Effects of chemical and surgical sympathectomy on expression of beta- adrenergic receptors and guanine nucleotide-binding proteins in rat submandibular glands

SW Bahouth

Department of Pharmacology, College of Medicine, University of Tennessee, Memphis 38163.

Expression of beta 1-adrenergic receptors and guanine nucleotide- binding proteins in rat submandibular glands was determined after reserpine administration and sympathetic denervation. Pretreatment of rats with reserpine resulted in up-regulation of the density of beta 1- adrenergic receptors and the immunoreactivity of the 64-kDa species of beta 1-adrenergic receptor in submandibular membranes, by 2.6 +/- 0.3- fold (eight experiments), within 7 days. Steady state levels of beta 1- adrenergic receptor mRNA quantified by DNA-excess solution hybridization were 0.15 +/- 0.03 amol of beta 1-adrenergic receptor mRNA/micrograms of total cellular RNA (six experiments). beta 1- Adrenergic receptor mRNA increased by 50% within 8 hr after pretreatment with reserpine. Maximal levels of 0.37 +/- 0.04 amol of beta 1-adrenergic receptor mRNA/micrograms of RNA were attained by 4 days and these levels were sustained for the next 3 days (six experiments). Northern blot hybridization also revealed a 3-fold increase in the 2.5-kilobase beta 1-adrenergic receptor mRNA transcript, which was equivalent in magnitude to that determined by solution hybridization. Reserpine pretreatment also affected steady state levels of submandibular guanine nucleotide-binding proteins. Two immunoreactive forms of the alpha subunit of Gs, migrating as 42 kDa (major) and 50 kDa (minor), were detected in salivary membranes. The immunoreactivity of the 42-kDa species of Gs alpha declined by 50% after 7 days of continuous daily injections of reserpine. In contrast, steady state levels of Gi alpha 2 (41 kDa), Go (39 kDa), and G beta 2 (35 kDa) and their mRNAs in submandibular membranes were unaffected by reserpine pretreatment. The rate of beta 1-adrenergic receptor gene transcription assessed by nuclear run-on transcription assay in nuclei of submandibular glands was not altered by reserpine pretreatment. However, reserpine had a dramatic effect on the half-life of beta 1- adrenergic receptor mRNA in submandibular glands. The half-life of beta 1-adrenergic receptor mRNA in control submandibular glands was 3.5 hr, whereas it increased to 8 hr in reserpine-pretreated glands. Reserpine- promoted stabilization of beta 1-adrenergic receptor mRNA provides a mechanism for up-regulation of postjunctional beta 1-adrenergic receptors in sympathetically innervated tissues.

Volume 42, Issue 6, pp. 971-981, 12/01/1992
Copyright © 1992 by American Society for Pharmacology and Experimental Therapeutics

This article has been cited by other articles:

				K. Janssens, O. Krylyshkina, N. Hersmus, H. Vankelecom, and C. Denef {beta}1-Adrenoceptor Expression in Rat Anterior Pituitary Gonadotrophs and in Mouse {alpha}T3-1 and L{beta}T2 Gonadotrophic Cell Lines Endocrinology, May 1, 2008; 149(5): 2313 - 2324. [Abstract] [Full Text] [PDF]

				P. I. Adolfsson, I. Haug, G. Berg, and S. P.S. Svensson Changes in {beta}2-adrenoceptor expression and in adenylyl cyclase and phosphodiesterase activity in human uterine leiomyomas Mol. Hum. Reprod., September 1, 2000; 6(9): 835 - 842. [Abstract] [Full Text] [PDF]

				B. G. Tholanikunnel, J. G. Granneman, and C. C. Malbon The M[IMAGE] 35,000 [IMAGE]-Adrenergic Receptor mRNA-binding Protein Binds Transcripts of G-protein-linked Receptors Which Undergo Agonist-induced Destabilization J. Biol. Chem., May 26, 1995; 270(21): 12787 - 12793. [Abstract] [Full Text] [PDF]