Ultrastructural cytochemistry of atrial muscle cells. VI. Comparative study of specific granules in right and left atrium of various animal species

Abstract

Specific (A-, B-and D-) granules as well as multivesicular bodies (MVB) with a dense core from the right and left atrium of a variety of mammals (mouse, rat, hamster, guinea pig, rabbit, young and old cat) were compared by quantitative ultrastructural and cytochemical methods as regards number, size, localization and reactivity. The number of specific granules was greater in the right atrium of the rat and lesser in the same atrium of the guinea pig. In the rat this difference was due t o a greater number of all three types of specific granules in the right atrium. In the guinea pig, both A and B granules were more numerous in the left atrium. A greater number of granules was also found in the left atrium of hamster, rabbit and young and old cat but the difference with the right atrium was not significant. All atria contained the same type of specific granules but A-and B-granules were present in the left atrium not only in the paranuclear area, as in the right atrium, but also throughout the sarcoplasm. In both atria, all specific granules were argentaphobic when stained according to the periodic acid-thiocarbohydrazide-silver proteinate technique of Thiery. They reacted positively t o phosphotungstic acid-hydrochloric acid (PTA) (pH 0.3) as did the cell coat, residual bodies (Cgranules), lysosomes, Z-disks and a small portion of the Golgi complex. The PTA and PAS stains were abolished by acetylation, restored by saponification, unchanged by methylation and greatly diminished by sulfation. The MVB with a dense core, identical to those already noted in the cells of various endocrine glands, and thought to be crinophagic, were rare in the right atrium of all species and absent in that of the rat. They were much more numerous in the left atrium, particularly of hamsters, guinea pigs and cats and, to a lesser degree, of mice, rabbits and rats. They were silver negative. Their dense core reacted to PTA but their matrix, contrary to classical MVB without a dense core, did not.

Fine Structure of Atrial Natriuretic Peptide (ANP) -granules in the Atrial Cardiocytes in the Hamster, Guinea Pig, Rabbit, Cat and Dog

“…On the other hand, the distribution pattern of granules was common to all species examined in that the granules were more frequently observed in the perinuclear region than between myof ibrillar bundles. These cellular distributions of ANP-granules were consistent with those in the previous reports [2,7].…”

“…Using morphometry, the size and number of ANP-granules were examined in various mammalian species by Jamieson and Palade [9], Tomisawa [28], and Cantin et al [2].…”

A-type Natriuretic Peptide Level in Hypertensive Transgenic Mice

“…Ultrastructural morphometry: The number of secretory granules of the right auricular cardiocytes was measured according to the modified morphometry method of Cantin et al [6]. Thin sections were viewed on a JEM-2000 EX electron microscope at a magnification of × 3,000.…”

“…Thin sections were viewed on a JEM-2000 EX electron microscope at a magnification of × 3,000. Ten photographs were randomly chosen from sections of the right auricular cardiocytes of each mouse in accordance with the criteria proposed by Cantin et al [6]. The counting of ANP-granules was done on 25 cm × 30 cm prints at a final magnification of × 14,000, corresponding to an area of 382.7 µm 2 .…”

Fine Structure of the Atrial Cardiocytes in the House Musk Shrew (<I>Suncus murinus</I>)

“…Concerning the number of atrial secretory granules, Cantin et al [3] have reported on various mammals, and they described that the average total number of ANP-granules in the right atrium of the rat was 103.84, and of the hamster was 48.84. They commented that the total number of ANP-granules in atria decreased with increasing size of the animals.…”