| Experimental Study on the Effect of Injection of the Parotid Gland Extract into the Central Nervous System upon Serum Calcium
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Suk Chui Kang |
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Department of Pediatrics, College of Medicinet Seoul National University |
| 中樞神經에 있어 耳下腺抽出物이 血淸 calcium變化에 影響을 미치는 部位에 關한 實驗的 硏究
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姜碩哲 |
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서울大學校 醫科大學小兒科學敎室 |
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| Abstract |
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According to salivary gland endocrine theory the hormone like substance, known as parotin and
extracted from the parotid gland, is biologically active in lowering the serum calcium level and
promoting calcification of the teeth and bones. The parotid gland extract is also known to activate
anterior pituitary function and eleborates an antagonistic action to the parathyroid gland extract
and thyroid gland. Recent studies, however, suggest that calcium homeostasis is mainly regulated
by two endocrine hormones, that is, parathormone of the parathyroid gland and calcitonin of
the ultimobranchial gland. The promotion or inhibition of their secretions is determined by the
level of calcium in circulation. There was no evidence that the anterior pituitary gland or other
parts of the central nervous system had any direct effect on their secretions.
Recent study suggested that adrenal cortical steroid, which was known to influence bone
growth and calcium metabolism, could inhibit the action of both parathormone and calcitonin.
Other studies on the regulation of salivary secretion reported that the diencephalon, especially
hypothalamus served as an integrate area of salivation and there was a positive correlation
between the salivary flow and calcium concentration of the saliva and serum.
The author, hereby, made an experimental study to find out the sites of the central nervous
system in which might exert central regulatory effect on calcium metabolism through the parotid
gland extract. The Korean white male rabbits weighing 1.8 kg were used for this study，
Before experiment no meals were given for at least 24 hours. Normal physiological saline was
employed for the control study. The purified parotid gland extract, parotin, was at first injected
intravenousely (1 mg/kg and 2 mg/kg, respectively) and then into various areas of the central
nervous system e.g. pre-optic area, anterior hypothalamus, posterior hypothalamus, mid-hypothala-
mus, median eminence, mammillary body, hippocampus, caudate nucleus, amygdala, putamen，
midbrain and salivary nucleus by using stereotaxic apparatus in amount of 0.05 ml. (0.25 mg)
bilaterally. Serum calcium was estimated with atomic absorption spectrophotometer.
The results were summarized as follows:
1. The serum calcium was decreased 10〜 14 % by intravenous injection of the parotid gland extract.
2. A marked decrease of serum calcium was observed by injection of the parotid gland extract
into the preoptic area (14% reduction rate) and anterior hypothalamus (16% reduction rate).
3. A slight but insignificant decrease of serum calcium was observed by injection of the
parotid gland extract into the posterior hypothalamus(8% reducton rate), mammillary body (9%)
and hippocampus (8%).
4. No noticeable change of serum calcium was observed by injection of the parotid gland
extract into the mid-hypothalamus, median eminence, caudate nucleus, amygdala, putamen, midbrain and salivary nucleus.
With the results of the above the author could conclude that the anterior hypothalamus and the
preoptic area might be the central regulatory sites of calcium metabolism through the action of
parotid gland extract.
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