Physiological factors affecting secretion of parotid hormone

Area of Science:

• Endocrinology
• Physiology
• Dental Research

Background:

• A parotid hormone (PH) is identified as a key component of the hypothalamic-parotid gland endocrine axis (HPEA).
• This hormone is known to stimulate a dentinal fluid transport (DFT) mechanism in rat teeth.

Purpose of the Study:

• To investigate the role of the hypothalamic-parotid gland endocrine axis (HPEA) in regulating dentinal fluid transport (DFT).
• To determine the effect of feeding on parotid hormone (PH) secretion and its relation to DFT.

Main Methods:

• Infusion of porcine hypothalamus-thalamic tissue extract (PHTE) into anesthetized and conscious rats and pigs.
• Parotidectomy was performed in some animals to assess the role of the parotid gland.
• Measurement of plasma immunoreactive PH (iPH) titers and stimulation of DFT.

Main Results:

• PHTE infusion stimulated DFT in intact rats but not in parotidectomized rats.
• Feeding pigs significantly increased plasma iPH levels (5-8 fold), an effect abolished by parotidectomy.
• PH secretion and saliva secretion from parotid glands appear to be independently controlled.

Conclusions:

• The parotid gland plays a crucial role in the HPEA and PH secretion.
• PH secretion, stimulated by feeding, may enhance tooth resistance to decay during periods of high oral microbial acidogenic potential.
• The findings suggest a novel physiological mechanism for dental protection linked to endocrine regulation.