Leptin-induced satiation mediated by abdominal vagal afferents.

Leptin is a hormone secreted into the systemic blood primarily by white adipose tissue. However, leptin also is synthesized and stored by cells in the gastric mucosa. Because gastric mucosal leptin is secreted in response to ingestion of a meal, we hypothesized that it might contribute to satiation (meal termination) by acting on gastrointestinal vagal afferent neurons. To test whether leptin is capable of acutely reducing short-term food intake, we measured consumption of a liquid meal (15% sucrose) following low-dose leptin administration via the celiac artery, which perfuses the upper gastrointestinal tract. Leptin (1, 3, 10 mug) was infused via a chronically implanted, nonocclusive celiac arterial catheter or via a jugular vein catheter with its tip in the right cardiac atrium. Fifteen percent sucrose intake was then measured for 30 min. We found that leptin dose dependently inhibited sucrose intake when infused through the celiac catheter but not when infused into the general circulation via a jugular catheter. Plasma leptin concentrations in the general circulation following celiac arterial or jugular leptin infusions were not significantly different. Celiac arterial leptin infusion did not reduce meal size in vagotomized or capsaicin-treated rats. Finally, we also found that reduction of meal size by celiac leptin infusion was markedly enhanced when coinfused with cholecystokinin, a gastrointestinal satiety peptide whose action depends on vagal afferent neurons. Our results support the hypothesis that leptin contributes to satiation by a mechanism dependent on gastrointestinal vagal afferent innervation of the upper gastrointestinal tract.

Use of clozapine in primary care.

While clozapine represents a revolutionary advance in the treatment of schizophrenia, it carries with it a formidable side-effect profile. Agranulocytosis may indeed be life-threatening to a small number of patients. The nurse practitioner must be aware of this and other side effects in order to competently care for patients with psychiatric problems. It is also essential that there be a collaborative relationship between the nurse practitioner and a mental health provider. Only through appropriate consultation and referral will the needs of psychiatric patients be met in a timely and comprehensive manner.

The effect of a relaxation technique on coronary risk factors.

This study examined the effect of a relaxation technique on plasma lipids, weight, blood pressure, and blood glucose. Sixteen outpatient males were randomly assigned to control or experimental groups. The experimental group was taught a relaxation technique that they used throughout the study. The control group was started in a reading program. Subjects were followed by a nurse practitioner and dietitian for eight weeks. Results revealed a significant reduction in systolic blood pressure and a marginally significant reduction in low density lipoprotein (LDL) cholesterol in the experimental group. Both control and experimental groups self-reported high compliance with diet and adherence to prescribed intervention. State anxiety was found to be inversely related to changes in total cholesterol and LDL cholesterol.