RESUMEN
Release of immunoreactive somatostatin (I-SRIF) and immunoreactive substance P (I-SP) was studied from slices prepared from upper dorsal horn (UDH) and lower dorsal plus ventral horn (LDH-VH) of rat spinal cord. Superfusion with capsaicin (10 microM) led to release of I-SRIF and I-SP from UDH slices but not from LDH-VH slices. The capsaicin-evoked release of I-SP was 6 fold higher than that of I-SRIF. A pulse of 60 mM K+ applied after the capsaicin pulse caused release of I-SRIF and I-SP from UDH as well as LDH-VH slices. Pretreatment of rats with capsaicin (125 mg/kg, s.c.) led to a nearly 40% depletion of I-SP in slices from UDH only. Capsaicin-evoked release from these slices was reduced by 81% for I-SRIF and by 79% for I-SP. Release evoked by K+ remained unchanged. These results indicate that capsaicin causes release of both I-SRIF and-I-SP and that this release is most likely restricted to primary sensory neurons. The marked reduction of the release of I-SP after systemic capsaicin pretreatment may well represent one of the, or even the reason for the insensitivity of capsaicin pretreated rats towards chemogenic pain.
Asunto(s)
Capsaicina/farmacología , Ácidos Grasos Insaturados/farmacología , Neuronas/efectos de los fármacos , Somatostatina/metabolismo , Médula Espinal/metabolismo , Sustancia P/metabolismo , Animales , Técnicas In Vitro , Masculino , Neuronas Motoras/efectos de los fármacos , Potasio/farmacología , Ratas , Somatostatina/inmunología , Médula Espinal/efectos de los fármacos , Sustancia P/inmunologíaRESUMEN
Primary cultures of dispersed hypothalamic cells were prepared from embryonic rats to study the release of immunoreactive somatostatin. The immunoreactive somatostatin content of these cultures increased during the first 2 weeks after plating and was readily measurable for several weeks thereafter; this material was characterized by gel permeation and reverse-phase chromatography. Depolarization of the cells with 60 mM K+ or with veratridine resulted in a calcium-dependent release of immunoreactive somatostatin which cochromatographed with synthetic somatostatin on reverse-phase chromatography. Tetrodotoxin blocked the veratridine-evoked release. However, even in the absence of exogenous stimuli, immunoreactive somatostatin was released by the cells into the medium. More than 70% of this tonic release was found to be calcium dependent and to be inhibited by tetrodotoxin, indicating that spontaneous electrical activity in the cultures leads to a release of immunoreactive somatostatin. gamma-Aminobutyric acid inhibited the tonic release of immunoreactive somatostatin and this was reversed by bicuculline. These findings support the hypothesis that gamma-aminobutyric acid inhibits somatostatin release in vivo.
Asunto(s)
Hipotálamo/metabolismo , Somatostatina/metabolismo , Ácido gamma-Aminobutírico/farmacología , Animales , Bicuculina/farmacología , Calcio/farmacología , Células Cultivadas , Cromatografía en Gel , Hipotálamo/citología , Hipotálamo/efectos de los fármacos , Potasio/farmacología , Radioinmunoensayo , Ratas , Somatostatina/inmunología , Tetrodotoxina/farmacología , Veratridina/farmacologíaRESUMEN
An antiserum was raised in guinea pigs against purified normal human N-acetylgalactosamine-6-sulfate sulfatase, the enzyme affecting in Morquio's disease type A. The antiserum precipitated most of N-acetylgalactosamine-6-sulfate sulfatase from a concentrate of normal human urine. The antigen-antibody complex was enzymatically active. Urine concentrates from five patients with Morquio's disease type A did not contain material competing with the normal enzyme for binding to soluble or Sepharose-bound antibodies. No precipitin arc was obtained on immunodiffusion of antiserum and urine from the single patient investigated by this method. From the sensitivity of the indirect immunoassay it was concluded that the urine of the five patients contained less than 5% of the normal amount of cross-reacting material.
Asunto(s)
Condroitinasas y Condroitín Liasas/inmunología , Condroitinsulfatasas/inmunología , Epítopos , Mucopolisacaridosis IV/enzimología , Anticuerpos/aislamiento & purificación , Reacciones Antígeno-Anticuerpo , Niño , Preescolar , Cromatografía en Gel , Reacciones Cruzadas , Femenino , Humanos , MasculinoRESUMEN
The glycosaminoglycan metabolism of cultured endothelial cells and of cells grown from the intima and from the media layer of bovine aorta thoracia was investigated in a comparative study. The following results were obtained: 1. Endothelial cells have in common with intima and media cells the distribution of newly formed sulfated glycosaminoglycans into extracellular, pericellular and intracellular compartments. Endothelial cells, however, synthesize lower amounts of glycosaminoglycans and distribute them in a different ratio into the three pools. 2. Though all the various cell lines synthesize chondroitin 4-sulfate, chondroitin 6-sulfate, dermatan sulfate, heparan sulfate and small amounts of keratan sulfate, endothelial cells exhibit a unique distribution pattern of sulfated glycosaminoglycans in each of the three compartments. Generally, a high proportion of heparan sulfate and chondroitin 6-sulfate and a very low dermatan sulfate content was detected. 3. Heparan sulfate produced by endothelial cells has a higher N-sulfonate content when compared with that from other sources. The cell membrane-associated heparan sulfate, especially, exhibits some heparin-like features as judged by nitrous acid degradation and susceptibility towards heparitinase.