Rapid hepatic metabolism blunts the endocrine action of portally infused GLP-1 in male rats.

Glucagon-like peptide-1 (GLP-1) is an enteral peptide that contributes to the incretin effect. GLP-1 action is typically described as endocrine, but this mechanism has been questioned because rapid inactivation in the circulation by dipeptidylpeptidase 4 (DPP4) results in a short half-life, limiting the amount of the hormone that can reach the pancreatic islet. An alternative mechanism for GLP-1 to regulate insulin secretion through neuroendocrine signaling originating from sensors in the portal vein has been proposed. We hypothesized that portal infusion of GLP-1 would cause greater glucose-stimulated insulin secretion than equimolar administration into the jugular vein. To test this, hyperglycemic clamps with superimposed graded infusions of GLP-1 into the jugular or portal veins of male rats were performed. These experiments were repeated with pharmacologic DPP4 inhibition to determine the effect of GLP-1 metabolism in the jugular and portal venous beds. Contrary to our hypothesis, we found a higher insulinotropic effect with jugular compared with portal GLP-1, which was associated with higher plasma concentrations of intact GLP-1. The greater insulinotropic effect of jugular venous GLP-1 persisted even with pharmacological DPP4 inhibition. These findings do not support an important role of portal vein GLP-1 signaling for the incretin effect but highlight the hepatoportal bed as a major site of GLP-1 degradation that persists even with pharmacological inhibition. Together, these results support rapid inactivation of enterally released GLP-1 in the liver as limiting endocrine actions on the ß-cell and raise questions about the conventional endocrine model of pharmacologic effects of DPP4 inhibitors.

Prophylactic mastectomy with immediate reconstruction combined with simultaneous laparoscopic salpingo-oophorectomy via a transmammary route: a novel surgical approach to female BRCA-mutation carriers.

INTRODUCTION: Breast reconstruction with salpingo-oophorectomy can easily be performed in patients with genetic mutations increasing the risk for mammary and ovarian carcinoma. However, many patients are skeptical about having several surgeries, as they may result in additional anesthesiological risks as well as multiple visible scars. Therefore, the purpose of this study was to evaluate the feasibility of prophylactic mastectomy and breast reconstruction combined with simultaneous transmammary salpingo-oophorectomy for BRCA carriers. MATERIALS AND METHODS: Of the six patients (1 %) who chose prophylactic mastectomy with salpingo-oophorectomy at our hospital four patients had BRCA-1 mutations, one patient had a BRCA-2 mutation and one patient had a family inheritance pattern with no mutations. All patients chose to reduce their risk for mammary and ovarian cancer by undergoing bilateral mastectomy and bilateral salpingo-oophorectomy. Prophylactic mastectomy with immediate reconstruction was performed, followed by bilateral salpingo-oophorectomy with a procedure that relies on transmammary access and reduces the number of necessary surgeries without compromising cosmetic results, surgical risks and operating time. RESULT: The mean age of the patients was 46.7 ± 1.8 years (SD). The mean operative time was 190.2 ± 13.7 min. No complications were observed during the operations. The mean intra-operative loss of blood was 363.3 ± 77.9 ml. The operative method was successful in all six cases and was performed with no complications. All of the patients were satisfied with the cosmetic results. CONCLUSION: In conclusion, prophylactic mastectomy and breast reconstruction combined with simultaneous laparoscopic salpingo-oophorectomy via transmammary access is feasible, easy to perform and provides an intriguing and novel approach to female BRCA carriers who desire operative prophylactic measures in one surgical session with no visible abdominal scars and no additional risks and complications.

Bilateral prophylactic skin-reducing nipple-sparing mastectomy with immediate breast reconstruction using only a vascularized dermal-subcutaneous pedicle: technique and possible advantages.

PURPOSE: To present a new surgical technique regarding breast reconstruction after skin-reducing nipple-sparing mastectomy. METHOD: The current trend for immediate breast reconstruction after skin-reducing mastectomy mainly supports the insertion of subpectoral implants or the use of autologous breast reconstruction techniques. Herein for the first time, we present a case of bilateral prophylactic skin-reducing nipple-sparing mastectomy with immediate breast reconstruction, using only a dermal-cutaneous pedicle. RESULTS: The postoperative course was uneventful. Forty days postoperatively the aesthetic result was excellent. CONCLUSIONS: We believe that such technique in selected cases can present several advantages as low cost, reduced possibilities for complications associated to implant insertion or autologous reconstruction techniques and an easier mammography follow-up.