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W Z Traczyk

Publications and source records attributed to W Z Traczyk.

64 records · Page 4Linked to original sources
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Shifting of the brain stem physiological impedance after ovariectomy and oestradiol implantation in rabbits.

Experiments were carried out on female rabbits with electrodes implanted chronically into the midbrain, dorsal hippocampus and the cerebral cortex. Physiological impedance of the brain stem, i.e. the lowest energy of trains of electric impulses stimulating the midbrain modulated through a feedback by the hippocampal theta rhythm and maintaining EEG arousal pattern, served as a measure of excitability of the brain stem reticular formation. After ovariectomy performed in 12 female rabbits, a rise in the brain stem physiological impedance was observed in relation to control measurements -- by 84.8%, on the average. In 8 ovariectomized female rabbits the physiological impedance decreased by 47.4% after subcutaneous implantation of oestradiol benzoate tablets. After removal of the implanted tablets the impedance increased by a mean value of 100.1% in all the female rabbits.

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Substance P isolated from bovine hypothalamus: amino acid composition.

Using the method of Chang and Leeman for isolation the sialogogic undecapeptide from bovine hypothalamus partly purified Substance P was obtained. The final steps of purification were omitted to prevent losing of other peptides possessing biological activity of Substance P. The qualitative and quantitative content of amino acids in the hypothalamic extract was determined and fourteen amino acids were found. Four of them were not present in the sialogogic undecapeptide or neurotensin. It can be concluded that in the hypothalamic tissue apart from sialogogic undecapeptide and neurotensin, there are other peptides related to these two.

Amino Acids↗
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The effect of intraventricular 6-hydroxydopamine on the content of oxytocin and vasopressin in the hypothalamus and pituitary gland of water-deprived rats.

The effect of intraventricular 6-hydroxydopamine on the content of oxytocin and vasopressin in the hypothalamus and pituitary gland of water deprived rats. Acta Physiol. Pol., 1977, 28 (6): 497-504. Rats received one infusion of 200 microgram 6-hydroxydopamine with 25 microgram of ascorbic acid into the lateral cerebral ventricle. After 57 days some rats were deprived of water for 4, 8 or 12 days. Then, the animals were sacrificed by decapitation. Oxytocin was determined in extracts from the posterior pituitary lobe and hypothalamus by the method of Van Dongen and Hays, while the vasopressin content was determined by the method of Dekanski. It was found that 6-hydroxydopamine injection into the cerebral ventricles causes a rise in oxytocin content in the hypothalamus and prevents its fall during--4--12 days of dehydration.

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Effect of intracerebroventricular administration of substance P and its hexapeptide fragment on the estrus cycle in female rats.

The purpose of the reported experiments was the study of the effects of intracerebroventricular (i.c.v.) administration of substance P (SP 1--11) and its hexapeptide C-terminal fragments SP 6--11 and (pGlu6)SP6--11 on the length of the estrus cycle. In the animals with a regular sequence of estrus aliquots of 250 pmol of the three peptides: SP 1--11, SP 6--11 and (pGlu6)SP 6--11 on the carier dextrane were infused into the left lateral cerebral ventricle through a chronically implanted cannula. For control, dextran solution in 0.9% NaCl was infused in a similar way. I.c.v. infusion of dextran in 0.9% NaCl, SP 1--11 and (pGlu6)SP 6--11 caused no significant changes in the length of the estrus cycle during which the infusion was done. Infusion of SP 6--11 prolonged the diestrus phase in most animals. This observation indicates that SP 6--11 exerted an effect on the hypothalamic mechanism controlling the secretion of gonadotropins by the hypophysis.

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The influence of amino acids, vasopressin and oxytocin on spontaneous contraction of the right auricle of the right atrium of two-day-old rats in vitro.

Studies were carried out on the right auricle of the right atrium of two-day-old rats placed in a special chamber perfused with Ringer-Locke solution at room temperature. The contractions rate of the auricle was counted with the use of a stereomicroscope. The following amino acids dissolved in Ringer-Locke solution were tested: glycine, glutamic acid, serine, alanine, aspartic acid, gamma aminobutyric acid, leucine, and peptides: vasopressin and oxytocin. Glutamic acid in a concentration of 10(-1) mol/l induced a decrease in auricle contraction rate by 25%. Alanine in concentration 10(-2) mol/l induced a decrease by 22%. Leucine in concentration 10(-2) mol/l induced a decrease by 16% and in concentration ten times higher a decrease by 28%. The other tested amino acids, vasopressin and oxytocin in concentration used had no influence on the rate of contraction frequency of the isolated auricle.

Amino Acids↗
PubMedDate not supplied

Appearance of a cardiodepressant factor in the medium incubating in situ the posterior pituitary lobe of the rat. I. Isolation of active compound.

The experiments were carried out with 2 groups of male rats under urethane-chloralose anaesthesia. In the 1st group the anterior pituitary lobe was removed and the posterior one was incubated in situ in McIlwain's solution. The incubating fluid was collected with methanol, centrifuged, and the supernatant was lyophilized. The lyophilized fluid incubating the posterior pituitary lobe in situ was filtered on a Sephadex G-15 column and fractions with cardiodepressant activity were passed through a SP Sephadex C-25 column. The cardiodepressant activity was tested on an isolated auricle of the right atrium of a two-day-old rat. The cardiodepressant activity of the fractions was evaluated. The fluid incubating the posterior pituitary lobe was found to contain a factor reducing the contraction rate of the isolated auricle. In the control group the sphenoid bone was exposed and bathed in McIlwain's solution, in the same approach as the posterior pituitary lobe. The fluid bathing the sphenoid bone in situ was filtered on a Sephadex G-15 column. No cardiodepressant activity was found in the fractions.

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Effect of increased concentrations of ca++ and mg++ in the fluid perfusing the cerebral ventricles, and hypoxia on evoked tongue jerks.

Effect of increased concentrations of Ca++ and Mg++ in the fluid perfusing the cerebral ventricles, and hypoxia on evoked tongue jerks. Acta Physiol. Pol., 1978, 29 (1): 27-36. The infraorbital nerve, the sensory part of the trigeminal nerve, was stimulated in rats under chloralose anaesthesia. Electric stimuli of 0.2 Hz caused retractive movements of the stretched tongue. These evoked tongue jerks (ETJ) were recorded directly on a kymograph or on a linear recorder. Using a stereotaxic apparatus cannulas were inserted into both lateral ventricles of the brain for infusion of McIlwain-Rodnight's fluid at a rate of about 50 microliter/minute. The cannula for outflow of the perfusing fluid was inserted into the cerebellomedullary cistern. The ETJ was enhanced by 43%, on the average, during perfusion of the cerebral ventricles with solutions with fivefold increased concentration of calcium ions, and decreased by a mean value 24% when the perfusing solution contained a higher concentration of magnesium ions. After 10 min of breathing with increased respiratory dead space, which caused hypoxia and hypercapnia, the amplitude of ETJ diminished by 65%, on the average.

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PubMedDate not supplied

Cardiodepressor and vasodepressor activities of partially purified bovine hypothalamic extract.

About 2000 bovine hypothalami were homogenized, extracted, purified and three times filtrated on Sephadex G - 25 column. During the first and second filtration the fractions with vasodepressor activity were collected for further purification. During the third filtration about 40 fractions possessing vasodepressor activity were found. The fractions emerging before vasopressin decreased the arterial blood pressure and induced transient bradycardia in rats. The results indicate that some fractions of hypothalamic extract produce vasodepressor response by vasodilatation only and the other ones by simultaneous vasodilatation and heart rate decrease.

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