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Reflex‐Elicited Increases in Female Rat Parotid Protein Synthesis Involving Parasympathetic Non‐Adrenergic, Non‐Cholinergic Mechanisms
Author(s) -
Ekström J.,
Reinhold A.C.
Publication year - 2001
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/eph8602255
Subject(s) - endocrinology , atropine , medicine , cholinergic , denervation , reflex , muscarinic acetylcholine receptor , parasympathetic nervous system , stimulation , adrenergic , autonomic nervous system , chemistry , receptor , heart rate , blood pressure
Normal rats or rats parasympathetically denervated on one side by cutting the auriculo‐temporal nerve were maintained on a liquid diet for 1 week. After fasting overnight, experimental rats were then offered hard, pelleted food over a period of 2 h, while unfed animals served as controls. The reflex‐induced increase in the [ 3 H]leucine incorporation into trichloroacetic acid‐insoluble material of the parotid glands following intake of the food in the presence of the muscarinic blocker atropine and α‐ and β‐adrenoceptor antagonists was greater (104%) than in the absence of the blockers (75%) in normal rats. The picture was the same when the innervated glands of rats subjected to unilateral parasympathetic denervation were examined. In this case, the protein synthesis increased by 108% in the presence of the blockers and by 63% in their absence. Analysis of the parasympathetically denervated and contralateral innervated glands revealed no support for a cholinergic or adrenergic contribution to this response. The increase in protein synthesis in the innervated glands was 86% in the rats treated with atropine, whilst it was 76% in those treated with α‐ and β‐adrenoceptor antagonists. The protein synthesis in the denervated glands increased by 57% in the absence of receptor blockade. Neither atropine (51%), nor a‐ and b‐adrenoceptor antagonists (52%), nor a combination of the three blockers (55%) affected the response of the denervated glands. A large part of the response in the presence of the traditional autonomic receptor blockers was thus dependent on the parasympathetic auriculo‐temporal nerve. Under natural feeding conditions, the parasympathetic non‐adrenergic, non‐cholinergic (NANC) mechanisms are likely to contribute to the synthesis of secretory proteins.