Annulate lamellae in frog adenohypophysis under normal and experimental conditions

Cytoplasmic annulate lamellae have been observed in frog (Rana ridibunda) adenohypophysis pars distalis from normal spring animals and from others which were submitted to experimental conditions inducing selective activation of different cell types. Cell activation, because of either the normal active period in the frog cycle or the experimental treatments, seems to be correlated with the occurrence annulate lamellae. These annulate lamellae consist of a succession of two relatively parallel membranes interrupted periodically by discontinuities similar to nuclear pores. Sometimes they have been observed connected to endoplasmic reticulum.     

Subtypes of serum group specific component (Gc) in normal conditions and in pathology

In the framework of the ecogenetic research programme, the data are presented on the genetic polymorphism of the vitamin D-binding protein (Gc) in various USSR populations. Blood serum samples were studied, taken from the Russians of the town Yegorievsk, Moscow Region (p = 321) and 113 Russian patients with tuberculosis using the method of isoelectrofocusing. The information was obtained of the Gc frequencies in two population units of Buryats of Aginsky and Ost-Ordynsky Autonomous Districts of Chita and Irkutsk Regions, including the Olkhon island (on the lake Baikal), in totality, 593 individuals and 13 local groups. The position of the studied Russian and Buryat groups within the gene frequency co-ordinate space is well in line with the estimated area of their localization, with regard to the world distribution. Among the Buryat populations studied, there is distinct heterogeneity for which the factor Gc1F plays a leading role within the Gc system/responsible for 92% of all possible genetic variability. Gc factor frequencies in Buryats range within the following limits: 1F.-0.3864-0.6023, 1S-0.1895-0.4535, 2-0.1364-0.2581. For the Russians of Yegorievsk and the patients with tuberculosis of Moscow and Moscow Region following allele frequencies are established: 1-F0.1169, 1S-0.5476, 2-0.1364 and 1F-0.1106, 1S-0.5531, 2-0.3363, respectively, which indicates that no association exists between Gc variants and tuberculosis. The correlation of the Gc allele frequency distribution with the ratio of insulin-independent diabetes (type 2) world-wide indicates that expression of high frequency of diseases is accompanied with comparatively rare characteristic combination of frequencies of three Gc alleles.     

Spectral-fluorescent characteristics of rat transcortin in normal conditions and during experimental circulatory insufficiency

Spectral-fluorescent parameters of rat transcortin isolated from blood plasma of intact rats and rats with circulatory insufficiency were studied. The differences in the Schtern Folmer constants and the dissociation constants for the transcortin-corticosterone complex obtained during the protein titration by corticosterone may be due to different tryptophanyl surroundings in the molecules of the studied proteins. This may be a consequence of the conformational rearrangements of the corticosteroid-binding globulin molecules.     

Ultrastructural study of Kupffer cells in teleost liver under normal and experimental conditions

Summary The Kupffer cells in the liver of the teleost fish, Pimelodus maculatus, are attached by desmosomes to the endothelial cells lining the sinusoids. These provide a strong attachment allowing them to resist the passage of blood. Following perfusion with India ink, both endothelial and Kupffer cells ingest India ink particles by pinocytosis and micropinocytosis. It is suggested that both cell types may represent two different functional states of the same cell.     

Nuclear bodies in the rat adrenal glomerular zone in normal and experimental conditions

The presence of nuclear bodies in the glomerular zone of the rat adrenal cortex has been shown both in normal conditions and after the stimulus of low sodium diets causing an increase in their number. These results indicate that these organelles are a normal nuclear component of the cells of this zone, and that they can experience significant increases in quantity and complexity due to various functional stimuli.     

The structure and activity of the hypophysis of Rana temporaria in normal and in experimental conditions

Summary Volumetric, karyometric and histological studies were done on the pars distalis of the hypophysis of Rana temporaria, in normal and in experimental conditions.In the normal pars distalis, a gradient of activity of the P.A.S.-positive cells is described which shows a close relation with the blood supply. This relation strongly suggests the presence of a gradient of humoral factors which would influence the activity of the pars distalis. This gradient is not dependent on the influence of A.F.-positive neurosecretory fibres. In the P.A.S.-negative cells (O.G.-cells) a similar gradient could not be found. In transplants of pars distalis the gradient of activity is absent.There exists a striking difference between autotransplants and homotransplants of pars distalis in the eye, and also between autotransplants on the iris and autotransplants in the cornea.A parallelism between autotransplants of pars distalis on the iris and the pars distalis of animals deprived of their median eminence could be established. In both groups the pars distalis shows a similar decrease in volume. The glandular cells are well differentiated, but show a low activity. This low activity is most pronounced in the P.A.S.-cells. The normal variability in staining of the P.A.S.-cells has diminished: in general, the great majority of the P.A.S.-cells are P.A.S.-purples. The gradient of activity of the pars distalis has disappeared. The seasonal development of the gonads and of the secundary sexual characteristics is absent. This absence is probably not caused by a decrease of the total number of P.A.S.-cells of the pars distalis. It is probably due to the low activity of the P.A.S.-cells, which cannot be ascribed to the absence of the neurosecretory influence of the magnocellular preoptic nuclei.A preliminary note on the gradient of activity of the pars distalis has been published (Dierickx 1963c).     

The synaptic ribbons of the guinea-pig pineal gland under normal and experimental conditions

Summary Synaptic ribbons (SR), functionally enigmatic structures of mammalian pinealocytes, were studied electron microscopically with regard to number, intracellular localization and topographical relationships, both under normal and experimental conditions. Pineal glands of guinea-pigs serving as controls contained 1.75 ribbon fields/unit area in the males and 2.58 in the females. In animals subjected to continuous illumination for 64 days the number of ribbon fields increased 20-fold in the males and 9-fold in the females. Continuous darkness (26 to 70 days) had varying effects; in some animals SR increased either strongly or moderately, in others they appeared unchanged. Under continuous illumination a higher percentage of ribbon fields bordered the cell membrane than in the controls. Moreover, paired ribbon fields occurred. The topographical analysis revealed that 98 % of the ribbon fields bordering the cell membrane lay opposite another pinealocyte and the remainder opposite nerve fibres, blood vessels and collagenous fibres. It is suggested that SR of mammalian pinealocytes do not represent non-functioning phylogenetic relics but true organelles possibly involved in coupling adjacent pinealocytes functionally.This study was supported by a grant from the Deutsche Forschungsgemeinschaft, Bonn.