Effects of propranolol on induced water intake and on the subfornical organ surface

Scanning electron microscopy of central nervous system cerebrospinal-fluid-contacting surfaces: a bibliography (1963-1995)

This bibliography is compiled to assist in locating papers related to the application of scanning electron microscopy (SEM) to cerebrospinal-fluid-contacting surfaces in vertebrates. The use of SEM by neuroscientists has continued apace since the publication of the first bibliography in 1980. SEM studies now include more than 50 species of vertebrates and range from cyclostomes to humans; they encompass development from embryo to senescence and concern both normal and pathologic morphology. Although remarkable strides have been made toward a greater understanding of many aspects of the structure and function of cerebrospinal-fluid-contacting surfaces, many significant problems await the judicious application of scanning electron microscopy.

Further evidence that a beta-adrenergic mechanism regulates water intake: role of the subfornical organ

The daily water intake was reduced in rats by subcutaneous administration of propranolol. The fluid intake after 24 h of dehydration in nephrectomized animals was decreased by propranolol. In intact rats diazepam did not modify the postdehydration water intake. Propranolol injected into subfornical organ decreased water consumption after 24 h of fluid deprivation but did not change the dipsogenic response to carbachol given in the same structure. These results suggest that a beta-adrenoceptor mechanism participates in the regulation of the daily water intake. After a stimulus such as dehydration, beta-blockade modifies water consumption by a non-renal mechanism. This mechanism involves neither a general depressant nervous activity nor a local anesthetic action and could be located in a periventricular structure, the subfornical organ.

Effect of beta-adrenergic antagonists on experimentally induced drinking in female rats

The nonspecific beta-adrenergic antagonist d,l propranolol, the specific beta 1-adrenergic antagonist atenolol, and the specific beta 2-adrenergic antagonist butoxamine were administered intraperitoneally (IP) to ovariectomized female rats in order to determine the role of beta-adrenergic receptors in drinking. D,l propranolol and atenolol administered at doses of 6, 12, and 18 mg/kg significantly attenuated the one-hour water intakes of rats administered angiotensin II (200 micrograms/kg, SC) and the water intakes of rats deprived of water for 24 hours. D propranolol, which has little beta-adrenergic blocking ability, administered at doses of 6 and 12 mg/kg, and butoxamine, administered at doses of 25 and 35 mg/kg, had no significant effects on the water intakes of angiotensin II treated or water deprived rats. Regardless of the dose, d,l propranolol, atenolol, and butoxamine failed to significantly alter the water intakes of rats administered 1.0 M NaCl (10 ml/kg, IP) The results provide evidence that beta 1-adrenergic receptors, but not beta 2-adrenergic receptors, are involved in mediating the increased water intakes induced by angiotensin II and water deprivation. On the other hand the increased water intake due to administration of hypertonic saline does not appear to mediated by beta-adrenergic receptors.