REACTIVITY TO VEGETATIVE DRUGS IN THE ACUTE RADIATION SICKNESS

Journal Article · Tue Jan 01 00:00:00 EST 1963 · Sb. Ved. Praci Lekar. Fak. Karlovy Univ. Hradci Kralove

OSTI ID:4105643

Danysz, A; Proniewski, H; Wisniewski, K; Zaczek, T; Polocki, B

< ; < > 8 ; 9 8 8 ; < ; 8 : to dogs (400 r), cats (400 r), gninea pigs (450 r), and mice (180-200 r). The course of radiation illness was estimated on the basis of leukocyte count. During radiation sickness the changes in pharmacologic action and toxicity of various drugs affecting the autonomic nervous system were investigated. By tests on the reactivity of mouse intestine in situ it was shown that at the peak of acute radiation sickness the toxicity of parasympathicotonics (pilocarpine, prostigmine), especially of acetylcholine, sympathicolytics (Priscol), and ganglioplegics (nicotine) decreased. The toxicity of parasympathicolytic drugs (atropine) was higher. No changes of toxicity of sympathicotonics (adrenaline, iproniazid) were found, except for ephedrine, whose toxicity after irradiation significantly increased. Mouse intestinal motility tests showed a reduction 3--6 days postirradiation in the pharmacologic effects of parasympathicotonics (acetylcholine, prostigmine), especially of pilocarpine and ganglioplegics (nicotine, hexamethonium). At the same time the effects of sympathicotonic drugs (adrenaline, Sympatol) increased; on the contrary the monamine oxidase (MAO) inhibitor (iproniazid) showed a marked decrease in effect. With sympathicotonic drugs, pressor effects, changes of ECG, vasoconstrictive and mydriatic effects, and the contractive action on the nictitating membrane of cat were investigated. The pressor effects of adrenaline in dogs rose in the course of radiation sickness. No changes of pressor effects of noradrenaline and ephedrine were found, but the time of post-ephedrine hypertension was prolonged. In the acute stage of the illness, catecholamines evoked more significant changes in the ECG in dogs. During radiation sickness in cats, phasic changes in reactivity of the blood vessels in an isolated limb to catecholamines were observed: in the first phase, diminution; however, at the peak of the disease an increase in vasoconstrictory effects was seen. The action of iproniazid was insignificantly diminished. The mydriatic effect of catecholamines increased at the peak of radiation sickness. The reactivity of the nictitating membrane of cat did not change after smaller doses of adrenaline. In tests of parasympathicotonic drugs, the sensitivity of isolated guinea pig organs (intestine, uterus) to acetylcholine, pilocarpine, and prostigmine at the peak of radiation sickness was markedly diminished, but the sensitivity of intestinal smooth muscle to histamine remained unchanged. With parasympathicolnic drugs, an increase of mydriatic effect of atropine in irradiated mice was observed. Thus in most cases there were increased pharmacologic effects of directacting adrenergic drugs and decreased effects, but increased toxicity, of MAO inhibitors. The diminished pharmacologic effects and toxicity of parasympathicolytic drugs was also shown. The effects and toxicity of ganglioplegic drugs and toxicity of sympathicolytic drugs showed a marked decrease. The results indicrte increased susceptibility of adrenergic receptors and diminished susceptibility of cholinergic receptors on the peak of radiation sickness. It is suggested that these changes may arise from the characteristic disturbances in functional state of the vegetative nervous system, and particularly on the neurohormonal basis. To verify this, catecholamine level in the adrenals and cholinesterase activity was determined. Crtecholamine levels in the adrenals of irradiated mice varied phasically. In the first phase of radiation sickness (1--7 days) this level diminished to approximates 50% of the initial value. In the second phase it showed an increase of nearly 10 times. During radiation sickness a marked fall of acetylcholinesterase activity in the uterus, intestine, and brain of the gninea pigs was found. This supports the postulated parasympathicotonia at the peak of radiation sickness. The influence of increased acetylcholine level after prostigmine on the antiperistaltic action of adrenaline and on the toxicity

• Research Organization: Medical Academy, Bialystok, Poland
• NSA Number: NSA-18-011882
• OSTI ID: 4105643
• Journal Information: Sb. Ved. Praci Lekar. Fak. Karlovy Univ. Hradci Kralove, Vol. Vol: 6; Other Information: Orig. Receipt Date: 31-DEC-64
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
ACETYLCHOLINE
ADRENAL GLANDS
ADRENALINE
ALKALOIDS
AMINES
ANIMALS
ATROPINE
BLOOD CIRCULATION
BLOOD VESSELS
BRAIN
CATS
CHOLINESTERASE
DOGS
DRUGS
ENZYMES
EPHEDRINE
ESERINE
EYES
GUINEA PIGS
HISTAMINE
HORMONES
INTESTINE
LEUCOCYTES
MICE
NERVOUS SYSTEM
NICOTINE
ORGANIC BROMINE COMPOUNDS
PHYSIOLOGY
PILOCARPINE
QUANTITY RATIO
RADIATION DOSES
RADIATION SICKNESS
TISSUES
TOXICITY
X RADIATION