Microcirculation of the pancreas in the rat and rabbit with special reference to the insulo-acinar portal system and emissary vein of the islet.

Incomplete Vascular Casting for a Scanning Electron Microscope Study of the Microcirculatory Patterns in the Rat Pancreas.

“…Although these intravital light microscopic methods are useful for direct observation of blood flow, their use may be limited; deep and wide areas are hardly observed by the intravital methods. Furthermore, the images from the intravital methods are not always clear because of the limited resolution and shallow focus of the light microscope (OHTANI, 1983;OHTANI et al, 1986). This shortage is supplemented by the incomplete casting/scanning technique introduced in the present paper.…”

“…X200 in the rat islets, the blood mainly flows from the A-D cell mantle to the B cell core (FUJITA, 1973;OHTANI et al, 1986). Microcirculation patterns of blood have been studied by intravital light microscopy of living tissues or organs which are sometimes injected with India ink, fluorescent dyes, microspheres or other substances (BUNNAG et al, 1963;MCCUSKEY and CHAPMAN, 1969;LIFSON et al, 1980;FRAZER and HENDERSON, 1980;OHTANI, 1983;OHTANI et al, 1986). Although these intravital light microscopic methods are useful for direct observation of blood flow, their use may be limited; deep and wide areas are hardly observed by the intravital methods.…”

“…This paper demonstrates findings by scanning electron microscopy of such cast specimens, especially those reproduced by complete and incomplete arterial injections. The rat pancreas is the target organ of the present study, since its microcirculatory pattern has caused much dispute (BONNER-WEIR and ORCI, 1982), including a complicated insulo-acinar portal system which has additional venous drainages (OHTANI et al, 1986).…”

Survival of encapsulated islets: More than a membrane story

“…The endocrine tissue, which in humans includes approximately 1 million IOL, is scattered in the exocrine pancreas and constitutes only 1%2% of its biomass, while utilizing 10%20% of the total blood flow into the organ [113115] . The proportion of arteriole endings and of vascular density in IOL and exocrine tissue is similar [116,117] . IOL are supplied with arterial blood via one or more arterioles which, after penetrating the capsule, form dense, glomerularlike network of capillaries.…”

Three-dimensional Organization of the Connective Tissue Fibers of the Human Pancreas: A Scanning Electron Microscopic Study of NaOH Treated-Tissues

“…GRUBE and BOHN (1983) reported that a heterocellular layer of endocrine cells was observed mainly adjacent to such centrally located capillaries in small islets, whereas the vasa eff erentia were surrounded predominantly by B-cells. In this connection, the hypothesis proposed for some mammals (FUJITA, 1973;FUJITA and MURAKAMI, 1973;OHTANI et al, 1986) that the blood flows from the A and D-cell area to the B-cell area also seems applicable to the human islet of Langerhans. In larger islets, however, vessels preferentially entering the islet core have not been observed so far, instead, a rather uniform capillary network was noticed in the islet.…”