Pericycle

…In amphibian capillaries, there are cells with projections on the outside of the endothelial cells that are said to have contractility; these are called Rouget's cells. Similar cells are found in higher animals, called pericytes, but their contractility has not been confirmed. With a few exceptions, the circulatory systems of most invertebrates lack endothelial cells, and even in cephalopods and crustaceans that have hearts and arteries, the parts that correspond to capillaries are nothing but tissue gaps. …

*Some of the terminology explanations that mention "pericyte" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…両生類の毛細血管で，内皮細胞の外側に突起をもつ細胞があって収縮性をもつとされ，これをルジェー細胞Rouget’s cellという。高等動物でも類似の細胞がみられ，周細胞pericyteというが，収縮性は確かめられていない。一部の例外を除き，大部分の無脊椎動物の循環系は内皮細胞を欠如し，心臓や動脈をもつ頭足類や甲殻類でも，その毛細血管に相当する部分は組織間隙にほかならない。…

※「pericyte」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報