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E Peschke

Publications and source records attributed to E Peschke.

At least 37 records · Page 2Linked to original sources
PubMed1996

Circannual morphometric investigations of the rat suprachiasmatic nucleus after pinealectomy, ganglionectomy and thyroidectomy.

We karyometrically investigated the nucleus suprachiasmaticus (SCN) which had been manipulated in several ways in order to analyze the functional importance of the pineal gland on the primary pacemaker of mammals in the course of the year. The manipulation modes were (i) pinealectomy (PX), and (ii) sympathetic denervation of the pineal by bilateral extirpation of the upper cervical ganglia (ganglionectomy, GX). Additionally, the influence of the inactivated pineal, obtained through hypothyroidism which was realized by (iii) subtotal thyroidectomy (TX), was also investigated. With respect to annual oscillations the results of our investigations were able to illustrate the following. (1) The SCN consists of at least two parts (ventrolateral and dorsomedial) each with different functions and relationships. The nuclei of the ventrolateral cells are bigger and there are many indications both in our own research and from literature that the neurons of this part are involved in the generation of rhythms. (2) The size of the cell nuclei of the ventrolateral part shows annual patterns. In the course of the year the maxima of the nuclear volume were registered in March and September (bimodal pattern, equinox, L:D = 12:12). PX, GX or TX only negligibly changed the bimodal annual pattern. However, in comparison the smallest cell nuclei were registered in the winter (short day). The much smaller cell nuclei of the dorsomedial part likewise show bimodal patterns but only in the experimental groups. The control group of this part shows an unimodal annual curve with a minimum at long-day conditions (June, L:D = 16:8). (3) All manipulations which inactivated the pineal or reduced the content of melatonin (PX, GX, and TX) were followed by an increase (activation) of cell nuclei of the SCN. In contrast to these effects, an increase of thyroxine (by exposure to cold), has an opposite effect (not documented here). In conclusion these results indicate, without a doubt, that a negative correlation exists, functionally, between the SCN and the pineal (in the same annual experiment the nuclear size of the pinealocytes was increased, under short-day conditions in December, and decreased under long-day circumstances in June). Additionally, it could be shown that the degree of negative correlation between the pineal and the SCN was seasonally dependent. The lowest effects of PX, GX and TX were registered at short-day conditions (December, L:D = 8:16).

Animals↗
PubMed1996

Postirradiated and nonirradiated gliosarcoma: immunophenotypical profile.

BACKGROUND: Thirty-one gliosarcomas (25 nonirradiated and 6 postirradiated tumors) were selected based on the presence of two distinctive areas: a malignant gliomatous and a sarcomatous component. In all cases, the sarcomatous component appears like fibrosarcoma or malignant fibrous histiocytoma. Two tumors showed additional areas consisting of osteochondroid differentiation. METHODS: All tumors were examined using antibodies against Ulex europaeus agglutinin I (UEA), glial fibrillary acidic protein (GFAP), vimentin (VM), epithelial membrane antigen (EMA), desmin, collagen IV, alpha-1-antitrypsin (alpha-1-AT) and smooth muscle actin (SMA). RESULTS: While the VM highlighted the sarcomatous areas of all tumors there were only scattered spindle cells that were GFAP-positive in the same areas. The alpha-1-AT was diffusely reactive in the sarcomatous areas in 20 cases. Focal immunoreactivity was seen with SMA (20 tumors), UEA (8 tumors), EMA (5 tumors), collagen IV (5 tumors) and desmin (4 tumors) in the nonvascular sarcomatous cells. CONCLUSIONS: The range of immunophenotypical expression is likely to be a reflection of the capacity of a multipotential progenitor to undergo divergent differentiation. There is a very little morphological difference between the postirradiated and nonirradiated tumors except that a higher proportion of postirradiated tumors are immunoreactive to SMA and desmin.

Brain Neoplasms↗
PubMed1996

Morphometry of pineal synaptic ribbon profile numbers after cytochalasin D treatment.

Synaptic ribbons (SRs) are electron-dense, plate-shaped synaptic organelles, to which electron-lucent synaptic vesicles (SVs) are attached by tiny stalks. In the mammalian pineal gland SRs are dynamic organelles, waxing and warning in number under different physiological and experimental conditions. The way in which SRs are formed, or catabolized, is not known. Since it has been suggested that actin may be part of SRs, in the present study the effect of the actin-disrupting drug cytochalasin D (CD, 1 microgram/ml, for 4 h) was examined in cultured guinea pig and rat pineal glands. The glands were preincubated for 48 h so that intra-pineal sympathetic nerve fibres degenerate and no longer release noradrenaline which may distort the results. CD had no effect on SR profile numbers in guinea pigs, but decreased them in rats (p > 0.05). The nonsignificant depressive effect of CD in rats was verified in a second experiment. To clarify the issue, acutely cultured rat pineal glands were treated with CD for 4 h, without effect. The results taken together suggest to us that CD has no major effect on pineal SR profile numbers, but that in rats preincubation for 48 h makes them vulnerable to catabolic processes. In all the experiments, the electron-dense plate of the SRs was qualitatively unaffected. However, the SVs were often larger and more irregular in shape and the stalks linking the SVs with the SRs were less frequently seen in CD-treated glands. In guinea pig pineals, in which SRs frequently lie in groups and parallel to each other, neither the distance between neighboring SRs nor the thickness of individual SRs were affected by CD. It is concluded that actin is not a major component of the SRs and the connecting stalks.

Animals↗
PubMed1990

Circannual oscillations of function compared with morphometric changes in the thyroid gland of the Wistar-rat.

To investigate biological rhythms of the thyroid gland circannual oscillations of thyroxine (T4), triiodothyronine (T3), and thyrotropin (TSH) were compared in serum samples of untreated young male Wistar-rats with the circannual changes of thyroid weights and with the relative proportion of colloid, epithelium, and interstitium of the thyroids. Animals were kept under standard environmental conditions, however, lighting conditions simulated the natural day-night changes. Thyroid weights, T4, T3, and TSH showed a statistically significant circannual rhythm with maxima in winter and spring and minima in summer and autumn. The same circannual patterns were observed in the proportion of epithelium and interstitium of the thyroids, while the colloid exhibited an inverse circannual pattern. These data were verified by biomathematical methods, like locally adjusted functional approximation, analysis of variance, and Spearman rank correlation. Our results represent an example for the concordance between functional and morphometrical changes in the course of circannual oscillations. Furthermore, these data confirm our earlier results describing higher T4-levels in the winter time (short-day) and lower serum titers in the summer time (long-day).

Animals↗
PubMed1990

[The effect of ganglionectomy and cold exposure on the ventromedial hypothalamic nucleus, blood glucose and liver glycogen in regard to circadian rhythms].

To analyse the importance of the ventromedial hypothalamic nucleus (VMH) for the circadian regulation of the carbohydrate metabolism rats were investigated after bilateral cervical sympathetic ganglionectomy (SCGx) 30 d earlier and exposure to cold (10 degrees C) 72 h earlier. In order to assess the circadian rhythms of nuclear volume oscillations of the VMH, blood glucose, and liver glycogen 4 times a day (light-dark cycle: 14L:10D, light on 05.00 h) rats were sacrificed at midlight and middark as well as 1 h after the onset of the light and dark periods. The circadian curves were calculated in a model-free way by the procedures of locally adjusted polynomial approximation. Ganglion removal and exposure to cold resulted in an increase of blood sugar and of nuclear volume of the VMH, but only of its lateral part. The liver glycogen decreased. Additionally, both the coordination between the circadian curves of the nuclear volume and of the blood glucose as well as of the inverse curves of the liver glycogen was destroyed after SCGx. These results are in agreement with the conviction that the enhanced blood glucose activates the VMH. The augmentation of blood glucose was discussed in connection with influences of the likewise increased thyrotropin-releasing hormone and thyrotropin on the increased plasma levels of catecholamines, with secondary increased plasma levels of glucagon as well as decreased insulin levels after SCGx and exposure to cold. The sympathetic denervation of the pineal gland (SCGx) produced the mentioned desynchronization of the curves. At the present we are not able to explain the approximate restitution of the circadian rhythms after additional exposure to cold.

Animals↗
PubMed1989

Circannual serum creatine kinase patterns after ganglionectomy and pinealectomy of the Wistar rat.

Previous investigations have shown that an inverse correlation exists between serum thyroxine levels (T4) and serum creatine kinase activity (CK) both in hypothyroid and hyperthyroid states. In the present study, serum T4 levels and total serum CK activity were analysed after thyroidectomy (TX), ganglionectomy (extirpation of the superior cervical sympathetic ganglion) (GX), or pinealectomy (PX) four times a year (March, June, September, and December). Blood samples were taken four times daily (at midlight, middark, and at 1 hour after the onset of the light and dark periods). Animals were kept under an artificial light schedule that simulated natural light-dark periods. The annual main values of serum T4 levels were significantly decreased after the operations, whereas serum CK activities were increased. Our circannual investigations demonstrated an inverse correlation between serum T4 levels and total serum CK activity (under hypothyroid circumstances). In addition, the circannual pattern of the serum CK activity demonstrated maxima under short-day (winter) conditions and minima under long-day (summer) conditions. GX and PX provoke an unimportant shift (a little longer than 2 months) in maxima and minima of the annual rhythm. Circannual curves exhibited differences in the degree of the increase of serum CK activity of GX and PX groups. These results indirectly confirm the assumption that experimental sympathetic denervation or removal of the pineal gland will induce a hypothyroid state over the long term.

Animals↗
PubMed1989

[Morphometric and histologic studies of the significance of the paraventricular nucleus for the thyroid gland axis after ganglionectomy and cold exposure with special consideration of the pineal gland].

To analyse the role of the peripheral sympathetic fibres for the nucleus paraventricularis, the nuclear size and the neurosecretory material were studied 30 d after bilateral cervical ganglionectomy (GX). In order to examine the influence of GX at normal temperature (24 degrees C) and exposure to cold (10 degrees C), rats were subjected to a 72 h exposure to cold before killing. Additionally thyroxine (T4), serum thyrotropin (TSH), and pituitary TSH were investigated. 4 times a day (light-dark cycle: 14L:10D, light on 05h00), the rats were sacrificed: middle light, middle darkness, 1 h after "light on" and 1 h after "light off". Ganglion removal resulted in a highly significant decrease of serum-T4 and increase of serum- and pituitary-TSH (primary hypothyroidism). Under these circumstances, the morphometric findings are showing a statistically significant magnification of the paraventricular nuclear volume and a loss of neurosecretory material. On the other hand, exposure to cold increased the T4- and TSH-levels and diminished the nuclear size of nucleus paraventricularis. The neurosecretory material was enhanced. Finally, GX diminished the effect of exposure to cold of the T4- and TSH-levels. The average nuclear size of the paraventricular nuclei was similar to the volume of the GX alone, so that the effect of exposure to cold was put out. These results indicate that there exists a negative correlation between T4 (but not TSH) and nucleus paraventricularis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Periodic local approximation for the model free description of measurement courses of biorhythmic processes--demonstration example for the selection of smoothness parameters].

Measured time series with known basic periodicity may be modelfreely evaluated by procedures of local adjusted approximation. Examples of motility time series recorded in chronobiological experiments in the seasonal course of a year demonstrate aspects of choosing values of the smoothing parameter and the resulting effects for the quantitative description of the measured variations as well as for their interpretation.

Animals↗
PubMed1989

Morphometric investigations of the pineal gland after ganglionectomy and thyroidectomy under the aspect of circadian and seasonal variations.

It is well established that the pineal gland is involved in the regulation of thyrotropin (TSH) secretion. Previous investigations in our laboratory showed that under hypothyroid conditions the nuclear size of pinealocytes was diminished while an increase in the size of nuclei was seen under hyperthyroid conditions. In the present study we confirmed these results while considering circadian and circannual oscillations. After ganglionectomy (GX, removal of the sympathetic superior cervical ganglia) the mean annual values of the nuclear size of pinealocytes, pineal weights and thyroxine (T4) levels were diminished, whereas the pituitary weights increased. Comparable, but more drastical reactions were found after thyroidectomy (TX). The diminution of the nuclear size of pinealocytes was more pronounced in the wintertime (December, L: D = 8: 16), the finding for the summertime (June, L: D = 16: 8) being similar. Under short-day conditions the nuclear size was larger than under long-day regimes. In the winter the enhancement of the nuclear size was accompanied by decreased pituitary weights and increased T4 levels while under long-day conditions lower size of pinealocytes and T4 levels were associated with higher weights of pituitary glands. The statistically significant circadian patterns of the nuclear size of pinealocytes showed that the largest nuclei occurred at the end of the light phase or at the onset of the dark phase. In June, the largest nuclei were found in the middle of dark (control) or in the early light phase (ganglionectomy). Considering the circadian patterns of pineal weights and T4 levels, these results underline the existence of a functional connection between the pineal gland and the thyroid axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Creatine kinase in hypo- and hyperthyroid rats under consideration of the circadian oscillations.

Thyroxine level (T4) and total creatine kinase-activity (CK) were measured in serum samples from male Wistar-rats to investigate the relationships of serum titers after exposure to cold and thyroidectomy (TX). 72 hours exposure to cold (10 degrees C) produced a statistically significant elevation of T4 and a diminuation of CK-activity. In contrast to this protocol, TX (90 days after operations) reduced the T4 level and enhanced the CK-activity. These reactions were likewise statistically significant. The presented results are in agreement with the previous proposal which consists in inverse correlation between the T4 level and the CK-activity at hypo- and hyperthyroid states. Additionally it was shown that the highest activity of the serum CK appears in the first half of the light phase of the day under normal ambient temperature (24 degrees C) as well as under exposure to cold (10 degrees C).

Animals↗
PubMed1988

Changes in the daily rhythm of serum testosterone levels following superior cervical sympathetic ganglionectomy in the cold-exposed rat: the role of the pineal.

The effect superior cervical sympathetic ganglionectomy (Gx) exerted on the daily rhythm of serum testosterone levels was investigated in cold-exposed rats. Rhythmic changes in pineal and pituitary weights were also measured. 1. Exposure to cold (10 degrees C for 72 h) resulted in a significant decrease of serum testosterone level and in an increase of the pineal weight. 2. In neutral ambient temperature (24 degrees C) Gx, 30 d after operation, led to a moderate, statistically insignificant increase of serum testosterone levels and to decreased pineal weights (statistically significant). 3. The reactions provoked by cold exposure were counteracted by Gx. Testosterone levels, as well as the pineal weight, showed no remarkable change in the Gx, cold-exposed animals. 4. These results confirm our assumption that experimental manipulations of the pineal gland can provoke significant changes in the neuroendocrine system only under special loading circumstances, e.g., cold exposure. Sympathetic denervation of the pineal gland counteracts the cold-induced decrease of testosterone levels by counteracting the pineal antigonadotropic activity. 5. The empirical regression curves of the investigated parameters indicate that Gx or cold exposure provide a shift in the upper and lower limits of the daily rhythm. Partly inverted rhythms were also observed. 6. The presented results are discussed in relation to the parallel changes previously described in serum thyroxin, cholesterol, thyrotropin (TSH), and pituitary TSH levels. Thyroidal-gonadal interactions, as well as cold exposure as a stress-generating factor, have been considered in the possible explanation of the data herein reported.

Animals↗
PubMed1988

Circannual oscillations of thyroxine and cholesterol levels after pinealectomy and ganglionectomy related to the weight changes of the pineal, pituitary, and thyroid glands.

Circannual rhythms of thyroxine (T4) and cholesterol blood levels, as well as of pineal, pituitary and thyroid weights were compared in intact, pinealectomized (Px), and ganglionectomized (Gx) rats. Special emphasis was put on the similarities and differences between the effect of Px and of Gx exerted on the neuroendocrine regulation of thyroid function. Animals were kept under changing lighting schedules simulating the natural seasonal conditions (December, L:D 8:16; June, L:D 16:8; March and September, L:D 12:12). Animals were killed 90 d after surgical interventions in the above-mentioned 4 months. In each season, animals were killed at four time points of the daily rhythm, and the means of the four data of a single day were used for further analysis evaluating circannual changes. All the investigated five parameters showed a monophasic circannual rhythm. The lowest T4 blood level was measured in summer; in contrast, cholesterol level and organ weights had a maximum in the same season of the year. The annual mean value of T4 level was diminished, while cholesterol level and pituitary and thyroid weights were increased in Px and Gx animals. Pineal weight showed a decrease in the Gx animals. Both Px and Gx failed to influence the circannual rhythms of the measured parameters. However, a significant T4-decreasing effect of Px and Gx was observed in the second half of the year, whereas a cholesterol-level-increasing effect, as well as thyroid hypertrophy, was registered in the first half of the year. These results suggest a prothyroid function of the pineal gland.

Animals↗
PubMed1988

[Morphometric studies on the lateral habenular nucleus of Wistar rats after bilateral excision of the superior cervical ganglia and cold exposure with special reference to the pineal gland].

To analyse the role of peripheral sympathetic fibres in the regulation of thyroxine (T4), serum thyrotropin (TSH), pituitary TSH, and nuclear size of the lateral habenular nuclei rats were studied 30 d after bilateral cervical ganglionectomy (GX). In order to examine the influence of GX at normal temperature (24 degrees C) and exposure to cold (10 degrees C), rats were subjected to a 72 h exposure to cold before killing. 4 times a day (light-dark cycle: 14L: 10D, light on 05h00) the rats were sacrificed: middle light, middle darkness, 1 h after "light on" and 1 h after "light off". Ganglion removal resulted in a highly significant decrease of serum-T4 and increase of serum- and pituitary-TSH (primary hypothyroidism). Under these circumstances, the karyometric findings are showing a statistically significant magnification of the lateral habenular nuclear volume. In contrast to GX, exposure to cold increased T4- and TSH-levels and reduced the lateral habenular nuclear size. GX diminished the effect of exposure to cold of the T4- and TSH-levels and normalized the habenular nuclear volume. These results indicate that there exists a negative correlation between T4 (but not TSH) and lateral habenular nuclear size. Under consideration of previous investigations of the pineal nuclear size in hypo- and hyperthyroid state, our results are in agreement with the hypothesis of other authors that it is probably an inhibitory feed-back loop between the lateral habenula and the pineal gland (see also the high gamma-aminobutyric acid [GABA] content in the habenular complex). On the other hand, it was possible to confirm that the habenular complex is integrated into the thyroid circuit.

Animals↗
PubMed1986

[Thyroid reactions in Wistar rats during the circadian rhythm after ganglionectomy at normal temperature and under cold exposure with regard to the influence of the epiphysis cerebri].

Serum thyroxin (T4), serum TSH, and pituitary TSH were measured by radioimmunoassay (RIA) and serum cholesterol by Liebermann-Burchard reaction in rats 4 times a day (light-dark cycle: 14 L: 10 D) after gangliectomy (bilateral extirpation of the Ganglia cervicalia superiora) at cold and normal temperature conditions. 80 male Wistar rats were divided into 4 groups: sham-operated group, 24 degrees C (297 K); sham-operated group, 10 degrees C (283 K); gangliectomy, 24 degrees C (297 K), and gangliectomy, 10 degrees C (283 K). We have sacrificed the rats 30 d after operations at the following day-times: middle light, middle darkness, 1 h after light "on" and 1 h after light "off" (they were exposed to cold 72 h before killing). It was found that gangliectomy significantly depressed blood level of thyroxin. On the other hand, it enhanced the serum cholesterol and TSH levels as well as the pituitary TSH content. Exposure to cold increased thyroxin, serum TSH and pituitary TSH. The cholesterol level, however, was significantly decreased. Gangliectomy causes a reduction of the cold-induced stimulation of thyroxin (significant), serum TSH, and pituitary TSH content (significant). The cholesterol (in relation to the cold-exposure alone) was significantly increased under these conditions. We have found similar results in another long-time experiment (90 d exposure) after gangliectomy as well as after pinealectomy. There also appears a lowered thyroxin and an increased cholesterol level (in dependency on the seasons). Gangliectomy induced a decrease of the pineal weight and a compensatory thyroid growth. Exposure to cold induced an increase of pituitary and pineal weights. Gangliectomy provokes a reduction of the cold-induced augmentation of the pineal weight. The results indicate that gangliectomy diminishes the total levels of circulating T4 in the presence of an intact pineal gland and reduces the cold-induced increase of T4 in long-time experiments (30 and 90 d post operationem). Both gangliectomy and cold condition led to an enhancement of serum TSH and pituitary TSH content. The exposure to cold was found to have a more severe influence. In the present study, we also have discussed the sympathetic denervation effect of the gangliectomy in relation to the thyroid and pineal gland. Due to certain contradictory data in the literature, we have also discussed the TRH-5-hydroxytryptamine (respectively melatonin) antagonism, though we were not able to determine whether peripheral and/or central mechanisms play the more important role in their regulation.

Animals↗
PubMed1986

[Effect of ganglionectomy (superior cervical ganglia) at normal temperature and exposure to cold on the circadian rhythm of liver glycogen and blood glucose levels of the Wistar rat with regard to the pineal gland].

Liver glycogen content and blood glucose level of 80 male Wistar rats were measured 4 times a day, 30 d after following surgeries: sham-operation without exposure to cold, sham-operation with exposure to cold (283 K, 72 h before killing), extirpation of the ganglia cervicalia superiora (GX) without exposure to cold, extirpation of the ganglia cervicalia superiora with exposure to cold (283 K, 72 h before killing). Exposure to cold alone as well as GX with and without exposure to cold modify the unimodal daily patterns (curves were calculated by means of empirical regression) of liver glycogen content and blood glucose level: there are changes from contrary localization of the maxima (and minima) of both, liver glycogen content and blood glucose level (exposure to cold alone) to nearly equal localization (GX alone). Compared to control group, all surgeries reduce the liver glycogen content statistical-significantly and also enhance the blood glucose level. Combination of GX with exposure to cold shows the strongest effect. In this case, the influence of GX is visible, but the effect is not significantly different from this of exposure to cold alone, which causes a high activation of the metabolism. To the contrary, a statistically significant influence is to be seen after GX alone, but the effect is lower than this one of exposure to cold. Extirpation of the ganglia cervicalia superiora and the resulting sympathetic denervation of the pineal gland is answered by comparable reactions of the investigated parameters as the extirpation of the pineal gland itself (90 d post operationem). Diminuation of liver glycogen content and enhancement of blood glucose level characterize the influence of gangliectomy (30 d post operationem) in this way, that the ratio of effect of factors causing hypo- and hyperglycemia is changed in favour of the latter.

Animals↗