Development of peptidergic systems in the rat brain

The brain contains a large variety and number of peptides some of which were known earlier as hypothalamic hormones (vasopressin, oxytocin, luteinizing hormone-releasing hormone, thyrotropin-releasing hormone, somatostatin) or as pituitary hormones (the family of opiomelanocortins), while others, not primarily known as hypothalamic or pituitary hormones, may also have endocrine effects (substance P, angiotensin II, neurotensin, bombesin, vasoactive intestinal peptide (VIP), gastrin-cholecystokinin, glucagon, carnosine, bradykinin). These peptides, which form a new class of putative neurotransmitters, are present early in brain development and show important sex differences in both their pattern of innervation and their effects. Their peripheral effects may include intrauterine growth of the placenta and fetus, the timing of birth, acceleration of the course of labour and responses to haemorrhage (redistribution of cardiac output and stimulation of blood cell formation). Endogenous peptides are probably involved in brain development, which may explain their general, permanent and sex-dependent effects when given in the period of rapid brain development. Although peptides might in the future be useful for stimulating recovery from retarded brain development, at present one should be aware of the potential dangers of their use in, for example, obstetrics.

Transforming growth factor alpha in developing rats

Transforming growth factor-alpha (TGF-alpha) concentrations were measured in lung, brain, liver, and kidney of rats at three different ages (20 days gestation and 9 and 50 days postnatal). TGF-alpha concentrations were maximal in the lung and brain by 20 days of gestation and showed minimal changes during nursing (day 9) and young adulthood (day 50). The liver, which also showed maximal TGF-alpha concentration by 20 days of gestation, demonstrated a progressive reduction with age to nadir values in the young adult. In contrast to the pattern in other tissues, kidney had the lowest concentration of TGF-alpha in late gestation and showed an increase by 50 days of age. As TGF-alpha acts via the epidermal growth factor (EGF) receptor, its function in development may be analogous to that of EGF. Thus TGF-alpha may have a role in lung maturation and postinjury repair, liver repair and regeneration, and neuronal cell growth.

Isolation and partial characterization of a human amelogenin from a single fetal dentition using HPLC techniques

A strategy based on high pressure liquid chromatography (HPLC) techniques for the isolation or a principal amelogenin molecule from a single human dentition is described. A partial sequence (33 residues) for this 24 kDa amelogenin is presented and related to earlier studies of human 5 kDa tyrosine-rich amelogenin polypeptides (TRAPs). A failure to identify amino acid residue #25 (tryptophan in other amelogenins) suggests that this 24 kDa amelogenin is the progenitor of the human TRAP-2 molecule and provides further support for the possibility of several human amelogenin gene products, generated by splice-junction selection, from the single amelogenin gene in the same individual. Alternatively, multiple amelogenins may arise by expression of both the AMELX and AMELY loci.

Immunohistological distribution of the secretory endometrial protein, 'pregnancy-associated endometrial alpha 2-globulin', a glycosylated beta-lactoglobulin homologue, in the human fetus and adult employing monoclonal antibodies

We have previously demonstrated that pregnancy-associated endometrial alpha 2-globulin (alpha 2-PEG), the human glycosylated beta-lactoglobulin homologue (HG-BLG), is quantitatively the major secretory soluble protein product of the secretory endometrium during the latter half of the menstrual cycle and decidua spongiosa of the gestational endometrium during early pregnancy, and is principally localized to the glandular epithelium. In the present study employing monoclonal antibodies in immunohistological techniques, the distribution and localization has been examined in normal and pathological tissues of the adult and first-trimester fetus. No significant staining for alpha 2-PEG was detected in any nonreproduction-associated tissue in the normal adult nor any tissue in the fetus. In the adult, most intense staining was associated with the endometrial glandular epithelium in the uterus or in ectopic sites in patients with endometriosis. During the menstrual cycle and pregnancy, appearance of alpha 2-PEG in endometriosis was strongly linked with its appearance in uterine endometrial tissue, suggesting that endometriotic tissue exhibited competence to respond to the same hormonal milieu required to induce synthesis in the uterine endometrium. Localization to the mucosal epithelium of the Fallopian tube was consistent with synthesis of alpha 2-PEG, albeit at low levels, and staining at this site reflected fluctuations of staining within the uterus. Of the pathological specimens examined, staining was only detected in a proportion of ovarian carcinomas. No staining was detected in the mammary gland, a site of beta-lactoglobulin synthesis, whether obtained during pregnancy or lactation.(ABSTRACT TRUNCATED AT 250 WORDS)

Localization of renin substrate in fetoplacental tissue

Specific polyclonal rabbit anti-human renin substrate-antibodies were used in order to study the distribution of renin substrate immunoreactivity in human fetal and placental tissue. Renin substrate was immunohistochemically detected in human decidua and placenta, as well as in 19 weeks old human fetal liver and kidney. The presence of renin substrate in fetoplacental tissue supports the concept of a locally functioning renin-angiotensin system.

Analysis of 3'-azido-3'-deoxythymidine levels in tissues and milk by isocratic high-performance liquid chromatography

A sensitive high-performance liquid chromatographic (HPLC) assay was established to analyze levels of the antiretroviral agent 3'-azido-3'-deoxythymidine (AZT, zidovudine) in serum, milk and tissue extracts. After methanol precipitation, serum samples could be injected directly into the HPLC apparatus, whereas tissue extracts required further clarification. Recovery of AZT was virtually complete. Isocratic elution with a mobile phase consisting of 6% acetonitrile and 0.1 M ammonium acetate, pH adjusted to 4.5 with glacial acetic acid, resulted in good resolution of AZT and its metabolites; retention times for AZT and the internal standard, p-nitrophenol, were 20 and 37 min, respectively. Using this method, we have demonstrated that AZT crosses both the blood-brain and placental barriers and is excreted into milk at high levels.

Expression patterns of the T antigen and the cryptic T antigen in rat fetuses: detection with the lectin amaranthin

The lectin amaranthin, purified from the seeds of Amaranthus caudatus, has been shown to react specifically with the Gal beta 1,3GalNAc-alpha and the NeuAc alpha 2,3Gal beta 1,3GalNAc-alpha sequence which represent the T antigen and the cryptic T antigen, respectively. We report here the development of labeling techniques that apply amaranthin to stain paraffin sections from rat fetuses. Amaranthin staining was inhibited by pre-incubation of lectin-gold complexes with 10 mM Gal beta 1,3GalNAc-alpha-O-benzyl (synthetic T antigen) or 10 mM Gal beta 1,3GalNAc-alpha-O-aminophenylethyl-human serum albumin (T antigen neoglycoprotein), asialoglycophorin, asialofetuin, and asialomucin. The beta-elimination reaction also abolished the lectin staining demonstrating specificity for O-glycosidically linked structures. A comparison with monoclonal anti-T antigen antibody immunostaining demonstrated that amaranthin detects the T antigen and its cryptic form in tissue sections. Application of the galactose oxidase-Schiff sequence abolished amaranthin (and anti-T antibody) binding to the T antigen but not to its cryptic form, and therefore permitted their differentiation in tissue sections. Histochemical evidence was obtained indicating that amaranthin is a more specific anti-T reagent than peanut lectin. Data are presented that show the differential expression of the T antigen and the cryptic T antigen in organs and cells of rat fetuses late in gestation. Therefore, amaranthin can be used for histochemical detection of the T antigen and the cryptic T antigen, and facilitates discrimination between them.

17 beta-hydroxysteroid oxidoreductases of human fetal and adult tissues: immunological cross-reactivity with an anti-human placental cytosolic 17 beta-hydroxysteroid oxidoreductase antibody

To determine whether the immunological determinants of human placental 17 beta-hydroxysteroid oxidoreductase (17 beta-HSOR) were present in 17 beta-HSORs of tissues of the human fetus and adult and of various non-human cells maintained in culture, western immunoblot analysis was conducted by use of a polyclonal antibody directed against determinants of the placental cytosolic enzyme. Tissues and cells were evaluated for the presence of immunocross-reactive proteins with a relative molecular mass (Mr) similar to that of placental 17 beta-HSOR (approximately 34,000). By use of homogenates of human fetal tissues, immunostaining of 17 beta-HSORs of Mr approximately 34 kDa was detected in trophoblast, fetal adrenal neocortex, fetal zone of the adrenal gland, liver, intestine, kidney, brain, lung, skin, heart, spleen, pancreas, chorion laeve, and, occasionally, amnion. Immunostaining at Mr approximately 34 kDa also was demonstrated by use of cytosolic preparations of fetal tissues and, in some cases, by use of unwashed microsomal fractions; this protein was either absent or present in almost undetectable amounts in washed microsomes, except for placenta and fetal brain. Immunostaining at approximately 34 kDa was demonstrated occasionally in decidua of pregnant women by use of homogenates, but was not detected in endometrium or myometrium of non-pregnant women, testis of an adult man, mouse and rat Leydig tumour cells, mouse and rat adrenal tumour cells, and normal bovine adrenocortical cells.

Human 'pregnancy-associated endometrial alpha 1-globulin', a 32 kDa insulin-like growth factor-binding protein: immunohistological distribution and localization in the adult and fetus

We have previously shown that pregnancy-associated alpha 1-globulin, a small molecular weight (32 kDa) insulin-like growth factor-binding protein (IGF-BP), is quantitatively the major secretory protein product of the decidualized endometrium during human pregnancy and is localized principally in the decidual cell. In the present study, employing monoclonal antibodies in immunohistological techniques, the distribution and localization of IGF-BP has been examined in normal and pathological tissues of the adult and first trimester fetus. In the adult, most intense reactivity was associated with endometrial stroma and their derived decidual cells in the uterus or in ectopic sites in patients with endometriosis. During the menstrual cycle, the appearance of IGF-BP in endometriotic tissue was linked with its appearance in uterine endometrial tissue. The only other adult cells where significant staining was detected was in the luteal cells of the corpus luteum. Production of the protein was not a feature of carcinomas. In the fetus, the protein was localized in lymphoid-myeloid progenitor cells and hepatocytes of the liver and at lower levels in testicular Leydig cells and adenocortical cells. These observations suggest highly specific tissue expression of this protein and support a specialized role for this protein in progenitor cells of the lymphomyeloid system, in certain steroid hormone-producing cells and in the decidual cell in pregnancy.

Expression of novel basement membrane components in the developing human kidney and eye

The distribution of two novel human, basement-membrane (BM) collagens has been characterized by immunohistochemical analysis of developing and mature tissue using monoclonal antibodies specific for the non-collagenous (NC1) domain of each molecule. A distribution more restricted than that of type IV collagen was observed. In the kidney, the 28K parent molecules appear relatively late, at the early capillary-loop stage of glomerular development, whereas type IV collagen is present in all BM, including those of the ureteric bud, S-form, primitive glomerulus, and vessels. Antibody to the Alport familial nephritis antigen (a 26K peptide), which is missing from epidermal BM and glomerular BM in Alport syndrome, reacted with the ureteral bud BM and all stages of glomerular BM development from the early capillary-loop stage onward, but not with BM of more primitive glomeruli (vesicles and S forms). In the human fetal eye, the collagen molecules from which the 28K NC1 peptides are derived appear later in development than type IV collagen. They are present in trace amounts in Bruch's membrane but are not detected until after birth in the retinal internal limiting membrane and cuticular and non-pigmented epithelial BM of the ciliary process. In contrast, the BM of the lens capsule and Descemet's membrane were reactive with anti-28K antibodies early in development. In all instances, the 28K peptides are detected in BM that also contain the Alport antigen, although the later is present in some BM not containing the 28K peptides. The distribution of Alport antigen and type IV collagen in developing eye is similar to that observed in the mature eye. The 28K parent molecules appear to be expressed in concert with the maturation of the BM, coincident with fusion of glomerular endothelial and epithelial BM, whereas the lens capsule BM and Descemet's membrane contain these restricted components much earlier in gestation.

Ontogeny of epidermal growth factor receptor and lipocortin-1 in fetal and neonatal human lungs

The ontogeny and distribution of the epidermal growth factor (EGF) receptor and lipocortin-1, a major cellular substrate of the EGF receptor, were evaluated in a developmental series of fetal and neonatal human lungs (8 to 41 weeks' gestation and stillborn to 16 days' postnatal age). The peroxidase anti-peroxidase technique with two polyclonal antibodies recognizing the EGF receptor and one polyclonal antibody recognizing lipocortin-1 were used for immunohistochemical localization. Extensive or scattered bronchiolar EGF receptor immunoreactivity appeared in the entire series of frozen lung specimens from 15 to 32 weeks' gestation. Bronchial glands exhibited EGF receptor immunostaining from 19 weeks onward, and immunoreactivity in bronchial epithelium was detected from 23 weeks onward. Most tracheas showed extensive lipocortin-1 immunoreactivity in the epithelium beginning at 10 weeks' gestation. Immunostaining was also seen in cells lining the ducts of submucosal glands after 15 weeks' gestation and in nonmucous acinar cells of tracheal glands after their appearance at 18 weeks' gestation. Bronchial epithelium exhibited lipocortin-1 immunoreactivity from 12 weeks' gestation onward. Bronchial gland necks became immunostained from 16 weeks' gestation onward, followed by acinar immunostaining as they subsequently developed. Bronchiolar epithelium was immunostained as early as 12 weeks, beginning with the largest airways, and by 24 weeks extending distally to the bronchioloalveolar portals. Lipocortin-1 immunostaining of larger conducting airway epithelium was primarily confined to ciliated cells. Neither EGF receptor nor lipocortin-1 immunoreactivity was detected in alveolar type I or type II cells, fibrocytes, chondrocytes, or smooth muscle cells at any gestational age. These developmental patterns suggest that the EGF receptor and lipocortin-1 may participate in normal growth factor-induced proliferation of the conducting airways and their glands in the human fetal lung and trachea.

Distribution of free amino acids in streptozotocin-induced diabetic pregnant rats, their placentae and fetuses

Amino acid levels in the non-pregnant streptozotocin (STZ)-induced diabetic rat have been shown to be abnormal. Our preliminary studies showed that placental transport, fetal serum levels and tissue uptake of the non-metabolizable amino acid alpha-amino isobutyric acid (AIB) were decreased in STZ-diabetic pregnant rats. In the present experiments, amino acid concentrations were measured in maternal (MS) and fetal (FS) sera and placentae (PL) by high performance liquid chromatography (HPLC) after triple extraction in 80% ethanol. Control (C), STZ-diabetic (D) and insulin-treated diabetic (DI) animals were studied at 22 days gestation. Pregnant diabetic rats had low serum levels of Gln, Lys, and Ser and insulin treatment corrected Gln and Ser but not Lys levels. Branched-chain amino acids did not show the large elevation characteristic of the non-pregnant diabetic rat. Placental levels of Tau, Gln, HPr, Thr and Lys were depressed in the diabetic animals and insulin treatment only partially improved these amino acid profiles. Placental amino acid levels did not always reflect maternal serum levels. Serum levels of most amino acids were lower in the fetus of the diabetic rat than in the fetus of the control rat. The notable exception was Ala which was higher in the fetuses of the diabetic animals. Insulin treatment of the mother did not correct many of the fetal amino acid levels even though maternal and fetal serum glucose levels at the time of autopsy were normal. The ability to maintain normal serum levels of many amino acids is impaired in the fetus of the diabetic rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of hyaluronic acid and chondroitin sulfate proteoglycans in the presumptive aganglionic terminal bowel of ls/ls fetal mice: an ultrastructural analysis

The terminal colon of the ls/ls mouse is aganglionic because an intrinsic defect prevents its colonization by cells migrating from the neural crest. Previous studies showed that laminin, type IV collagen, and glycosaminoglycans accumulate in the region of the presumptive aganglionic ls/ls bowel through which crest-derived cells would be expected to migrate. It was suggested that crest-derived cells might fail to enter the abnormal bowel because they receive inappropriate signals from a defective extracellular matrix. This hypothesis was evaluated by analyzing the ultrastructure of the extracellular matrix in mutant and control gut. Tissue was fixed in the presence of ruthenium red before or after selective enzymatic digestion. Heparan sulfate proteoglycan (diameter approximately equal to 15 nm) and chondroitin sulfate proteoglycan (diameter approximately equal to 20-50 nm) granules were found in both control and presumptive aganglionic gut. The heparan sulfate proteoglycan granules were primarily located within formed basal laminae, while chondroitin sulfate proteoglycan granules decorated plasma membranes and 5 nm hyaluronic acid microfibrils that formed a network in the extracellular matrix. At day E11.5, the mutant gut differed from the control in the following: 1) Hyaluronic acid microfibrils were longer and more numerous. 2) There were larger numbers of chondroitin sulfate proteoglycan granules associated with cell membranes and with hyaluronic acid microfibrils. By day E13 the spaces between mesenchymal cells of the outer wall of the control bowel contained a regular lattice of hyaluronic acid microfibrils studded with chondroitin sulfate proteoglycan granules. Instead of this lattice, tangles of excessively long hyaluronic acid microfibrils, coated more heavily than in the control with chondroitin sulfate proteoglycan granules, were found in the presumptive aganglionic gut. These results confirm that the extracellular matrix is abnormal in the presumptive aganglionic bowel of the ls/ls mouse; moreover, they also indicate that the defect involves not one, but several components of the extracellular matrix, as well as their distribution. The defective extracellular matrix is apparent at a time when crest-derived cells would be expected to be migrating in the terminal bowel and is located in their path. The observations thus support the idea that a localized abnormality of the extracellular matrix interferes with the colonization of the terminal bowel by crest-derived cells in the ls/ls mouse.

Transplacental transfer of human antinuclear antibodies in mice by injection of lupus IgG in pregnant animals

Pregnant female Balb/c mice were injected with IgG fractions from patients with systemic lupus erythematosus, in order to study the in vivo passage of antinuclear antibodies (ANA) across the placenta. After injection of monospecific sera directed against nDNA, Sm, nRNP, Ro(SSA) and La(SSB), ANA were found in fetal circulation and trapped in the liver, spleen kidney and skin of fetus. Also, ANA were demonstrated in placental tissue and cord. The placental IgG-Fc receptors apparently played a major role in ANA entry into the fetus. Our study demonstrates that human ANA can be passively transferred into experimental animals to study their kinetics during pregnancy.

Acid hematin pigmentation of the cornea in stillborn fetuses

During the postmortem histopathologic evaluation of eyes from stillborn fetuses we noted the presence of a prominent undescribed corneal pigment in 18 of 55 stillborn fetuses. The corneal pigment was frequently associated with documented meconium-stained amniotic fluid, and in no instance was a stained cornea coupled with recorded clear amniotic fluid. Pigmented corneas came from stillborn fetuses with a longer duration of intrauterine death than nonstained corneas. The pigment stained black with the Fontana-Masson stain, was birefringent, and treatment of tissue sections with 5% potassium permanganate and 5% oxalic acid as well as with saturated alcoholic picric acid solution removed the pigment indicating that it is acid hematin. The most likely cause of the acid hematin-stained corneas was tissue acidity created in utero with prolonged intrauterine death.

Relative abundance and molecular size of immunoreactive insulin-like growth factors I and II in human fetal tissues

Previous studies which have quantitated tissue mRNA transcripts have suggested that IGF II is expressed in substantially greater amounts than IGF I during human fetal development. However, this has not been tested directly by recovery and quantitation of IGF peptides from fetal tissues. Tissues from human fetuses were extracted in 1 M acetic acid, and insulin-like growth factor (IGF) I and II immunoreactive species separated from the supernatants by acidic gel filtration. When total immunoreactive IGF I or II eluting from Sephadex G50 between approximately 6 and 15 kDa molecular weight was estimated, allowing for likely blood contamination, tissues from five fetuses contained, on average, 230 fM/mg cell DNA IGF I and 690 fM/mg IGF II. The ratio of IGF II: IGF I peptide content varied from 1.6 in muscle to 7.8 in thymus. Separation of tissue supernatants, fetal plasma and fetal fibroblast-conditioned culture medium on Sephadex G75 revealed that immunoreactive IGF II eluted with molecular weights between 8 and 15 kDa, in addition to 7.5 kDa. While fetal tissues contain more IGF II than IGF I immunoreactivity, the likely presence of IGF II peptide does not agree with the great excess of mRNA for IGF II reported previously.

Developmental patterns for pancreatic opioids in the rat

Developmental patterns for rat pancreatic opioid peptides and islet hormones were studied from gestational day 20 through adulthood. Fetal tissue was obtained as well as pancreas at birth (day 0), and postnatal days 3, 7, 14, and 21, and 7 weeks. The hormones measured included insulin, glucagon, and somatostatin. The opioids measured were beta-endorphin, Met- and Leu-enkephalins, and the high molecular weight enkephalin precursors. Pancreata were pooled as necessary and extracted (acid alcohol, or hot acetic acid), and opioids were further purified on reversed-phase C-18 (Sep-pak) cartridges. In all instances measurements were made by radioimmunoassays. Precursor peptides were first digested (with trypsin and carboxypeptidase B) prior to immunoassay. All opioids and hormones except the precursors for enkephalins showed a well-defined surge in pancreatic concentration during the first postnatal week. In contrast, the precursors had the highest concentration in the fetus, and by the seventh day of life had decreased by greater than 50%. This progressive decrease may represent maturation of the enkephalin convertase and trypsin-like enzymes in the islets. The opioid and hormonal surges that we have described are similar to the surge in islet concentration of thyroid-releasing hormone (TRH) previously described in neonatal rat islets. It is suggested that these postnatal alterations in opioid and hormone concentration relate to a specific function in the development of the endocrine pancreas.

Ontogeny of ACTH(1-24) receptors in rat adrenal glands during the perinatal period

Binding of ACTH to receptors was studied on crude adrenal membranes from fetal and newborn rats. 125I-Labelled ACTH(1-24) was used as the radioligand, the steroidogenic potency of which was 100-fold lower than that of unlabelled ACTH(1-24). Binding was specific, rapidly equilibrated and temperature dependent. Scatchard analysis of the binding data revealed a single class of binding sites with a dissociation constant of about 100 nmol/l at all stages of development studied. The concentration of ACTH receptors expressed per mg membrane proteins decreased in fetuses between days 17 and 21 of gestation and remained stable in newborn rats from weeks 1 to 4. The number of ACTH receptors expressed per adrenal increased regularly in fetal and newborn rats. The perinatal evolution of these concentrations of ACTH receptors is related to the increase in the size of the adrenals and the changes in cytoplasmic structures of the adrenocortical cells. When the number of ACTH-binding sites was expressed per microgram DNA, maximum values occurred in fetuses on day 19 of gestation, and minimum values in newborn rats, 1 week after birth. There was an excellent correlation between the plasma levels of immunoreactive ACTH and corticosterone and the number of ACTH receptors per microgram DNA during the perinatal period. Other results suggest that ACTH is able to up-regulate the number of its own receptors.

Localization of collagen types in regional segments of the fetal bovine aorta

Types I, III, and IV collagens were localized immunocytochemically in muscular and small arteries of fetal bovine tissues and in different regional segments of the aorta. The distribution of these collagens was found to be unique, not only with respect to collagen type and fiber orientation but also to the specific region of the vessel being examined. Collagen types I, III, and IV often codistribute in the intimal and medial regions of blood vessels, whereas types I and III show selective association in fibers with varied morphology in the adventitial layer. Specific segments of the aorta (proximal thoracic versus distal abdominal) were examined to determine the relative distribution and morphologic presentation of the collagens. In the ascending region of the aorta proximal to the heart, the types I, III, and IV collagen colocalized in the intimal and medial layers. Types I and III collagen predominated in the relatively small adventitial layer, whereas type IV collagen was found only in association with the media of small blood vessels and capillaries in this layer. In the descending thoracic region of the aorta distal to the arch, types I and IV collagens were distributed throughout the intimal and medial layers, whereas type III collagen localization was variable depending on the antibody used for detection. The adventitia stained predominantly for type III collagen that was distinctly organized in folded arrays of fibers. These same fibers stained less intensely with antibody to type I collagen. The abdominal aorta near the common iliacs stained in a fashion similar to that of muscular arteries of the organs and tissues examined, i.e., types I and IV collagen were found in the intimal and medial layers, whereas type III collagen localized heavily to the adventitial layer, with differential staining in the intima and media depending on the antibody used. Additional staining of the adventitial region of the abdominal aorta with type I and type IV collagen antibodies was the same as in the proximal and descending regions. Since the abdominal aorta sustains decreased levels of pulsatile distension compared with the ascending thoracic aorta, type III collagen distribution and its association with other matrix components may be important in regulating the range of distensibility of the vessel wall.

Carbofuran poisoning of pregnant woman and fetus per ingestion

A case of carbamate pesticide poisoning of a pregnant woman by carbofuran ingestion is presented. The mother recovered from the poisoning in the hospital but necrosis of the fetus was found. Toxicological findings of the liver, brain, and kidney of the fetus revealed carbofuran in concentrations comparable with the mother's blood. Our findings in the case contribute to the research on permeation of the placental barrier by chemical substances.

Extraadrenal steroid 21-hydroxylation is not mediated by P450c21

The 21-hydroxylation of progesterone to deoxycorticosterone (DOC) and of 17-hydroxyprogesterone to 11-deoxycortisol in the human adrenal cortex is mediated by a single enzyme termed P450c21. Extraadrenal tissues can clear circulating progesterone and progesterone sulfate by 21-hydroxylation to DOC and DOC-sulfate. It has previously been established that such extraadrenal 21-hydroxylase activity is widely distributed in adult and fetal tissues, but it has not been known if extra-adrenal 21-hydroxylation is mediated by the same P450c21 enzyme found in the adrenal. We examined human RNA from fetal adrenal, liver, kidney, lung, brain, heart, skin, spleen, testis, and placenta by solution hybridization to human P450c21 probes transcribed from cloned human P450c21 cDNA, followed by nuclease protection and acrylamide gel electrophoresis. No P450c21 mRNA was detectable in any extraadrenal tissue. The sensitivity of the assay would have detected P450c21 mRNA at 0.01% of its abundance in the human fetal adrenal. Similar experiments in rats showed no P450c21 mRNA in brain, heart, kidney, liver, lung, testis, ovary, or uterus. These results clearly demonstrate that one or more enzymes other than the classical adrenal 21-hydroxylase are responsible for human and rat extraadrenal 21-hydroxylation.

An analysis of total RNA translation products of rat liver during regeneration with a comparison to fetal liver

We explored differences in the mRNA populations of regenerating, sham-operated, and fetal rat liver using two-dimensional gel electrophoresis to resolve the radiolabeled protein products of liver total RNA translated in vitro. Twenty-four translation products were changed significantly after partial hepatectomy and sham hepatectomy. Nine of the 24 products changed after partial hepatectomy only, while the remainder also changed after sham hepatectomy. Two of the nine increased during regeneration to relative levels similar to those found in fetal liver. However, substantial differences also exist between the translation products of regenerating and fetal liver. These results suggest that the response to partial hepatectomy involves the alteration of mRNAs present in normal liver and that this response does not duplicate the fetal pattern of hepatic total RNA translation activity.

Expression of insulin-like growth factor-II mRNA in fetal kidney and Wilms' tumor. An in situ hybridization study

The pattern of insulin-like growth factor II (IGF-II) mRNA expression in developing kidney and Wilms' tumor was examined with in situ hybridization. In developing kidney, IGF-II was primarily expressed in blastemal cells and lost with their differentiation. In triphasic Wilms' tumor, a similar relationship was found. But in a monomorphous Wilms', tumor cells with epithelial differentiation expressed IGF-II mRNA. These data suggest that IGF-II may be involved in fetal nephrogenesis, that its expression is inversely coupled to normal epithelial differentiation, and that this differentiation may be aberrantly regulated in Wilms' tumor.

The expression of the neu oncogene product in breast lesions and in normal fetal and adult human tissues

The expression of the neu oncogene product was investigated in invasive and non-invasive ductal carcinomas of the breast, non-neoplastic lesions of the breast, fragments of normal adult and fetal breasts and in several other normal and fetal tissues at different weeks of pregnancy by means of an immunohistochemical study with monoclonal antibodies. The staining pattern along the cytoplasmic membrane was specific for malignancy and occurred in 29% of the breast carcinomas. It was observed in invasive carcinomas as well as in ductal carcinoma in situ and it showed a significantly higher expression in premenopausal women than in postmenopausal women. This higher expression was also present in oestrogen receptor-negative tumours. The tubules of the fetal and adult kidney, the absorption cells of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult skin, the adult endocervix, the endometrium, the C-cells of the thyroid, hepatocytes and all ductal cells of the fetal breast showed a constant diffuse intracytoplasmic granular staining. staining. The same granular intracytoplasmic staining pattern was focally observed in rare cases of normal breast tissue in adults and in some cases of epitheliosis, aprocrine metaplasia and some breast carcinoma cells, which did not express neu oncogene product on their membrane. Western blot experiments showed that the cytoplasmic protein had a molecular weight of 155 kD (kilodaltons); the membrane protein is the known 185 kD neu protein.

Localisation of chromogranin A and B, met-enkephalin-arg6-gly7-leu8 and PGP9.5-like immunoreactivity in the developing and adult rat adrenal medulla and extra-adrenal chromaffin tissue

The localisation of chromogranins A and B, met-enkephalin-arg6-gly7-leu8 (met-enk 8) and protein gene product 9.5 (PGP 9.5) in the adrenal medulla and extra-adrenal chromaffin tissue has been studied in the developing rat by immunogold-silver staining. In the adult rat adrenal the cytoplasm of all medullary chromaffin cells showed a positive response with chromogranin A and B; in each case occasional groups of cells with a low reactivity that may have been NA cells were seen. Chromogranin A was first detected in adrenal medullary and extra-adrenal chromaffin cells at 18 days of gestation whilst chromogranin B was not detected in animals younger than 7 days. In 15 days old animals the adrenal medullary response to A and B was of the same intensity as that seen in the adult. Less than 1% of adult medullary chromaffin cells were responsive to met-enk 8 staining and medullary cells were unreactive in the fetus, with only extra-adrenal chromaffin tissue responding prenatally. During the first postnatal week immunoreactive cells appeared in the adrenal medulla in considerably greater proportions than in the adult gland. In contrast, positively stained nerve terminals associated with chromaffin cells and abundant in the adult adrenal were not detected during the first week of life. Immunoreactive nerve terminals were first seen early in the second week of life at a time when positive chromaffin cells were becoming less common. PGP 9.5 was located in all chromaffin cells of the adult adrenal and was readily detected in chromaffin cells in the adrenal and in extra-adrenal locations of the earliest stage examined (E16). Our findings suggest that the ontogenesis of the chromogranin-like immunostaining reflects the maturation of chromaffin granules and the PGP 9.5 immunostaining detected a protein common to cells of neuronal origin and expressed at an early stage of differentiation. The reciprocal relationship between the presence of enkephalins in chromaffin cells and in their presynaptic terminals merits further investigation.

Histochemical study of the differentiation of microglial cells in the developing human cerebral hemispheres

Applying nucleoside diphosphatase (NDPase) histochemistry, the appearance and differentiation of microglial cells in the developing human cerebral hemispheres were investigated by light and electron microscopy. In the pallium of the 38 days old human embryo, a few round NDPase-positive cells (round cells) were observed in the expanding zone. Although distinct blood vessels had not yet formed within the wall of the pallium, some cellular elements resembling haemopoietic cells were noticed in the expanding zone. In the 51 days old fetus, blood vessels displaying NDPase activity were seen in the mantle and marginal layers, and some invaded the matrix. Several round NDPase-positive cells were distributed, mainly around the vascular sprouts (primitive blood vessels) in the matrix. In the marginal layer, NDPase-positive cells exhibiting short cytoplasmic processes were encountered (poorly ramifying cells). In the 58, 66 and 82 days old fetuses, the round NDPase-positive cells were seen mainly in the matrix or subcortical layer where vascular sprouts were conspicuous and the poorly ramifying cells were in the subcortical and marginal layers. In the two latter fetuses, NDPase-positive cells showing long highly ramifying cytoplasmic processes (highly ramifying cells) were noted mainly in the marginal layer and sometimes in the subcortical layer. In the 5 months old fetuses, numerous NDPase-positive cells were distributed in the mantle, subcortical and marginal layers, and most of them appeared to belong to the populations of the poorly or highly ramifying cells. On the basis of the ultrastructural features, the round cells and highly ramifying cells were regarded as amoeboid cells and microglial cells, respectively. These findings suggest that at least some amoeboid cells are transformed into microglial cells via the stages of poorly ramifying microglial cells, and also that, in the human cerebral hemispheres, appearance of the microglial elements is closely related with vascularisation, especially in the early developmental stages.

Immunohistochemical localization of transport mediators in Wilms' tumor: comparison with fetal and mature human kidney

Immunostaining for Na+, K+-ATPase, carbonic anhydrase (CA) II, and band 3 anion channel glycoprotein was compared in developing and mature human kidneys and in Wilms' tumors. In fetal kidneys, ATPase first appeared in proximal and distal tubules. At birth an adult pattern was present with abundant enzyme in all segments of the distal tubule and lesser amounts in proximal and collecting tubules. CA II was detected in fetal kidneys first in proximal and then in distal tubules and eventually, as in the adult, throughout the nephron. Band 3 glycoprotein was not detected in fetal kidneys and only weak staining was present in the basolateral plasmalemma of intercalated cells in newborn and infant kidneys. The number of cells reactive for band 3 and the intensity of staining in a given cell increased to near adult levels at about 2 years. This finding may provide a partial explanation for the 'physiological acidosis' characterized by a low systemic pH in newborn and young infants. ATPase was present in basolateral membranes of most epithelial cells in nonanaplastic Wilms' tumors but was absent in the epithelial component of two anaplastic Wilms' tumors. CA II was detected only in a few epithelial cells in four tumors. Neoplastic epithelial cells reactive for CA II also stained for ATPase but not vice versa. Band 3 glycoprotein was not detected in any Wilms' tumor. These findings show that the immunohistochemical assessment of protein involved in electrolyte transport provides a further means for determining the relative level of differentiation of tumor cells of epithelial origin and suggest that these methods may be a valuable aid in determining the prognosis of some carcinomas.

The receptor for epidermal growth factor is present in human fetal kidney, liver and lung

In animals a pharmacological doses of the growth-promoting peptide epidermal growth factor (EGF) has an effect on the growth and/or maturation of several organs such as the lung, the kidney, the liver and the gastrointestinal tract. Since EGF elicits its function via binding to specific cellular receptors the presence of these receptors predicts a possible physiological role for EGF and EGF agonists. We have studied the presence of the EGF-receptor on human fetal membrane preparations from the kidney, the liver, the lung and the placenta (gestational age 13-20 weeks). The 4 membrane preparations all bind labeled EGF thus allowing us to calculate the apparent affinity constant and the number of receptors present per mg of membrane protein. The apparent affinity constant (gestational age 13-20 weeks) varies between 0.5 and 3.5 X 10(9) mol-1, median 1.3 X 10(9) mol-1 (n = 40). No difference is observed for the 4 tissues examined, and no difference is found as a function of the gestational age. The number of receptors present per mg of membrane protein (gestational age 16-20 weeks) are (range and (median) 90-220 (130) fmol, n = 10 for the kidney, 80-480 (250) fmol, n = 9 for the liver, 90-690 (300) fmol, n = 10 for the lung, and 2100-4200 (3400) fmol, n = 7 for the placenta. Results for a fetus of gestational age 13 weeks show high values for kidney receptors (240 fmol) and lung receptors (800 fmol) and low values for the placenta receptors (410 fmol).

[Cyclic AMP and cyclic GMP level in cells of spontaneously aborted fetuses with trisomic and triploid karyotypes]

Contents of intracellular cAMP and cGMP were studied in cultivated fibroblasts from 4 spontaneous abortuses with trisomy 7 and trisomy 9 as well as in 4 triploid cell strains. Six diploid cell strains from medical abortuses were used as controls. Distinct increase in cAMP content both calculated per I mg of cell protein or per a cell was found in trisomic strains, whereas the cAMP content increase in triploid strains was detected only per a cell. The data obtained suggest that functions of membrane complexes were impaired in the cells with anomalous karyotype.

Pattern of expression of c-erbB-2 oncoprotein in human fetuses

The pattern of expression of the c-erbB-2 oncoprotein was investigated in whole mount preparations of 11 human fetuses by immunocytochemistry using two polyclonal antibodies, 20N and 21N. c-erbB-2 was widely expressed within all three germ layers. Expression remained relatively constant in epithelial, mesodermal and extraembryonic tissues, but varied over time during the development of the fetal skeleton. Western blotting failed to detect c-erbB-2 in normal fetal tissues but did confirm expression in a microvillous membrane preparation of placenta. c-erbB-2 expression is widespread in the human fetus and occurs at an earlier stage than epidermal growth factor receptor.

EGF- and TGF-alpha-like peptides in human fetal gut

The presence of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) immunoreactivities in fetal human tissues was studied immunohistochemically at different gestational ages. EGF and TGF alpha immunoreactivities were detected from the 20th gestational wk. EGF immunoreactivity was limited to the small intestine, but TGF alpha immunoreactive cells were present in the colon also. According to radioreceptor assay, the intestine of a 19-wk-old human fetus contained 10 times more EGF receptor-binding substance than EGF, as measured by immunofluorometric assay. Chromatographic analysis suggests that TGF alpha-like peptides account for at least part of this activity, as so argues in favor of the presence of TGF alpha- and EGF-like peptides in the human fetal gut. Whether they are synthesized in the fetus is yet unknown.

Presence of acetylated and shortened endorphins in human fetal pituitary gland

A total of 21 human fetal pituitaries was collected from spontaneous abortions (11 cases) or prostaglandin (PG)-induced abortions at the second trimester. Pituitaries were homogenized, fractionated by HPLC, and the fractions were tested by specific RIA for alpha-endorphin (EP) (beta-EP 1-16), gamma-EP (beta-EP 1-17), beta-EP (beta-EP 1-31), and their alpha-N-acetylated derivatives. In the fetal pituitaries collected after spontaneous abortion, the contents of alpha-EP (23.4 +/- 7.5 pmol/mg protein, mean +/- SE) and gamma-EP (28.9 +/- 9.7) were similar to those of beta-EP (28.6 +/- 7.4). Both beta-EP/alpha-EP (1.2 +/- 0.3) and beta-EP/gamma-EP (1.1 +/- 0.3) ratios approached unity. Although 35.7 and 30.2% of alpha-EP and gamma-EP were acetylated, acetyl-beta-EP was only 8.4% of the total beta-EP immunoreactivity. In the five cases of PG-induced abortion that were more than 20 wk of pregnancy, the pituitary content of beta-EP (75.9 +/- 21.2) and gamma-EP (26.2 +/- 7.5) were significantly higher than in samples collected after spontaneous abortion (13.3 +/- 8.2 and 5.9 +/- 1.8, respectively, p less than 0.01). On the contrary, neither alpha-EP (31.3 +/- 5.2), acetyl-alpha-EP (0.94 +/- 0.28), acetyl-gamma-EP (0.65 +/- 0.07), acetyl-beta-EP (0.35 +/- 0.05) pituitary contents in PG-induced abortions differed from those measured after spontaneous abortion (alpha-EP: 25.6 +/- 6.6; acetyl-alpha-EP: 0.92 +/- 0.41; acetyl-gamma-EP: 0.82 +/- 0.30; acetyl-beta-EP: 0.96 +/- 0.44).(ABSTRACT TRUNCATED AT 250 WORDS)

Low polarity ligands of sex hormone-binding globulin in pregnancy. Part I--Characterization

Certain previously unidentified substances of low polarity binding to the sex hormone binding globulin (SHBG) in pregnancy were investigated. This material consisted of four major peaks (designated 1a, 1b, 2 and 3) as defined in maternal serum on Sephadex LH-20 chromatography. They were characterized with respect to changes in their concentration at various gestational ages and at premature and term labour in maternal serum, cord serum, placenta and maternal urine. Levels were much higher in placenta than in serum, suggesting that all four peaks were of placental origin. In the serum of mothers not in labour, while there was a significant increase in the mean serum concentration of peak (1a + 1b) and peak 3 for 12-24 weeks to 30-38 weeks gestation, there was no significant difference in the mean level of peak 2. However, there was a significant decrease in the serum levels of peak 2, but not peaks (1a + 1b) and 3, from 30-38 weeks gestation to 39-41 weeks gestation (P less than or equal to 0.05). In the serum of mothers in premature labour (30-38 weeks gestation), the levels of peak 2 but not those of peak (1a + 1b) and 3, were decreased (P less than or equal to 0.01) compared to those not in labour. These findings are consistent with the identification of peak 1a as 5 alpha-dihydroprogesterone, peak 1b as progesterone and peak 3 as 2-methoxyestrone as described in part 2. The decrease in the levels of peak 2 (for which the identification remains unconfirmed) in association with premature and impending term spontaneous labour suggest that it may be involved in the maintenance of pregnancy.

Developmentally regulated expression of the neural cell adhesion molecule (NCAM) by mouse thymocytes

The expression of the neural cell adhesion molecule (NCAM) has been investigated during thymus ontogeny. NCAM mRNA was readily detectable at day 19 of gestation, the youngest age studied. Its level declined after birth to become undetectable at 3 weeks of age. Cell surface expression of NCAM protein was detected on 14% of day 15 fetal thymocytes and peaked during the perinatal period, when around 40% of the thymocytes expressed low to medium levels of NCAM. At postnatal day 2, the vast majority of the NCAM+ cells were also CD4+ and CD8+. At embryonic day 15, NCAM appeared also to be expressed by CD4- thymocytes since 14% of the cells were already NCAM+ whereas CD4 was virtually undetectable. In frozen section of the newborn thymus, surface staining for NCAM was present on a subpopulation of cells in the cortex, rare in the medulla and absent from the sub-capsular area. In conjunction with other cell adhesion molecules, NCAM could play a role in cell interactions during thymic development.

Placental transfer and fetal effects of maternal sodium beta-hydroxybutyrate infusion in the baboon

We examined the effects of maternal sodium beta-hydroxybutyrate (NaBOHB) on the primate fetus to investigate the impact of ketosis not associated with acidosis on fetal metabolism. After a loading dose (600 mg/kg), NaBOHB was infused for 70 min (300 mg/kg.hr) into the maternal femoral vein of eight pregnant baboons, and placental transfer and fetal and maternal metabolic changes were observed during an acute experimental protocol. Maternal arterial levels rose from 0.70 +/- 0.21 to 5.42 +/- 0.93 mM (p less than 0.001), and fetal arterial levels from 0.34 +/- 0.09 to 2.76 +/- 0.64 mM (p less than 0.01). A maternal-fetal gradient of approximately 2:1 was observed in both baseline and steady-state infusion conditions and is similar to the human maternal-fetal ketone gradient. This is in contrast to the sheep where significantly higher gradients have been described. The elevated lactate, from 1.90 +/- 0.34 to 2.88 +/- 0.54 mM (p less than 0.05) and somewhat decreased pO2 values in the fetus from 54.8 +/- 8.9 to 45.0 +/- 3.8 mm Hg (p greater than 0.05 less than 0.1), without change in oxygen consumption (2.00 +/- 0.28 versus 1.73 +/- 0.15 mM/min) are features common to conditions of increased levels of fetal energy substrate. NaBOHB does not appear to contribute to oxidative energy metabolism of the whole fetus but may contribute to lipid stores. The significance of higher levels of BOHB in the primate fetus compared to the sheep fetus remains to be elucidated.

The fate of intravenously injected tissue ferritin in pregnant guinea-pigs

The organ distribution of intravenously injected hepatic ferritin either labelled with 59Fe or with 59Fe and 125I, was studied in pregnant guinea-pigs. At 5 h 71.2% of injected 59Fe was present in the placenta and fetus. Transfer of 59Fe to the fetus was slow, with 11.2% present at 5 h and 38.6% at 21 h. Analysis of a placental cellular lysate for 59Fe and 125I revealed that the injected iron was present as intact ferritin at 2 h but by 21 h the ferritin had been catabolized, the 125I excreted and the 59Fe incorporated into endogenous ferritin. Most of the fetal 59Fe counts were detected in the liver, with 35.3% of the transferred 59Fe in ferritin, 30.4% in haemoglobin and 10.6% in a low molecular weight pool. The uptake of labelled ferritin by the placenta was inhibited by a 300-fold molar excess of unlabelled ferritin but not by albumin, asialofetuin or by the injection of carbon particles. A nonsignificant reduction in uptake was noted after injection of mannosylated bovine serum albumin. The mannosidase inhibitor swainsonine had no effect. Iron transfer to the fetus was not affected by various microtubular inhibitors. Presaturation of endogenous transferrin with oral carbonyl iron prevented iron release from the feto-placental unit back into the maternal circulation. In consequence, marrow 59Fe uptake by the maternal marrow was reduced. The ferrous chelator 2,2'-bipyridine significantly reduced 59Fe transfer to the fetus and this occurred irrespective of whether the chelator was given prior to or after 59Fe ferritin administration. The ferric chelator desferrioxamine had no such effect. Electron microscopy of placental tissues revealed endocytosis of ferritin molecules. These results indicate that the guinea-pig placenta takes up homologous tissue ferritin and transfers the iron slowly to the fetus after reductive mobilization. The process is compatible with a receptor-mediated pathway.

Atrial natriuretic factor during the perinatal period: equal depletion in both atria

Data in the literature concerning atrial natriuretic factor (ANF) physiology in the fetus and newborn, although limited, suggest significant activity during the perinatal period. To characterize further ANF physiology during this time, we documented immunoreactive ANF (IR-ANF) concentrations in the right and left atria before and immediately after birth as well as in the hearts of immature and adult rats. There was a significant decrease in the concentration of IR-ANF in both right and left atria on the d before birth that persisted for the first 48 h of life [d 20 fetal right 570 (106, 90), left 580 (86, 75); d 21 fetal right 270 (70, 55), left 214 (117, 75); 1 d right 206 (39, 33), left 229 (41, 35); 2-d right 352 (35, 32), left 237 (26, 23) [geometric mean (upper SE, lower SE) in ng ANF/mg protein]. Repletion of ANF stores began in the right atrium on d 2 of life and in the left atrium between d 2 and 5. The highest levels of IR-ANF were observed at d 15 [d 5 right 1439 (53,51), left 1547 (83,79); d 15 right 2034 (90,86), left 1943 (108, 102); adult right 1380 (119, 109), left 963 (118, 105)]. In contrast to normal adult animals, factors mediating the observed change affect both atria equally during the perinatal period. The concentration of IR-ANF in the right and left atrium of the fetal, newborn, and immature animals was equal. These data document significant alterations in intraatrial IR-ANF concentrations in the perinatal period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic hormone, cortisol, and progesterone changes in the lamb during the perinatal period

Although the changes in circulating concentrations of adrenocorticotropic hormone, cortisol, and progesterone are well established for the fetal and neonatal lamb, there is little information on these hormones in the immediate perinatal period. We have examined the relationship between these hormones and systemic blood gas tensions and substrate concentrations in the perinatal period. Measurements were made in arterial blood of seven unanesthetized fetal sheep at 138 to 141 days' gestation during low- and high-voltage electrocortical activity. After cesarean delivery each newborn lamb was studied again at 2, 5, and 10 minutes and at 2 and 24 hours while awake. There was no correlation between fetal or maternal adrenocorticotropic hormone, cortisol, or progesterone and fetal electrocortical activity. Within 2 to 5 minutes of delivery there was a dramatic increase in neonatal immunoreactive adrenocorticotropic hormone concentrations associated with an increase in plasma cortisol. Neonatal Pao2 rose progressively, but a mixed respiratory and metabolic acidosis was evident during the first 10 minutes after delivery. This was partially corrected by 2 hours of neonatal life and was fully corrected by 24 hours of life. We conclude that rapid responsiveness of the fetal pituitary-adrenal axis occurs in response to birth in the absence of active labor, and we suggest that this may have survival value for the preterm fetus.

Regulation of the glucose transporter in developing rat brain

We have found a complex alteration in the expression of the glucose transporter protein and mRNA in developing rat brain tissue. Before birth (gestational days 19-20), the rat brain glucose transporter was comprised of a diffuse protein doublet of approximately 43,000 and 50,000 mol wt (Mr) by Western blot analysis. Immediately after birth (1-2 days), the total amount of immunoreactive glucose transporter decreased approximately 5-fold, primarily due to a loss of the higher (50,000) Mr component with a relatively smaller decrease in the 43,000 Mr band. Subsequently, the amount of the 43,000 Mr band progressively increased from days 5 to 60 and the 50,000 Mr band increased from days 15 to 60. By 60 days postdelivery, the relative amounts of the glucose transporter protein were similar to those on the 19th gestational day. N-Glycanase treatment of the developing rat brain membranes demonstrated that the regulation of the two different Mr weight glucose transporter species occurred as a result of differential glycosylation. In contrast to the Western blot analysis, [3H] cytochalasin-B binding studies demonstrated no significant developmental alteration in the total amount of glucose transporter protein in rat brain tissue. However, consistent with the Western blots, Northern blot analysis using rat brain transporter cDNA revealed a dramatic decrease in the content of the glucose transporter mRNA immediately subsequent to birth, followed by a gradual increase back to the prenatal levels. These data suggest that the rat brain-type glucose transporter is developmentally regulated, but may be associated with the compensatory expression of another unidentified glucose transporter protein in newborn rats.

Distribution of angiotensin II receptors and renin in the mouse fetus

To investigate the ontogeny of the renin-angiotensin system we studied the characteristics and location of angiotensin II (AII) receptors in mouse fetuses and examined sites of renin mRNA expression by in situ hybridization and Northern blot analysis. Autoradiographic analysis of the binding of 125I-[Sar1,Ala8]AII to slide-mounted frozen sections of 17-day-old DBA/2N mice revealed abundant AII receptors widely distributed throughout the body. High receptor density was found in primitive mesenchymal tissue under the epidermis and surrounding muscle and cartilage, in skeletal and smooth muscle, and in all layers of the adrenal cortex. Lower receptor density was seen in the kidney, liver, and lungs. The autoradiographic staining was abolished by incubation of the sections with excess unlabeled AII. Scatchard analysis of the binding of 125I-[Sar1,Ala8,]AII to membrane-rich fractions of eviscerated fetuses showed a single type of high affinity receptors with a Kd of 2.9 x 10(-9) M and a receptor concentration of 3300 fmol/mg protein. Localization of renin mRNA was analyzed by in situ hybridization using an antisense 35S-labeled riboprobe transcribed from a mouse renin2 cDNA clone. Hybridization to fetal tissue sections showed high intensity staining in the kidney and adrenal cortex. Northern blot analysis confirmed the high expression of renin mRNA in the fetal kidney. The presence of an active renin-angiotensin system in the fetus was confirmed by the demonstration of renin-like activity and bioactive AII in fetal extracts. The widespread distribution of AII receptors in the fetus, compared to the discrete localization to specialized tissues in the adult, may indicate a unique role for the peptide during development.

Expression of lacto series type 2 antigens in human renal cell carcinoma and its clinical significance

We performed immunohistochemical examination of serial sections of human fetal and adult renal tissue as well as human renal carcinoma tissue, using monoclonal antibodies T5A7, 1B2, FH2, FH4, and FH6. These monoclonal antibodies were directed to lacto series type 2 antigens with sugar-chain structures: lactosylceramide, lactoneotetraosylceramide (paragloboside), Lex (a chemically well-defined fucosyl carbohydrate antigen), difucosyl Lex, and sialosyl-difucosyl Lex, respectively. The staining pattern in fetal renal tissue changed significantly according to the stage of organogenesis. In addition, expression of the antigens, especially paragloboside and sialosyl-difucosyl Lex, was closely related to the prognosis of the patient. These results suggest that the expression of a series of oncofetal antigens in development or differentiation of organs is reflected in the reversion to an immature pattern of antigenic expression in tumor tissue. The pattern of antigen expression in renal tumors offers a good criterion for ascertaining the degree of tumor differentiation and malignancy and is valuable for determining prognosis.

Membrane fluidity of trophoblast cells and susceptibility to natural cytotoxicity

This study examines the relationship between membrane lipid microviscosity and susceptibility of villous trophoblast to lysis by natural cytotoxic cells. Trophoblast-enriched cell suspensions prepared from term human placentae were treated with cholesteryl hemisuccinate (CHS)--a modulator of membrane lipid microviscosity. CHS-treated cells were more susceptible targets for natural lymphocyte cytotoxicity than were untreated controls. In binding experiments, increased binding of lymphocytes to CHS-treated target cells was found. Preincubation with progesterone prevented membrane rigidification by CHS. Progesterone, cortisol, and estriol restored the impaired resistance of CHS-treated trophoblast cells to lysis. We determined microviscosity and progesterone concentration in villous surface membranes, prepared from placentae from idiopathic spontaneous abortions and normal first-trimester pregnancies. An inverse relationship was found between progesterone content and microviscosity of the membranes. Microviscosity of the membranes from abortion placentae was significantly higher (P less than .01) and progesterone concentration was significantly lower (P less than .001) than those in the membranes of normal first trimester placentae.

Two fetal antigens (FA-1 and FA-2) and endometrial proteins (PP12 and PP14) isolated from amniotic fluid: localisation in the fetus and adult female genital tract

Monospecific antisera against two fetal antigens (FA-1 and FA-2), alphafetoprotein (AFP) and two endometrial proteins (PP12 and PP14) were used to examine the distribution of these proteins and antigens in human trophoblast and gestational endometrium in first and third trimesters of pregnancy, normal human ovary and fetal tissues by indirect immunoperoxidase histochemical localisation techniques. Fetal liver stained exclusively for FA-1 and AFP which was used as a reference protein. Staining for FA-2 was seen in fetal connective tissue, in particular the basement membrane. FA-1 and FA-2 did not stain positively in decidua, trophoblast or ovarian tissue. Gestational endometrium stained positively for PP14 exclusively in the glandular epithelium, whilst staining for PP12 was seen only in the stromal cells. Trophoblast, both early and late, and ovarian tissue did not stain positively for any of the four substances tested.

A tumor-associated fibronectin isoform generated by alternative splicing of messenger RNA precursors

Fibronectin (FN) represents the mixture of a number of structurally different molecules (isoforms) whose make-up varies depending on the FN sources. FN from cultured transformed human cells has a very different isoform composition with respect to its normal counterpart. In fact, SV-40-transformed WI-38VAI3 human fibroblasts produce high levels of a FN isoform (B-FN) which is very poorly expressed in their normal, WI-38, counterpart. We have recently demonstrated that the B-FN isoform derives from a differential splicing pattern of the FN primary transcript which leads, in transformed cells, to a high level expression of the exon ED-B (Zardi, L., B. Carnemolla, A. Siri, T. E. Petersen, G. Paolella, G. Sebastio, and F. E. Baralle. 1987. EMBO (Eur. Mol. Biol. Organ.) J. 6:2337-2342). Here we report on the production and characterization of a monoclonal antibody (BC-1) which recognizes an epitope within the protein sequence coded for by the ED-B exon. This monoclonal antibody makes it possible to carry out immunohistochemical analysis of the distribution of the ED-B-containing FN isoform (B-FN) in human tissues. The results show that while in normal, adult, human tissues total FN has a widespread distribution, the B-FN isoform is restricted only to synovial cells, to some vessels and areas of the interstitium of the ovary, and to the myometrium. On the contrary, the B-FN isoform has a much greater expression in fetal and tumor tissues. These results demonstrate that, in vivo, different FN isoforms have a differential distribution and indicate that the B-FN isoform may play a role in ontogenesis and oncogenetic processes.

Glutathione and cysteine enhance and diethylmaleate reduces thiabendazole teratogenicity in mice

The effects of cysteine (CYS), glutathione (GSH) and diethylmaleate (DM) on the teratogenicity of thiabendazole (TBZ) were investigated. On day 9 of gestation mice were given ip a dose of 0, 50 or 100 mg CYS/kg body weight, or 0, 400 or 800 mg GSH/kg, or 0, 0.05, 0.10, 0.15 or 0.60 DM/kg. One hr later they were dosed orally with 0, 250, 500 or 1000 mg TBZ/kg. All foetuses were removed from the uterus on day 18 of gestation, and were examined for external and skeletal anomalies. The number of malformed foetuses was increased in mice pretreated with CYS or GSH and was decreased in those pretreated with DM, in comparison with numbers in the corresponding group treated with TBZ alone GSH pretreatment enlarged the area under the curve (AUC) of TBZ and 5-hydroxyTBZ, a representative metabolite, in foetal tissue. DM pretreatment reduced the AUC of TBZ and 5-hydroxyTBZ.

Immunological distribution of one form of insulin-like growth factor (IGF)-binding protein and IGF peptides in human fetal tissues

Insulin-like growth factors (IGFs) are expressed by, and are biologically active on, human fetal cells. The mitogenic actions of IGF-I are modulated by the 21-41 kDa class of IGF-binding proteins (IGF-BPs). Using a rabbit anti-human IGF-BP antibody raised against a highly pure 26 kDa IGF-BP derived from amniotic fluid, we have compared the cellular location of IGF-BP and IGF peptides in tissue sections from prostaglandin-induced human abortuses of 14-16 weeks of gestation. The monoclonal and polyclonal antibodies used were raised against human IGF-I, but did not distinguish between IGF-I and IGF-II. Positive staining for IGF-BP was seen in every tissue except brain, spleen and thyroid. With the exception of skin, the cellular distribution of IGF-BP was similar to that of IGF peptides. Strong immunostaining was found in hepatocytes, hepatic erythropoietic cells, pulmonary epithelium, the tubular epithelium of kidney, intestinal epithelia, the fetal adrenal cortex and cardiac and skeletal muscle fibres. In skin, IGF-BP was located throughout the dermis and in the germinal layer of the epidermis. IGF peptide in skin was restricted to the deeper dermal layers. In the tibial epiphyseal growth plate both IGF-BP and IGF peptide were located in chondrocytes throughout the proliferation and hypertrophic zones. The similarity in distribution of IGF-BP and IGF peptides in fetal tissues suggests that the latter may exist predominantly complexed to IGF-BP in or on the surfaces of cells in vivo. The distribution of IGF-BP may define the sites of biological action of IGF peptides.

Localization of the integral membrane glycoprotein synaptophysin and the surface glycoprotein Egp-34 in the embryonic and adult human inner ear

By using well-defined monoclonal antibodies, the distribution of synaptophysin and the glycoprotein Egp-34, the first of its kind, was analyzed immunohistochemically in the fetal and the adult human inner ear. In fetal labyrinths, a distinct immunoreactivity for synaptophysin occurred in the apical region of both outer and inner hair cells as well as in nerve terminals adjacent to both cochlear and vestibular hair cells. In adult hair cells, immunoreactivity was found throughout the cytoplasm. Synaptophysin may act as an important calcium binding protein in the sensory transduction of hair cells. A selective expression of Egp-34 was found in the area of marginal and intermediate cell infoldings in the stria vascularis. A similar localization pattern was found for a number of membrane transport enzymes. The glycoprotein Egp-34 is probably of importance for the active mechanisms regulating the homeostasis of endolymph.