No abstract

No abstract

No abstract

The absolute number of large-diameter myelinated fibers is smaller in cross-sections of thin as compared to those of thick spinal cord. When elucidating the pathophysiology of compressive myelopathy, it is necessary to study not only the circumstances surrounding the spinal cord, but this kind of factor intrinsic to the spinal cord itself.

An adrenal pheochromocytoma producing somatostatin (SRIF) and vasoactive intestinal polypeptide (VIP) in a 17‐year‐old boy is presented. High concentrations of immunoreactive (IR)‐SRIF were found in plasma taken from the antecubital vein (31.0–33.0 pg/ml) and the inferior caval vein near the tumor (54.6 pg/ml), but after removal of the tumor the values became normal (11.0–15.2 pg/ml). In two portions of the resected tumor, considerable but different amounts of IR‐SRIF (151.7 and 12.1 ng/g wet wt) and IR‐VIP (13.0 and 5.5 ng/g wet wt) were demonstrated with size heterogeneities. Immunohistochemically, many IR‐SRIF cells and a few IR‐VIP cells were observed, but no cell reacting with both anti‐SRIF and anti‐VIP sera was found. Electronmicroscopically, many tumor cells had catecholamine‐like granules (250–350 nm in diameter) while some others had VIP‐like granules (100–140 nm in diameter). However, no granules resembling the SRIF granules seen in the pancreatic D cells were found. This seems to be the first report of an adrenal pheochromocytoma that produces SRIF and VIP simultaneously. It provides information on the histogenesis of hormone‐producing neurogenic tumors. Cancer 52:282‐289, 1983.

No abstract

The concentrations of immunoreactive somatostatin (IR-SRIF) in plasma samples taken from the umbilical artery (UA), umbilical vein (UV), and maternal antecubital vein (MV) were measured in 23 cases of normal delivery at term. High concentrations of IR-SRIF were detected in the plasma from the UA (mean +/- SD, 73.2 +/- 40.6 pg/ml), the value being about 2.5 times that in the UV (29.5 +/- 17.5 pg/ml; P less than 0.001). An arterio-venous gradient was observed in all 23 subjects. The plasma level of IR-SRIF in the MV (10.9 +/- 4.6 pg/ml) was significantly lower than those in the UA (P less than 0.001) and UV (P less than 0.001) and was almost the same as that in nonpregnant women (12.7 +/- 5.4 pg/ml). Chromatographic analysis of an extract of plasma from the UA gave only one peak of immunoreactive material, which was eluted in the same position as synthetic SRIF-14. A similar result was obtained in nonpregnant women. No correlation was found between the plasma level of IR-SRIF and that of GH, insulin, glucagon, or gastrin in the UA. The present findings suggest that the high concentration of IR-SRIF in the feto-placental circulation originates from the fetus and reflects a particular role of this peptide in the process of functional maturation of the neuroendocrine system in early human life.

Ontogenetic development of GRF-containing neurons in the rat hypothalamus was studied employing antisera which were generated against hpGRF (1-44)NH2 and rhGRF(1-43)OH: anti-hpGRF-C and -rhGRF sera recognize the species-specific C-terminal portions of the peptides, and anti-hpGRF-MC and -N sera recognize hpGRF(27-44)NH2 and the N-terminal portion of hpGRF(1-44)NH2, respectively. The anti-hpGRF-C and -rhGRF sera stained different neuronal cell bodies, which were localized in distinct hypothalamic areas. The former serum did not stain the axonal terminals in the median eminence, but the latter stained them strongly. The anti-hpGRF-MC and -N sera stained neuronal cell bodies, some of which corresponded to those immunolabelled with anti-hpGRF-C or -rhGRF serum. The anti-rhGRF serum first demonstrated immunoreactive perikarya in the ventral-lateral border of the arcuate nucleus of 19.5-day-old fetuses that had received an intraventricular colchicine administration 24 h previously. The immunoreactive fibers were recognized first in the external layer of the median eminence of untreated fetuses on day 19.5 of gestation, and then they increased in amount with development. No immunoreactive fibers, however, were found in the median eminence of colchicine-treated animals during the fetal period. It is concluded that in rats GRF may be synthesized in the perikarya on day 18.5 of gestation and conveyed to the median eminence without delay via axonal flow.