Medical Students' Attitude Toward Organ Donation: Understanding Reasons for Refusal in Order to Increase Transplantation Rates

OBJECTIVES

To assess, among medical students, the willingness to donate their own organs or those of a family member, and to establish reasons for refusal.

MATERIALS AND METHODS

During the 2016 academic year, an anonymous survey was conducted among University of Buenos Aires School of Medicine second-year students.

RESULTS

Of the total 1012 respondents, 81.92% would agree to donate and 18.08% would not. Thirty two percent would not authorize donation of a family member's organ. Almost all (94.1%) students reported they had little information about organ donation. Reasons for refusal included: fears about the possibility of not being really dead when considered for organ ablation (36.4%); lack of confidence in (25.8%) or lack of information about the organ procurement and transplantation system (14.6%); no interest in organ donation (9.3%); and religious reasons (6%). Brain death was considered irreversible by 59.7% of donors and by only 51% of non-donors (P = .036). Contact with a transplanted person was more frequent in the donor group (30.9% vs 21.3%, P = .01). More donors were found among the group who discussed the subject with their families than among the group who did not (69.1% vs 62.9%, P = .053).

CONCLUSIONS

A considerable percentage of medical school students would not be willing to donate their own or a family member's organs. Main reasons are mistrust of the system, lack of information about donation programs, and poor understanding of the brain death concept. Contact with an organ recipient and discussing the subject in the family both favored donation.

Comparative effects of melatonin and vitamin E in restoring aortic relaxation in pancreatectomized rats

In a previous study we reported the efficacy of melatonin to restore the decreased relaxation response to acetylcholine (ACh) or to sodium nitroprusside (SNP) in aortic rings of rats turned hyperglycemic by subtotal pancreatectomy. The effect was amplified by pre-incubation in a high (44 mmol/l) glucose solution, a situation that resulted in oxidative stress. We hereby compare the effect of another antioxidant, vitamin E, with that of melatonin on ACh response in intact aortic rings or on SNP response in endothelium-denuded aortic rings obtained from pancreatectomized or sham-operated rats. Dose-response curves to ACh or SNP were performed in the presence or absence of melatonin or vitamin E (10-5 mol/1) in 10 or 44 mmol/1 glucose medium. Melatonin was more effective than vitamin E in restoring ACh- or SNP-induced relaxation of aortic rings in a high glucose medium. The differences between the two antioxidants may rely on the ability of melatonin to diffuse readily into intracellular compartments.

Effect of melatonin treatment on oxygen consumption by rat liver mitochondria

The objective of this study was to examine the in vivo effect of melatonin on rat mitochondrial liver respiration. Two experiments were performed: For experiment 1, adult male rats received melatonin in the drinking water (16 or 50 microg/ml) or vehicle during 45 days. For experiment 2, rats received melatonin in the drinking water (50 microg/ml) for 45 days, or the same amount for 30 days followed by a 15 day-withdrawal period. At sacrifice, a liver mitochondrial fraction was prepared and oxygen consumption was measured polarographically in the presence of excess concentration of DL-3-beta-hydroxybutyrate or L-succinate. Melatonin treatment decreased Krebs' cycle substrate-induced respiration significantly at both examined doses. The stimulation of mitochondrial respiration caused by excess concentration of substrate recovered after melatonin withdrawal. Basal state 4 respiration was not modified by melatonin. Melatonin, by curtailing overstimulation of cellular respiration caused by excess Krebs' cycle substrates, can protect the mitochondria from oxidative damage.

Effect of melatonin on 24h changes in plasma protein levels during the preclinical phase of Freund's adjuvant arthritis in rats

The 24h rhythms in plasma protein concentration were examined in rats on the third day after injection of Freund's complete adjuvant or adjuvant's vehicle, performed 3h after light on. In rats treated with adjuvant's vehicle, peak values of albumin and gamma globulin occurred during the nocturnal activity span (P < .02 and P < .0001, respectively), while those of alpha-1, alpha-2, and beta globulins were found late during the rest span (P < .002, P < .0001, and P < .0004, respectively). Freund's adjuvant administration abolished temporal changes in plasma albumin and beta globulin levels. It also decreased the amplitude of daily changes in alpha-1 and alpha-2 globulin (P < .05) and diminished mean values of alpha-2 globulin (P < .01). Pretreatment of rats with melatonin (30 microg daily) for 11 days, 11h after light on, counteracted mycobacterial adjuvant-induced suppression of the 24h rhythms in albumin and alpha-1, alpha-2, and beta globulins. The results further support the existence of preventive properties of a pharmacological dose of melatonin in situations in which a lost of circadian rhythmicity is expected.

Extracellular acidification related to the stimulation of catecholamines release by strontium in the bovine adrenal medulla

The possible modifications of extracellular pH associated with the secretion of catecholamines evoked by the introduction of 2.2 mM Sr2+ to a Ca(2+)-free, buffer-free, Locke solution were investigated in decorticated perfused bovine adrenal glands. A progressive and reversible decrease of external pH accompanied the catecholamine release promoted by Sr(2+)-introduction into the perfusion fluid. This extracellular acid shift was practically undetected when the chromaffin tissue was stimulated by the addition of Sr2+ to a buffered medium. Both the secretory response as well as the extracellular pH drop mediated by Sr(2+)-introduction to a Ca(2+)-free, buffer-free, Locke solution were markedly inhibited by methoxyverapamil (0.3 mM), Mg2+ (20 mM) and hyperosmolarity (750 mOsm). The exposure of the adrenal medulla to a Ca(2+)-free, buffer-free, high-K+ solution containing 2.2 mM Sr2+ for 6 min promoted a significant enhancement of both the secretory response and the acidification of the perfusates compared with the responses evoked by Sr2+ in a 5.6 mM K+ medium. These results are consistent with the existence of a close relationship between extracellular acidification and the release of catecholamines triggered by the introduction of Sr2+ to the perfusion fluid.