Reflex splanchnic nerve stimulation increases levels of proenkephalin A mRNA and proenkephalin A-related peptides in the rat adrenal medulla
| Autor: | O. H. Viveros, Jau-Shyong Hong, Emanuel J. Diliberto, C. D. Unsworth, Tomoyuki Kanamatsu |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Enkephalin Methionine Stimulation Biology Splanchnic nerves Chlorisondamine chemistry.chemical_compound Catecholamines Internal medicine Reflex Muscarinic acetylcholine receptor medicine Animals Insulin RNA Messenger Protein Precursors Multidisciplinary Nucleic Acid Hybridization Parasympatholytics Splanchnic Nerves Enkephalins Hypoglycemia Rats Proenkephalin medicine.anatomical_structure Endocrinology chemistry Adrenal Medulla Catecholamine Adrenal medulla hormones hormone substitutes and hormone antagonists Research Article medicine.drug |
| Zdroj: | Proceedings of the National Academy of Sciences. 83:9245-9249 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.83.23.9245 |
| Popis: | The effect of reflex splanchnic nerve stimulation on proenkephalin A biosynthesis was investigated in the rat adrenal medulla. Tissue levels of native [Met5]enkephalin-like immunoreactivity (IR) (measured by direct RIA of tissue extracts), cryptic [Met5]enkephalin-like IR (calculated as the increase in [Met5]enkephalin-like IR detected in tissue extracts after sequential digestion with trypsin and carboxypeptidase B), and proenkephalin A mRNA were determined in adrenal medulla from rats sacrificed at various times after a period of insulin-induced hypoglycemia. Two hours of insulin hypoglycemia, which produced intense reflex stimulation of the splanchnic nerves as evidenced by a 55% decrease in the adrenal medulla catecholamine levels, resulted in a 3-fold increase in proenkephalin A mRNA levels in this tissue. The proenkephalin A mRNA levels reached a maximum 15-fold increase over control values 24 hr after this period of hypoglycemic stress and then gradually declined with an approximate half-life of 4 days. Native and cryptic [Met5]enkephalin-like IR had increased 9-fold and 12-fold, respectively, 24 hr after this period of hypoglycemia, and both demonstrated maximum increases of 130-fold and 50-fold, respectively, after 96 hr. Combined pretreatment (i.p. administration) with the ganglionic and muscarinic blocking agents chlorisondamine (5 mg/kg of body weight) and atropine (1 mg/kg) blocked the increase in levels of proenkephalin A mRNA seen in the rat adrenal medulla following insulin hypoglycemia. These data indicate that reflex splanchnic nerve discharge stimulates proenkephalin biosynthesis, probably at the level of gene expression. |
| Databáze: | OpenAIRE |
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