타액선 및 취선 외분비기능의 비교 검색

Abstract

[한글]

타액선은 주로 외분비선 장기이며 소화선 장기중에서는 취장과 구조상 기능상 공통점이 많았다. 구조상 두 외분비선은 선세포와 관세포로 구성되고 전해질 분비외에 다같이 amylase를 선세포에서 생성, 축적, 분비한다. 소화효소의 합성과정은 타액선이나 취선 모두

비슷하여, endoplasmic reticulum의 ribosome에서 생성되어, Golgi vesicle, condensing vacuole을 거쳐 zymogen granule에 저장되었다가 분비자극으로 인하여 배출관 내로 유출된다. 분비조절에 있어서는 취장이 자율신경계 및 홀몬의 지배를 받으나 타액선은 전적으

로 자율신경계의 지배를 받고 홀몬의 영향은 미약하다. 타액선 분비에 대한 자율신경계의 역할은 다른 장기와는 달리 정도의 차는 있지만 아드레나린성 및 코린성 자극 모두 분비항진 효과를 나타낸다.

Isoproterenol은 설치류에서는 선장기 특히 타액선 장기의 세포증식 및 세포비대를 나타내고 DNA, RNA 및 총단백량을 증가시키며(Selye 1961, Baserga 및 Heffler, 1967, Radley 1968)이에는 β수용체를 통한 cyclic AMP가 관여한다고 보고되고 있다(Sutherland and

Robison 1966, Malamud 1969). 한편 Martinez등(1975, 1979)은 일련의 실험을 통하여 일주일간 reserpine을 투여하면 타액선 조직이 Cystic fibrosis와 비슷한 양상을 보인다고 보고한 바 있다. 취장 외분비선 기능은 타액선과 달리 자율신경계뿐 아니라 홀몬의 영향

이 지대하다. 즉 secretin은 취액 전해질 분비항진을, cholecystokinin-pancreozymin(CCK-PZ)은 효소단백 분비증가를 출현시키며, 그 외에도 많은 소화기계 흘몬들이 영향을 주며

특히 secretin, CCK-PZ 및 gastrin은 취장비대효과률 나타번다(홍, 1978).

따라서 본 실험에서는 타액선과 취선의 amylase 및 이의 isoensyme분비를 관찰하고 나아가 장기 비대 효과를 지닌 isoproterenol, cholecystokinin-octapeptide(CCK-OP) 및 실

험적 cysticfibrosis를 일으키는 reserpine을 투여하여 시기별로 이들 외분비선의 amylase 분비변동을 검색하였으며 또한 fluoride가 amylase분비에 미치는 영향을 비교 검색하였다.

실험동물로는 체중 70∼80g되는 어린 흰쥐를 암수 구별 없이 사용하였으며 다음 4개군으로 나누어 각 약물을 3,5,7,9,12일 또는 15일 동안 하루 한번씩 복강내에 전처치하였다.

1. 대조군 : 생리적 식염수 1ml/kg

2. Isoproterenol 처치군;10mg/kg

3. Cholecrstokinin-octapeptide처치군:2μg/kg

4. Reserpine 처치군;0.5mg/kg

각 동물은 이상의 처치를 끝내고 실험 전날은 굶겨 목부분을 잘라 희생시켜 한쪽 이하선 및 취장의 uncinate 부분율 적출하였다. Case 및 Clausen(1973)외 방법에 따라 Krebs Ringerbicarbonate buffer에서 자 선장기 절편의 amylase분비를 관찰하였으며 acetrlctoline 10-(-5)**M로 분비를 자극하였다. Amylase는 Bernfeld(1955)법으로 측정하였으며 Ampholine carrierampholyte PH3-10을 사용하여 등전집초률 실시하였다.

실험성적을 요약하면 다음과 같다.

1. Isoproterenol을 반복투여하면 투여기간에 비례하는 이하선, 악하선과 심장의 비대를 나타냈으며 톡히 이하선 비대가 현저하였다.

2. 이하선 절편의 amylase유리는 acetylcholine(ACh)자극으로 항진되며 isoproterenol처치군에서는 투여기간에 따라 amlyase유리저하를 나타내어 투여 12일 이후에는 일층 현저히 저하되었으나 reserpine전처치군에서는 투여기간에 따라 amylase 분비항진을 나타냈다.

3. 취장 절편의 amylase 유리는 ACh자극으로 항진되고 reserpine처치군에서는 투여기간에 E따라 amylase 분비항진이 현저하였으며 CCK-OP처치군에서는 투여 9일 이후부터 항진

되었다.

4. NaF는 ACh에 의한 이하선의 amylase 유리를 초가에 항진시키나 취장에서는 별 변동이 없었다.

5. 등전집초법으로 이하선 및 취선에서 분비된 amylase를 분리한 바 취장 amylase는 음극(-)쪽에, 이하선 amylase는 양극(+)쪽에 3개씩의 주된 동종효소를 나타냈다.

이상의 성적으로 보아 이하선 및 취장의 외분비 기능은 서로 흡사한 상통성(相通性)을 가지고 있으나 약물반응, 분비기전 및 동종효소는 차이가 있음을 알 수 있었다.

Comparative Studies on the Exocrine Secretion of Salivary Gland and Pancreas

Hang Jack Cho

Department of Medical science The Graduate School, Yonsei University

(Directed by Professor Sa Suk Hong, M.D.)

The salivary secretion is important to the hygiene and comfort of the mouth and

teeth, and saliva contains α-amylase which contributes to normal digestion.

Salivary secretion depends almost exclusively on autonomic nervous system, i.e.,

stimulation of cholinergic and alpha-adrenergic receptor elicits the formation of a

moderate amount of saliva rich inelectrolytes, whereas stimulation of beta receptor

causes the secretion of a scanty volume of saliva rich in protein which appears to

be mediated by cyclic AMP. Salivary gland enlargement and growth can be induced by

chronic administration of the sialogogue, isoproterenol but chronic treatment of

rats with reserpine exhibit morphologic and secretory alterations of salivary

glands which closely resemb1e those findings reported in cystic fibrosis. Salivary

gland is morphologically and physiologically similar to exocrine pancreas, however,

pancreatic secretion is regulated mainly by cholinergic and hormones, and

cholecystokinin has trophic effects on pancreas besides enzymes stimulation.

Present study was undertaken to compare the secretory functions of salivary gland

and pancreas with special reference to the effects of chronic treatment of

reserpine, isoproterenol and cholecystokinin-octapeptide. Growing rats weighing

67∼80g of either sex were treated as follows; reserpine(0.5 mg/kg),

isoproterenol(10mg/kg) or cholecystokinin-octapeptide (2/mg/kg), i.p., daily for

3,5,7,9,12 and 15 day.

The rats were then decapitated and the parotid gland and uncinate pancreas were

isolated. The glands were incubated in screw top vials, containing 2ml Krebs-Ringer

bicarbonate buffer gassed with 95% O^^2 and 5% CO^^2, shaken continuously in a

water bath maintained at 37℃(Case and Clausen, 1973) and the enzyme secretion were

stimulated with acetylcholine(10**-5M).

The results obtained are summarized as follows :

1. Isoproterenol elicited enlargement of salivary glands and heart in reaponse to

therepeated treatment in growing rats.

2. Isoproterenol suppressed the basal and acetylcholine-stimulated amylase

release from the parotid slices but did not affect the pancreatic secretion.

3. Reserpine treatment potentiated the acetylcholine-stimulated amylase release

from both parotid and pancreas, but response of parotid gland was only transient.

4. Acetylcholine-stimulated amylase release from Pancreas was increased by

CCK-octapeptide treatment.

5. Fluoride increased the amylase release from parotid gland transiently

6. Fractionation of amylase by isoelectric focusing showed that broth media

incubated with parotid gland and pancreas had 3 main isozymes each on cathodal and

anodal side, respectively.

With these findings it can be recognized that secretory functions of parotid

gland and pancreas are shown many similarities, however, the secretory mechanisms

and enzyme proteins are well distinguishable.

[영문]

The salivary secretion is important to the hygiene and comfort of the mouth and teeth, and saliva contains α-amylase which contributes to normal digestion.

Salivary secretion depends almost exclusively on autonomic nervous system, i.e., stimulation of cholinergic and alpha-adrenergic receptor elicits the formation of a moderate amount of saliva rich inelectrolytes, whereas stimulation of beta receptor

causes the secretion of a scanty volume of saliva rich in protein which appears to be mediated by cyclic AMP. Salivary gland enlargement and growth can be induced by chronic administration of the sialogogue, isoproterenol but chronic treatment of

rats with reserpine exhibit morphologic and secretory alterations of salivary glands which closely resemb1e those findings reported in cystic fibrosis. Salivary gland is morphologically and physiologically similar to exocrine pancreas, however,

pancreatic secretion is regulated mainly by cholinergic and hormones, and cholecystokinin has trophic effects on pancreas besides enzymes stimulation.

Present study was undertaken to compare the secretory functions of salivary gland and pancreas with special reference to the effects of chronic treatment of reserpine, isoproterenol and cholecystokinin-octapeptide. Growing rats weighing 67∼80g of either sex were treated as follows; reserpine(0.5 mg/kg),

isoproterenol(10mg/kg) or cholecystokinin-octapeptide (2/mg/kg), i.p., daily for 3,5,7,9,12 and 15 day.

The rats were then decapitated and the parotid gland and uncinate pancreas were isolated. The glands were incubated in screw top vials, containing 2ml Krebs-Ringer bicarbonate buffer gassed with 95% O^^2 and 5% CO^^2, shaken continuously in a

water bath maintained at 37℃(Case and Clausen, 1973) and the enzyme secretion were stimulated with acetylcholine(10**-5M).

The results obtained are summarized as follows :

1. Isoproterenol elicited enlargement of salivary glands and heart in reaponse to therepeated treatment in growing rats.

2. Isoproterenol suppressed the basal and acetylcholine-stimulated amylase release from the parotid slices but did not affect the pancreatic secretion.

3. Reserpine treatment potentiated the acetylcholine-stimulated amylase release from both parotid and pancreas, but response of parotid gland was only transient.

4. Acetylcholine-stimulated amylase release from Pancreas was increased by CCK-octapeptide treatment.

5. Fluoride increased the amylase release from parotid gland transiently

6. Fractionation of amylase by isoelectric focusing showed that broth media incubated with parotid gland and pancreas had 3 main isozymes each on cathodal and anodal side, respectively.

With these findings it can be recognized that secretory functions of parotid gland and pancreas are shown many similarities, however, the secretory mechanisms and enzyme proteins are well distinguishable.