Fine structure of the interstitial cells of leydig in the boar

Abstract

The interstitial cells of the testis of the boar have been characterized by electron microscopy. The bulk of the cytoplasm, to one side of an eccentrically placed nucleus, consisted predominately of a tightly packed agranular endoplasmic reticulum in a system of anastomosing tubules. Free ribosomes and a few short strands of granular endoplasmic reticulum were present only in a perinuclear or subplasmalemma1 location. Mitochondria were abundant as a cluster in the center of the cytosome. Surrounding them were dense bodies, most of which were bounded by a single limiting membrane. The internum of the dense bodies exhibited a variety of appearances. Filaments of 70A were common but they were absent near the plasmalemma.Between contiguous cells, irregularly disposed microvilli protruded into an intercellular space of variable dimensions. Some sites of membrane fusion, resulting in maculae occludentes, were observed between adjacent cells, while small desmosomes were observed but rarely. Coated vesicles were frequent near to and continuous with the plasmalemma as well as deeper within the cell, especially in association with elements of the Golgi apparatus.The fine structure of the normal interstitial cellZ has been described in several species : human (Fawcett and Burgos, '56, 'SO), rat (Christensen, '59; Leeson, '63; Schwartz and Merker, '65), opossum (Christensen and Fawcett, '61), rabbit (Crabo, '63), mouse (Can and Carr, '62; Christensen and Fawcett, '66) and guinea pig (Christensen, '65). Study of the fine structures of interstitial cells presents several technical difficulties : (1) their sparse distribution in the testis of man and the usual laboratory mammals, (2) the difficulties attendant to cutting blocks of tissue, since the lack of connective tissue results in fraying of the tubules, and ( 3 ) difficulty in preservation of the abundant and labile agranular endoplasmic reticulum. The problem of limited distribution was obviated by Christensen and Fawcett ('61) in choosing the opossum, which has a profusion of interstitial cells, while in the guinea pig, with many fewer interstitial cells, Christensen ('65) was able to obtain coherent blocks and good preservation only by perfusion of isolated testes with glutaraldehyde.In search of a good species to serve as a study model, we have turned to the boar. The interstitial celIs of the boar were the subject of early study by Ancel and Bouin ANAT. REC., 158: 333-350.('03) who also concluded that the interstitial cells, or interstitial gland of the testis, as they termed it, were responsible for the hormones which were needed for the development of the secondary sex characteristics and sexual instincts. In a quantitative study, Bascom and Osterud ('27) observed that the adult boar testis contained about 37% by volume of interstitial cells. Also, according to our experience, there is sufficient tenacity to the organ that coherent blocks can be obtained -indeed, the tissue is quite "tough." MATERIALS AND METHODSMaterial for this study was provided by testes...

Electron Microscopic Study on the Testicular Interstitial Cells in the Mouse

“…In its nucleus (N) two spheridies (arrows) and nucleoli (NL) are seen. The arrow-head indicates a filopodium of the Leydig cell taken up in a coated invagination forms have been confirmed in a variety of species (BELT andCAVAZOS, 1967, 1971;DE KRETSER, 1967a;SINHA and SEAL, 1967;CHRISTENSEN, 1970CHRISTENSEN, , 1975CONNELL, 1972;USUI, 1976;WING and LIN, 1977). Distinction between tubular and lamellar cristae in a single section was not always easy, and this apparently caused different conclusions reached by different authors in the same animal species-YAMADA (1965), NAGANO (1965) and DE KRETSER (1967b) vs. DE KRETSER (1967a) and CHRISTENSEN (1970; SCHWARZ and MERKER (1965) and USUI (1976) vs. MURAKAMI (1966) and LORDING and DE KRETSER (1972.…”

“…The majority of the previous authors supported the view that the smooth membranes of the interstitial cells formed a network of interconnected tubules extended throughout the cytoplasm, which could transform into flattened, sometimes fenestrated cisternae (FAWCETT and BURGOS, 1960;CHRISTENSEN and FAWCETT, 1961;CRABO, 1963;LEESON, 1963;CHRISTENSEN, 1965CHRISTENSEN, , 1970CHRISTENSEN, , 1975NAGANO, 1965;CHRISTENSEN and FAWCETT, 1966;BELT andCAVAZOS, 1967, 1971;AOKI, 1968AOKI, , 1970MERKOW et al, 1968b;BLACK and CHRISTENSEN, 1969;PELLINIEMI and NIEMI, 1969;GONDOS et al, 1974;CONNELL and CHRISTENSEN, 1975;WEAKER, 1977;WING and LIN, 1977). Against this view, some authors proposed vesicular type SER membranes (MERKOW et al, 1968a;BAILLIE, 1964;SCHWARZ and MERKER, 1965).…”

“…Many investigators of Leydig cells have given attention to variations in the amount of lipid droplets and glycogen particles in different life stages including fetuses, because these inclusions, especially lipid droplets, were thought to be involved in androgen biosynthesis in the Leydig cells (FAWCETT and BURGOS, 1960;CRABO, 1963;LEESON, 1963;BAILLIE, 1964;CHRISTENSEN, 1965CHRISTENSEN, , 1970CHRISTENSEN, , 1975NAGANO, 1965;MURAKAMI, 1966;CHRISTENSEN and FAWCETT, 1966;BELT andCAVAZOS, 1967, 1971;DE KRETSER, 1967a;MERKOW et al, 1968;SINHA and SEAL, 1969;BLACK and CHRISTENSEN, 1969;ICHIHARA, 1970;RUSSO, 1970;LORDING and DE KRETSER, 1972;GONDOS and CONNER, 1972;GONDOS et al, 1974;RHODIN, 1974;CONNELL and CHRISTENSEN, 1975;WEAKER, 1977 and the present author). According to these authors glycogen particles are generally abundant in fetal and immature animals, while in mature adults they become sparsely dispersed throughout the cytoplasm as shown in the present study.…”

“…The present author demonstrated the centriole within the juxtanuclear Golgi complex. The individual Golgi complexes of the Leydig cell have shown the same ultrastructure in a variety of animal species including man; they were composed of partially fenestrated flattened cisternae closely stacked in parallel (Golgi lamellae) and associated vesicles, a few of which were coated (BELT andCAVAZOS, 1967, 1971;CONNELL, 1972;USUI, 1976;WEAKER, 1977). Conspicuous, round clusters of vesicles in the Golgi complexes which have been shown by CHRISTENSEN and FAWCETT (1961) and USUI (1976) were also noticed in the mice, although their functional significance is unknown.…”

Mechanisms of aging in relationship to steroid biotransformations and the thiobarbituric acid reactive material in rate testicular tissue in vitro

“…The large population of Leydig cells in the boar appeared to be prolonged for several months after birth after which they decreased in number. Leydig cells in the testes of the young animals were present in larger numbers than in the adult, and the cells contained a poorly developed agranulated endoplasmic reticulum and dense bodies (Bell and Cavazos, 1966). Gillman (1948) showed in both man and horse that the fetal Leydig cells reached a maximum development at or about midterm of fetal life, but regression ensued thereafter.…”