Change in immunological and biochemical parameters in germ-free animals in response to T-activin

The influence of immunoregulating humoral thymus factor T-activin (fraction AFT-6) on the activity of xenobiotic metabolism enzymes (EMX) and cellular-dependent cytotoxicity was investigated in germ-free guinea-pigs. Germ-free and conventional animals were injected 5 micrograms of T-activin intraperitoneally, on 3 successive days. The control animals were injected a physiologic saline. A day after the last injection the animals were killed, and EMX and K cell activity was measured. It was found that EMX activity in germ-free animals was decreased. T-activin stimulated cytochrome P-450, NADP-cytochrome-C-reductase, glutathione-S-transferase, benzopyrene hydroxylase and epoxyhydrase activity. In conventional animals the activity of these enzymes remained unchanged under the influence of T-activin. K-cell activity in germ-free animals was decreased, as compared to conventional guinea-pigs. Under the influence of T-activin the parameter increased and stood at about 70% of normal values.     

Effects of acyclic analogs of atrial natriuretic factor on proliferative processes of the epithelial tissue in white rats]

The effect of atrial natriuretic factor (ANF) synthetic linear truncated analogues AP-H-6-OH and AP-FOR-6-OH on corneal, skin, duodenum and colon epithelium proliferation has been studied on male rats. The epithelium mitotic activity and DNA synthesis were evaluated 4 and 24 h after intraperitoneal injection of 10 or 100 micrograms/kg peptides. In a dose of 10 micrograms/kg both ANF synthetic analogues inhibited proliferation processes in corneal epithelium, but activated the DNA synthesis in duodenum and colon epithelium. AP-FOR-6-OH (10 micrograms/kg) decreased the mitotic activity of skin epithelium and increased the silver grain density over the cell nuclei at the same time. 100 micrograms/kg ANF analogues stimulated cell mitogenesis in all organs studied. According to the data obtained ANF linear truncated analogues influence on epithelium proliferation is similar to effector of previously studied cyclic atriopeptin AP II.     

Study of the action of immunomodulator T-activin on electric properties of plasma membranes of thymus cells by the use of fluorescent probes

T-activin alters the electric properties of plasmatic membranes of the T-activin treated suspension of mouse (CBAX X057B1) F1 thymic cells. These alterations were registered by means of negative charged fluorescent probe l-anilino-naphthalene-8-sulfonate (ANS) and positive charged 4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM) by measurement of their fluorescence in the individual thymic cell. Apparently, T-activin leads to depolarization of transmembrane potential on plasmatic membrane of thymic cells. It seems that action of T-activin is similar to the effect of polycations, which alter cells ionic streams during lymphocyte activation. However, there is a version, that T-activin acts like neuraminidase, but it is activity less expressed.     

Effects of atrial natriuretic peptide AP II on proliferation processes in the epithelial tissue of white rats]

The effect of atrial natriuretic peptides synthetic analog AP II on corneal, skin, tongue and duodenum epithelium proliferation have been studied on male rats. The epithelium mitotic activity and DNA synthesis were evaluated in 4 and 24 h after intraperitoneal injection of 10 or 100 micrograms/kg AP II. 10 micrograms/kg AP II was found to have different influence on organs epithelium: it decreased the mitotic activity of skin and corneal epithelium, but activated the proliferation processes in tongue and duodenum epithelium. 100 micrograms/kg AP II stimulated cell mitogenesis in all organs studied. According to data obtained atrial natriuretic peptides are able to participate in cell division regulation in vivo.     

Annual mitotic activity in the intestinal epithelium of the musselCrenomytilus grayanus

The seasonal dynamics of cell reproduction in the intestinal epithelium of the musselCrenomytilus grayanus are described in detail. Mitotic indices in the intestinal epithelium varied throughout the year from 0.005 to 0.26% (averaged data) and from 0.003 to 0.37% (individual data). Cyclic seasonal changes were found in the mussel’s intestinal epithelium. In general, the average values of mitotic activity in the intestinal epithelium were low (the mitotic index was 0.13%); there was a rise in activity in late April–June and September and a decline in July–August and especially in January–March. The winter-early spring period was characterized by a profound inhibition of cell reproduction and the transition of cells to the resting state. An outburst of proliferation occurred in the spring, due to a manifold increase in the number of cells in the mitotic cycle. The musselC. grayanus may be a good model for the study of the two extreme states of proliferation and their alternation in marine animals in nature. The diel dynamics of mitotic activity in the intestinal epithelium were followed during the most active growth period (May). The mitotic index (MI) varied during the day within a narrow range, deviating from the daily average value by no more than one third; no pronounced diel rhythm was found. Optimum water temperatures for cell reproduction ranged from 5 to 18°C.     

Circardian rhythm of mitoses in the epithelium of the cornea after splenectomy]

In corneal epithelium of CBA mice the index of colchicine mitoses diminished after splenectomy in the day period characterized by rising mitotic activity in control animals. The duration of active phase of cell division rhythm shortened while the maximum of mitotic activity delayed in comparison with control animals. The total amount of cells entering mitosis during 24 hours diminished by 27.7% and the rate of physiological regeneration of corneal epithelium decreased.     

Cytostatic effect of cyclophosphane on esophageal tumors and epithelium of mice

Investigation of cytostatic activity of cyclophosphamide in sarcoma 37 and esophagus epithelium in albino mice with respect to the diurnal rhythm of mitotic activity and the number of labeled nuclei was performed. Apparently the tumour cells in the G1-phase and at the beginning of the S-phase of the mitotic cycle were the most sensitive to the inhibitory effect of this drug. During the completion of the DNA-synthesis period the cell resistance to the action of the cytostatic increased. Cells at the G1-phase of the mitotic cycle were sensitive to the inhibitory action of cyclophosphane in the esophageal epithelium.     

A study of diurnal proliferative activity in tumour and small intestine of C3H mice bearing a transplanted mammary carcinoma

Diurnal changes in proliferative activity were investigated in tumour and small intestinal epithelium of mice bearing a transplanted mammary carcinoma. In addition to mitotic and labelling index studies, the metaphase-arrest technique with vincristine (VCR) was employed. In the tumour there was no clear evidence of a significant diurnal rhythm in proliferative activity but in the small intestinal epithelium such a rhythm was clearly demonstrated. A higher cell production rate (kB) measured by metaphase-arrest and higher labelling and mitotic indices were seen in the mid to late part of the dark period. The peak mitotic index was seen 3 to 6 h after the labelling peak in the small intestine. The basal third of the crypt which is believed to include the stem cell compartment of this tissue showed larger diurnal fluctuations in both labelling index and kB than the rest of the proliferative compartment.     

Cell population kinetics and the cell population mechanisms of the circadian rhythm of proliferative activity in mouse esophageal epithelium]

The dynamics of 3H-thymidine labeled mitosis and diurnal rhythm of proliferative activity was studied. The isotope was injected to BALB/C mice at the peak of diurnal rhythm of DNA synthesis activity of basal layer cells of oesophageus epithelium. It has been established that the increase in the mitotic index during 24 hours depends on the increase in number of cells being in S-period. The data show that the increase of mitotic index at diurnal rhythm occurs at the expense of 75% of new G0-cells which entered into the mitotic cycle, and of 25% of re-entering cells that had divided during the maximal mitotic activity a day before. It is found that the duration of mitotic cycle of cell population which entered into the mitotic cycle synchronously is almost equal to the period of diurnal rhythm of mitotic activity, i.e. 24 hours.     

Physiologic regeneration of jejunal epithelium following bilateral subdiaphragmatic vagotomy in rats]

Seven days after vagotomy in rats there was an increase of the mitotic activity of the epithelium of the small intestine; this index was about 1.5 greater in the experimental ats in comparison with control animals. Daily rhythm of the mitotic activity was constant under these conditions, but the amplitude of daily fluctuations was levelled. Vagotomy failed to alter the stable regimen of renovation of the cell population of the "crypt-villus" system.     

Changes in the mitotic activity of the corneal epithelium of white rats following coolong of the animals at different times of the day]

A study was made of the influence of moderate hypothermia on the mitotic activity of albino rat corneal epithelium. The animals were cooled by the contact method for one hour to 28 degrees C; such procedure was conducted at 6 a.m., at noon, and at 6 p.m.; the epithelial reaction to cooling proved to depend on the time, the greatest suppression of mitotic activity (14-fold) occurring at daytime 3 hours after the cooling. A tendency to normalization of cell division was observed 6 and 12 hours after the cooling. The number of mitoses decreased 3 hours after the evening cooling, no changes in the mitotic activity in 3 and 6 hours after the morning cooling; cell division was found to be suppressed in 12 hours.     

The effect of 5-fluorouracil on the mitotic cycle and DNA synthesis in the epithelium of mouse small intestine.

The examinations were performed on 42 mice of the Porton strain. The experimental animals were injected intraperitoneally with the dose of 75 mg of 5-fluorouracil per kg body weight. The first experimental group received injections of [3H]thymidine within 48 hours and the second group within 96 hours of the injection of 5-fluorouracil. Two mice from each group were killed at within 1, 2, 4, 8, 12, 24, and 48 hours of the [3H]thymidine injection. Calculations of the mitotic index and time of duration of individual phases of the mitotic cycle in epithelial cells of the small intestine were based on application of the autoradiographic method. These studies lead to the conclusion that 5-fluorouracil disturbs the course of metabolic processes in the cell, which are also related with the distribution of the genetic material. Histological examinations show that 5-fluorouracil produces profound morphological changes in the intestine, which affect both the intestinal epithelium and the connective tissue stroma. The autoradiographic tests revealed a considerable suppression of the mitotic activity of the epithelium of intestinal crypts. Moreover, it was shown that 5-fluorouracil inhibits the mitotic activity of the intestinal epithelium by diminishing the number of cells capable of entering into mitosis. Nevertheless, by 96 hours following introduction of a single dose of 5-fluorouracil normal morphological structure and mitotic activity of the intestinal wall cells are restored.     

Effect of beta-adrenoreceptor blockade on cell division processes in the corneal and tongue epithelium of white rats with chronic oxygen starvation

A study was made of the changes in the mitotic activity, DNA synthesis, and the number of pathological mitoses after administration of the beta-adrenoblocker propranolol in the corneal and tongue epithelium of white rats kept in pressure chamber for 7 days (4 h daily) at a "height" of 9000 meters. The mitotic and the label indices (inclusion of 3H-thymidine by the epithelium nuclei) were analysed for mitotic activity and DNA synthesis, respectively. The experiments showed that the mitotic activity, DNA synthesis, the number of pathological mitoses were stabilized due to the propranolol administration.     

Interaction of T-activin with peritoneal macrophages

The action of T-activin on peritoneal macrophages of CBA mice after its introduction into the animals has been studied. In intact mice the phagocytic activity of macrophages and their resistance to the cytopathogenic action of Salmonella typhimurium live cells remains unchanged. The injection of corpuscular pertussis vaccine into mice leads to a decrease in the resistance of macrophages to the action of salmonellae. The simultaneous injection of T-activin into mice in doses of 0.1 and 1.0 microgram per animal abolishes the damaging action of the vaccine. The analysis of the in vitro action of T-activin on macrophages of intact mice revealed that the preliminary incubation of cells with the preparation sharply increases their resistance to the action of salmonellae, while its introduction simultaneously with bacteria or after them rapidly leads to the death of macrophages. The action of T-activin is supposed to be linked with triggering the biosynthetic processes mediating the resistance of macrophages to the cytopathogenic action of salmonellae.     

Further studies on the biological characteristics of an endogenous colon mitosis inhibitor: Comparison with some structurally related peptides

Previous work indicates that the colonic epithelial cell proliferation in mice is reversibly inhibited by the tripeptide pGlu-His-GlyOH found in aqueous extracts of the intestine. In the present study we examined the possible tissue specificity of the colon mitosis inhibitor. The mitotic rate in the small intestine, epidermis and forestomach in mice was registered after a single i.p. injection of the tripeptide. A significantly reduced rate of cell renewal was found at 18 h in the epidermis whereas no inhibition was observed in the forestomach or ileal epithelium. To investigate whether the amino acid sequence of the tripeptide is essential for the inhibitory effect, three structurally related bioactive peptides were tested and compared to the effect of CMI. CMI showed a bell-shaped dose-response relationship as previously shown, whereas the mitotic rate was not reduced in the colonie epithelium after treatment with either an epidermal mitosis inhibitory pentapeptide, or the dipeptide pGlu-GlyOH, or an analogue of luteinizing hormone-releasing hormone. The efficacy of the tripeptide was dependent on the basal rate of cell renewal in the colonie epithelium. When the tripeptide was given at the circadian nadir of cell proliferation a delayed reduction of the proliferative activity was observed at 6 h after treatment, whereas treatment when the rate of cell proliferation was at its circadian zenith gave an immediate mitotic inhibition.     

Further studies on the biological characteristics of an endogenous colon mitosis inhibitor: comparison with some structurally related peptides

Previous work indicates that the colonic epithelial cell proliferation in mice is reversibly inhibited by the tripeptide pGlu-His-GlyOH found in aqueous extracts of the intestine. In the present study we examined the possible tissue specificity of the colon mitosis inhibitor. The mitotic rate in the small intestine, epidermis and forestomach in mice was registered after a single i.p. injection of the tripeptide. A significantly reduced rate of cell renewal was found at 18 h in the epidermis whereas no inhibition was observed in the forestomach or ileal epithelium. To investigate whether the amino acid sequence of the tripeptide is essential for the inhibitory effect, three structurally related bioactive peptides were tested and compared to the effect of CMI. CMI showed a bell-shaped dose-response relationship as previously shown, whereas the mitotic rate was not reduced in the colonic epithelium after treatment with either an epidermal mitosis inhibitory pentapeptide, or the dipeptide pGlu-GlyOH, or an analogue of luteinizing hormone-releasing hormone. The efficacy of the tripeptide was dependent on the basal rate of cell renewal in the colonic epithelium. When the tripeptide was given at the circadian nadir of cell proliferation a delayed reduction of proliferative activity was observed at 6 h after treatment, whereas treatment when the rate of cell proliferation was at its circadian zenith gave an immediate mitotic inhibition.     

Infradian rhythms of the esophageal epithelium mitotic activity, corticosterone and thyroxin level in Japanese quail Coturnix japonica

Everyday dynamics of corticosterone and thyroxin levels on blood serum, as well as esophageal epithelium proliferation activity in Japanese quail males, have been investigated over a period of 16 days. It was estimated that different individuals synchronically exhibited a 4-day rhythm of the corticosterone serum level. The thyroxin level displayed a 3-day biorhythm. The mitotic index in the esophageal epithelium negatively correlated with the corticosterone level. The revealed infradian rhythms of the corticosterone and thyroxin levels, as well as esophageal epithelium mitotic index, should be taken into account while carrying out experiments concerning the determination of the hormone level and mitotic activity of epithelial tissues.     

The effect of using T-activin in the therapy of the newborn with suppurative surgical infection

A total of 156 newborn infants with suppurative surgical infection (SSI) were observed; 73 of them had sepsis and 83 a severe localized process. In 47 patients with sepsis and 34 with localized infection, T-activin was included in complex therapy while the other infants formed the control group. It has been established that T-activin leads to an increase in the quantity of the active population of T-lymphocytes in the peripheral blood and to enhanced functional activity of T-lymphocytes in the newborn with SSI independent of generalization of the process. Bactericidal activity of circulating phagocytes is improved. The clinical course of SSI is less severe with more pronounced positive changes in the symptoms, hospital stay of the children is shortened, lethality is reduced. The effect of T-activin on the dynamic of the indices of the immune state is more marked in a septic process.     

Effect of T-activin on the formation of conditioned reflex and manifestations of unconditioned reflex of avoidance in August strain rats]

It has been revealed that intraperitoneal injection of T-activin (humoral factor of the thymus) to August rats leads to more rapid and stable conditioned reflex formation to a sound and to a decrease of avoidance time when electric current is given to a shuttle chamber. Furthermore, less amount of uneffective series in testing unconditioned avoidance is registered in the test animals. A positive T-activin effect on conditioned reflex formation and unconditioned reflex manifestation is probably connected with its ability to alter hippocampus functional parameters and (or) with anti-stressor properties of the preparation.