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The angioarchitecture of estrous, pseudopregnant and pregnant rabbit ovary as seen by scanning electron microscopy of vascular corrosion casts (1997)

Nottola, Stefania A. ; Macchiarelli, Guido ; Motta, Pietro M.

Springer

Cell & tissue research 288 (1997), S. 353-363

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ISSN: 1432-0878

Keywords: Key words: Ovary ; Vascularization ; Vascular corrosion casts ; Scanning electron microscopy ; Countercurrent mechanism ; Rabbit (New Zealand white)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Abstract. Ovarian angioarchitecture was studied by scanning electron microscopy of vascular corrosion casts in estrous, pseudopregnant (stimulated with human chorionic gonadotropin) and pregnant rabbits. In all samples, the proper ovarian branch of the ovarian artery (ramus ovaricus) entered the ovarian hilus near the caudal pole of the organ and ran parallel to the major axis of the hilus. The extraovarian venous drainage was formed by several vessels emptying into a distal large vein. The ramus ovaricus exhibited various degrees of coiling and branched in the medulla. The coiling of the ramus ovaricus and its ramifications were maintained in all samples. A venous meshwork and/or flat vein branches closely enveloped the arterial coils found in the hilus and outer medulla. At this level numerous arteriovenous contacts were demonstrated in all samples. The coiled arteries, prior to entering the ovarian cortex, supplied several small peripheral follicles which were drained by the hilar veins. In the cortex the coiled arteries branched in numerous thin, straight or slightly undulated arterioles which supplied developing estrous follicles and pseudopregnant corpora lutea. The arterioles supplying the pregnant corpora lutea were long, large and tightly spiraled. The venous drainage followed the modifications of the arterial supply. These data demonstrate that ovarian cycle and pregnancy induced significant changes in the cortical vessels, which adapted their structure to the temporary functional needs of the recruited follicles or corpora lutea. Hilar and medullary vessels have permanent structures that may represent morphological devices for (a) a continuous control of the blood flow (spiral arteries) and (b) a local recirculation of endocrine products (arteriovenous contacts) comparable to the ”countercurrent mechanism” previously shown to operate in ovaries of other species, but not yet found in rabbits.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s004410050821

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Human zona pellucida during in vitro fertilization: An ultrastructural study using saponin, ruthenium red, and osmium-thiocarbohydrazide (1992)

Familiari, Giuseppe ; Nottola, Stefania A. ; Macchiarelli, Guido ; [et al.]

New York, NY [u.a.] : Wiley-Blackwell

Molecular Reproduction and Development 32 (1992), S. 51-61

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ISSN: 1040-452X

Keywords: Oocyte ; Polypronuclear ovum ; Fertilization ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: The human zona pellucida (ZP) and its changes during in vitro fertilization in oocytes at different maturational stages and polypronuclear ova at one- to four-cells stages were studied by transmission electron microscopy (TEM) and correlative scanning electron microscopy (SEM). To define the microstructure of the ZP, its amorphous masking material was removed using a detergent (saponin), and its structural glycoproteins were stabilized with a cationic dye, ruthenium red, followed by osmium-thiocarbohydrazide treatment. These methods allowed in all samples the clear visualization of variously arranged networks of filaments composing the outer and inner surfaces of the ZP. These filaments were straight or curved, 0.1-0.4 μ in length and 10-14 nm thick as seen via TEM or 22-28 nm thick as seen via SEM (the difference in thickness was due to the presence of the metal coating for SEM). The filament arrangement was remarkably different between the inner and outer surfaces of the ZP and among the various stages studied. The filaments of the outer surface of the ZP were basically arranged in “large” and “tight” meshed networks. Mature oocytes and fertilized (polypronuclear) ova had a regular alternating pattern of wide and tight meshed networks of filaments. On the other hand, immature and atretic oocytes displayed almost exclusively a tight meshed network of filaments. The inner surface filaments of the ZP of unfertilized oocytes at any stage were arranged in repetitive structures characterized by numerous short and straight filaments anastomosing with each other and sometimes forming at the intersections small, rounded structures. After fertilization, the inner surface of the ZP displayed numerous areas where filaments fused together. Collectively, these data clearly reveal that oocyte maturation and fertilization in humans are accompanied by changes of ZP filaments arrangement, which may be relevant in the processes of binding, penetration, and selection of spermatozoa. © 1992 Wiley-Liss, Inc.

Additional Material: 6 Ill.