Stimulation of .ALPHA.-amylase release and cyclic AMP accumulation by catecholamine in rat parotid slices in vitro.

Abstract

The role of cyclic AMP in a-amylase release by catecholamines was studied in rat parotid slices. The order of potency required for cate

Mechanism of regulation of amylase release by .ALPHA.- and .BETA.-adrenergic agonists in rat parotid tissue.

“…In the experiment of Butcher et al, however, the amount of amylase release by catecholamines was measured at 45 min after the addition of these agonists. As reported in our previous report (YosHIMURA et al, 1982a), the high rate of amylase release by catecholamines was only maintained for up to about the first 10 or 15 min, after which the rate of release gradually decreased. These results suggest that the condition used by Butcher et al, may not be optimal to observe the potentiation.…”

“…34, No. 4, 1984 significantly higher than that by the combined addition 0.2 ,uM norepinephrine and 0.5 mM isobutyl-methylxanthine, although the reverse takes place in the amount of cyclic AMP accumulation (YosHIMURA et al, 1982a). The results that the derivatives of cyclic AMP such as dibutyrylcyclic AMP stimulated amylase Japanese Journal of Physiology Fig.…”

“…A small increase in cyclic AMP by ~3-adrenergic agonists was sufficient for maximum stimulation of amylase release (YOSHIMURA et al, 1982a), but a similar increase in cyclic AMP by forskolin did not stimulate the maximum amount of amylase release. The amount of amylase release and cyclic AMP changed in parallel when lower doses of isobutyl-methylxanthine were used, but higher doses of isobutyl-methylxanthine further increased cyclic AMP without causing a significant increase in amylase release.…”

beta‐Adrenoceptor alterations coupled with secretory response in rat parotid tissue.

“…Judging from the results on the cyclic AMP content, adenylate cyclase activity in the parotid tissue was sub-sensitive after IPR pre-treatment regardless ofthe incubation period. A marked difference between changes in cyclic AMP content and amylase secretion in rat parotid tissue was also reported (Butcher et al 1975;Yoshimura, Nezu & Chiba, 1982;CarlsbS, Danielsson, Henriksson & Idahl, 1982;Henriksson, 1982). Thus the linkage of adenylate cyclase activity with amylase secretion requires further study.…”

Augmentation of isoproterenol-stimulated tissue cyclic AMP level by cholinergic agonists in rat parotid gland.

“…As described in our previous report (YOSHIMURA et a!., 1980) the loss into medium was not more than 5 to 10 % of the total (tissue plus medium) cyclic AMP; therefore, this last factor does not explain the increased level of cellular cyclic AMP. Augmentation of isoproterenolstimulated tissue cyclic AMP by oxotremorine and A23187 was observed in the presence of 0.1 mM isobutylmethylxanthine, the concentration of which almost completely inhibited the activity of low Km phosphodiesterase in the rat parotid gland (YosHIMURA et al, 1982). Diterpene forskolin, which stimulates cyclic AMP production in a variety of tissues, is supposed to activate adenylate cyclase via a direct interaction with the catalytic subunit or a closely associated protein (SEAMON and DALY, 1981;SERMON et a1.,1981).…”