A modified method for vascular casting and scanning electron microscopy: its utility in the demonstration of rat pancreatic insulo-acinar and other blood vascular systems.

Monomeric methyl methacrylate resin, supplemented with 1.0% benzoyl peroxide and 1.0% N, N-dimethyaniline, enables good vascular casts useful for scanning electron microscopy when the injected organs or tissues are promptly heated in a microwave processor. The details of this vascular casting and scanning method are described with a clear demonstration of the rat pancreatic blood vascular bed, in particular, its intralobular, extralobular and translobular insulo-acinar portal systems and other vascular routes, including the insulo-venous vessels, which are sinusoidal in nature.

Lysine-mediated tissue osmication in combination with a tannin-osmium conductive staining method for non-coated scanning electron microscopy of biological specimens.

Glutaraldehyde fixed rat kidney blocks showed no charging effect when treated with lysine and osmic acid and viewed in a scanning electron microscope using an acceleration voltage of 5-30 kV and a specimen current of 1 X 10(-10) A. The podocyte processes and endothelial micropores of the glomerulus were visible without metal coating. Glutaraldehyde fixed, tannin-osmium impregnated and lysine-osmium treated specimens also showed no charging effect in the scanning electron microscope, yielding instead much clearer scanning images which were comparable to those obtained from gold-coated specimens or from tannin-osmium-thiocarbohydrazide-osmium impregnated specimens (Murakami and Jones, 1980).

Blood vascular architecture of the rat parathyroid glands: a scanning electron microscopic study of corrosion casts.

Blood vascular beds of the rat parathyroid glands were reproduced with a methacrylate casting medium and observed with a scanning electron microscope. The rat possesses only a single pair (one left and the other right) of parathyroid glands. Each gland was found to contain a rich capillary network which was completely isolated from the capillary plexus of the thyroid gland. Each parathyroid gland received some small afferent arteries from the superior thyroid artery and emitted a thick efferent vein continuous with the superior thyroid vein. The capillary network of the parathyroid gland consisted of freely anastomosing capillaries. The afferent arteries were divided in the superficial and deep layers of the gland. The thick efferent vein arose in the deep layer of the gland. Some small or accessory efferent veins arose in the superficial layers of the gland. These also drained into the superior thyroid vein.

Pedal arteries of monkeys, with special reference to the plantar metatarsal arteries.

In the Japanese, Formosan and crab-eating monkeys, the dorsal metatarsal arteries and their lateral distal perforating branches were well developed and supplied, directly or via the catella plantaris distalis, the plantar digital arteries. In the black ape, the plantar digital arteries arose from the medial plantar artery. The plantar metatarsal arteries of these monkeys, including the black ape, arose from the catella plantaris proximalis or deep plantar arch and were classified into the superficial plantar metatarsal (sM), superficial plantar intermetatarsal (sI), deep plantar metatarsal (dM) and deep plantar intermetatarsal (dI) arteries in relation to the interosseous muscles and metatarsal bones. This classification largely coincides with that of the human hand and foot (Murakami, 1969, 1971) and the monkey hand (Nakai et al., 1987).