Antiulcer activity of the calcium antagonist propyl-methylenedioxyindene. IV. Effects on gastric lesions in rats induced by cold-restraint stress and thyrotropin-releasing hormone

Restraint stress in biomedical research: an update

Since the publication of our initial review of restraint stress in 1986, much work has continued with this technique, either as a tool for the investigation of other pharmacological, physiological, or pathologic phenomena or with restraint stress itself serving as the object of the study. As we noted in 1986, the major use of restraint has been for the induction of stress responses in animals and, more specifically, for the investigation of drug effects, particularly as they affect typical stress-related pathology--gastrointestinal, neuroendocrine, and immunological agents have been extensively studied. In compiling this update on restraint stress and its effects, we noted an increasing emphasis on central nervous system mechanisms in peripheral disease, especially gastrointestinal disease. In particular, many CNS-active agents have been tested for their effects on gastric and duodenal lesion formation and gastric secretion, including antidepressants, antipsychotics, anxiolytics, noradrenergic, serotonergic, dopaminergic, and peptidergic compounds. Some of these agents are especially active in the gastrointestinal tract even when administered centrally, further solidifying the concept of a brain-gut axis. The present update includes studies of: methods and procedures, pre-restraint manipulations, post-restraint/healing effects, and drug effects. In addition, a current bibliography of reports that have employed restraint is included.

Antiulcer activity of the calcium antagonist propyl-methylenedioxyindene--V. Localization of site of action

1. Propyl-methylenedioxyindene (pr-MDI) is an intracellular calcium antagonist which inhibits cold-restraint stress ulceration at subcardiovascular doses (less than or equal to 30 mg/kg). It also inhibits gastric acid secretion evoked by RX77368 (a stable analog of thyrotropin-releasing hormone, the putative mediator of cold-restraint stress ulcers). 2. The objective of this investigation was to localize the site of the inhibitory effect of pr-MDI on gastric acid secretion stimulated by intracisternal (i.c.) administration of RX77368 (100 ng) in rats. 3. Peripheral administration of pr-MDI (30 mg/kg i.p. or i.v.) inhibited the elevated basal and the RX 77368-induced acid secretion in conscious 2-hr pylorus-ligated rats. This effect was completely blocked in anesthetized (urethane or pentobarbital) acute gastric fistula rats. 4. Intracisternal administration of pr-MDI (0.1-1 mumol) produced a dose-related inhibition of acid secretion in conscious pylorus-ligated rats. However, urethane anesthesia completely blocked the inhibitory effect of i.c.-administered pr-MDI (1 mumol) on RX77368-induced acid secretion. 5. Since previous studies indicate that anesthesia does not inhibit peripheral actions of pr-MDI (e.g. the antiarrhythmic effect), the convergent evidence suggests that the inhibitory effect of pr-MDI on gastric acid secretion is mediated primarily via the central nervous system.