145305

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The anterograde degeneration technique, using the Fink-Heimer method, and retrograde cell tracing with horseradish peroxidase (HRP) were used to analyze the afferent and efferent fiber projections of the olfactory bulb complex, consisting of the main olfactory bulb (MOB), the anterior olfactory nucleus (AN) and the accessory olfactory bulb (AOB) in the cat. The results reveal that the ipsilateral and contralateral fibers running via the anterior commissure to join the internal plexiform layer of both the ipsilateral and contralateral MOBs originate from the AN, whereas the ipsilateral fiber terminals running into the outer part of the plexiform layer of the pyriform cortex originate from the MOB and AOB. In consideration of the olfactory functional relays, it is suggested that the AN, both in the dorsolateral part and external layer, most likely stimulates some afferent and efferent impulses of the olfactory impact in the mammal.

ISSN:1422-6405    

DOI:10.1159/000145306

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000145307

出版商:S. Karger AG    

年代:1980

数据来源: Karger