Microcirculation in the islets of langerhans of the mouse

Abstract

A technique for the study of microcirculation in living islets, using quartz rod and cinephotomicrography, is presented, together with results of a study of insular microcirculation. With this technique, conditions are standard, results are reproducible and the findings are recorded permanently. The pancreas, bathed constantly in Locke-Ringer's solution at 37"C, is lifted with the spleen from the body, supported on the tip of Knisely's hollow-tipped fused quartz rod, and the lobules are separated gently. Circulation in the transilluminated islets, which are pale yellow, spherical or ovoid bodies with a distinctive vascular pattern, is studied with the biobjective, binocular microscope. For cinephotomicrography, the camera is aligned over one eyepiece of the microscope and the film is exposed at 64 frames per second, using a 750 watt projection bulb as light source. Direct anastomoses of insular and acinar capillaries are not observed. Blood flow in the islets of the anesthetized mouse is rapid and constant, under these conditions of observation. Intravenous epinephrine and ephedrine cause temporary interruption of blood flow in the islets, whereas norepinephrine slows but does not stop the circulation. Pitressin also causes slowing of insular blood flow. Insulin, glucagon, hydrocortisone, glucose, alloxan and diphenylthiocarbazone have no acute effect upon the insular microcirculation. A possible relation between the circulatory effect and the hyperglycemic effect of epinephrine and ephedrine is suggested.

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

“…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.…”

The Insulo-Acinar Portal and Insulo-Venous Drainage Systems in the Pancreas of the Mouse, Dog, Monkey and Certain other Animals: A Scanning Electron Microscopic Study of Corrosion Casts.

“…LA lobular artery, LD lobular periductal plexus, LV lobular vein. x160, left Inset: x140, right Inset: x130 been demonstrated by several authors mainly in the murine pancreas: in the mouse by light microscopy of India ink-injected, methyl salicylate-cleared and teased tissues (BECK and BERG, 1931) and by intravital microscopy of the pancreas of living animals (BRUNFELDT et al, 1958;BUNNAG et al, 1963); in the rat by scanning electron microscopy of vascular casts (BONNER-WEIR and ORCI, 1982;OHTANI et al, 1986). The coexistence of the portal and venous drainages has been suggested in the mouse by light microcscopy of India ink-injected, cleared and teased tissues (BECK and BERG, 1931), and demonstrated in the rat by scanning electron microscopy of vascular casts (OHTANI et al, 1986).…”

The life story of the pancreatic B cell

“…It is conceivable that a major regulating influence is exerted on the B cell by constituents in the blood, and the islet blood flow may be regarded as the main avenue by which the cell is kept informed of the nutritional state of body. Interest in the regulation of the islet blood flow dates back several decades [27][28][29][30] but it was not until recently that reliable techniques for a more complete mapping of the structural and functional properties of this important signal system have been worked out. The rich vascular supply of the islets has been known for a long time and an example of its appearance is given in Figure 4.…”