Ultrastructural distribution of NADPase within the Golgi apparatus and lysosomes of mammalian cells.

Cytochemical studies with over 40 different mammalian cell types have indicated that NADPase activity is associated with the Golgi apparatus and/or lysosomes of all cells. In the majority of cases, NADPase is restricted to saccular elements comprising the medial region of the Golgi stack and an occasional lysosome. There is often weak NADPase activity in other Golgi compartments such as the trans Golgi saccules and/or elements of the trans Golgi network. In some cells, however, strong NADPase activity is found within these latter compartments, either exclusively in trans Golgi saccules or elements of the trans Golgi network, or in combination with medial Golgi saccules and each other including (1) medial Golgi saccules + trans Golgi saccules, (2) medial Golgi saccules + trans Golgi saccules + trans Golgi network, or (3) trans Golgi saccules + trans Golgi network. In some rare cases, no NADPase activity is detectable in either Golgi saccules or elements of the trans Golgi network, but it is observed in an occasional lysosome or throughout the lysosomal system of these cells. It is unclear at present if these variations in the distribution of NADPase across the Golgi apparatus, and between the Golgi apparatus and lysosomal system, are due to differences in targeting mechanisms or to the existence of "bottlenecks" in the natural flow of NADPase along the biosynthetic pathway toward lysosomes. While no clear pattern in the association of strong NADPase activity with lysosomes was apparent relative to the ultrastructural distribution of NADPase activity in Golgi saccules or elements of the trans Golgi network, the results of this investigation suggested that cells having NADPase localized predominantly toward the trans aspect of the Golgi apparatus (in trans Golgi saccules or elements of the trans Golgi network or both) have few NADPase-positive lysosomes. The only exception is hepatocytes which were classified as predominantly trans but had noticeable NADPase activity within medial Golgi saccules and elements of the trans Golgi network as well, and highly reactive lysosomes. Other cells showing highly reactive lysosomes including (1) Kupffer cells of liver and those forming the proximal convoluted tubules of the kidney, both of which also had strong NADPase activity within medial and trans Golgi saccules and elements of the trans Golgi network, (2) Leydig cells of the testis and interstitial cells of the ovary, which also showed strong NADPase activity within medial Golgi saccules, and (3) macrophages from lung, spleen and testis, and Sertoli cells from the testis all of which showed no Golgi associated NADPase activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrastructure of fresh and frozen-thawed spermatozoa of high and low fertility lines of chickens.

Level of damage caused by freezing and thawing to four spermatozoal organelles (individual mitochondrion, midpiece, nucleus, and perforatorium) and the relationships of the integrity of these organelles in fresh and frozen-thawed semen with fertility were examined. Semen sample from 10th generation males of a line of chickens selected for increased duration of fertility of frozen-thawed semen and the corresponding randombred control line were used. In both the selected and control lines, the freeze-thaw process caused significant (P less than .05) detrimental damage to the ultrastructure of the mitochondria, midpiece, and perforatorium but not to the nucleus. Types of damage were identical in both lines. Granulated nuclei were observed in both frozen-thawed and freshly ejaculated spermatozoa and were referred to as a nuclear defect. This nuclear defect was associated with reduced fertility, the effect being more severe with frozen-thawed semen. Where the incidence of the nuclear defect was greater than 2% in frozen-thawed semen, fertility was found to be very low or nil regardless of the degree of structural integrity of the mitochondria, midpiece and perforatorium. Highly significant (P less than .01) positive correlation coefficients were observed for percentage fertility 2 to 8 days postinsemination and duration of fertility in days with percentages of normal mitochondria (.80 and .92), midpiece (.79 and .87), nucleus (.86 and .94), and perforatorium (.84 and .97) for fresh semen. With frozen-thawed semen, the positive correlation coefficients were significant (P less than .05) for midpiece (.64 and .69) and nucleus (.63 and .71) and nonsignificant for mitochondria (.52 and .50) and perforatium (.20 and .30).(ABSTRACT TRUNCATED AT 250 WORDS)

Glycoprotein synthesis in Sertoli cells during the cycle of the seminiferous epithelium of adult rats: a radioautographic study.

Glycoprotein synthesis in Sertoli cells was investigated in rats sacrificed at various intervals (10, 30 min; 1, 4, 8, 24 h) after a single intratesticular injection of [3H] fucose. Thin sections of glutaraldehyde-fixed testes were radioautographed and the relative concentration of the label over the various cytoplasmic components of the Sertoli cells was analyzed quantitatively from electron microscopic photographs. The analysis was performed at the various stages of the cycle of the seminiferous epithelium grouped as follows: I-IV, V-VII, VIII-XI, XII-XIV. The incorporation of [3H] fucose into glycoproteins took place initially in the Golgi apparatus of the cells and the labeled glycoproteins later migrated to the lysosomes and plasma membrane. The corrected grain counts over the various cytoplasmic components of the Sertoli cell at various intervals after [3H] fucose injection, indicated that the synthesis of glycoproteins detected by radioautography after [3H] fucose injection was constant during the cycle of the seminiferous epithelium. Furthermore, the rate of transfer of the labeled glycoproteins from the Golgi apparatus to the lysosomes and plasma membrane was also noncyclic.

A cytochemical study of the Golgi apparatus of the spermatid during spermiogenesis in the rat.

The reactivity of the various components of the Golgi apparatus of rat spermatids for three phosphatase activities (nicotinamide adenine dinucleotide phosphatase, NADPase; thiamine pyrophosphatase, TPPase; cytidine monophosphatase, CMPase) and the incorporation of 3H-fucose by the spermatids was analyzed at the 19 steps of spermiogenesis, i.e., during and after this organelle elaborated the glycoprotein-rich acrosomic system. During steps 1-3, the Golgi apparatus produced, in addition to the proacrosomic granules, multivesicular bodies that became associated with the chromatoid body. NADPase was located within the four of five intermediate saccules of Golgi stacks, and TPPase was found in the last one or two saccules on the trans aspect of the stacks from steps 1 to 17 of spermiogenesis. CMPase was located within the thick saccular GERL elements found in the trans region of the Golgi apparatus from steps 1 to 7 of spermiogenesis, but the CMPase-positive GERL disappeared from the Golgi apparatus after its detachment from the acrosomic system at step 8. Th acrosomic system itself was reactive from CMPase and TPPase but was negative for NADPase, while the multivesicular bodies were CMPase and NADPase positive but unreactive for TPPase. Tritiated-fucose was readily incorporated within the Golgi apparatus of steps 1-17 spermatids; in steps 1-7 it was subsequently incorporated within the acrosomic system and multivesicular bodies. These various data indicated (1) that the Golgi apparatus of spermatids, although it loses its CMPase-positive GERL element in step 8, retains evidence of functional capacity until it degenerates in step 17; (2) that in early spermatids the various saccular components of the Golgi are specialized with respect to enzymatic activities; and (3) that each Golgi region may contribute in a coordinated fashion to the formation of the acrosomic system and multivesicular bodies.