Holm B, Schagatay E, Kobayashi T, Masuda A, Ohdaira T, Honda Y
Department of Animal Physiol., University of Lund.
Appl Human Sci. 1998 Sep;17(5):181-7. doi: 10.2114/jpa.17.181.
The Ama have existed for more than 2000 years in Japan and Korea. They have been diving for seaweed and molluscs. Their traditional way of fishing, with goggles or a mask, but without a wetsuit, is still practised as a result of laws against overfishing. We investigated cardiovascular diving responses, expressed as heart rate (HR) reduction, peripheral vasoconstriction indicated by skin blood flow (SkBF) and mean arterial blood pressure (MAP) during breath-hold face immersion in a group of eight elderly male Ama at Chikura, Japan. Their data were compared to those from three other groups: a) elderly non-divers; b) young divers and c) young non-divers. Our previous studies have shown that young divers show a more pronounced bradycardia than young non-divers. The present study of elderly Ama and elderly non-divers was performed to investigate if this difference persists in old age. We found that, in spite of many years of diving experience, HR reduction of the elderly professional divers observed during face immersion did not differ from that of elderly non-divers, but it was much less pronounced than in the two younger groups. We conclude that even if a well-developed diving response at young age has been reduced to the level of non-divers, the Ama are still able to continue their work of diving in old age. Ama that has been a traditionally female occupation, is mostly practised by men at Chikura today. No young have been recruited for this profession. Therefore, the present Ama are senior and the traditional breath-hold diving will probably cease to exist in the near future. The probable reasons for these changes are discussed.
阿马族在日本和韩国已存在了2000多年。他们一直潜水采集海藻和软体动物。由于禁止过度捕捞的法律，他们仍采用传统的捕鱼方式，戴着护目镜或面罩，但不穿潜水服。我们在日本千叶县对一组八名老年男性阿马族潜水员进行了研究，观察他们在屏气面部浸入水中时的心血管潜水反应，以心率（HR）降低、皮肤血流量（SkBF）和平均动脉血压（MAP）表示的外周血管收缩情况。他们的数据与其他三组进行了比较：a）老年非潜水员；b）年轻潜水员和c）年轻非潜水员。我们之前的研究表明，年轻潜水员比年轻非潜水员表现出更明显的心动过缓。本研究对老年阿马族潜水员和老年非潜水员进行，以调查这种差异在老年时是否仍然存在。我们发现，尽管有多年的潜水经验，但老年职业潜水员在面部浸入水中时观察到的心率降低与老年非潜水员没有差异，但比两个年轻组要轻得多。我们得出结论，即使年轻时发达的潜水反应已降至非潜水员的水平，阿马族在老年时仍能继续他们的潜水工作。阿马族传统上是女性职业，如今在千叶县大多由男性从事。没有年轻人被招募到这个行业。因此，现在的阿马族都是老年人，传统的屏气潜水可能在不久的将来就会消失。文中讨论了这些变化可能的原因。
