THE ADRENERGIC AND CHOLINERGIC INNERVATION OF GALLBLADDER AND EXTRAHEPATIC BILIARY DUCT SYSTEM IN THE CAT AND HUMAN

Part I. Experimental Study: Fluorescence Histochemical and Histochemical Study Concerning Intrinsic Innervation of the Biliary Duct System in the Cat

Abstract

The human gallbladder has independent but mutually related two functions, namely, absorption of water and electrolytes by the mucous membrane of the gallbladder and contraction of the smooth muscle. In reference to the muscular structure and innervation particularly intrinsic cases which are closely related to the motility and absorption of the biliary duct system, we investigated the adrenergic and cholinergic innervation by means of the fluorescence histochemical method developed by Falck and Hillarp and the histochemical method of Karnovsky. We also determined the level of catecholamine in the tissue of the biliary duct system in order to clarify the intrinsic autonomic nerve in the cat. The results are as follows.
1) According to our findings by the fluorescence method, the adrenergic fibres in the gallbladder wall rose from the serous membrane, formed an adventitial plexus around the blood vessel. And the adrenergic fibres were found abundantly in the smooth muscle layer to form muscular plexus and were partially innervated to the mucous layer. But patterns of the adrenergic fibres reaching the surface of the mucous layer were not observed.
2) As for cholinergic fibres, both the true ChE activity and pseudo ChE activity, were observed in various layers of the biliary duct system, but there was no localized difference between the two.
3) Adrenergic fibres of the common bile duct were clearly observed. The more abundantly they were distributed to the terminal parts of the common bile duct.
4) Biogenic monoamines other than adrenaline and noradrenaline were not detected.
5) The nerve cells observed in the gallbladder and common bile duct were accounted for mostly by Dogiel 11 type.
6) Digestive tract hormones were not detected in the biliary duct system in the cat, but studies by means of the immunofluorescence method are under way.
7) Proliferation of adrenergic fibres and a decrease in cholinergic fibres were observed in the truncal vagotomy group.
8) According to determination of noradrenaline content in the biliary duct system, noradrenaline was found to be in the greatest amounts in the cystic duct and the smallest in the common bile duct. The vagotomy group showed a higher content of noradrenaline compared with the untreated group.