Experimentary study of the rat salivary gland following subtotal excision by laser

Research Project

Project/Area Number	59440083
Research Category	Grant-in-Aid for General Scientific Research (A)
Allocation Type	Single-year Grants
Research Field	Otolaryngology
Research Institution	The Nippon Dental University
Principal Investigator	FURUMOTO Keiichi 日本歯科大学 (50060398)
Project Period (FY)	1984 – 1985
Project Status	Completed (Fiscal Year 1985)
Budget Amount *help	¥8,000,000 (Direct Cost: ¥8,000,000) Fiscal Year 1984: ¥8,000,000 (Direct Cost: ¥8,000,000)
Keywords	<CO_2> laser / subtotal excision / 唾液腺
Research Abstract	The salivary gland is usually excised totally because of possible of postoperative complications. In some cases, however, preservation of a part of the glandular body is possible and <CO_2> iaser allowing closure of the cut surfase can be applied. We partially excised the rat submandibular gland by <CO_2> laser, and the recovery process was investigated. The following findings were obtained. 1) Histpathology : Marked thermal degeneration was found from immediately through two days after excision. It was distinguishable into the first layer, composed of honeycome structures, and the second, composed of coagulation and necrosis of tissue. Inflammatory symptoms were also marked in the same period. The inflammatory symptoms began to decrease at seven days, and an almost normal condition with an unclear cut surfase was restored at 21 days. 2) Angiography : There was a region of disturbed blood flow from immediately through two days after excision, and the blood circulation in the cut surfase was completely blocked. Thereafter, vascularization was vigorous in areas bordering normal tissue, resulting in the formation of the vascular plexus at seven days. The region of disturbed blood flow was unclear at 21 days, the vascular system in the cut surfase recovering to normal. 3) Submandibular functional test : Both the <^(99m)Tc> <O(^-_4)> uptake and <^(99m)Tc> <O(^-_4)> clearance tests showed a 30-40% increase in the uptake rate from immediately through four days after excision. In terms of the stimulatory secretion ratio, hyposalivation was noted immediately after excision, but the function was restored to normal on and after seven days.