acid-phosphatase and Cleft-Palate

A morphological, electron microscopic, and biochemical study was undertaken to analyze the genesis of hadacidin-induced cleft palate in hamster fetuses. Gross and light microscopic observations indicated that hadacidin affected the growth of vertical palatal shelves to induce cleft palate. Electron microscopic observations showed that initial hadacidin-induced changes were seen in the mesenchymal cells. Within 12 hr of drug administration, the perinuclear space was swollen and a lysosomal response injury was evident in the mesenchymal cells. Subsequently, 24 hr after hadacidin treatment, lysosomes appeared in the epithelial cells; changes were also seen in the basal lamina which included separation of the lamina densa from the basal cells, duplication of lamina densa, and complete loss of basal lamina. Between 36 and 42 hr post-treatment, the cellular and basal lamina changes subsided, and the epithelium of vertical shelves underwent stratification. Biochemical determination of enzyme acid phosphatase indicated that the levels of enzyme activity in both the control and treated palatal tissues corresponded to the appearance of lysosomes. Measurement of cAMP levels suggested that the peak activity of cAMP corresponded to that of enzyme acid phosphatase and cell injury. The cAMP activity in hadacidin-injured cells, however, was significantly lower in comparison to that of the dying cells of control palates. Hadacidin treatment also affected DNA synthesis in the developing primordia of the palate. It was suggested that hadacidin injures the precursor cells of the palate prior to the appearance of the primordia, and subsequently affects their proliferative behavior, stunting the vertical growth of the palatal shelves and inducing a cleft palate.

Topics: Acid Phosphatase; Animals; Cleft Palate; Cricetinae; Cyclic AMP; DNA; Female; Fetus; Glycine; Male; Mesocricetus; Microscopy, Electron; Teratogens

In the present study, the morphological, histochemical, biochemical, and cellular aspects of the pathogenesis of bromodeoxyuridine (BrdU)-induced cleft palate in hamster fetuses were analyzed. Morphological observations indicated that BrdU interferes with the growth of the vertical shelves and thus induces cleft palate. At an ultrastructural level, BrdU-induced changes were first seen in the mesenchymal cells. Eighteen hours after drug administration, the initial alterations were characterized by swelling of the nuclear membrane and the appearance of lysosomes in the mesenchymal cells of the roof of the oronasal cavity. During the next 6 hr, as the palatal primordia developed, lysosomes were also seen in the overlying epithelial cells. The appearance of lysosomal activity, which was verified by acid phosphatase histochemistry, was temporally abnormal and was interpreted as a sublethal response to BrdU treatment. Later the cellular alterations subsided; 48 hr after BrdU treatment, they were absent in both the epithelial and mesenchymal cells of the vertically developing palatal shelves. Subsequently, unlike controls (in which the palatal shelves undergo reorientation and fusion), the BrdU-treated shelves remained vertical until term. Biochemical determination of DNA synthesis indicated that although there was an inhibition of DNA synthesis at the time of appearance of palatal primordia, a catch-up growth during the ensuing 12 hr may have restored the number of cells available for the formation of a vertical palatal shelf. It was suggested that BrdU affected cytodifferentiation in the palatal tissues during the critical phase of early vertical development to induce a cleft palate.

Topics: Acid Phosphatase; Animals; Bromodeoxyuridine; Cell Division; Cleft Palate; Cricetinae; DNA; Epithelium; Histocytochemistry; Mesocricetus; Microscopy, Electron; Palate; Thymidine

A study was undertaken to analyze the ultrastructural aspects and the enzyme acid phosphatase cytochemistry and biochemistry of the pathogenesis of cyclophosphamide (CP)-induced cleft palate in hamster fetuses. The initial CP-induced alterations were the appearance of lysosomes in the mesenchymal cells of the vertically developing palatal primordia within 8 hr of drug administration. The mesenchymal lysosomal activity, which increased during the next 16 hr, was abnormal and interpreted as a sub-lethal response to CP treatment. Subsequently, the lysosomal activity in the mesenchyme diminished gradually and, 48 hr after CP treatment, was absent. At this time, lysosomes were seen in the epithelial cells of the vertical palate. Fifty-six hours after CP treatment, unlike controls where palatal shelves were already fused, lysosomal activity subsided in the epithelial cells. Changes, however, continued to be seen at the epithelial-mesenchymal interface. These changes were characterized by discontinuity in the basal lamina, and by epithelial-mesenchymal contacts. They persisted for 8 hr but were absent thereafter. Sixty-four hours after CP administration, the vertical shelves became horizontal and remained so until term. Following analysis of data, both from the literature and from the present study, it was suggested that CP first affected mesenchymal cell proliferation, and then its cytodifferentiation, during the critical phase of early vertical development; consequently the reorientation of the shelves to a horizontal plane was delayed, inducing cleft palate.

Topics: Acid Phosphatase; Animals; Cleft Palate; Cricetinae; Cyclophosphamide; Fetus; Histocytochemistry; Mesocricetus; Microscopy, Electron; Palate

The present study analyzes the morphological, histochemical, and ultrastructural aspects of the pathogenesis of 6-mercaptopurine (6MP)-induced cleft palate in hamster fetuses. Gross and light microscopic observations indicated that 6MP stunts the growth of vertical palatal shelves and thus induces cleft palate. Ultrastructural analysis showed that, in contrast to controls, 6MP-induced alterations were first seen in the mesenchymal cells 24 hr after drug administration. The initial alterations were characterized by swelling of the nuclear membrane. During the next 12 hr, lysosomes were seen first in the mesenchymal cells and then in the cells of the medial edge epithelium (MEE) of the developing palatal primordia. The appearance of lysosomes was temporally abnormal and was interpreted as a sublethal response to 6MP treatment. Subsequently, the nuclear alterations and the lysosomes diminished; and 48 hr after 6MP administration, they were absent from the palatal tissues. Ninety hours after 6MP administration, unlike the controls (in which the palatal shelves were already fused), changes were seen at the epithelial-mesenchymal interface in the developing cleft palatal shelves. These changes were characterized by breakdown of the basal lamina and epithelial-mesenchymal contacts. Eventually, at term, the MEE of the vertical shelf stratified. It was suggested that 6MP affected cytodifferentiation in the palatal tissues during the critical phase of early vertical shelf development and thereby induced cleft palate.

Topics: Acid Phosphatase; Animals; Cleft Palate; Cricetinae; Female; Gestational Age; Mercaptopurine; Mesocricetus; Morphogenesis; Pregnancy

Responses of the epithelial and mesenchymal cells of the developing hamster secondary palate to hadacidin, 5-fluorouracil, and hydrocortisone were analysed. Correlation of data on cellular response with morphological and biochemical observations suggested that several aspects of differentiation of palatal cells needs to be analysed before pathogenesis of teratogen-induced cleft palate can be defined.

Topics: Acid Phosphatase; Animals; Cleft Palate; Cricetinae; Cyclic AMP; Female; Fluorouracil; Gestational Age; Glycine; Hydrocortisone; Palate, Soft; Pregnancy; Teratogens

Sequential alterations in 5-fluorouracil-treated hamster fetal palate were studied by light and electron microscopy and by acid phosphatase cytochemistry. At an early stage in 5-fluorouracil-treated fetuses, when the palatal shelves were vertical, lysosomes first appeared in cells of the prospective fusion epithelium and then in the cells of subjacent mesenchyme. In contrast to controls, increasing numbers of both the epithelial and mesenchymal cells of the vertical palate showed lysosomal injury in 5-fluorouracil-treated fetuses as development progressed. Subsequently, the basal lamina in the vertical palate showed alterations, characterized initially by disturbances in lamina lucida, by fingerlike extensions of lamina densa, and ultimately by its complete breakdown. At a later stage, when shelves became horizontal, the lysosomes were absent in both the epithelial and mesenchymal cells, and the basal lamina continuity was restored. Unlike controls, however, 5-fluorouracil-treated horizontal shelves never contacted one another. Instead, the epithelia of the horizontal shelves underwent stratification. It appears that premature formation of lysosomes in palatal epithelial and mesenchymal cells following 5-fluorouracil treatment disrupts normal cytodifferentiation and affects the integrity of the basal lamina; both effects are associated with cleft-palate development.

Topics: Acid Phosphatase; Animals; Cleft Palate; Cricetinae; Fluorouracil; Histocytochemistry; Mesocricetus; Microscopy, Electron; Palate

Microdissection of lyophilized sections of fetal heads permits the analysis of relatively pure samples of epithelium and mesenchyme. These techniques were applied to a study of acid phosphatase and beta-glucuronidase activities in the developing palate in A/Jax mice. Acid phosphatase was found to be more concentrated in the palatal epithelium than the underlying mesenchyme. Conversely, beta-glucuronidase was more concentrated in the mesenchyme than the epithelium. A disparate developmental pattern of acid phosphatase and beta-glucuronidase activity was observed in the oral epithelium: acid phosphatase activity increased from intra-uterine Day 17 into neonatehood and beta-glucuronidase activity decreased towards term. Analysis of cortisone-induced palatal shelves showed increased activity of both acid phosphatase and beta-glucuronidase in the presumptive fusing epithelium.

Topics: Acid Phosphatase; Animals; Animals, Newborn; Cleft Palate; DNA; Epithelium; Fetus; Glucuronidase; Mice; Mice, Inbred Strains; Palate

One theory of the development of cleft palate in rats involves the action of lysosomal enzymes secreted by epithelial cells at the time of fusion of the palatal shelves. To test this theory we studied the biochemistry of the palates of fetal rats daily between days 14 and 19 (from 3 days before to 3 days after palate closure). Triamcinolone was administered once im on gestation day 14 to Wistar rats; 0.5 mg/kg body weight produced approximately 50% cleft palates. Pooled control palatal tissue was compared with pooled experimental tissue; that from fetuses with clefts being pooled separately from those not affected. Acid phosphatase and beta-glucuronidase were assayed. Concentration vs. time curves for both enzymes were very similar. Prior to the time of palate closure both enzymes were present in low concentration. Between days 16 and 17, the normal time of closure, there was an abrupt increased in enzyme concentration, with experimental tissue showing a significant elevation over control tissue on days 17 and 18. Alkaline phosphatase was also present in small amounts before closure and significantly higher in control tissue on day 17. Protein was depressed in palates having clefts on day 17; thus the ratio of enzyme activities to protein synthesis was significantly elevated at a critical time. Unaffected experimental palates had a normal ratio. These results suggest imbalanced acid phosphatase, beta-glucuronidase, and alkaline phosphatase activity compared with protein synthesis at the time of palate closure following triamcinolone in rats.

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Autopsy; Cleft Palate; Female; Glucuronidase; Palate; Phosphoric Monoester Hydrolases; Pregnancy; Proteins; Rats; Triamcinolone Acetonide

Topics: Acid Phosphatase; Animals; Cleft Palate; Female; Histamine H1 Antagonists; Histocytochemistry; Male; Palate; Piperazines; Rats

Topics: Acid Phosphatase; Alkaline Phosphatase; Cleft Lip; Cleft Palate; Esterases; Female; Fetus; Histocytochemistry; Humans; Lip; Maxilla; Nasal Septum; Palate; Pregnancy; Tooth Germ; Twins