ABSTRACT
The time profile of total proteins and albumin in line with two amino acids, Phe and Glu, are of great importance due to their indicative value of the healing and/or deterioration of burn wounds. In this experiment, rats exposed to scalding that produced a second-degree burn were divided into four groups: control, placebo, MEBO ointment, and copper (I) nicotinate complex ointment (an antioxidant anti-inflammatory) for four weeks. The three treatments showed noticeable similarities in the Phe profiles, with a slight drop 24 hours post burn, a peak elevation by the second week, and a slight, insignificant decline by the third week, with the placebo group showing highest values over normal (P< 0.05). In the Glu profile, large differences were observed: two set profiles, one representing MEBO and copper (I) nicotinate showed one peak in the second week, and the other representing placebo showed two peaks in the first and third weeks. Albumin and total protein time profiles showed the same trend throughout the whole experiment, and are in line with a reformed metabolic state parallel to wound closure. These results reveal that MEBO and copper nicotinate have comparable effects on wound healing in scald burns, and that plasma Glu profile is a better systemic indicator reflecting the regularity and steadiness of the healing process in MEBO and copper complex treatment.
Les évolutions temporelles de la protidémie, de l'albuminémie ainsi que de Phe et Glu sont de bons prédicteurs de l'évolution vers la cicatrisation ou non des brûlures. Dans cette étude expérimentale, des rats ayant subi une brûlure du 2ème degré par ébouillantement ont été divisés en 4 groupes : contrôle, placebo (P), pansements au MEBO ou au complexe cuivre (I) acide nicotinique (CuNic) pendant 4 semaines. Les trois groupes traités avaient des profils de Phe superposables, avec une légère diminution initiale, un pic dans la 2ème semaine et une augmentation non significative durant la 3ème quand le groupe P avait des valeurs élevées (p<0,05). Les profils de Glu étaient plus disparates : un (MEBO et CuNic) avec un pic en 2ème semaine, les autres avec 2 pics (1ère et 3ème semaines). Ces profils étaient aussi observés avec les protides et l'albumine et correspondaient à des évolutions cicatricielles et métaboliques. MEBO et CuNic ont des effets comparables sur la cicatrisation après ébouillantement, au mieux explorés par l'évolution de Glu.
ABSTRACT
1. In order to establish the subunit composition of neuronal nicotinic receptors in rat superior cervical ganglia (SCG), their single-channel properties were compared with those of recombinant receptors expressed in Xenopus oocytes, using outside-out excised patch recording. 2. The mean main conductance of SCG channels from adult and 1-day-old rats was 34.8 and 36.6 pS, respectively. Less frequent openings to lower conductances occurred both as isolated bursts and as events connected to the main level by direct transitions. There was considerable interpatch variability in the values of the lower conductances. 3. Nicotinic receptors from oocytes expressing alpha3beta4 and alpha4beta4 subunits had chord conductances lower than that of SCG neurones (22 pS for alpha3beta4 and 29 pS for alpha4beta4). 4. Prolonged recording from both native and recombinant channels was precluded by 'run-down', i.e. channel activity could be elicited for only a few minutes after excision. Nevertheless, SCG channel openings were clearly seen to occur as short bursts (slowest component, 38 ms), whereas recombinant channels opened in very prolonged bursts of activity, the major component being the slowest (480 ms). 5. Addition of the alpha5 subunit to the alpha3beta4 pair produced channels with a higher conductance than those observed after injection of the pair alone (24.9 vs. 22 pS), suggesting incorporation of alpha5 into the channel. Addition of the beta2 subunit did not change alpha3beta4 single-channel properties. In one out of fourteen alpha3alpha5beta4 patches, both ganglion-like, high conductance, short burst openings and recombinant-type, low conductance, slow burst openings were observed. 6. Channels produced by expression in Xenopus oocytes of neuronal nicotinic subunits present in rat SCG as a rule differ from native ganglion receptors in single-channel conductance and gross kinetics. While it is possible that an essential nicotinic subunit remains to be cloned, it is perhaps more likely that oocytes either cannot assemble neuronal nicotinic subunits efficiently into channels with the correct composition and stoichiometry, or that they produce post-translational channel modifications which differ from those of mammalian neurones.