Morphological examination of the accessory sex glands of the Barki bucks (Capra hircus).

BACKGROUND: The present investigation was prepared to describe the accessory sex glands of the Barki bucks grossly and by light microscopy. MATERIALS AND METHODS: There are four sex glands: ampullary, vesicular, prostate, and bulbourethral. The ampullary gland is an enlargement of the terminal part of the ductus deferens, its glandular part has branched tubuloalveolar glands, and its secretory alveoli lined with a pseudo-stratified epithelium composed of cuboidal to columnar cells. The vesicular gland takes the appearance of a cluster of grapes and the left vesicular gland is enlarged and higher than the right one. The vesicular gland is a lobulated tubuloalveolar gland with wide intralobular space and the gland contain a secretory unit which lined by pseudo-stratified columnar epithelium, and the interlobular ductules lined by the stratified epithelium, while the interlobular duct lined by simple cuboidal epithelium; moreover, the lining epithelium of secretory part consists of tall columnar cells. The prostate gland consists only of the disseminated part and is enclosed by a connective tissue capsule that was thin dorsally, thick laterally, and reduced in thickness ventrally. The prostatic acini are lined by simple cuboidal epithelium. RESULTS: The bulbourethral gland was similar in size to the walnut and surrounded by a capsule and there are interlobular connective tissue septa that divided the gland into lobes and lobules of different sizes. The bulbourethral gland contained secretory units lined by the tall simple columnar epithelium of mucous type with basely located nuclei and eosinophilic cytoplasm contains granular secretion. CONCLUSIONS: The gross and microscopic examination of the four accessory sex glands gave valuable information in the future pathology diagnosis of the accessory sex glands of the Barki bucks.

Prevalence, vasculature, and innervation of myocardial bridges in dogs.

OBJECTIVE: To report gross anatomic examination of the canine myocardial bridge (MB), a muscular band found above the coronary artery (CA), with respect to its occurrence, location, vascularization, and innervation. SAMPLE POPULATION: 629 canine hearts obtained within 1 to 3 hours after euthanasia. PROCEDURE: After an incision was made at the left fifth intercostal space, the pericardial sac was cut open, and if an MB was present, the heart, lungs, and annexed structures were removed together and subsequently subjected to macroscopic examination of MB musculature and innervation after formalin fixation. Vascular casting was performed by use of methyl methacrylate perfusion. RESULTS: Of the 629 canine hearts examined, 189 (30%) had MB, occurrence of which was independent of sex, age, and breed. Among 13 MB-containing specimens examined in detail, there was great variation in thickness (0.11 to 2.24 mm; mean, 0.45 mm) of MB and distance (24 to 236 microns; mean, 103 microns) between the MB and the paraconal interventricular branch of the left CA (PIBL). One pair or 2 pairs of blood vessels from the PIBL supplied the MB muscle. Venous blood returned to the coronary circulation via the branches of the great coronary vein coursing on both sides of the PIBL, in close contact with the PIBL and the groove wall. The 2 veins rejoined at the upper portion of the PIBL and passed obliquely to the coronary groove under the left auricle, and finally drained the blood through the coronary sinus into the right ventricle. Innervation to the MB muscle was derived from nerve branches of the middle cervical ganglion and left vagus nerve. CONCLUSION: Prevalence and localization of MB in dogs and human beings are similar. Vascularization of the MB muscle originates from the PIBL. The cervical ganglion and vagus nerve control the MB muscle.

Cardiac rod body: hypertrophic Z-line in an aged pony.

Numerous rod bodies were found in a heart sample from a 33-year-old pony by a conventional electron-microscopic technique. The rod bodies were concentrated in localized areas of both atria and ventricles, without a specific pattern of distribution. The rods appear to have a typical crystalline-like structure which presumably contains actin backbone filaments and alpha-actinin as major protein constituents. Diminution, fragmentation, and disorganization of the myofibrils, random expansion of electron-dense materials, especially at the fasciae adherens of the intercalated disc, an increase of intercellular space, frequently associated with connective tissue elements, and accumulation of glycogen granules, lipofuscin, mitochondria, and nonviable organelles in the rod body-containing cells suggested that rod-containing myocytes are in a degenerating stage and that rod body formation occurs in atrophic cardiomyocytes rather than normal or hypertrophic cardiomyocytes in the aged pony heart.

Hypertrophic Z-line observed in aged one-humped camel (Camelus dromedarius).

The ultrastructure of cardiac muscle from 3 aged one-humped camels (Camelus dromedarius) was examined to see if aged camels also develop hypertrophic Z-lines as observed in the heart of aged humans and other animals. The results proved that the aged camel heart develops hypertrophic Z-lines together with other age-associated alterations, including loss of myofibrils and myofilaments, increase of intermyofibrillar spaces and intercellular spaces, and disruption of mitochondrial cristae and intercalated disc structure. Hypertrophic Z-lines are somewhat smaller than those of other species, but occur both in the atria and ventricles. Although the majority of cardiac muscle samples revealed a normal structure, the finding of hypertrophic Z-lines in camel heart is the first such observation in a ruminant animal. The anomalous camel muscle resembles that of other species in terms of cell alterations commonly associated with aged hearts.

Proximal paraconal interventricular myocardial bridge in dog: ultrastructural characterization.

The ultrastructure of the dog myocardial bridges (MB), named here the proximal paraconal interventricular-myocardial bridge (PPI-MB), was examined to determine if its structure is identical to that of ordinary cardiac muscle. This study is preparatory to the establishment of PPI-MB as a physical and physiological model system to examine the influence of MB on coronary flow in cardiac function. Five of 46 dog hearts examined possessed PPI-MB, the occurrence of which was independent of sex, age and breed. The dog PPI-MB was localized in a limited area in the proximal third of the paraconal interventricular groove. PPI-MB myocytes and myofibrils were arranged quite straight and smooth, with minimum branching. PPI-MB myocytes formed side-by-side cell junctions through the mediation of mitochondria. Connective tissue elements were involved in terminal cell adhesion to form the myomyous junction beside the intercalated disc. The excitation conductive system of sarcoplasmic reticulum-T tubule often showed a triad. Numerous nerve axons or nerve ending-like structures appeared. Many structural views deviated somewhat from common cardiac muscle structure. This paper represents the first detailed description of PPI-MB muscle.