HORMESİS: TOKSİK AJANLARIN DÜŞÜK DOZLARINA UYUM SAĞLAMADA ÖNCÜL FENOMEN

Hormesis, toksik maddelerin düşük konsantrasyonlarında yaşamı devam ettirebilmeyi ve bu maddelere karşı geliştirilen adaptif olguları açıklamak için öne sürülen bir kavramdır. Bu kavram, toksik molekül ve ortam şartlarının hem yaşamı destekleyici hem de yok edici iki zıt etkiye (bifazik etki) sahip olduğunu ifade eder. Toksik ajanların düşük dozları ile aktifleşen hormesis mekanizması, canlılara adaptif cevap kazandı- rır. Hücrelerdeki adaptif cevabın özel bir şekli olan hormesiste, koruyucu proteinler, antioksidan enzimler ve şaperon proteinleri rol alır. Hormetik uyaranlara bağlı olarak artış gösteren bu moleküller, hücrenin ayakta kalmasını destekler. Hormetik uyaranlar, cevaplar ve bunların düzenlenmesi, hormetik sistemin bileşenlerini oluşturur. Organizmalardaki hormetik olayların moleküler ve hücresel seviyede anlaşılması; yeni ilaçların geliştirilmesinde, hastalıkların önlenmesi ve tedavisinde yeni ufuklar açacaktır. Ayrıca son yıllarda toksik ajanların hormetik davranışları, mahkemeye delil olarak sunulmaya başlanmış, büyük ceza indirimleri sağlanmış veya davalar dü- şürülmüştür. Dolayısıyla maruz kalınan toksik maddenin doz cevap ilişkisinin yorumlanmasında bilirkişiler ve yargıçlar, hormesis olgusunu dikkate almalı ve toplanan deliller bu olgu ışığında değerlendirilmelidir.

NTECEDENT PHENOMENA FOR ADAPTATION TO LOW DOSES OF TOXIC AGENTS

Hormesis explains survivingwith low concentrations of toxicsubstances and adaptive eventsacquired towards these toxicsubstances. This term expressesthat toxic molecules and environmentconditions have both survivalsupportive and destructiveeffects (biphasic). Hormesis providesadaptive response to livingsystems which is activated withlow concentration of toxic substances.Protective proteins, antioxidantenzymes and chaperonproteins take role in hormesiswhich is a special form of adaptiveresponse in cells. These moleculesincreasing by hormetic stimulation,support cells for surviving.Hormetic stimulants, responsesand their regulation build up thehormetic system’s components.Understanding the molecularand cellular levels of hormeticprocesses in organisms providedevelopment of new drugs andtreatments, prevention of diseases.Moreover, hormetic behaviorsof toxic agents appeared to bepresented to courts as scientificevidence in recent years, so thateither the abatement or dismissalbecame possible. Therefore,legal experts and judges shouldtake hormesis into considerationin terms of dose-response relationshipinterpretation for theexposed toxic agents, and alsocollected evidences should beevaluated through the hormesisperspective.

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