B. Peter et al., DEGRANULATION OF RAT SALIVARY-GLANDS FOLLOWING TREATMENT WITH RECEPTOR-SELECTIVE AGONISTS, Clinical and experimental pharmacology and physiology, 22(5), 1995, pp. 330-336
1. The aim of this study was to find a drug that induces an almost com
plete degranulation of secretory cells in rat parotid and submandibula
r glands. 2. Phenylephrine (alpha-adrenergic), isoproterenol (beta-adr
energic) and mecholine (muscarinic cholinergic) were tested. Time and
degree of maximal depletion of acinar and granular convoluted tubule c
ells were determined morphologically. 3. Following phenylephrine-injec
tion (5 mg/kg or 10.2 mg/kg, i.p.), no effect on the acinar granulatio
n level was observed in either of the glands, while about 50-60% granu
lar convoluted tubules were degranulated for at least 120-180 min post
injection. 4. With isoproterenol (5, 10, 40, 70 or 100 mg/kg, i.p.), d
egranulation of 100% of the acinar cells in the parotid and 80% of the
acinar cells in the submandibular gland was observed 90 min post-inje
ction. Granular convoluted tubule cells did not respond to this beta-a
drenergic drug. 5. Mecholine (3.75 or 7.5 mg/kg, i.p.) induced mainly
degranulation of granular convoluted tubule cells (about 50% after 120
min). Numbers of granulated acinar cells decreased only slightly in b
oth glands (about 10%, 90-120 min). 6. From this study it appears that
with a relatively low dosage (5 mg/kg, i.p.) of isoproterenol, a high
level of degranulation can be induced in acinar cells of rat parotid
and submandibular glands without toxic side effects. Concerning granul
ar convoluted tubules, only moderate degranulation was observed with p
henylephrine and mecholine, respectively.