The effects of a high fat diet on leptin mRNA, serum leptin and the response to leptin are not altered in a rat strain susceptible to high fat diet-induced obesity.

Osborne-Mendel (OM) and S5B/Pl rats differ in their sensitivity to develop obesity when fed a high fat (HF) diet; OM rats become obese, whereas S5B/Pl rats remain thin. We have investigated the possibilities that either an impaired leptin response or resistance to leptin action underlies the sensitivity to this form of obesity in OM rats. In Experiment 1, OM and S5B/Pl rats fed a nonpurified diet were killed at d 0 or were fed either a HF (56% fat energy) or a low fat (LF, 10% fat energy) diet for 2 or 7 d. The HF diet increased serum leptin significantly by d 2 to levels that were similar in both rat strains. At 7 d, leptin levels were lower than at d 2 but remained higher than levels in the d 0 control groups. The leptin mRNA:18S RNA ratio in epididymal adipose tissue increased to higher levels in HF-fed OM rats than in S5B/Pl rats fed that diet. However, although the LF diet had no effect in S5B/Pl rats, it increased leptin mRNA levels in epididymal adipose tissue of OM rats compared with the controls fed the nonpurified diet. In Experiment 2, OM and S5B/Pl rats were fed HF or LF diets for 5 wk. At that time, their feeding response to a range of leptin doses (0, 1, 5 or 10 microgram) given intracerebroventricularly was tested after overnight food deprivation. There was a similar dose-dependent reduction in energy intake in response to leptin in both OM and S5B/Pl rats. These responses were independent of the diet. The data suggest that the susceptibility of OM rats to HF diet-induced obesity is not related to either a loss of central sensitivity to leptin or a failure to enhance leptin production acutely, although the failure to maintain chronically increased levels of serum leptin could contribute to the obesity.

Perceptual aberration and brain hemisphere reversal of foreperiod effect on time estimation.

An auditory warning signal of 3 seconds' duration was followed by tachistoscopic presentation of a single dark dot to either the left or the right visual field (N = 18). The warning signal was presented monaurally to the left or to the right ear. The duration of the warning signal constituted foreperiod. The task was verbal estimation of the duration of the dot. For those who showed little or no sign of aberration of personal body image, as detected by Chapman's Perceptual Aberration Scale, time estimation of dot duration tended to be longer when the warning signal was presented to the left ear than to the right ear. For those who showed substantial sign of such aberration, the laterality of foreperiod effect was reversed, so that time estimation of dot duration was longer for the right ear than for the left ear. There was no such hemispheric reversal in terms of visual field.

Sulphated cholecystokinin octapeptide inhibits ethanol consumption in the rat.

Twenty-three hr water deprived rats received access to 5% ethanol solution for 30 min daily. Intraperitoneal injection of sulphated cholecystokinin octapeptide (CCK-8, 2.0-16.0 micrograms/kg) significantly inhibited ethanol consumption, but injection of desulphated CCK-8 did not affect ethanol consumption. These results confirm a previous report that CCK-8 suppresses ethanol intake, and indicate that inhibition of ethanol consumption by CCK-8 depends on sulphation of its tyrosyl residue. This chemical specificity of action of CCK-8 is also characteristic of other known behavioral and physiological effects of peripherally-administered cholecystokinin-like peptides.

[Dextranomer in the postoperative of anorectal surgery]. / Dextranómero en el postoperatorio de cirugía anorrectal.

Twenty patients were treated with the usual hemorrhoidectomy and fistulectomy techniques; from the nature of the region it was assumed that the postoperative wounds developed infection. Dextranomer was applied locally on 10 patients and the other 10 served as controls. It was observed that the medicament was easy to apply and the patient adapted himself to it quickly enough; none of the group under study presented collateral effects which might contraindicate its use. The healing period was considerably reduced in the problem-group and the patients went back to their usual tasks before expected. Photographic series were taken from all of them during postoperative days until healing. There were not complications in any of the groups under study.