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Biomedical subjects

A Szadowska

Publications and source records attributed to A Szadowska.

126 records · Page 7Linked to original sources
PubMedDate not supplied

The effect of 6-hydroxydopamine and some hypotensive drugs on lypressin induced hypertension in rats.

Intracerebroventricular injection of 6-hydroxydopamine (6-OH-DA) prevented the development of the lypressin (LVP)-induced hypertension. Administration of 6-OH-DA to hypertensive rats significantly decreased, but did not normalize, blood pressure. A fourteen-day treatment with clonidine, guanethidine, reserpine, dihydralazine, propranolol and furosemide produced a transient decrease in blood pressure in LVP-hypertensive rats. Eight weeks after the withdrawal of hypotensive drugs blood pressure again reached the value corresponding to that in untreated LVP-hypertensive rats.

Animals↗
PubMedDate not supplied

Synthesis and effect of asymmetric 1,4-bis(aminoacyl) piperazines on neuromuscular transmission.

The condensation of asymmetrically substituted 1,4-bis(haloacyl) piperazines with secondary amines yielded asymmetric 1,4-bis (aminoacyl) piperazines 3-6, which were further transformed into the respective dimethiodides 3b-6b by treatment with methyl iodide. Those compounds were found to inhibit the neuromuscular transmission by blocking the motor end-plate receptors. Compounds containing piperidine moiety and branched acyl chain 4b displayed enhanced activity.

Acetylcholine↗
PubMedDate not supplied

Effects of some hypotensive drugs on the clearance of I125 hippurate in rats after acute and subacute ethanol intoxication.

The influence of dihydralazine, propranolol, clonidine, furosemide and reserpine on the clearance of I125 hippurate in rats in alcohol intoxication was investigated. It was found that both in acute and subacute ethanol intoxication the renal blood flow was impeded. Reserpine and propranolol did not significantly change the half time of I125 hippurate in blood both in animals treated and not treated with alcohol. Furosemide prolonged the clearance of hippurate and increased kidney ischemia in alcohol intoxication. Dihydralazine and clonidine increased the effective renal blood flow in normal animals but not in acute and subacute ethanol intoxication.

Alcoholic Intoxication↗
PubMedDate not supplied

Effect of intraperitoneally injected lysine vasopressin on noradrenaline turnover in certain brain regions of the rat.

In the first part of the study penetration of blood-brain barrier by lysine vasopressin (LVP) was studied. After i.p. injection 125J-LVP or its large fragments appeared in the hypothalamus, hippocampus, tuberculum olfactorium and brain stem. In these structures the effect of i.p. injected LVP on noradrenaline level and turnover rate was studied. LVP produced an increase of noradrenaline level in the hypothalamus, hippocampus and tuberculum olfactorium. In the brain stem no marked changes in noradrenaline content were found. In all the examined brain structures LVP slowed down turnover rate of noradrenaline.

Animals↗
PubMedDate not supplied

Effects of clonidine, guanethidine and furosemide on the development of vasopressin hypertension in rat.

The influence of clonidine, guanethidine and furosemide on the development of arterial hypertension was studied in rats with hypertension induced by repeated administration of lysine vasopressin. It was found that these drugs administered during long time periods together with lysine vasopressin prevented the development of arterial hypertension. When any of these drugs was given in combination with vasopressin plasma renin activity failed to rise and the level and turnover of catecholamines in rat brain were unchanged.

Animals↗
PubMedDate not supplied

The responsiveness of M2-muscarinic receptors in the posterior hypothalamus and brain stem of vasopressin hypertensive rats.

The response of an endogenous inhibitor of cAMP-dependent protein kinase (type I inhibitor) to tremorine was used as an index of sensitivity of control muscarinic M2-receptors. Tremorine induced a dose-dependent increase in type I inhibitor activity in the posterior hypothalamus and brain stem. The action of the compound was blocked by pretreatment with aminophylline and atropine. Prolonged, 28 days treatment with lysine vasopressin (1 U/kg/day ip) induced hypertension and modified the dose-response curve for tremorine. Five times higher doses of tremorine than in normotensive rats were necessary to induce statistically significant increase in type I inhibitor activity in the posterior hypothalamus and brain stem suggesting subsensitivity of M2-muscarinic receptors in the brain areas responsible for the regulation of blood pressure.

Aminophylline↗
PubMedDate not supplied

Synthesis, structures and biological activity of some N1-substituted 4-oxocinnolines.

The method of preparation of N1-substituted 4-hydroxycinnolines is described, by alkylation with methyl bromopropionate of the corresponding 4-hydroxycinnolines. The obtained esters were further converted into amides and hydrazides. The effect of several synthesized derivatives on central nervous system was studied. The structure of some of them was confirmed by the X-ray analysis.

Animals↗
PubMedDate not supplied

Turnover of catecholamines in some regions of the rat brain during prolonged vasopressin administration and after its withdrawal.

Turnover of noradrenaline (NA) and dopamine (DA) in some regions of the rat brain was determined after 1 and 3 weeks of daily injections of lysine vasopressin (LVP) and 2 weeks after the termination of 28-day LVP injections. Disappearance of 3H-DA was estimated in the hemispheres, brain stem and striatum and of 3H-NA in the hemispheres and brain stem after intraventricular injection of 3H-tyrosine. A significant acceleration of 3H-NA disappearance from the hemispheres was found in all the experimental animals and from the brain stem 3 weeks after LVP adminstration and 2 weeks after its withdrawal. No marked changes in dopamine turnover in the examined regions of the rat brain were found. Since prolonged vasopressin administration produces hypertension in the rat it seems likely that central NA, but not DA, plays a role in the vasopressin-induced hypertension.

Animals↗