Murakami T, Kikuta A, Taguchi T, Ohtsuka A, Ohtani O
Department of Anatomy, Okayama University Medical School, Japan.
Arch Histol Jpn. 1987 May;50(2):133-76. doi: 10.1679/aohc.50.133.
Complete casts of the hypophyseal and hypothalamic blood vascular beds of newborn, pubescent, adult and aged rats were produced by infusion of low viscosity methacrylate media, dissected under a binocular light microscope, and observed with a scanning electron microscope. The primary capillary plexus projected capillary loops into the median eminence and infundibular stalk. These loops were composed of anastomosing capillaries, being numerous in the central area of the anterior lip of the median eminence. The well developed long loops received their proper afferent arterioles from the arterial terminals in the primary plexus, and emitted their proper efferent venules continuous with the long portal vessels. The loops in newborn rats were poorly developed, appearing as simple ball-like protrusions of the capillaries of the primary plexus. Many branches of the anterior, middle and accessory middle hypophyseal arteries penetrated the primary plexus, and ascended as infundibular ascending arterioles in the median eminence and infundibular stalk. These infundibular ascending arterioles continued into the capillary bed of the hypothalamus, especially in its basilar and peri-ventricular areas. The subependymal capillary network was fairly independent, and located dorsal to the loops. This network received some of the infundibular ascending arterioles, and emitted infundibular descending venules continuous with the long portal vessels. The subependymal network also received the infundibular descending arterioles from the hypothalamic arteries, and emitted the infundibular ascending venules continuous with the hypothalamic veins. Thus, neither a feedback nor a retrograde portal route from the hypophyseal capillaries to the hypothalamic capillaries was noted. The capillary bed of the pars tuberalis was observed only in the adult and aged rats; it was a very coarse network which was derived from the primary capillary plexus and connected to the secondary capillary plexus.
通过注入低粘度甲基丙烯酸酯介质，制作新生、青春期、成年和老年大鼠垂体和下丘脑血管床的完整铸型，在双目光学显微镜下进行解剖，并使用扫描电子显微镜进行观察。初级毛细血管丛向正中隆起和漏斗柄投射毛细血管袢。这些袢由相互吻合的毛细血管组成，在正中隆起前唇的中央区域数量众多。发育良好的长袢从初级丛中的动脉终末接受其自身的传入小动脉，并发出与长门静脉血管相连的自身传出小静脉。新生大鼠的袢发育不良，表现为初级丛毛细血管的简单球状突起。垂体前、中及中副动脉的许多分支穿透初级丛，并在正中隆起和漏斗柄中作为漏斗上升小动脉上升。这些漏斗上升小动脉延续至下丘脑的毛细血管床，尤其是其基底和脑室周围区域。室管膜下毛细血管网相当独立，位于袢的背侧。该网络接受一些漏斗上升小动脉，并发出与长门静脉血管相连的漏斗下降小静脉。室管膜下网络还接受来自下丘脑动脉的漏斗下降小动脉，并发出与下丘脑静脉相连的漏斗上升小静脉。因此，未发现从垂体毛细血管到下丘脑毛细血管的反馈或逆行门静脉途径。仅在成年和老年大鼠中观察到结节部的毛细血管床；它是一个非常粗糙的网络，源自初级毛细血管丛并与次级毛细血管丛相连。
