Investigations on the turnover of adrenocortical mitochondria

Summary The effects of a chronic treatment with angiotensin II (up to 15 consecutive days) on the mitochondria of the rat zona glomerulosa cells were investigated by electron microscopic and stereological methods. Angiotensin induced a significant increase in the volume of the mitochondrial compartment. Up to the 3rd day of treatment this was due only to the hypertrophy of the organelles, and from the 3rd to the 15th day exclusively to mitochondrial proliferation. The hypothesis that angiotensin controls the growth and proliferation of rat zona glomerulosa mitochondria is discussed.     

Culture procedure of mesothelial cells from the rat parietal pleura

Cultures were made of mesothelial cells obtained by scraping the parietal pleura of the adult rats. The growth was restricted to close polyhedric epithelial-like cells, forming a monolayer. The cellular proliferation continued until the 7th day, followed by a stationary phases. In subcultures the mesothelial cells kept their epithelial type. The cultures were stopped on the 20th day.     

Growth pattern switch of renal cells and expression of cell cycle related proteins at the early stage of diabetic nephropathy

Renal hypertrophy, partly due to cell proliferation and hypertrophy, has been found correlated to renal function deterioration in diabetes mellitus. We screened the up-regulated cell cycle related genes to investigate cell growth and the expression of cell cycle regulating proteins at the early stage of diabetic nephropathy using STZ-induced diabetic rats. Cyclin E, CDK(2) and P(27) were found significantly up-regulated in diabetic kidney. Increased cell proliferation in the kidney was seen at day 3, peaked at day 5, and returned to normal level at day 30. Cyclin E and CDK(2) expression also peeked at day 5 and P(27) activity peaked at day 14. These findings indicate that a hyperplastic growth period of renal cells is followed by a hypertrophic growth period at the early stage of diabetes. The growth pattern switch may be regulated by cell cycle regulating proteins, Cyclin E, CDK(2), and P(27).     

The role of separate subpopulations of bone marrow elements in regulating the proliferation processes of hemopoietic and tumor cells]

The role of intercellular interactions in regulation of proliferation process in normal and tumor cells has been studied in experiments with mouse hybrids F1 (CBA X C57BL/6). The cytostatic activity to tumor cells has been shown to possess both adherent and nonadherent cells of bone marrow. The adherent cell-effectors inhibit, nonadherent ones stimulate the DNA synthesis in myelokaryocytes of normal bone marrow. During the activation of bone-marrow proliferation (under 10-hour immobilized stress) the cytostatic effect of nonadherent cells to tumor ones grows; the myelokaryocyte proliferation is stimulated on the 4th day after immobilized stress. The cytostatic activity of adherent cell-effectors remains to be low up to 7th day after immobilization. The maximum of depression in cytostatic function of the adherent elements coincides with the peak of bone marrow proliferation activity (6th day). The character of changes in cytostatic activity of adherent cells to tumor and nontumor ones is of the same type. The data obtained testify to the generality of regulation mechanisms in proliferation of tumor and normal cells.     

Macrophage activation in the immune response

In inbred white rats, immunized with sheep erythrocytes, contents and phagocytic activity of the spleen and pulmonary macrophages have been studied on the 3d, 4th, 5th, 6th, 7th, 11th, 14th and 20th days of the experiment in the light, scanning and transmissive electron microscope, as well as the effect of the cells mentioned on proliferation of lymphoid elements. Maximal phagocytic activity of the splenic and alveolar macrophages is observed on the 7th day of the experiment. At the same time, certain drop in the lymphoid cells proliferation takes place. The change in the macrophages contents also influences proliferation of the lymphoid cells.     

The action of the cells of hemopoietic organs in chick embryos on mouse CFUdc and CLFUdc]

The humoral influence of cells of hemopoietic organs of chicken embryos of different terms on the development of the colony and cluster formation of mononuclears of the bone marrow of mice was studied in joint cultivation in two-compartment cylindrical diffuse microchambers. The process of formation of colonies and clusters is inhibited by cells of the yolk sac on the 2nd-4th day of the development, by cells of the liver on the 8th-12th day, of the spleen on the 13th-18th day and of the bone marrow--on the 15th day. The yolk sac cells were found to have most considerable inhibiting influence on proliferation and differentiation of cells on the 2nd day of the development of chicken embryo. The yolk sac cells on the 6th day stimulate the formation of colonies and clusters. The yolk sac, beginning from the 4th day of the development, and the liver release humoral factors promoting the formation of erythroid colonies. The erythroid colonies are formed but when cultivated on the vascular membrane of the chicken embryo; the erythroid colonies are not formed when cultivated in the abdominal cavity of mice. Local erythropoietinoid factors are not synthetized by the spleen and bone marrow cells. A supposition is put forward that a combination of the local inhibiting and erythropoietic effects promotes the erythroid differentiation of cells.     

Proliferative activity of cells of the intermediate lobe of the rat pituitary during the postnatal period.

Cellular proliferation was studied in the intermediate lobe (IL) of the pituitary gland of developing rats by labelling cells at the S-phase of the cell cycle with bromodeoxyuridine (BrdU). The number of BrdU-labelled cells in the IL decreased from birth until the 14th postnatal day and was low from that day until the end of the first month after birth. Throughout the postnatal period a large proportion of BrdU-labelled cells was found in the marginal layer (ML) of the IL, suggesting for the ML a role as a germinative layer of the IL during postnatal growth. Double immunostaining with anti-BrdU and anti-MSH showed that MSH cells actively proliferate as from the day of birth. Cells doubly immunostained with anti-BrdU and anti-S100 protein were first seen on the 14th postnatal day. From then onwards, most proliferating cells were labelled with either anti MSH or anti S-100 protein. This, together with the high proportion of proliferating cells found in the ML marks a clear difference with the pattern of cellular proliferation previously reported during a similar period in the anterior lobe of the rat pituitary.     

Ultimobranchial body and parathyroid gland of the parrot Psittacula psittacula in response to experimental hypercalcemia

Psittacula psittacula when subjected to long term hypercalcemia by intramuscular injections of vitamin D2 (20,000 I.U.) on alternate days and by increasing dietary calcium, exhibit a rise in the serum calcium level after 10, 20 and 30 days of treatment as compared to their corresponding controls. The ultimobranchial cells show progressive hypertrophy up to 20th day of the treatment. From 20th day till the end of the experiment (30 days) these cells show feeble staining response. The parathyroid glands suffer from degenerative changes due to its inactivity under chronic hypercalcemia.     

Alteration of compensatory ovarian hypertrophy in the hamster by melatonin

Hamsters were unilaterally ovariectomized on day four of the estrous cycle and the subsequent compensatory ovarian hypertrophy (COH) and compensatory follicular stimulation studied on each of the following nine days. The hypertrophy stabilized at approximately 35% by the end of the second postoperative cycle, with greater ovarian weights observed on the mid-cycle days. Melatonin injections significantly reduced follicular counts when unilateral ovariectomy was performed on either day three or day four of the estrous cycle and necropsy was on the same day of the cycle, four days later.     

Radioautographic study of the cell proliferation of the pigment epithelium of the retina in albino clawed frogs

The proliferative activity of pigment epithelium was studied by means of 3H-thymidine autoradiography after the removal of retina, lens and iris with the ciliary-terminal zone in the adults. The cell population of pigment epithelium was shown to be heterogeneous on the level of proliferative activity. A low level of proliferation is characteristic of the cells of epithelial monolayer and the cells leaving it and forming aggregates. An intensive local proliferation leading to the formation of expansions was found in the pigment epithelium layer in 7% of cases. On the 20th day after the operation, the index of labelled nuclei in the expansions amounted to 43.4--59.3% and the mitotic index to 1.4--2.1%. On the 75th day elements of atypical retinal differentiation, besides the high proliferative activity, were observed in one expansion.     

Ghrelin联合三氧化二砷对骨髓间充质干细胞增殖与成骨分化的影响

该文主要探究Ghrelin对三氧化二砷(As2O3)导致的骨髓间充质干细胞(BMSCs)增殖和成骨分化的影响。BMSCs设为对照组、As2O3组、Ghrelin组和联合(As2O3+Ghrelin)组。MTT法检测细胞增殖能力;成骨诱导的第7天和第14天,Real-time PCR及Western blot分别检测成骨相关因子OPN、ALP、RUNX2的mRNA及蛋白表达;第21天,茜素红染色分析钙盐沉积情况。结果显示,细胞增殖能力Ghrelin组>对照组>联合组>As2O3组。与对照组比,As2O3组各因子表达均显著下调(P<0.05),Ghrelin组第14天OPN蛋白表达无显著变化,其余因子均上调(P<0.05);联合组与As2O3组比,第14天OPN基因表达和第7天ALP蛋白表达无显著差异,其余均显著上调(P<0.05)。钙盐沉积:Ghrelin组>对照组>联合组>As2O3组。提示0.5μmol/L As2O3抑制BMSCs增殖和成骨分化,600 ng/mL Ghrelin增强细胞增殖和成骨分化;且Ghrelin能减弱As2O3导致的BMSCs增殖和成骨分化抑制作用。     

Structure and behaviour of ultimobranchial gland in response to vitamin D3--induced hypercalcemia in male Clarias batrachus

Hypercalcemia was induced in Clarias batrachus by treating them with vitamin D3 (5,000 I.U./100 g body wt.) and/or 0.5% solution of CaCl2. The animals were killed on 1st, 3rd, 5th, 9th, 13th and 17th days after the initiation of the experiment. Histological preparations of the ultimobranchial gland (UBG) were made. The gland exhibits nuclear hypertrophy, hyperplasia and loss of staining response corresponding to the rise in serum calcium levels. At later intervals, the UBG shows exhaustion and degeneration which is evident from vacuolization and nuclear shrinkage of the ultimobranchial cells after day 13 in groups B and C and day 9 in group D.     

维生素C通过调控脂肪形成相关基因的转录促进猪前体脂肪细胞的增殖与分化

探讨维生素C（Vit C）诱导猪前体脂肪细胞增殖分化最佳浓度及在分化过程中,5种脂肪形成相关基因peroxisome proliferator activated receptor gamma(PPARγ)和retinoid X receptor alpha(RXRα),脂肪细胞分化标志基因lipoprotein lipase (LPL),生脂基因phosphoenolpyruvate carboxykinase(PEPCK)、stearoyl CoA desaturase(SCD) mRNA表达时序性的变化. 以3　d龄猪前体脂肪细胞为实验对象,用Vit C诱导猪前体脂肪细胞增殖分化,分别在增殖分化第2、4、6和8 d收获细胞,利用MTT测定其增殖程度;油红O染色提取法检测其脂肪含量;采用SQ RT PCR法检测脂肪生成相关基因PPARγ、RXRα、LPL、PEPCK和SCD mRNA表达的变化. 结果显示,PPARγ mRNA在诱导分化第2 d时有低水平表达,在诱导分化过程中表达量逐步升高,在终末分化阶段仍保持高水平表达;RXRα mRNA在诱导分化第2和4 d表达量很低,诱导分化第6 d时表达增加.在诱导分化第8 d,RXRα mRNA表达与第6 d相比差异不显著,直至终末分化. 脂肪细胞分化标志基因LPL在第2 d开始表达,第4和6 d逐步升高,在终末分化阶段仍保持高水平的表达;生脂基因PEPCK和SCD mRNA在第2和4 d开始表达,第6和8 d仍保持高水平的表达. 研究结果表明,100 μmol/L的Vit C促进猪前体脂肪细胞增殖能力最强;250 μmol/L Vit C能显著促进猪前体脂肪细胞分化. 其作用机制可能是通过对转录因子PPARγ和RXRα及标志基因LPL mRNA时序性表达的调控来进行的,促进生脂基因的表达,从而诱导脂肪细胞的分化.     

Proliferating cell nuclear antigen of the rat thyroid gland before and after birth]

We were studied the proliferative activity of the thyroid gland's cells of embryo and adult Wistar rats due to using the antiserum against the cell nuclear antigen (PCNA). The 100% of cells in thyroid's embryo was a positive on the 16th, 17th, 18th stages of the embryonic development (stages by Kornegy). The percent of PCNA-positive cells considerably increased to 67% on the 19th stage. This fact the 20th and 21th stages of prenatal development relatively the previous stage coordinate with starting of the thyroid hormones in fetal thyroid gland and the first follicles formation. The small increasing of number of PCNA-positive cells detected on the 20th and 21th stages of prenatal development relatively the previous stage. Considerable elevation of the proliferating cells to 75% immediately before the birth (22th stage). An infant rats had have the 39% of proliferating cells. The 51% cells divided on the 5th day of postnatal development. Considerable decreased of the cell's division was occurred until the postnatal day 60. Using of the PCNA antiserum allowed to study cell proliferation in thyroid gland during pre- and postnatal rat development.     

An assessment of the relative contribution of the processes of cellular proliferation, polyploidization and hypertrophy to the increase in liver mass at various stages in the postnatal development of rats

Changes in isolated hepatocyte dry mass, its ploidy and liver mass at different stages of the rat postnatal ontogeny were investigated. The determination of these processes and special calculation made it possible to estimate quantitatively a relative contribution of cell proliferation, polyploidization and hypertrophy, not associated with DNA synthesis to the increase in the liver mass at different stages of the rat development. During the first week after the rat's birth, its liver growth is provided by 61 and 39% with hepatocyte proliferation and hypertrophy, respectively. Between the 14th and the 21st days of development, when considerable functional changes occur in the rat liver, the contributions of proliferative and polyploidization processes, and of cell hypertrophy into the liver mass increasing are roughly identical. Later on, the contribution of cell hypertrophy into the liver growth is noticeably reducing to reach within 1-2 months only 1%. On this developmental stage the liver mass increment by 2/3 is provided due to cell proliferation and by 1/3--to its polyploidization. As a whole, the accelerated growth of the rat liver from the birth to sex puberty is described as follows: the contribution of processes of proliferation and polyploidization, and of cell hypertrophy correspond to 28, 30 and 42%, respectively; afterwards, the liver growth being retarded. Within the period from 2 to 6 months, the liver mass increase is provided mainly (up to 76%) by cell proliferation, the shares of polyploidization and cell hypertrophy being 8 and 16%, respectively.     

Reparative processes in the liver and adrenal cortex of rats following an experimental vascular crisis

Reparative processes in the liver and the adrenal cortex of hemiadrenalectomized female rats, which sustained an acute circulatory disturbance as a result of orthostasis, were investigated by means of quantitative methods (cytometry, kariometry, nucleolometry, determination of cell content calculation of nucleo-cytoplasmic, nucleolo-nuclear ratios). Common features in regeneration of the organs under study were found. During the first days of the experiments the count of the dying cells increased and simultaneously the quantity of amitoses and binucleated cells in the liver grew. The cell composition of the organs was stabilized by the 15th day in the adrenal gland and by the 45th day in the liver. During the first week after orthostasis mitotic activity of epithelial cells rose in both the organs. Later the regeneration took place at the intracellular level (activation of the nuclear apparatus and hypertrophy of the cell cytoplasm).     

Morphogenesis and pathogenesis of chronic lung diseases. vii. Kinetics of alkaline phosphatase active cells during the development of experimental lung granulomas.

The circulating cells arriving at the formation site of the experimentally induced lung granuloma were quantitatively and qualitatively determined during their development by estimation of alkaline phosphatase active free cells. These represent 32 per cent the 2nd day and 27 per cent the 4th, of all the lung granuloma cells, and rapidly decrease to 8 per cent the 8th day, to 4 per cent the 11th and to only 1.5 per cent the 15th day. The participation of alkaline phosphatase circulating cells appears to be important only the first days, the process becoming by proliferation and differentiation a histiocytic, epithelioidic, and lympho-plasmocytic structure under the influence of antigenic and non-antigenic components of the used immunologic adjuvant.     

Chondrocyte hypertrophy can be induced by a cryptic sequence of type II collagen and is accompanied by the induction of MMP-13 and collagenase activity: implications for development and arthritis.

The objective of this study was to determine whether a peptide of type II collagen which can induce collagenase activity can also induce chondrocyte terminal differentiation (hypertrophy) in articulate cartilage. Full depth explants of normal adult bovine articular cartilage were cultured with or without a 24 mer synthetic peptide of type II collagen (residues 195-218) (CB12-II). Peptide CB12-II lacks any RGD sequence and is derived from the CB12 fragment of type II collagen. Type II collagen cleavage by collagenase was measured by ELISA in cartilage and medium. Real-time RT-PCR was used to analyze gene expression of the chondrocyte hypertrophy markers COL10A1 and MMP-13. Immunostaining for anti-Ki67, anti-PCNA, (proliferation markers), type X collagen, cleavage of type II collagen by collagenases (hypertrophy markers) and TUNEL staining (hypertrophy and apoptosis markers) were used to detect progressive maturational stages of chondrocyte hypertrophy. At high but naturally occurring concentrations (10 microM and up) the collagen peptide CB12-II induced an increase in the expression of MMP-13 (24 h) and cleavage of type II collagen by collagenase in the mid zone (day 4) and also in the superficial zone (day 6). Furthermore the peptide induced an increase in proliferation on day 1 in the mid and deep zones extending to the superficial zone by day 4. There was also upregulation of COL10A1 expression at day 4 and of type X staining in the mid zone extending to the superficial zone by day 6. Apoptotic cell death was increased by day 4 in the lower deep zone and also in the superficial zone at day 7. The increase in apoptosis in the deep zone was also seen in controls. Our results show that the induction of collagenase activity by a cryptic peptide sequence of type II collagen, is accompanied by chondrocyte hypertrophy and associated with cellular and matrix changes. This induction occurs in the mid and superficial zones of previously healthy articular cartilage. This response of the chondrocyte to a cryptic sequence of denatured type II collagen may play a role in naturally occurring hypertrophy in endochondral ossification and in the development of cartilage pathology in osteoarthritis.     

A histoquantitative study of the effect of maternal hypervitaminosis A on the differentiation of the foetal mouse skin.

The skin of albino mouse foetuses aged 13, 15, 17, 19 and 21 days was studied histologically and quantitatively. The skin of foetuses aged 21 days after maternal hypervitaminosis A, was compared with that of 21 days controls. On the 13th day, the epidermis consisted of one layer of cuboidal cells. The stratum intermedium appeared on the 15th day, the stratum granulosum on the 19th day and the stratum corneum on the 21st day of intrauterine life. The quantitative study showed that although the epidermis increased more rapidly in thickness in the interval between the 13th and 17th day than in the subsequent 4 days, yet in the latter period differentiation of the stratum granulosum and corneum took place. On the other hand, the rate of proliferation of the epithelial cells concerned in the follicle formation was more rapid in the last two days of intrauterine life than in any previous prenatal stage. After maternal hypervitaminosis A, the whole thickness of the epidermis was reduced by 50% and the dermis showed an oedematous appearance. The hair follicle primordia showed a decreased volume.     

Luteinizing hormone,progesterone and the morphological development of normal and superovulated corpora lutea in sheep

The development of granulosa-lutein cells was studied in 27 normal and 32 superovulated ewes between days 0-4(day 0 began with the preovulatory LH peak in normal animals and the HCG injection in superovulated ewes). The pattern of differentiation was similar in both groups. Following initial hormonal stimulation (0-12 hours after LH or HCG), granulosa cells were approximately 100 mu2 and contained small, pleomorphic nuclei with large amounts of clumped chromatin. Elongate cells lining the basement membrane possessed large, heterogeneous dense bodies, and a well-developed Golgi apparatus. Mitotic figures were observed up to 6 hours prior to ovulation. Sixteen to 20 hours following the LH surge or HCG injection, hypertrophy of granulosa cells was evident. Nuclei contained definitive nucleoli. Blood vessels in the theca interna were abundant and highly dilated. Ovulation occurred approximately 24 hours after the LH peak or HCG injection. Visible signs of luteinization were evident 6-12 hours after ovulation. A slight increase in serum progesterone levels was detected. The second post-ovulatory day was characterized by continuing hypertrophy of granulosa cells and extensive proliferation of smooth endoplasmic reticulum and mitochondria. Nuclei of granulosa cells were larger and possessed extremely large nucleoli. Numerous mitotic figures were apparent within the corpus luteum. Serum progesterone concentrations began increasing at 60-72 hours after hormone stimulation. By the end of the third post-ovulatory day, the corpus luteum consisted of large, pleomorphic, parenchymal cells, interspersed between capillaries and connective tissue elements. Only an occasional mitotic figure was apparent within the corpus luteum at 100 hours. Light microscopic autoradiography of 5, 10, and 15 day corpora lutea taken from ewes pulsed with 3H thymidine at specific times before and after ovulation revealed that granulosa cells did not undergo secondary mitoses following ovulation. In contrast, thecal, mesenchymal and endothelial cells did mitose on day 3.