Observations on the fine structure of the sebaceous flank gland of the Indian musk shrew,Suncus murinus viridescens (Blyth)

Abstract

The fine structure of the sebaceous gland acini which form the bulk of the flank gland in the Indian musk shrew was studied. The secretion of the gland appeared to be mainly lipoid in nature, seen as numerous intracellular lipid droplets showing varying degrees of osmophilia from light to intense dark. The mitochondria contained one to several electron dense inclusions which were discharged from disrupted mitochondria and were seen floating in the cytoplasm and also in the ducts of the gland complex. It is suggested that these inclusions which presumably contain high concentrations of waxessynthesized within the mitochondria, form the major components of the holocrine secretion discharged from the flank gland of the shrew.

Further observations on the ultrastructure of the flank gland of the musk shrew,Suncus murinus viridescens (Blyth)

“…The size, number and nature of occurrence of the mitochondrial inclusions in the sebaceous gland tubules of male shrews have been discussed earlier (Balakrishnan et al 1984), and present observations revealed that the mitochondrial inclusions are similar in size, number and in the nature of occurrence in both sexes of the species. These results differ from the observations of Sansone et al (1970) on mice preputial gland only in the number of the mitochondrial inclusions.…”

“…These results differ from the observations of Sansone et al (1970) on mice preputial gland only in the number of the mitochondrial inclusions. Balakrishnan et al (1984) found a few mitochondrial dense inclusions in the cytoplasm and in the ducts of the sebaceous tubules, probably as a result of their discharge from the mitochondria. The close association of mitochondria with lipid droplets in the differentiated gland cells suggest that the mitochondria not only have the function of energy production and release but also.…”

“…The undifferentiated sebaceous cells are characterised by the absence of any lipid droplets, whereas during the process of differentiation, small lipid droplets are developed and then fused to form large droplets as seen in well differentiated sebaceous gland cells. However, the presence of numerous mitochondria with characteristic electron dense inclusions (Balakrishnan et al 1984) in both undifferentiated and well differentiated cells of both sexes and their absence in the adjacent muscle fibres of this glandular tissue is of considerable interest. Presence of the mitochondrial inclusions thus forms a specificfeature of the sebaceous glandular cells.…”

“…The specialized integumentary glands in the Indian musk shrew, Suncus murinus viridescens have been the subject of detailed investigation in recent years (Balakrishnan 1975;Balakrishnan and Alexander 1985). An investigation on the fine structure of the sebaceous cells of the flank gland of the male shrew was also made (Balakrishnan et al 1984). The present report represents the results of further detailed investigations on the ultrastructure of the flank gland of S. m. viridescens.…”