Studies on iron metabolism in the early stage of hookworm infection
There have been several reports concerning iron metabolism in hookworm infection of adult stage of hookworam. Masuya(1960). Nagayama(1960) reported that there was no evidence to show 3 disturbance of mobilization or utilization of iron in hookworm disease.
Kitayama(1950) presumed that anemia-inducing factor of hookworm would exist throughout that any anemia-inducing toxin contained in the larval metabolit or larval body was believed to have no connection with the factor of early stage anemia of hookworkm infection. Therefore the anemia-inducing factors in the early
stage of hookworm disease were believed to the blood loss due to the lung damage and early blood sucking in the intestine.
The present study is designed to confirm whether the iron metabolism is related to the early of hookworm anemia.
1. Two groups of dogs were infected with 5,000 and 10,000 hookworm larvae respectively and the following research has been carried out.
a) Hemoatological examination: Five dogs infected with 10,000 hookworm larvae each and two dogs with 5,000 larvae each. Hemoglobin(by Cyanmethemoglobin method) was measured before and until 10 days after infection. Hemoglobin was decreased 2
days after infection. However, the Sideroblasts in the bone marrow showed no decrease(15∼17) at the very early stage, but at the end of a month it decreased remarkably91∼4%).
b) Serum iron: Four dogs were infected with 10,000 larvae and two dogs with 5,000 larvae. The titration was carried on with Junior electric photometer using 2.2'-Dipyridyl. The infected groups showed a decrease of serum of serum iron at 2∼5 days after infection but recovered in 10 days after in infection.
c) Iron absorption: 10,000 larvae and 5,000 larvae were given to two dogs of each group. Ferric alum(3mg/kg) and Ascobric acid(200mg) were given orally to five dogs including on control and th titration were carried out every 2 hours for 8 hours
with Junior electric photometer using ,2'-Dipyridyl. Generally it showed a peak during 2∼4 hours after the administration and the rate of absorption increased in 5,000 or 10,000 larvae group and the control group.
d) Postmortem examination: Five dogs were sacrificed 4,5 and 7 days after infection. A piece of middle portion of small intestine, bone marrow(Ilium), liver, spleen and lung were sliced, fixed and stained in routine way. There were no special changes except the inflammatory process and hemorhage in the lungs, and the proliferated bone marrow.
Ⅱ.Excretion of iron.
Four young dogs were infected with 2,000 hookworm larvae. Four days after the infection 5μC of Fe**59 were given orally and the iron content in the discharged feces was calculated by Well-type scintilation counter. Most of the Fe**59 given orally was excreted in feces within 24 hours in both the control and the infected group. The infected group excreted the same amount in the early stage as that of the control, and after 8 days after infection(4th day after oral administration of Fe**59) a less than control.
Ⅲ. Gastric acidity in hookeworm infected dogs.
It has been recognized that the ingested iron should be reduced from 3 valent to 2 valent in the presence of gastric acid in order to be absorbed from the intestinal membrane. A Pavlov's pouch was prepared in 2 dogs which were free from hookworm infection, and 10 days after operation 10,000 hookwork larvae were given orally. Gastric acidity (free acid) was measured daily for 10 days after infection.
On the first day, the free acid was reversely increased and there was no manifestation of hypoacidity in the early stage of hookworm infection.
SUMMARY AND CONCLUSION
In massive infection (5,000∼10,000) of Ancylostoma caninum larvae to proper hosts, the following findings were noted.
1. Hemoglobin was decreased from the 2nd day of infection.
2. Sideroblasts in bone marrow showed slight increase in the fifth day after infection but gradually decreased. One month after the infection the value was lowered to 1∼4%.
3. Serum iron decreased temporarily 2∼5days after infection.
4. Serum iron level showed slightly higher elevation in the infected group than control.
5. Histopathological findings in the early stage of infection showed nothing particular in small intestine, liver, spleen, except the severe hemorrhage and the inflammatory process in lungs with well proliferated bone marrow findings(4th day after infection).
6. Iron excretion: The amount of iron excretion from the bowel was higher, in the infected group than the control. However, through item 4 and 5, it was thought that the reason was not the poor iron absorption from the intestine but the swallowed
bloody sputa originating from lung hemorrhage and intestinal hemorrhage in the early stage of hookworam infection.
7. Gastric acidity in the early stage of hookworm infection did not decrease to inhibit the reduction of ingested three valent iron.
It was concluded that no significant inhibition of iron metabolism in the early stage of hookworm infection was found.