Epidermal growth factor-like material in rat submandibular gland

Area of Science:

• Endocrinology
• Cell Biology
• Histology

Background:

• Epidermal growth factor (EGF) plays crucial roles in cell growth and differentiation.
• The submandibular gland is a known source of EGF, but its specific cellular localization and regulation in rats require further investigation.

Purpose of the Study:

• To identify the specific cell types in rat submandibular glands expressing epidermal growth factor (EGF).
• To investigate the influence of sex and androgen administration on EGF production and localization within these glands.

Main Methods:

• Immunohistochemical staining using an antiserum specific for mouse EGF was employed to detect EGF in rat submandibular gland tissues.
• Radioimmunoassays were utilized to quantify EGF levels in gland extracts and assess cross-reactivity with mouse EGF.

Main Results:

• Granular convoluted tubule (GCT) cells were the sole cell type showing positive immunochemical staining for EGF.
• No significant sexual dimorphism was observed in the frequency or size of EGF-immunoreactive cells or in overall EGF content.
• Testosterone administration led to a notable increase in both the number of EGF-stained GCT cells and the total EGF amount in the glands of both sexes.

Conclusions:

• Rat submandibular glands contain EGF, localized exclusively within GCT cells.
• EGF production in these glands is not inherently sexually dimorphic but is responsive to androgen stimulation.