The Anatomical Record : Advances in Integrative Anatomy and Evolutionary Biology

doi: 10.1002/ar.1091800301pmid: N/A

Flickinger, Charles J.

doi: 10.1002/ar.1091800302pmid: 4420809

The seminal vesicle secretes a variety of substances into semen, ranging from small molecules to enzymes. The formation of protein components of the seminal vesicle secretion was studied in male rats following an injection of leucine‐3H. Samples of seminal vesicle were fixed and prepared for light and electron microscope radioautography at intervals ranging between four minutes and two hours after the injection. In specimens prepared four minutes after administration of the precursor, the majority of silver grains overlay the rough endoplasmic reticulum. At subsequent intervals, the proportion of grains over the endoplasmic reticulum declined, and peaks of labeling were observed sequentially over the Golgi apparatus and over secretory vacuoles. The maximal labeling of the Golgi apparatus was attained between 10 and 30 minutes after the injection. Secretory vacuoles acquired their greatest radioactivity 30 minutes following administration of the leucine‐3H. Labeled secretions began to appear in the lumen 30 minutes after the injection, and they became heavily labeled by one hour. The results suggest that secretory proteins are synthesized in the rough endoplasmic reticulum and transported rapidly to the Golgi apparatus where secretory vacuoles are formed. The secretory vacuoles migrate to the apical ends of the cells and discharge their contents into the lumen. The transport and release of secretory proteins in the seminal vesicle is unusually rapid and exceeds the rate in many other protein secreting cells, including that of the ventral prostate.

Flickinger, Charles J.

doi: 10.1002/ar.1091800303pmid: 4370909

Proteins, including enzymes such as acid phosphatase, are among a variety of substances secreted into semen by the prostate gland. The formation, intracellular transport, and discharge of protein components of prostatic secretion were studied in the rat ventral prostate following an injection of leucine‐3H. Samples were prepared for light and electron microscope radioautography at intervals ranging from four minutes to two hours after the injection. In samples prepared four or ten minutes after administration of the precursor, most of the silver grains overlay the rough endoplasmic reticulum. Beginning 30 minutes after the injection, while label associated with the endoplasmic reticulum was declining, the proportion of grains over the Golgi apparatus began to increase, reaching a maximum in one‐hour samples. Secretory vacuoles at the apical ends of the cells became heavily labeled two hours after administration of the leucine‐3H. Labeling of secretions in the lumen of the prostatic alveoli was observed in samples taken two hours after the injection. These results indicate that secretory proteins in the prostate are synthesized in the rough endoplasmic reticulum, transported to the Golgi apparatus, and packaged into secretory vacuoles, which move to the apical ends of the cells and release their contents to the lumen. Additional analysis of the pattern of labeling of different elements of the Golgi apparatus suggests that some protein is transported sequentially from Golgi vesicles to stacks of cisternae and finally into Golgi vacuoles. Radioactive secretory proteins move through prostatic cells more slowly than through the seminal vesicle epithelium of the same animals. The main mode of protein secretion in the prostate appears to be a merocrine type, since apical protrusions such as have been suggested to participate in an apocrine form of secretion were observed infrequently and did not become heavily labeled.

Webber, W. A.; Lee, J.

doi: 10.1002/ar.1091800304pmid: 4418373

The parietal layer of Bowman's capsule in man and rat has been examined by transmission and scanning electron microscopy. In both species, cilia were found to be present in a regular pattern occurring one per cell. The cilia differed in length between the immature and mature human kidney, but were consistently located near the edge of the cell nucleus. Since they are not numerous enough to have a significant propulsive role, we have postulated that they may have some other specific function. In addition to the cilia, microvilli were regularly observed on the surface of the parietal cells. They tended to be more numerous along the margins of the epithelial cells and, in contrast to the cilia, their pattern was highly variable. This variability probably indicates that they are transitory structures which can be increased or decreased in response to as yet unknown stimuli.

Callas, Gerald

doi: 10.1002/ar.1091800305pmid: 4214514

Previously reported methods for the electron microscopic visualization of the surface layer (surfactant) of the alveolar lining cells have proved less than ideal and further development in this area is needed. Two percent agar in glutaraldehyde injected into the respiratory tree concurrently with vascular perfusion seems to offer some real advantage over techniques described by others. The combination of glutaraldehyde and agar acts both as an obstruction that holds surfactant against the alveolar surface and as a fixative due to the buffered glutaraldehyde component. This technique offers more consistent results and more extensive demonstration of the surfactant layer over the alveolar surface.

Bois, Richard M.; Pease, Daniel C.

doi: 10.1002/ar.1091800306pmid: 4424931

Glycol dehydration followed by rehydration prior to conventional fixation appears to demonstrate the essential identity of the thick filaments observed in unfixed, glycol dehydrated and conventionally fixed smooth muscle. Observed differences in the solubilities of actin and myosin filaments also suggest that the thick filaments of smooth muscle are not formed by the apposition of actin filaments or by the deposition of myosin upon actin filaments. Evidence that the thick filaments of smooth muscle are not formed by an unnatural aggregation of smaller myosin aggregates or by the dissociation of myosin “ribbons” during tissue preparation is also reported. Examinations of smooth muscle contracted or relaxed by pharmacological agents appear to indicate that the myosin content of smooth muscle is aggregated into filaments in both the contracted and relaxed cell.

Wezeman, Frederick H.; Kuettner, Klaus E.

doi: 10.1002/ar.1091800307pmid: 4138184

RivanolR, a fluorescent ethoxy derivative of acridine, interacts at different pH's with both glycosaminoglycans and proteins. The present study utilizes the specific interaction of RivanolR with acidic substances of the ground substance for histochemical studies of the cartilage matrix. This stain was applied to newborn mouse epiphyseal cartilages which were either unextracted or dissociatively extracted by graded concentrations of guanidinium chloride (GuHCl) from 0.5–3.0 M for four days at 25°C. Routinely prepared sections were then stained (0.1% solution) for two minutes at pH's ranging from 2.2–11.2. Stainability of the interterritorial matrix as well as the inner halo zone and outer corona zone of the lacunar matrix varied with pH. Whereas the interterritorial matrix decreased in stainability with rising pH, the halo and corona persisted in stainability up to pH 10.7. Dissociative extractions using GuHCl revealed the unextractable nature of the inner halo zone as well as the extractable nature of the corona above 1.0 M GuHCl concentration. Anionic sites on polyelectrolytes such as glycosaminoglycans are known to stoichiometrically bind many cationic dyes. The precise localization of stain‐reactive glycosaminoglycans or proteoglycans in the region of the perichondrocytic matrix by RivanolR supports prior observations using other cationic stains. Our data demonstrates that RivanolR enables one to visualize the unique perichondrocytic matrix which may be interpreted to be both chemically and morphologically a “matrix within a matrix”.

Benzo, Camillo A.; Green, Tim D.

doi: 10.1002/ar.1091800308pmid: 4609217

A radioimmunoassay for insulin, together with ultrastructural observations of the endocrine pancreas, were utilized to investigate developmental aspects of insulin storage and secretion in the chick embryo. Immunoreactive insulin was detected from the fifth embryonic day onwards, in both the pancreas and blood plasma. In addition, margination of well‐developed beta granules, and emiocytotic events were observed as early as the fifth embryonic day. The initial appearance of insulin, together with its subsequent developmental profile, correlate well with major metabolic events occurring in the embryonic chick, and are discussed in relation to a functionally responding system, the developing liver. The present data show that the chick endocrine pancreas has the potential for activity very early in development, and that insulin may be secreted at earlier embryonic stages than hitherto accepted.

Knudsen, J. F.; Costoff, A.; Mahesh, V. B.

doi: 10.1002/ar.1091800309pmid: 4419621

Ovarian and uterine morphological changes were examined in the maturing Holtzman rat, ages 22–40 days, using routine histological procedures. These findings were then correlated with serum follicle stimulating hormone (FSH) and luteinizing hormone (LH), in an effort to trace the sequence of events involved in the onset of puberty (i.e., the initiation of cyclicity) which occurred most consistently in our rats at 38 days of age. Ovaries exhibited no significant weight increases prior to day 36. However, microscopic changes became apparent as early as day 30, and continued to day 38, the day of the gonadotropin surge. During this time interval, the proportion of large type 6‐7 (potentially estrogen secreting follicles) increased dramatically relative to non‐antrum containing follicles. An increasingly hypertrophied and well differentiated theca interna of the larger follicles was also characteristic of this age interval. Closely paralleling the sequence of follicular maturation, quantitative and qualitative increases in all layers of the uterus occurred. As early as day 32, the luminal epithelium had increased some three to four‐fold over earlier age groups. Similarly, the stromal endometrium and myometrium increased significantly at this time. Further increments occurred through day 34, with a leveling off at this time.

Danon, David; Ekblad, E. B. Margareta; Strum, Judy M.

doi: 10.1002/ar.1091800310pmid: 4213640

Cationized ferritin was used to analyze the surface charges on the luminal epithelial cell membranes of urinary bladders from toad (Bufo marinus), bullfrog (Rana catesbiana), turtle (Pseudemys scripta and Clemmys caspica), and tortoise (Geochelone carbonaria and Testudo graeca). The labeling, done at a physiological pH on fixed or unfixed bladders, revealed differences in the distribution and density of negative charges along the luminal membrane surfaces. The epithelial surface of toad bladder did not label with cationized ferritin. Frog bladder labeled lightly and the labeling pattern varied between cell types. The epithelial membrane surfaces of reptile bladders were heavily labeled, in contrast to amphibian bladders. Luminal surfaces from fresh water turtles were not as heavily labeled as those from land tortoises. The degree of labeling varied from cell type to cell type in all reptile bladders except Pseudemys scripta. An analysis of the degree and pattern of labeling by cationized ferritin in bladders of all species studied might reflect a difference in the nature of the glycocalyx of a particular membrane, the presence or absence of negative surface charges or their availability (i.e., interference by mucus), and/or the nature of the chemical groups comprising the surface structure of the membrane.