Effects of acute and long-term atropine treatment on levels, release and response to VIP and PHI in the submandibular gland of cat and rat
| Autor: | Jan M. Lundberg, M. Dunér-Engström, Lars Lundblad, Bo Fredholm, Jan Fahrenkrug, Olof Larsson |
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| Rok vydání: | 1992 |
| Předmět: |
Atropine
Male Imipramine medicine.medical_specialty Physiology Submandibular Gland Vasoactive intestinal peptide Neuropeptide Stimulation Rats Sprague-Dawley Parasympathetic Nervous System Peptide PHI Internal medicine Cyclic AMP medicine Animals business.industry Organ Size Submandibular gland Rats Autonomic nervous system Endocrinology medicine.anatomical_structure Cats Guanosine Triphosphate business Acetylcholine Adenylyl Cyclases Vasoactive Intestinal Peptide medicine.drug |
| Zdroj: | Acta Physiologica Scandinavica. 146:357-367 |
| ISSN: | 1365-201X 0001-6772 |
| Popis: | We have studied the effects of acute and long-term treatment of cats and rats with atropine on the levels, release and effects of two peptides, vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI), that probably co-exist with acetylcholine in the parasympathetic nerves supplying the submandibular gland. Atropine treatment (progressively increasing doses from 2 to 15 mg kg-1 injected s.c.) for 14 days did not alter the contents of VIP- or PHI-like immunoreactivity (-IR) in the cat submandibular gland or in three other tissues (nasal mucosa, trachea and tongue). Acute as well as long-term atropine treatment decreased the vasodilatation following low-, but not high-, frequency parasympathetic nerve stimulation. During prolonged stimulation (60 min) there was a decreased vasodilatation response following both acute and long-term atropine treatment. The overflow of VIP-IR and PHI-IR following parasympathetic nerve stimulation was markedly increased by acute, but not by long-term atropine treatment. The VIP- or PHI-induced stimulation of cyclic AMP (cAMP) accumulation in the cat submandibular gland was not altered after long-term atropine treatment. Similarly, treatment of male Sprague-Dawley rats with atropine (20 mg kg-1) or imipramine (20 mg kg-1) for 14 days did not alter the sensitivity to VIP or to PHI of cAMP accumulation in the submandibular gland, nor was there any change in VIP-IR or PHI-IR content. In conclusion, although atropine treatment causes an acute increase in the overflow of VIP and PHI evoked by parasympathetic nerve stimulation, there is no depletion of peptide stores upon long-term treatment, nor is there any change in the effect of exogenous VIP and PHI on cAMP-accumulation. |
| Databáze: | OpenAIRE |
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