Biomedical subjects

M Logonder-Mlinsek

Publications and source records attributed to M Logonder-Mlinsek.

11 recordsLinked to original sources

PubMed1996

Mast cell histamine in gastric secretion--a study on the isolated portion of a guinea pig stomach.

The effects of an H3-agonist, R-alpha-methylhistamine (0.1 and 1 microM), on gastric acid secretion and on mast cell histamine release was studied on the isolated portion of guinea pig stomach. Secretion, induced by calcium ionophore, A23187 (1 microM), and by vagal stimulation was determined by continuous pH measurement, mast cell degranulation was examined histologically. Secretory effects were not significantly changed by H3-agonist. Mast cell degranulation, elicited by vagal stimulation, was not influenced by R-alpha-methylhistamine, but the degranulating effect of A23187 was clearly augmented by the H3-agonist. The results support the view that H3-receptors could influence the release of mast cell histamine in the guinea pig stomach.

Animals↗

PubMed1993

The long-term effect of a calcium diet on the bone tissue, C-cells and parathyroid glands of the rat.

In this experiment of 11 month-duration, 18 female Wistar rats received controlled amounts of calcium with food and water, to produce a state of either hypocalcemia or hypercalcemia. After a long-term low calcium diet hypocalcemia disappeared. This group of animals showed insignificant increases in the nuclear-cytoplasmic ratio of the parathyroid cells as well as in the total volume of the parathyroid glands, and a significant increase in the volume density of the osteoid. In the group receiving a high calcium diet, hypercalcemia was still present after 11 month. The insignificantly smaller and more numerous C-cells produced more calcitonin than normally. The parathyroid cells were significantly smaller and the numerical areal density of the osteoclasts was significantly lower than in the control group. It can be concluded that the parathyroid glands and C-cells are involved in the maintenance of blood calcium homeostasis during a long-term experiment on rats receiving low or high calcium diet.

Animals↗

PubMed1988

The interdependence of the follicular, parafollicular, and mast cells in the mammalian thyroid gland: a review and a synthesis.

The aim of this paper is to summarize some of our quantitative descriptive and experimental studies, to discuss them in view of the literature data, and to present a synthesis of the topic. The results of stereological analysis of some tissue components of the rat thyroid gland have been compared with the results of topological studies on the parafollicular cells of various mammalian species. Localization of the parafollicular cells in the central regions of the thyroid gland lobes, where the follicular cell activity seems to be greater than in the periphery of the lobes, has led to the hypothesis that the parafollicular cells regulate (stimulate and/or suppress) the activity of the follicular cells. Long-term application and antithyroid drugs to mice and rats has shown that excessive concentrations of thyrotropin provoke hyperplasia of both the follicular cells and the intrathyroid mast cells and, transiently, of the parafollicular cells. This and some of the literature data are congruent with the hypothesis that the parafollicular and mast cells also stimulate the follicular cells by their paracrine secretions. Long-term application of antithyroid drugs to mice and rats has shown that excessive concentrations of cular cells but also probably stimulation of the follicular cells, as judged by the stereological measurements. The biological meaning of the spatial integration of follicular and parafollicular cells seems to be a functional coordination of both epithelial cell lines, supported by intrathyroid mast cells.

Acid Phosphatase↗

PubMed1988

The effect of compound 48/80 and of electrical field stimulation on mast cells in the isolated mouse stomach.

It has been shown that compound 48/80 evokes acid secretion in the isolated mouse stomach by releasing histamine from mast cells. The aim of the present work was to study the distribution and type of mast cells in the isolated mouse stomach and to examine the effect of compound 48/80 and of electrical field stimulation (EFS) on these cells. Histological examination of the stomachs showed only the presence of connective tissue mast cells (CTMC) in all parts of the stomach except in the glandular mucosa where mucosal mast cells (MMC) predominated (MMC -71%, CTMC -29%). Compound 48/80 and EFS did not affect MMC, whereas CTMC showed marked degranulation in all parts of the stomach including the glandular mucosa. It can be concluded that CTMC, present in the gastric mucosa and being sensitive also to EFS, may be involved in the regulation of gastric secretion in the mouse.

Animals↗

PubMed1986

The effect of compound 48/80, substance P and pentagastrin on the isolated guinea pig atrium.

It has been shown that histamine is present in guinea pig hearts. In the present work, the effect of some substances, known to liberate mast cell histamine, on the isolated guinea pig atria was studied. Compound 48/80 (100 micrograms/ml), pentagastrin (10(-6) M) and substance P (10(-5) M) were added 2-3 times to the isolated organs and the frequency of contractions was measured. At the end of experiments, the atria were examined histologically for mast cell degranulation. Compound 48/80 and pentagastrin increased the frequency of contractions of isolated atria. Substance P provoked a dose-dependent decrease of contraction frequency; this effect was diminished by atropine (10(-5) M). All three substances provoked pronounced degranulation of mast cells present in the atrium, the effect of substance P being significantly greater than the effects of the other two substances. It can be concluded that mast cells, present in guinea pig atrium, are sensitive to the histamine liberators used; histamine is released in quantities high enough to produce an effect.

Animals↗

PubMed1983

The role of tissue mast cells in exocrine secretion: studies in the submandibular gland of the cat.

Histamine was found to be stored in the submandibular gland of the cat mainly in the mast cells. The amine is released from mast cells by compound 48/80 and pilocarpine. This was demonstrated in the in vivo and in vitro experiments and by histological examination. During the physiological stimulation of the gland, via the electrical stimulation of the chorda tympani nerve, significant changes of histamine content were not found. This could be explained by the increased synthesis of histamine during physiological stimulation. The physiological role of histamine in salivary secretion was demonstrated. The similarity between the roles of histamine, mast cells and chromaffine-like cells in salivary and gastric secretion is discussed.

Animals↗

PubMed1983

Mast cells in the submandibular gland of cat.

The effects of pilocarpine, compound 48/80 and the electrical stimulation of the chorda tympani nerve on the morphology of the mast cells from the submandibular gland of the cat were studied. All those different treatments of the gland caused the enlargement of the tissue mast cells. We observed also in the glands treated with pilocarpine and compound 48/80 a degranulation of mast cells. The degranulation was more expressed after the application of compound 48/80 to the animals.

Animals↗

PubMed1982

Carcinogenesis after sublethal ionizing irradiation and regular avoidance irritation.

160 mice of the BALB/C strain of both sexes, aged 3 months, were divided into four equal groups out of which two were regularly irritated by a combination of an optical signal and electrical stroke. After one month of irritation one nonirritated and one irritated group were whole body irradiated with a single dose of 6.65 Gy (1.83 Gy/min), the other two groups were sham irradiated. The mice lived until their spontaneous death or one year after irradiation, respectively, when the rest of the animals were sacrificed. The appearance of malignant tumors was noted. Irradiation shortened the survival time while the irritation had an appeasing, compensatory effect, more expressed in the males than in the females. After irradiation the number and assortment of the tumors increased and the latent period essentially shortened. In the irritated animals the number and assortment of the malignant tumors were reduced and a tendency for lengthening of the latent time period was seen; these differences, however, were not statistically significant. In spite of some differences the response in both sexes to irradiation and irritation or their combination was similar.

Animals↗

PubMed1981

Stress and radiation carcinogenesis in mice.

In the present experiment irritation consisting of a combination of an optic signal followed by a mild electroshock administered at regular intervals was started in 2 groups of animals at the age of 3 months. At 4 months of age, one of the irritated and one of the nonirritated groups were exposed to whole-body gamma irradiation at 20 daily doses of 0.5 Gy (50 rad(, 1.4 Gy/min (140 rad/min), while the other 2 groups were sham-irradiated. The animals were autopsied and the specimens were microscopically studied for the presence of malignant tumors. Malignant tumors involving particularly the testes and lungs and leukosis were found in 29% of males, whereas in females the tumor incidence with mammary, pulmonary and ovarian involvement and leukosis was 39%. The irradiation decreased the minimum latency time in the irritated males and both female groups. In males, the irritation lowered the cumulative prevalence of malignant tumors, a significant decrease being noted at the age of 15 months. In females, it was increased, with a significant rise observed to occur at the end of the experiment. The opposite effects of irritation on the radiation carcinogenesis in males and females can be attributed to the irradiation-induced specific alterations of the gonads in females and, in part, to a longer survival time observed in the irradiated females.

Animals↗

PubMed1979

Stress and Ehrlich ascites tumor in mouse.

The aim of the study was to investigate the interaction of the psychosomatic stress and the Ehrlich ascites tumor (EAT) growth in mice. The stressor consisted of combination of a light signal followed by a mild electric shock. The first experiment was performed on CBA mice irritated for 0, 2 and 4 weeks respectively, prior to intraperitoneal transplantation of the EAT. In the second study, mice of BALBc strain were used. Stress was applied 4 weeks before the tumor transplantation and continued throught the experiment. Both the irritated and the nonirritated animals were subjected to either intraperitoneal or subcutaneous inoculation of the EAT. In both experiments, mice were left to live until their spontaneous death. In the first experiment, after a 2-week irritation the experimental animals showed a significantly longer survival time as compared to the controls. Longer or shorter duration of the irritation had no significant effect on the results obtained. Results yielded by the second experiment showed no significant difference in the time of survival of the irritated and nonirritated animals after the i. p. transplantation, whereas after the s. c. inoculation of the EAT, the irritation significantly increased the survival period. The EAT in irritated mice was observed to have invaded the vitals later and less frequently than in the nonirritated animals. Quantitative histological analysis of some endocrine and lymphatic organs revealed signs of stress in the experimental animals. The EAT transplant, per se, had a stressogenic effect too.

Animals↗

PubMed1975

"Genital dyscrinism" as a cause of subfertility in mice of the CBA strain.

Following four generations of inbred mating (brother-sister) in three direct lineages of CBA strain mice, sterility appeared which from that generation forward became more frequent. The genital organs in animals of both sexes were altered. There was a noticeable occurrence of cysts in the ovaries of female animals already following the third month; in mice approximately one year of age this condition was followed by cystic glandular hyperplasia of the endometrium, sometimes complicated by disturbances in blood circulation, inflammation or even malignancy. In some female animals, manifesting, due to cysts, completely degenerated ovaries, the rest of the genital system was severely atrophic. Male animals frequently showed severe atrophy of the seminiferous epithelium along with preserved interstitial cells and hypertrophic seminal vesicles. These pathological changes represent an independent nosologic unit, for which the label "genital dyscrinism" has been proposed. The authors have considered an endocrine mechanism as the possible cause of these pathological changes which are presumed to be genetically conditioned.

Animals↗