STUDIES ON SYMPATHOMIMETIC ACTION OF ACETALDEHYDE

STUDIES ON SYMPATHOMIMETIC

ACTION OF ACETALDEHYDE

I. EXPERIMENTS WITH BLOOD PRESSURE AND NICTITATING

MEMBRANE

RESPONSES

JIRO AKABANE, SUEHIRO NAKANISHI, HIROSHI KOHEI, RIICHIRO MATSUMURA AND HIROSHI OGATA* Department of Pharmacology, Facultyof Medicine, ShinshuUniversity, Matsumoto Receivedfor publicationMarch 4, 1964

Since Handovsky (1) observed that intravenous administration of small amounts of acetaldehyde in anesthetized dogs produced a sharp rise in blood pressure and cardiac acceleration,

many investigations

aldehyde.

Nelson

(2) showed

have been done on the cardiovascular that acetaldehyde,

given

effects of acet

intravenously

, had a pressor activity resembling epinephrine, and that this pressor response was markedly potentiated by cocaine and it was not due to the liberation of epinephrine from the adrenal glands . Christensen

(3) reported

duplicated

that

by acetaldehyde

to acetaldehyde

was reversed

bital anesthesia.

the action

was not wholly due to the release that

and by Priscoline.

the actions of aldehydes were qualitatively Recently

of epinephrine

the pressor

from the adrenals

that

et al. (6) carried

appeared

that the releasing

of tyramine.

However,

aldehyde 赤羽

study on

of acetaldehyde

However,

by pretreatment

頴 央 ・公 平

the adrenal appeared

system by the

medulla. to differ

describe the mechanism

in normal

宏 ・松 村

animals

the findings

with dibenamine 理 一 郎 ・小片

acetalde

the sympathomimetic Further, from that

or mode of action

et al. (8) and Eade (7) suggested that the nature

by the aldehydes

than epinephrine. is reversed

with reserpine

animals

action of the aldehydes

he did not definitely

Romano

released

治郎 ・中西

vessels were ligated. in dogs was blocked

upon cardiovascular

from tissue stores other than

he has found

epinephrine

and was reversed

responses

that in spinal cats treated

to exert a part of their action

release of catecholamines

cholamine

in dogs

quite similar to epinephrine.

Eade (7) has reported

of acetaldehyde.

pentobar

out a long-range

the blood pressure

hyde caused a fall in blood pressure, and in the normal aldehydes

adrenal

was

response

response to acetaldehyde

response to acetaldehyde

Wingard

and found

the blood pressure and the pressor

drug, C-7337, in dogs under

that the pressor

blocking drug SY-28, when the bilateral

Seibert et al. (5) found by dibenamine

upon

"100 times larger"

by an adrenolytic

Feingold (4) reported

by an adrenergic

of epinephrine

in an amount

was more

of the cate

like that

of nor

that the pressor response to acet in normal

寛

* Department of Psychiatry, Faculty of Medicine, Shinshu University, Matsumoto

spinal cats, and the

depressor response to this drug is observed in chronically reserpinized spinal cats are not fully explained only by the action of acetaldehyde releasing norepinephrine. We have performed pharmacological studies on acetaldehyde for several years. Some years ago, Yokokawa (9) in this department investigated the cardiovascular actions of acetaldehyde. The effect of acetaldehyde on cardiovascular system may explain some pharmacological actions of alcohol, especially acute after-effects of alcoholic beverages (10). The present investigation was carried out in order to correlate the pressor response and the nictitating membrane response of the spinal cat to acetaldehyde and to elucidate the mechanism of action of acetaldehyde on the cardiovascular system. In this study the pressor and the nictitating membrane responses to acetaldehyde were compared with those caused by tyramine, epinephrine and norepinephrine. METHODS Spinal cats were used in all experiments. Spinal cats with bilateral cervical vago tomy were prepared by the procedure of Kumagai et al. (11). Blood pressure was recorded with a mercury manometer connected to a femoral artery and the response of the nictitating membrane were recorded with an isotonic lever. A polyethylene cannula was inserted into a small vein of a foreleg and all drugs were injected through the cannula. Usually an interval of 10 minutes was placed between doses. Infusions were given into the left femoral vein. Furthermore, acetaldehyde was injected into the ex ternal carotid artery ipsilaterally to the nictitating membrane for recording. Adrenal ectomy was performed by ligation of all connections between the glands and their surroundings, followed by an incision into the tied glands. In the second series of experiments the action of acetaldehyde on the adrenal medulla was studied by intraarterial injection of drug into the superior mesenteric artery (12) or by injection of drug into the aorta abdominalis in eviscerated animals. In the third series of experiments the chronically reserpinized cats were employed. Cats were given 2 to 5 mg/kg of reserpine intraperitoneally on two successive days, and the experiments were made on the third day. The drugs used were l-epinephrine hydrochloride, dl-norepinephrine hydrochloride, tyramine hydrochloride, cocaine hydro chloride, hexamethonium bromide, atropine sulfate and diphenhydramine hydrochloride. RESULTS I. Experimentsin the spinal cats without chronicreserpinetreatment 1) Intravenous injections of 0.5 to 20 mg/kg of acetaldehyde caused a pressor response resembling those due to epinephrine or norepinephrine, and the pressor response to acetaldehyde was dose-dependent (Fig. 1). Intravenous injections of 10 to 20 mg/kg of the drug induced the nictitating membrane contraction. Both the pressor and the nictitating membrane responses to acetaldehyde were not blocked by intravenous injec

FIG.

1.

Pressor

response

Spinal

cat,

to acetaldehyde.

2.8 kg.

FIG. 2. Effect of hexamethonium on a pressor response to acetaldehyde. Spinal cat, 3 kg. Between (a) and (b) 20 mg/kg of hexamethonium was given and then the previous in jections were repeated. TYR : tyramine, ACE : acet aldehyde, EPI : epinephrine, NOR : norepinephrine.

FIG.

3.

Effect Spinal

acetaldehyde,

of

adrenalectomy

cat,

3.5 kg, NOR

on bilateral

: norepinephrine.

the

pressor

vagotomy.

response TYR

to acetaldehyde. : tyramine,

ACE:

tion of hexamethonium chloride

(20 mg/kg), atropine

(2 mg/kg)

and diphenhydramine

hydro

(Fig. 2).

Adrenalectomy reduced the pressor response and the nictitating membrane response to intravenous injection of acetaldehyde (Fig. 3). But intraarterial injection of 0.1 mg/kg

FIG. 4. Effect of dibenamine treatment on the pressor response to intravenous acetaldehyde. Spinal cat, 3 kg. Between (a) and (b) 20 mg/kg of dibena mine was given and then the previous injections were repeat ed. EPI : epinephrine, NOR : norepinephrine, ACE : acetalde hyde.

FIG. 5. Effect of adrenalectomy on the blood pressure response to intravenous acetaldehyde after pretreatment with dibenamine. Spinal cat, 3.3 kg, bilateral adrenalectomy. Between (a) and (b) 20 mg/kg of dibenamine was given and then the previous injections were repeated. EPI : epinephrine, NOR : norepinephrine, ACE : acetaldehyde.

of acetaldehyde into the external carotid artery ("nictitating membrane injection") in duced a pronounced contraction of the nictitating membrane, even after section of the postganglionic fiber of the superior cervical nerve. Intraarterial injection of 5 to 10 mg/kg of acetaldehyde into the lingual artery ("ganglion injection") produced no con traction of the nictitating -membrane. The pressor response to acetaldehyde was reversed by pretreatment with dibenamine in doses of 20 mg/kg (Fig. 4). The depressor response to acetaldehyde after dibenamine was not blocked by intravenous injection of atropine. Bilateral adrenalectomy abolished the depressor response to acetaldehyde after intravenous dibenamine (Fig. 5). When 1 to 3 mg/kg of acetaldehyde was injected intraarterially close to the adrenal gland the pronounced pressor response and the marked nictitating membrane response were induced and these responses were not blocked by both intravenous injection of hexamethonium and atropine (Fig. 6). The pressor and the nictitating membrane responses were abolished by ligature of the bila teral adrenolumbar veins or by bilateral adrenalectomy. Both the pressor and the nictitating membrane responses to acetaldehyde were significantly potentiated by cocaine in doses of 10 to 20 mg. On the con trary, the pressor response to tyramine was considerably depressed by cocaine (Fig. 7). The pressor responses to both tyra mine and acetaldehyde were slightly potentiated by pretreatment with brety lium in doses of 5 to 10 mg/kg. The

FIG. 6. Effect of hexamethonium and atropine on the blood pressure response to intra-arterial injection of acetaldehyde into the superior mesenteric artery. Spinal cat, 3 kg. Between (a) and (b) 20 mg/kg of hexamethonium, and (b) and (c) 1 mg/kg of atropine were given and then the previous injections were repeated. ACh : acetylcholine, ACE : acetaldehyde.

pressor response to epinephrine was almost unchanged, whereas that to nor epinephrine was markedly potentiated by bretylium (Fig. 8). 2) Responseto acetaldehydeduring nor epinephrineor epinephrineinfusion: After the pressor response to acetaldehyde in each cat was observed, epinephrine, nor

Fir. 7. Effect of cocaine on a pressor response to intravenous acetaldehyde . Spinal cat, 3 kg. Between (a) and (b) 20 mg of cocaine was given and then the previous injections were repeated. TYR : tyramine, ACE: acetaldehyde, EPI : epinephrine, NOR : norepinephrine .

FiG. 8. Effect Spinal venously tyramine,

of bretylium on a pressor response to intravenous acetaldehyde. cat, 2.8 kg. Between (a) and (b) 10 mg/kg of bretylium was intra given and then the previous injections were repeated. TYR : ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

epinephrine

or acetaldehyde

to tyramine

was slightly potentiated,

was infused at a rate of 10 ,ug/kg/min. whereas that to acetaldehyde

The pressor response was slightly depressed

(Fig. 9). After termination of norepinephrine infusion the pressor response to acetalde hyde remained depressed. During infusion of epinephrine at a rate of 5,ag/kg/min similar results were obtained

(Fig. 10).

the pressor response to tyramine

During acetaldehyde

infusion at a rate of 3 mg/kg/min

was slightly depressed, but that to acetaldehyde

remained

FIG. 9. Effect of infusing norepinephrine on the blood pressure responses to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 2.8 kg. Between (a`) and (b) norepinephrine was infused at a rate of 10 dug/kg/min. During the infusion the previous injec tions were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

FIG. 10. Effect of infusing epinephrine on the blood pressure response to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 3.5 kg. Between (a) and (b) epinephrine was infused at a rate of 5 ag/kg/min. During the infusion the previous injec tions were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

unchanged.

The pressor

responses

to epinephrine

(Fig. 11). 3) Acute reserpine treatment : After

confirming

to acetaldehyde,

was injected

3 mg/kg of reserpine

and

norepinephrine

the appearance intravenously.

were depressed

of pressor A significant

response poten

FIG. 11. Effect of infusing acetaldehyde on the blood pressure response to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 3 kg. Between "'a) and (b) acetaldehyde was infused at a rate of 1 mg/kg/min. During the infusion the previous injections were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epine phrine, NOR : norepinephrine.

FIG. 12. Effect of reserpine on the pressor response to acetaldehyde. Spinal cat, 3 kg. Between (a) and (b) 3 mg/kg of reserpine was intravenously given and 30 minutes later the previous in jections were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

tiation of the effect of tyramine was observed about 30 minutes after reserpine injection. The response to the dose of 5 mg/kg of acetaldehyde was considerably depressed and that to norepinephrine was also depressed, whereas the response to epinephrine remained unchanged (Fig. 12).

I.I. Experiments in the spinal cats with chronic reserpine treatment Cats were

treated

chronically

and spinal transection Reserpine epinephrine

with reserpine

was done immediately

depressed

the pressor

and epinephrine.

to deplete

action

of tyramine

In chronically

reserpinized

of 5 to 20 mg/kg showed no action on the nictitating sor response carotid

in the blood pressure

artery

did not induce

(Fig. 13).

the nictitating

the tissue catecholamines , the blood pressure . and increased those of nor

before recording

animals

membrane

Acetaldehyde

membrane

acetaldehyde and produced

given

in doses a depres

into the external

response.

FIG. 13. Effect of infusing norepinephrine on the blood pressure responses to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 2.9 kg, chronically reserpinized. Between (a) and (b) norepine phrine was infused at a rate of 10 ,ug/kg/min. During the infusion the previous injections were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epine phrine,

During

NOR : norepinephrine.

norepinephrine

norepinephrine

and

infusion at a rate of 10 teg/kg/min,

epinephrine

were considerably

depressed,

the pressor whereas

responses

to

the depressed

pressor response to tyramine was restored. The depressor response to acetaldehyde tended to increase by norepinephrine infusion (Figs. 13 and 14). When the infusion of norepinephrine to tyramine

was stopped was smaller

FIG. 14. Effect response Spinal aldehyde,

the blood pressure immediately

than that during

of infusing

norepinephrine

norepinephrine

on the

fell and the pressor response infusion . On the contrary,

blood

pressure

to acetaldehyde. cat, 3 kg, chronically NOR : norepinephrine.

reserpinized.

ACE : acet

FIG. 15. Effect of infusing epinephrine on the blood pressure responses to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 3 kg, chronically reserpinized. Between (a) and b` epinephrine was infused at a rate of 5 mg/kg/min. During the infusion the previous injections were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

FIG. 16. Effect of infusing acetaldehyde on the blood pressure responses to doses of tyramine, acetaldehyde, epinephrine and norepinephrine. Spinal cat, 3.3 kg, chronically reserpinized. Between ,a) and b) acetaldehyde was infused at a rate of 3 mg/kg/min. During the in fusion the previous injections were repeated. TYR : tyramine, ACE : acetaldehyde, EPI : epinephrine, NOR : norepinephrine.

the depressor response to doses of acetaldehyde during norepinephrine infusion was abolished after the termination of infusion (Fig. 14). Intraarterial injection of 0.1 mg/kg of acetaldehyde into the external carotid artery induced a marked nictitating membrane response. When norepinephrine infusion was reestablished, the depressor response to acetaldehyde was observed again (Fig. 14). During epinephrine infusion at a rate of 5 ,ag/kg/min the pressor response to tyra mine was restored and the depressor response to acetaldehyde was not affected. The pressor responses to norepinephrine and epinephrine were markedly depressed (Fig. 15). During acetaldehyde infusion at a rate of 3 mg/kg/min the blood pressure responses to these four drugs remained unaltered (Fig. 16). DISCUSSION The pressor response to intravenous injection of acetaldehyde was reversed by pre treatment with dibenamine. The depressor response to acetaldehyde after dibenamine was abolished by bilateral adrenalectomy. When 1 to 3 mg/kg of acetaldehyde was in jected intraarterially close to the adrenal medulla a pronounced pressor response and the contraction of the nictitating membrane were observed and these responses were abolish ed by bilateral ligature of the adrenolumbar veins. Therefore, it is conceivable that acetaldehyde releases catecholamines, possibly epinephrine, from the adrenal medulla. Furthermore, it is of particular interest that the adrenal response to acetaldehyde is not blocked by both hexamethonium and atropine. Recently Perman (13) showed that acetaldehyde in doses from 10 to 50 mg/kg increased the secretion of epinephrine and norepinephrine from the adrenal medulla even after section of the splanchnic nerves and he observed a proportionally greater secretion of epinephrine but he did not analyze the detailed mechanism of action. Since the pressor response and the contraction of the nictitating membrane due to the intravenous injection of acetaldehyde were observed even after the bilateral adre nalectomy and the response of the nictitating membrane was induced by acetaldehyde in small doses given into the external carotid artery, the sympathomimetic action of acetaldehyde can not be explained solely on the basis of an action through the adrenal medulla. However, the pressor and the nictitating membrane responses to acetaldehyde are, at least partly, produced by the catecholamines released from the adrenal medulla. Regarding the action of tyramine on the adrenal secretion, Burn (14) suggested that tyramine causes some release of epinephrine from the adrenal medulla, although it was not very much. Stroemblad (15) perfused the cat adrenal gland with tyramine solution and he could not obtain any evidence for releasing action. Douglas and Rubin (16) investigated the role of calcium in the secretory response of the adrenal medulla to acetylcholine and reported that the removal of calcium from the perfusion fluid abolished the secretory response of the adrenal medulla to acetyl choline and suggested that acetylcholine might cause some brief changes in the medul lary cells in turn allow calcium ions to penetrate and trigger the catecholamine ejec

tion process. In chronically reserpinized animals acetaldehyde showed no action on the nictitat ing membrane and induced a depressor response on the blood pressure. The depressor response to acetaldehyde was intensified during norepinephrine infusion. This depres sor response may be the result of the direct action of acetaldehyde on the cardiovas cular system. Withrington and Zaimis (17) found that in cats, 24 hours after the ad ministration of 1 mg/kg of reserpine, the heart was in failure and any blood pressure changes, as a rule, were secondary to changes in heart contraction. We have studied the electrocardiogram in cats pretreated with reserpine, and found that R-R interval was considerably prolonged after intravenous injection of acetaldehyde and further pro longed by doses of acetaldehyde during norepinephrine infusion. In normal rabbits Yokokawa (9) reported that 50 mg/kg of acetaldehyde caused a reduction of R-R inter val instead of prolongation. The depressor response to acetaldehyde during norepine phrine infusion was abolished after termination of the infusion. We can not satisfac torily explain this finding. On the other hand, during or following the infusion of norepinephrine intraarterial injection of acetaldehyde into the external carotid artery produced a marked nictitating membrane contraction. As for the sympathomimetic effect of tyramine, Burn and Rand (18) concluded that tyramine normally exerted its action by releasing a norepinephrine like substance from the vessel walls. Trendelenburg (19) discussed that the sympatho mimetic action of tyramine was due to the liberation of norepinephrine from the post ganglionic adrenergic nerve terminals. In regard to the sympathomimetic effect of acetaldehyde, Eade (7) presumed the liberation of norepinephrine by this drug, but he pointed out that the releasing action of acetaldehyde appeared to differ from that of tyramine. Judging from the results obtained in our present experiments, the sympa thomimetic effects of acetaldehyde are difficult to be explained only by the action of norepinephrine released from catecholamine stores, which presumably are located in or near the nerve terminals. Secretion of catecholamines from the adrenal medulla plays a major role in the manifestation of sympathomimetic effects of acetaldehyde. It is concluded that acetaldehyde has an action, ganglion-stimulating action in a broad sense. This effect, however, is not blocked by hexamethonium and atropine. Furthermore, in chronically reserpinized cats the blood pressure response to acetaldehyde certainly dif fers from that to tyramine, but acetaldehyde is similar to tyramine in the action upon the nictitating membrane. SUMMARY The sympathomimetic action of acetaldehyde was investigated and the mechanism of action was discussed. 1. Intravenous injection of acetaldehyde, resembling epinephrine, produced a pres sor response and a pronounced contraction of the nictitating membrane. 2. Bilateral adrenalectomy reduced the pressor response and the nictitating memb

rane response to acetaldehyde. 3. The pressor response to acetaldehyde was reversed by pretreatment with dibena mine. Bilateral adrenalectomy abolished the depressor response to acetaldehyde after dibenamine. 4. When acetaldehyde was given intraarterially close to the adrenal medulla a marked pressor response and the contraction of the nictitating membrane were observed, and these responses were blocked neither by hexamethonium nor by atropine. 5. Cocaine significantly potentiated the pressor and the nictitating membrane responses to acetaldehyde. Bretylium slightly potentiated the pressor response to acet aldehyde. 6. In acute reserpine treatment the response to acetaldehyde was considerably depressed, whereas the response to tyramine significantly potentiated. 7. In chronically reserpinized animals acetaldehyde induced no action on the nictitating membrane and produced a depressor response. During norepinephrine in fusion the depressor response to acetaldehyde tended to increase, whereas the decreased pressor response to tyramine was restored. During or following norepinephrine infu sion close-intraarterial injection of acetaldehyde into the external carotid artery caused a marked nictitating membrane contraction. It is concluded that acetaldehyde releases catecholamines from catecholamine stores located in or near the nerve terminals as well as from the adrenal medulla, and action of acetaldehyde on the adrenal medulla is not blocked by both hexamethonium and atropine. REFERENCES 1) HANDOVSKY, H. : C. R. Soc.Biol.,Paris 123, 1242(1936) 2) NELSON, E.E. : Proc.Soc.exp.Biol.,N.Y.52, 23 (1943) 3) CHRISTENSEN, J.A. : Quart.J. Stud.Alc.12, 30 (1951) 4) FEINGOLD, A. : Proc.Soc.exp.Biol.,N.Y.80, 667 (1952) 5) SEIBERT, R.A., HUGGINS, R.A. ANDBRYAN, A.R.: Arch.int. Pharmacodyn. 89, 426 (1952) 6) WINGARD, P.H. ANDTEAGUE, R.S. : Ibid. 102, 65 (1955) 7) EADE, N.R. :J. Pharmacol. 127, 29 (1959) 8) ROMANO, C., MEYERS, F.H. ANDANERSON, H.H.: Arch.int. Pharmacodyn. 99, 378 (1954) 9) YOKOKAWA, Y. : ShinshuMed.J. 8, 255 (1959)(Japanese) 10) AKABANE, J.: Med.J. ShinshuUniv.5, 113 (1960) 11) KUMAGAI, H.,YUI,T., CGAWA, K. ANDCOGA, A. : MedicalScience 5, 132 (1953)(Japanese) 12) JONES, A., GOMEZ ALONSO DELASIERRA, B. ANDTRENDELENBURG, U. : J. Pharmacol. 139, 312(1963) 13) PERMAN, E.S. : Actaphysiol.scand.43, 71 (1958) 14) BURN, J.H. : Adrenergic Mechanisms, p. 491, Churchill, London (1960) 15) STROEMBLAD, B.C.R.: Brit.J. Pharmacol. 15, 328 (1960) 16) DOUGLAS, W.W.ANDRUBIN,R.P.: J. Physiol.159, 40 (1961) 17) WITHRINGTON, P. ANDZAIMIS, E.: Brit.J. Pharmacol. 17, 380 (1961) 18) BURN, J.H. ANDRAND,M.J. :J. Physiol.144, 314 (1958) 19) TRENDELENBURG, U. : J. Pharmacol, 134, 8 (1961)