Immune response of CBA mice in postnatal ontogeny

Changes in the pattern of immune response of the CBA mice during postnatal ontogenesis were studied on the models of cellular and humoral immunity. The functions mediated by the amplifier cells were shown to undergo the most significant changes. This was confirmed by a decrease in the activity of antigen-nonspecific T-suppressors, as estimated in a semisyngeneic system, an increase in the capacity of spleen lymphoid cells to induce the "graft versus host" reaction with the age and preservation of the function of hypersensitivity effectors of delayed type at the same level (after the age of 3-4 months). It is suggested that these changes might cause an age decrease in the suppressor activity of T-cells in a response to insoluble antigens.     

Antigenic rearrangement in the liver of mice and rats as a result of simultaneous effect of the carcinogens]

The antigenic structure of the livers of mice and rats after a single hepatocarcinogenic treatment was investigated using the immunodiffuse and immunofluorescent methods. The next day after carcinogen application changes characteristic of hepatocellular tumors were observed: decrease in the synthesis of organospecific antigens and intensification of the synthesis of heteroorganic antigens.     

Immunohistochemical study of cardiolipin and phosphatidylinositol in mouse liver]

Localization of two phospholipid haptens--cardiolipin and phosphatidylinositol--in mouse liver sections was studied by the indirect method of fluorescent antibodies. Two types of liver sections--paraffin and cryostat, and two type of fixation--in acetone, and in the acetone, buffer, and formalin mixture--were used. Antiphospholipid sera stain specifically the plasma membrane of hepatocytes and predominantly the membrane region overlooking the blood capillary. A possibility of detecting the specific phospholipid haptens depends on the method of obtaining the sections and their fixation. Two types of immunization give two types of antiphospholipid sera which differ by the stability, by the possibility of monospecific antibodies isolation from them on lipid immunosorbents, and by the types of liver section staining.     

Effect of the nude mutation on alpha-fetoprotein synthesis and hemopoiesis in the mouse liver in the postnatal period of development]

The dynamics of population of alpha-fetoprotein (AFP)-containing cells in the liver and the level of AFP in the blood of C3H/HeJ+/+ and thymus-less mutant C3H/HeJnu/nu mice during postnatal development was studied by means of indirect immunofluorescence and radial immunodiffusion. The content of AFP-positive hepatocytes and AFP concentration in the blood serum of C3H/HeJnu/nu mice were shown to exceed markedly those in C3H/HeJ+/+ mice beginning from the age of 2 weeks. The histological analyses has revealed the foci of hemopoiesis in the liver of adult C3H/HeJnu/nu mice, unlike in the liver of normal mice. The neonatal thymectomy of C3H/HeJ+/+ mice did not influence the parameters under study. A possible relationship between the increased AFP level and the preservation of hemopoiesis in the liver of the mice homozygous by the mutation nude is discussed.     

Effect of glucocorticoids on alpha-fetoprotein synthesis and liver structure in mice acutely poisoned with carbon tetrachloride]

Experiments on male C57BL mice demonstrated that the CCl4 inhalation for 15 minutes in a concentration of 0.05 ml to 4 l of air caused deep dystrophic lesions of the liver with the signs of necrobiosis. The signs of regeneration and cellular infiltration appeared almost in 24 hours accompanied by the secretion of alpha-fetoprotein into the blood. The foci of necrobiosis disappeared completely in 4 days, being replaced by the lymphoid cells with large hepatocytes in the circumference. In the animals given hydrocortisone (20 mg/kg) or dexamethasone (2 mg/kg) for therapeutic or prophylactic purpose the regenerative processes were decreased, and the number of animals producing alpha-fetoproteins fell from 92 to 60--65%.     

Cytofluorimetric study of the content of glycogen and its fractions in rat liver cells in the course of the 1st week of postnatal ontogeny]

A cytofluorometric study of the total glycogen and its fractions in rat liver cells using the fluorescent PAS reaction was made during 1--7 days of the postnatal development. It was established that glycogen content was small on the first two days of development. The glycogen content increases only on the third day after birth. The glycogen of the rat liver cells during a first week of the postnatal development is different from that detected in adult liver cells in two aspects: in 3 day old hepatocytes soluble and stable glycogen fractions are equal, while in adult rat liver cells the former makes 80--90%; during the first week of the postnatal development, the stable fraction of rat liver cell is more labile, while in the adult rat liver the soluble fraction of glycogen is more labiles.     

Interstrain differences in the maturation of congenital reflexes in 101/HY and CBA mice in early postnatal ontogeny]

We have identified interstrain differences in the rate of formation of certain reflexes and parameters of physical development in CBA/LacSto and 101/HY mice. We have shown that in young 101/HY mice, the maturation of reflexes reflecting the development of the vestibular, neurosensory, and neuromuscular systems, such as surface righting, bar holding, negative geotaxis, and auditory startle response, takes place later during postnatal life. Opening of eyes and auditory canals in mice of all studied groups takes place at the same time. In CBA females, maturation of cliff avoidance reflex occurs later than in 101/HY females; hair also appeared later. Body weight of young 101/HY mice of both sexes is significantly higher during the period of postnatal development from day 2 to day 20 than in the CBA strain. However, the relative brain weight was lower in the 101/HY strain. CBA males had a higher brain weight and also showed a faster rate of formation of inborn reflexes. We discuss possible factors underlying the observed difficulties in the rate of formation of reflexes in 101/HY and CBA young mice in relation to general background information about their genetic and neurobehavioral features. The results provide evidence that these differences are genetically determined; the rate of reflex formation does not depend on the overall physical development of mice and is rather due to a delay and/or abnormalities in nervous system development.     

Redox enzymes in the tissues of the large intestine in the postnatal ontogeny of rats]

Using histochemical methods, age-related changes in activity of some redox enzymes in muscular and superficial layers of the mucous membrane, as well as in neurons of the myenteric nervous plexus of the large intestine have been studied in albino rats 5-day-old, 1-, 5-, 13-, 24-month-old. In young animals (1-5-month-old) an essential increase of the enzymatic activity of the energy metabolism takes place, in mature animals--stabilization of these processes, senescence brings about multidirectional changes in them. Manifestation degree of the changes in energy metabolism, occurring in old age are determined by certain metabolic and functional peculiarities in the organ tissue. In old animals certain strain of the energy metabolism develops, resulting from discoordination of energetic cycles in tissue of the large intestine wall.     

Requirement of thyrotropin-releasing hormone for the postnatal functions of pituitary thyrotrophs: ontogeny study of congenital tertiary hypothyroidism in mice

We recently reported that TRH-deficient mice showed characteristic tertiary hypothyroidism. In the present study, we investigated how this tertiary hypothyroidism occurred particularly in pre- and postnatal stages. Immunohistochemical analysis revealed a number of TSH-immunopositive cells in the TRH-/- pituitary on embryonic day 17.5 and at birth. The mutant pituitary at birth in pups born from TRH-deficient dams also showed no apparent morphological changes, indicating no requirement of either maternal or embryonic TRH for the development of pituitary thyrotrophs. In contrast, apparent decreases in number and level of staining of TSH-immunopositive cells were observed after postnatal day 10 in mutant pituitary. Similar decreases were observed in the 8-week-old mutant pituitary, while no apparent changes were observed in other pituitary hormone-producing cells, and prolonged TRH administration completely reversed this effect. Consistent with these morphological results, TRH-/- mice showed normal thyroid hormone levels at birth, but the subsequent postnatal increase was depressed, resulting in hypothyroidism. As expected, TSH content in the TRH-/- pituitary showed a marked reduction to only 40% of that in the wild type. Despite hypothyroidism in the mutant mice, both the pituitary TSHbeta and alpha mRNA levels were lower than those of the wild-type pituitary. These phenotypic changes were specific to the pituitary thyrotrophs. These findings indicated that 1) TRH is essential only for the postnatal maintenance of the normal function of pituitary thyrotrophs, including the normal feedback regulation of the TSH gene by thyroid hormone; 2) neither maternal nor embryonic TRH is required for normal development of the fetal pituitary thyrotroph; and 3) TRH-deficient mice do not exhibit hypothyroidism at birth. Moreover, reflecting its name, TRH has more critical effects on the pituitary thyrotrophs than on other pituitary hormone-producing cells.     

Catecholamine sensitivity of the hypophyseal-adrenal system in the early ontogeny of rats]

The dynamics of the hypophyseal-suprarenal system reaction to catecholamines of different type of effect was studied in the Wistar rats during the first 16 days of life. The reaction to epinephrine was noted in 4 days old and to novodrin in 8 days old rats. Since the reaction to epinephrine acting on alpha- and beta-receptors appears ahead of that to novodrin acting selectively on beta-receptors, a suggestion was put forward to the effect that alpha-receptors matured more rapidly that beta-receptors. The increase of the system reaction to the stimulation of recepors sensitive to catecholamines was noted on the 12-14th days of life and appears to be related to the formation of central adrenergic mechanisms.     

Immunohistochemical study of ontogeny and phylogeny of a terminalN-acetylglucosamine cluster antigen

Summary In this work an immunohistochemical method was used to study the ontogeny and phylogeny of a terminalN-acetyglucosamine (GlcNAc) cluster antigen which is an epitope(s) of highly branchedN-linked oligosaccharides terminating in GlcNAc residues. The ontogenic studies demonstrated that expression of the antigen is developmentally regulated in lymphocytes, epithelia cells of endodermal origin and kidney mesangial cells of the chicken. The antigen was found in several other avian species studied, namely, the Japanese quail, duck, goose and turkey. Furthermore, the distribution of the antigen in all these species was similar. In adult animals, it was found in bursal and thymic lymphocytes, macrophages, spleen reticulum cells, epithelial cells of the intestine and bronchioles and capillary endothelial cells. The antigen was also detected in epithelial cells of the gastrointestinal tract of several lower vertebrates studies: the amphibian (frog), reptile (chameleon) and fish (rainbow trout). It was undetectable in various organs of the human, African green monkey, calf, pig, rat and guinea-pig, but was found in the intestinal epithelial cells of ten mouse strains. It is likely that biosynthetic processing leading to the formation of highly branchedN-linked glycans terminating in GlcNAc residues is conserved during evolution in birds and other lower vertebrates.     

Immunohistochemical study of the postnatal development of pituitary thyrotrophs in the rat,with special reference to cluster formation

Summary The postnatal development of rat pituitary thyrotrophs was investigated immunohistochemically on days 1, 3, 5, 10, 15 and 25. Fetal thyrotrophs are strongly immunoreactive. In the postnatal period, however, weakly immunoreactive thyrotrophs increase in number to constitute clusters on days 3–5. The numbers and dimensions of the clusters reach a maximum on day 10. Thereafter the clusters break down to give rise to single, scattered neogenic thyrotrophs. Thyrotrophs in clusters on day 10 were investigated by electron microscopy in adjacent sections. They can be characterized as an immature type of basophil, according to the classification of Yoshimura et al. (1977): 1) Type I basophils, which are irregularly shaped with elongate processes, and characterized by rows of secretory granules about 100 nm in diameter. 2) Type I/II basophils, i.e., forms intermediate between Types I and II, containing less numerous secretory granules about 100–150 nm in diameter. Type II basophils which correspond to the classical thyrotrophs are not fully developed on day 10. Thus, most thyrotrophs develop from the clusters in the neonatal period. Such neogenic thyrotrophs retain the immature characteristics of Type I and I/II cells and may develop into Type II cells during subsequent maturation.     

The blood microcirculatory bed of the tunica muscularis of the human esophagus in postnatal ontogeny]

The analysis of morphological and morphometrical data of the muscular membrane and its blood microcirculatory bed has demonstrated that their development during the postnatal ontogenesis advances unevenly. An intensified growth and development of the muscular membrane morphological structures, including its blood microcirculatory bed occurs from 3 up to 30 years of life. Their maximal growth is noted from 12 up to 30 years of age. The stages of intensified development of the muscular membrane and its blood microcirculatory bed change into stages of retarded growth, where processes of involutive character preponderate. This is especially noticeable from 60 and more years of age. The stages noticed in the muscular membrane development and its blood microcirculatory bed are characterized both by general and topographical morphofunctional peculiarities specific for every stage of organogenesis.     

The anatomy and topography of the lymphoid formations of the human stomach in postnatal ontogeny]

By means of macro-microscopical methods 80 stomachs from persons of various age have been studied. In the mucous membrane of the human stomach during all age periods of postnatal development the lymphoid tissue is present as diffusely scattered lymphocytes, their microaccumulations and lymphoid noduli. Maximal amount of the lymphoid noduli is observed during the second mature age. The greatest number of the lymphoid noduli per 1 cm2 of the mucous membrane surface is revealed in the area of the lesser curvature and in the pyloric part of the stomach. Most often the lymphoid noduli are situated in the depth of the lumen proper of the mucous membrane, somewhat more seldom--in its more superficial parts, in the muscular lamina and in the submucous tela. The lymphoid noduli with germinative centers are met beginning from the first childhood up to old age. The greatest amount of diffusively scattered lymphocytes is situated near the lymphoid noduli and in the deep layer of the lamina proper of the mucous membrane.     

Frequency and phase correlations of the biorhythms of metabolic indices in mice during their postnatal ontogeny

In laboratory mice the daily rhythms of feeding, plasma insulin, blood glucose and liver glycogen were investigated beginning from an age of 1 week to 52 weeks. For all parameters circadian and ultradian rhythms changing in the course of development could be quantified. During juvenile phase and inversion of all patterns connected with temporary increasing ultradian components takes place. The beginning and the end of this inversion are specific for various parameters, to that changing frequency and phase correlations could be obtained. The lowest degree of phase correspondence is found at weaning, it reaches its maximum in adults and decreases again in older mice. The possible consequences of demonstrated phenomena for the stability of the functional system and the existence of sensitive phases during postnatal ontogeny are discussed.